Endodontic procedures for retreatment of periapical lesions

  • Review
  • Intervention

Authors


Abstract

Background

When primary root canal therapy fails, periapical lesions can be retreated with or without surgery. Root canal retreatment is a non-surgical procedure that involves removal of root canal filling materials from the tooth, followed by cleaning, shaping and obturating of the canals. Root-end resection is a surgical procedure that involves exposure of the periapical lesion through an osteotomy, surgical removal of the lesion, removal of part of the root-end tip, disinfection and, commonly, retrograde sealing or filling of the apical portion of the remaining root canal. This review updates one published in 2008.

Objectives

To assess effects of surgical and non-surgical therapy for retreatment of teeth with apical periodontitis.

To assess effects of surgical root-end resection under various conditions, for example, when different materials, devices or techniques are used.

Search methods

We searched the following electronic databases: the Cochrane Oral Health Trials Register (to 10 February 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1), MEDLINE Ovid (1946 to 10 February 2016) and Embase Ovid (1980 to 10 February 2016). We searched the US National Registry of Clinical Trials (ClinicalTrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials (to 10 February 2016). We placed no restrictions regarding language and publication date. We handsearched the reference lists of the studies retrieved and key journals in the field of endodontics.

Selection criteria

We included randomised controlled trials (RCTs) involving people with periapical pathosis. Studies could compare surgery versus non-surgical treatment or could compare different types of surgery. Outcome measures were healing of the periapical lesion assessed after one-year follow-up or longer; postoperative pain and discomfort; and adverse effects such as tooth loss, mobility, soft tissue recession, abscess, infection, neurological damage or loss of root sealing material evaluated through radiographs.

Data collection and analysis

Two review authors independently extracted data from included studies and assessed their risk of bias. We contacted study authors to obtain missing information. We combined results of trials assessing comparable outcomes using the fixed-effect model, with risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, and 95% confidence intervals (CIs). We used generic inverse variance for split-mouth studies.

Main results

We included 20 RCTs. Two trials at high risk of bias assessed surgery versus a non-surgical approach: root-end resection with root-end filling versus root canal retreatment. The other 18 trials evaluated different surgical protocols: cone beam computed tomography (CBCT) versus periapical radiography for preoperative assessment (one study at high risk of bias); antibiotic prophylaxis versus placebo (one study at unclear risk); different magnification devices (loupes, surgical microscope, endoscope) (two studies at high risk); types of incision (papilla base incision, sulcular incision) (one study at high risk and one at unclear risk); ultrasonic devices versus handpiece burs (one study at high risk); types of root-end filling material (glass ionomer cement, amalgam, intermediate restorative material (IRM), mineral trioxide aggregate (MTA), gutta-percha (GP), super-ethoxy benzoic acid (EBA)) (five studies at high risk of bias, one at unclear risk and one at low risk); grafting versus no grafting (three studies at high risk and one at unclear risk); and low energy level laser therapy versus placebo (irradiation without laser activation) versus control (no use of the laser device) (one study at high risk).

There was no clear evidence of superiority of the surgical or non-surgical approach for healing at one-year follow-up (RR 1.15, 95% CI 0.97 to 1.35; two RCTs, 126 participants) or at four- or 10-year follow-up (one RCT, 82 to 95 participants), although the evidence is very low quality. More participants in the surgically treated group reported pain in the first week after treatment (RR 3.34, 95% CI 2.05 to 5.43; one RCT, 87 participants; low quality evidence).

In terms of surgical protocols, there was some inconclusive evidence that ultrasonic devices for root-end preparation may improve healing one year after retreatment, when compared with the traditional bur (RR 1.14, 95% CI 1.00 to 1.30; one RCT, 290 participants; low quality evidence).

There was evidence of better healing when root-ends were filled with MTA than when they were treated by smoothing of orthograde GP root filling, after one-year follow-up (RR 1.60, 95% CI 1.14 to 2.24; one RCT, 46 participants; low quality evidence).

There was no evidence that using CBCT rather than radiography for preoperative evaluation was advantageous for healing (RR 1.02, 95% CI 0.70 to 1.47; one RCT, 39 participants; very low quality evidence), nor that any magnification device affected healing more than any other (loupes versus endoscope at one year: RR 1.05, 95% CI 0.92 to 1.20; microscope versus endoscope at two years: RR 1.01, 95% CI 0.89 to 1.15; one RCT, 70 participants, low quality evidence).

There was no evidence that antibiotic prophylaxis reduced incidence of postoperative infection (RR 0.49, 95% CI 0.09 to 2.64; one RCT, 250 participants; low quality evidence).

There was some evidence that using a papilla base incision (PBI) may be beneficial for preservation of the interdental papilla compared with complete papilla mobilisation (one RCT (split-mouth), 12 participants/24 sites; very low quality evidence). There was no evidence of less pain in the PBI group at day 1 post surgery (one RCT, 38 participants; very low quality evidence).

There was evidence that adjunctive use of a gel of plasma rich in growth factors reduced postoperative pain compared with no grafting (measured on visual analogue scale: one day postoperative MD -51.60 mm, 95% CI -63.43 to -39.77; one RCT, 36 participants; low quality evidence).

There was no evidence that use of low energy level laser therapy (LLLT) prevented postoperative pain (very low quality evidence).

Authors' conclusions

Available evidence does not provide clinicians with reliable guidelines for treating periapical lesions. Further research is necessary to understand the effects of surgical versus non-surgical approaches, and to determine which surgical procedures provide the best results for periapical lesion healing and postoperative quality of life. Future studies should use standardised techniques and success criteria, precisely defined outcomes and the participant as the unit of analysis.

Resumen

Procedimientos de endodoncia para el retratamiento de las lesiones periapicales

Antecedentes

Cuando falla el tratamiento primario del conducto radicular, las lesiones periapicales pueden tratarse de nuevo con o sin cirugía. El retratamiento del conducto radicular es un procedimiento no quirúrgico que incluye la extracción de los materiales de relleno del conducto radicular del diente, seguido de la limpieza, el moldeado y la obturación de los canales. La resección del final de la raíz es un procedimiento quirúrgico que incluye la exposición de la lesión periapical mediante una osteotomía, la extracción quirúrgica de la lesión, la extracción de parte de la punta del final de la raíz, , la desinfección y, comúnmente, el sellado retrógrado o el relleno de la porción apical del conducto radicular restante. Esta revisión actualiza una publicada en 2008.

Objetivos

Evaluar los efectos del tratamiento quirúrgico y no quirúrgico para el retratamiento de los dientes con periodontitis apical.

Evaluar los efectos de la resección quirúrgica del final de la raíz en diversas condiciones, p.ej. cuando se utilizan diferentes materiales, dispositivos o técnicas.

Métodos de búsqueda

Se hicieron búsquedas en las siguientes bases de datos electrónicas: registro de ensayos del Grupo Cochrane de Salud Oral (Cochrane Oral Health Group) (10 febrero 2016), Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials) (CENTRAL; 2016, número 1), MEDLINE Ovid (1946 hasta 10 febrero 2016) y en Embase Ovid (1980 hasta 10 febrero 2016). Se hicieron búsquedas de ensayos en curso en el US National Registry of Clinical Trials (ClinicalTrials.gov) y en la World Health Organization (WHO) International Clinical Trials Registry Platform (hasta el 10 febrero 2016). No se establecieron restricciones en cuanto al idioma y fecha de publicación. Se realizaron búsquedas manuales en las listas de referencias de los estudios recuperados y las revistas importantes en el área de la endodoncia.

Criterios de selección

Se incluyeron ensayos controlados aleatorios (ECA) que incorporaron pacientes con patosis periapical. Los estudios podían comparar la intervención quirúrgica versus tratamiento no quirúrgico o podían comparar diferentes tipos de cirugía. Las medidas de resultado fueron la cicatrización de la lesión periapical evaluada después de un año de seguimiento o más; el dolor y el malestar postoperatorio; y los efectos adversos como la pérdida de dientes, la movilidad, la recesión de las partes blandas, el absceso, la infección, el daño neurológico o la pérdida del material de sellado de la raíz evaluados a través de radiografías.

Obtención y análisis de los datos

Dos autores de la revisión, de forma independiente, extrajeron los datos de los estudios incluidos y evaluaron su riesgo de sesgo. Se contactó con los autores de los estudios para obtener la información faltante. Se combinaron los resultados de los ensayos que evaluaban resultados comparables mediante el modelo de efectos fijos, con cocientes de riesgos (CR) para los resultados dicotómicos y diferencias medias (DM) para los resultados continuos, e intervalos de confianza (IC) del 95%. Se utilizó la varianza inversa genérica para los estudios de boca dividida.

Resultados principales

Se incluyeron 20 ECA. Dos ensayos en riesgo alto de sesgo evaluaron la intervención quirúrgica versus un enfoque no quirúrgico: resección del final de la raíz con relleno del final de la raíz versus retratamiento del conducto radicular. Los otros 18 ensayos evaluaron diferentes protocolos quirúrgicos: tomografía computadorizada de haz cónico (TCHC) versus radiografía periapical para la evaluación preoperatoria (un estudio en alto riesgo de sesgo); profilaxis con antibióticos versus placebo (un estudio en riesgo incierto); diferentes dispositivos de amplificación (lupas, microscopio quirúrgico, endoscopio) (dos estudios en alto riesgo); tipos de incisión (incisión en la base de la papila, incisión sulcular) (un estudio en alto riesgo y uno en riesgo incierto); dispositivos ultrasónicos versus fresas de pieza de mano (un estudio en alto riesgo); tipos de material de relleno del final de la raíz (cemento ionómero de vidrio, amalgama, material restaurativo intermedio [MRI], agregado de trióxido mineral [ATM], gutapercha [GP], ácido superetoxibenzoico [AEB]) (cinco estudios en alto riesgo de sesgo, uno en riesgo incierto y uno en bajo riesgo); injerto versus ningún injerto (tres estudios en alto riesgo y uno en riesgo incierto); y tratamiento con láser de bajo nivel de energía versus placebo (irradiación sin activación del láser) versus control (ningún uso del dispositivo de láser) (un estudio en alto riesgo).

No hubo pruebas claras de la superioridad del enfoque quirúrgico o no quirúrgico para la cicatrización al año de seguimiento (CR 1,15; IC del 95%: 0,97 a 1,35; dos ECA, 126 participantes) o a los cuatro o diez años de seguimiento (un ECA, 82 a 95 participantes), aunque las pruebas son de muy baja calidad. Más participantes del grupo de cirugía informaron dolor en la primera semana después del tratamiento (CR 3,34; IC del 95%: 2,05 a 5,43; un ECA, 87 participantes; pruebas de baja calidad).

En cuanto a los protocolos quirúrgicos, hubo algunas pruebas no concluyentes de que los dispositivos ultrasónicos para la preparación del final de la raíz pueden mejorar la cicatrización un año después del retratamiento, comparado con la fresa tradicional (CR 1,14; IC del 95%: 1,00 a 1,30; un ECA, 290 participantes; pruebas de baja calidad).

Hubo pruebas de una mejor cicatrización cuando el final de la raíz se rellenó con ATM que cuando fue tratado mediante el alisamiento del relleno ortógrado de la raíz con GP, después del año de seguimiento (CR 1,60; IC del 95%: 1,14 a 2,24; un ECA, 46 participantes; pruebas de baja calidad).

No hubo pruebas de que el uso de TCHC en lugar de radiografía para la evaluación preoperatoria fuera ventajoso para la cicatrización (CR 1,02; IC del 95%: 0,70 a 1,47; un ECA, 39 participantes; pruebas de muy baja calidad), ni que algún dispositivo de amplificación afectara la cicatrización más que otro (lupas versus endoscopio un año más tarde: CR 1,05; IC del 95%: 0,92 a 1,20; microscopio versus endoscopio a los dos años: CR 1,01; IC del 95%: 0,89 a 1,15; un ECA, 70 participantes, pruebas de baja calidad).

No hubo pruebas de que la profilaxis con antibióticos redujera la incidencia de infección posoperatoria (CR 0,49; IC del 95%: 0,09 a 2,64; un ECA, 250 participantes; pruebas de baja calidad).

Hubo algunas pruebas de que el uso de una incisión en la base de la papila (IBP) puede ser beneficioso para la preservación de la papila interdental en comparación con la movilización completa de la papila (un ECA [boca dividida]), 12 participantes / 24 sitios; pruebas de muy baja calidad). No hubo pruebas de menos dolor en el grupo de IBP el día uno posterior a la intervención quirúrgica (un ECA, 38 participantes; pruebas de muy baja calidad).

Hubo pruebas de que el uso coadyuvante de un gel de plasma rico en factores de crecimiento redujo el dolor posoperatorio en comparación con ningún injerto (medido en la escala analógica visual: un día posoperatorio DM -51,60 mm, IC del 95%: -63,43 a -39,77; un ECA, 36 participantes; pruebas de baja calidad).

No hubo pruebas de que la administración de tratamiento con láser con bajo nivel de energía (TLNB) previniera el dolor posoperatorio (pruebas de muy baja calidad).

Conclusiones de los autores

Las pruebas disponibles no proporcionan a los médicos guías fidedignas para tratar las lesiones periapicales. Se necesita investigación adicional para comprender los efectos de los enfoques quirúrgicos versus no quirúrgicos y para determinar qué procedimientos quirúrgicos proporcionan los mejores resultados para la cicatrización de la lesión periapical y la calidad de vida posoperatoria. Los estudios futuros deben usar técnicas estandarizadas y criterios de éxito, resultados definidos de forma precisa y el participante como la unidad de análisis.

Plain language summary

Procedures for retreatment of failed root canal therapy

Review question

We aimed to find out the best way to retreat patients for whom root canal therapy has failed. We wanted to know whether surgical or non-surgical retreatment was better, and if using specific materials, devices or procedures in surgery might improve healing of the lesion or reduce patient discomfort after surgery. This review updates one published in 2008.

Background

In root canal therapy, the infected pulp of a tooth is removed, and the root cavity is disinfected and filled with a sealing material. However, if micro-organisms that caused the infection are not completely removed, after some time they may cause a disease at the tip of the root, called a periapical lesion. Treatment for this requires a second intervention, which can be performed in the same way as the first treatment, from the crown into the root canal, to remove the existing filler and clean and disinfect as well as possible before sealing again. Alternatively, should this procedure fail, or if it is not feasible, a surgical intervention can be used.

Study characteristics

We conducted a wide search of medical and dental literature up to 10 February 2016. We identified 20 studies that randomised participants to groups receiving different forms of retreatment of periapical lesions. These studies evaluated nine different comparisons: surgical versus non-surgical treatment (two studies, one monitoring participants for up to 10 years); two diagnostic radiographic techniques (one study); the occurrence of postoperative infection with or without antibiotics (one study); use of different devices for enhancing the surgeon's view during the most critical steps of the surgical procedure (one study); the aesthetic appearance of the gum next to the treated tooth and pain after operation when two different types of gingival incision were used (two studies); use of minimally invasive ultrasonic devices or traditional rotating burs to manage the tip of the root (one study); use of different materials for filling the root-end (seven studies); filling of the periapical lesion with a grafting material (four studies); and exposure of the surgical site to a low energy level laser to reduce pain (one study).

Key results

There is no evidence that a surgical approach leads to better results compared with non-surgical retreatment at one year (or at four or 10 years) after intervention. However, people treated surgically reported more pain and swelling during the first week after treatment.

Different surgical techniques were evaluated. Healing at one-year follow-up seemed to be improved by use of ultrasonic devices, instead of the traditional bur, for root-end preparation. There was some evidence of better healing at one-year follow-up when root-ends were filled with mineral trioxide aggregate compared with their being treated by smoothing of orthograde gutta percha root filling.

Use of a graft composed of a gel enriched with the patient's own platelets applied to the defect during the surgical procedure significantly reduced postoperative pain. Exposure to a low energy level laser did not apparently reduce pain at the surgical site.

A small gingival incision may preserve the gum between two adjacent teeth, improving the aesthetic appearance and causing less pain after surgery.

There was no evidence that use of antibiotics reduces the occurrence of postoperative infection (although when the procedure is done well, infection is an extremely rare event).

Different ways of enhancing the surgeon's view did not lead to different results at least one year after operation, and results of retreatment were independent of the radiographic technique used to make the diagnosis.

Quality of the evidence

We judged the quality of the evidence to be poor; therefore we cannot rely on the findings. Only one study was at low risk of bias;we judged the majority to be at high risk of bias.

Author conclusions

It is difficult to draw conclusions, as the evidence currently available is of low to very low quality. More randomised controlled trials conducted to high standards are needed to find out the effects of the surgical versus non-surgical approach and, when surgery is used, which materials, devices or operative protocols are best for improving lesion healing and reducing patient discomfort.

Laički sažetak

Postupci za ponovno liječenje neuspješne terapije kanala zuba

Istraživačko pitanje

Cilj ovog Cochrane sustavnog pregleda literature bio je pronaći najbolji način ponovnog liječenja neuspjele terapije korijena zuba. Željeli smo saznati je li bolje kirurško ili konzervativno (ne-kirurško) ponovno liječenje i hoće li upotreba određenih materijala, uređaja ili postupaka tokom operacije potpomoći izlječenje patološke lezije ili smanjenje neugode u pacijenta nakon operacije. Ovo je obnovljena verzija sustavnog pregleda literature koji je prvi put objavljen 2008. godine.

Dosadašnje spoznaje

U terapiji kanala zuba, inficirana zubna pulpa se odstranjuje te se kanal dezinficira i puni materijalom za punjenje korijenskih kanala. Međutim, ako se mikroorganizmi uzročnici infekcije ne odstrane u potpunosti tijekom određenog vremena, uzrokuju oboljenje na vrhu korijena koje se zove periapikalna lezija. Liječenje periapikalne lezije podrazumijeva sekundarnu intervenciju koja se može izvesti na isti način kao i prva, od krune do kanala korijena ne bi li odstranili postojeći ispun te očistili i dezinficirali što bolje prije ponovnog punjenja. Druga je mogućnost napraviti kirurški zahvat ako taj postupak ne uspije ili ako ga nije moguće izvesti.

Obilježja uključenih istraživanja

Pretražili smo medicinsku literaturu dostupnu do 10. veljače 2016. Pronašli smo 20 istraživanja koji su nasumično razvrstali sudionike u grupe koje su primale različite oblike liječenja periapikalnih lezija. Ova istraživanja su procijenila devet različitih usporedbi: kirurško naspram nekirurškog liječenja (dva istraživanja od kojih je jedno pratilo sudionike do 10 godina); dvije radiološke dijagnostičke metode (jedno istraživanje); učestalost postooperativne infekcije s ili bez antibiotske zaštite (jedno istraživanje); upotreba različitih uređaja koji poboljšavaju pogled operatora tokom najkritičnijih koraka operativnog postupka (jedno istraživanje); estetika gingive zuba pored liječenog zuba i postoperativna bol kod upotrebe dva različita tipa gingivalne incizije (dva istraživanja); upotreba minimalno invazivnih ultrazvučnih uređaja ili konzervativna upotreba rotirajućih svrdla kod pristupa apeksu zuba (jedno istraživanje); upotreba različitih materijala za punjenje kanala korijena (sedam istraživanja); punjenje periapikalne lezije materijalom za presađivanje (četiri istraživanja); ekspozicija operativnog polja laseru niske energije u svrhu ublažavanja boli (jedno istraživanje).

Ključni rezultati

Ne postoje dokazi da kirurški pristup dovodi do boljih rezultata od nekirurškog pristupa jednu godinu (ili nakon četiri ili deset godina) nakon ponovnog liječenja. Međutim, pacijenti koji su operirani imali su više boli i oticanja tokom prvog tjedna nakon ponovnog liječenja.

Procijenjene su različite kirurške tehnike. Zacijeljenje tijekom jedne godine nakon upotrebe ultrazvučnih aparata jest poboljšano u usporedbi s upotrebom tradicionalnih svrdla za retrogradnu preparaciju korijena. Postoje određeni dokazi o boljem cijeljenju tijekom godine dana nakon punjenja korijenskih kanala mineral trioksidnim agregatom u usporedbi s ortogradnim punjenjem gutaperka štapićima.

Upotreba materijala za presađvanje u obliku gela obogaćenog pacijentovim trombocitima primijenjenog u defekt tijekom kirurške operacije značajno je smanjila postoperativnu bol u pacijenta. Ekspozicija laseru niske energije nije smanjila bol u kirurškom polju.

Mala gingivalna incizija mogla bi očuvati gingivu između dva susjedna zuba poboljšavajući i estetski dojam kao i uzrokovati manje boli poslijeoperativno.

Nije bilo dokaza da upotreba antibiotika smanjuje pojavnost postooperativnih infekcija (iako, kada se postupak napravi pravilno, infekcije su iznimno rijetke).

Različiti načini poboljšavanja pogleda operatera na operacijsko polje nisu doveli do različith rezultata barem do godinu dana nakon operacije i rezultati ponovnog liječenja nisu ovisili o upotrebi različitih radioloških tehnika.

Kvaliteta dokaza

Procijenili smo kvalitetu dokaza nedovoljnom; stoga se ne možemo pouzdati u rezultate. Samo jedno istraživanje je imalo malen rizik od pristranosti.

Zaključak autora

Teško je izvući zaključke budući su dostupni dokazi niske do veoma niske kvalitete. Potrebno je više randomiziranih kontroliranih istraživanja izvedenih po visokim standardima da bismo saznali utjecaj kirurškog nasuprot ne-kirurškom pristupu i, kada je kirurški pristup, koji materijali, uređaji ili operativni postupci su najbolji u poboljšanju liječenja lezije i smanjenja neugode za pacijenta.

Bilješke prijevoda

Hrvatski Cochrane
Prevela: Eni Ušljebrka
Ovaj sažetak preveden je u okviru volonterskog projekta prevođenja Cochrane sažetaka. Uključite se u projekt i pomozite nam u prevođenju brojnih preostalih Cochrane sažetaka koji su još uvijek dostupni samo na engleskom jeziku. Kontakt: cochrane_croatia@mefst.hr

Ringkasan bahasa mudah

Prosedur rawatan semula terapi kanal akar yang gagal.

Soalan ulasan

Kami bertujuan untuk mencari cara terbaik merawat semula pesakit dimana terapi kanal akar telah gagal. Kami ingin mengetahui sama ada rawatan semula surgikal atau bukan surgikal adalah lebih baik, dan jika menggunakan bahan, peranti atau prosedur spesifik dalam surgeri dapat meningkatkan penyembuhan lesi atau mengurangkan ketakselesaan selepas surgeri. Ulasan ini mengemaskini satu terbitan dalam tahun 2008.

Latarbelakang

Dalam terapi kanal akar, pulpa gigi yang telah dijangkiti dikeluarkan dan kaviti akar didisinfeksi dan dipenuhi dengan bahan pengap. Namun, jika mikroorganisme yang menyebabkan jangkitan tidak dibuang dengan sempurna, ia boleh menyebabkan jangkitan pada hujung akar yang dipanggil luka periapikal.Rawatan untuk kes begini memerlukan intervensi kedua, yang boleh dibuat dengan cara yang sama dengan rawatan pertama, dari korona ke dalam akar untuk membuang bahan pengap sedia ada, membersih dan disinfeksi sebaik mungkin sebelum memengap semula. Jika prosedur ini gagal, atau sukar dijalankan, intervensi surgikal boleh diguna.

Ciri-ciri kajian

Kami membuat carian meluas kesusasteraan perubatan dan pergigian sehingga 10 Februari 2016. Kami mengenalpasti 20 kajian yang membahagikan peserta secara rawak yang menerima pelbagai bentuk rawatan semula lesi periapikal. Kajian-kajian tersebut menilai sembilan perbandingan yang berlainan: rawatan surgikal berbanding bukan surgikal (dua kajian, satu kajian memantau peserta sehingga 10 tahun); dua melibatkan teknik radiograf diagnostik (satu kajian); kejadian jangkitan pos operatif dengan atau tanpa antibiotik (satu kajian); penggunaan pelbagai peranti untuk menambahbaik pemandangan doktor bedah pada langkah-langkah kritikal semasa prosedur surgikal (satu kajian); gambaran estetik gusi bersebelahan gigi yang dirawat dan sakit selepas pembedahan apabila dua jenis insisi digunakan (dua kajian); penggunaan peranti ultrasonik invasif minimum atau bur berpusing tradisional untuk mengendali hujung akar (satu kajian); penggunaan pelbagai bahan pengap hujung akar (tujuh kajian); memengap luka periapikal dengan bahan graf (empat kajian); dan pendedah kawasan surgikal kepada laser tahap tenaga rendah untuk mengurangkan sakit (satu kajian).

Keputusan utama

Tiada bukti yang menunjukkan pendekatan surgikal menghasilkan keputusan lebih baik berbanding rawatan semula bukan surgikal sehingga satu tahun (atau empat atau 10 tahun) selepas intervensi. Walaubagaimanapun, pesakit yang dirawat secara surgikal melaporkan lebih kesakitan dan kebengkakan dalam tempoh satu minggu selepas rawatan.

Pelbagai teknik surgikal dinilai. Penyembuhan adalah lebih baik dalam susulan setahun dengan penggunaan peranti ultrasonik berbanding bur tradisional dalam penyediaan hujung akar. Terdapat sedikit bukti penyembuhan yang lebih baik pada susulan setahun apabila hujung akar dipengap dengan agregat trioksida berbanding rawatan dengan pelicinan bahan pengap getah perca ortograd.

Penggunaan graf yang terbentuk dari gel yang diperkaya dengan platelet pesakit dan disapu pada bahagian kerosakan semasa prosedur surgikal mengurang sakit pos-operatif dengan ketara. Pendedahan kepada laser tenaga tahap rendah tidak mengurangkan sakit pada tapak surgikal.

Pemotongan gingiva yang kecil dapat memelihara gusi di antara dua gigi bersebelahan, meningkatkan paras rupa estetik dan menyebabkan kurang sakit selepas pembedahan.

Tiada bukti bahawa penggunaan antibiotik mengurangkan kejadian jangkitan pos-operatif (walaupun, apabila prosedur dilakukan dengan baik, jangkitan jarang berlaku).

Pelbagai cara menambahbaik pandangan doktor bedah tidak menunjukkan keputusan yang berbeza sehingga setahun selepas rawatan semula, dan keputusan rawatan semula tidak berkait dengan teknik radiograf yang diguna untuk membuat diagnosis.

Kualiti bukti

Kami mendapati kualiti bukti adalah rendah, oleh itu kita tidak dapat bergantung kepada keputusan-keputusan tersebut. Hanya satu kajian yang berisiko bias rendah, majoriti kajian adalah berisiko bias tinggi.

Rumusan penulis

Adalah sukar untuk membuat rumusan kerana bukti sedia ada berkualiti rendah. Lebih banyak kajian rawak terkawal yang bermutu diperlukan untuk menyiasat kesan pendekatan surgikal dan bukan surgikal, dan apabila surgeri diguna, bahan, peranti atau protokol operatif yang manakah lebih baik untuk meningkatkan penyembuhan lesi dan mengurangkan ketakselesaan pesakit.

Catatan terjemahan

Diterjemahkan oleh Noorliza Mastura Ismail (Kolej Perubatan Mrelaka-Manipal). Disunting oleh Ernie Yap (Hospital Universiti Kebangsaan Malaysia). Untuk sebarang pertanyaan berkaitan terjemahan ini sila hubungi noorliza.mastura@manipal.edu.my

Резюме на простом языке

Процедуры повторного лечения неудавшейся терапии корневого канала

Вопрос обзора

Мы стремились найти лучший способ повторного лечения пациентов, у которых не удалось лечение корневых каналов. Мы хотели выяснить, что было бы лучше, хирургическое или не-хирургическое лечение, и может ли использование специальных материалов, устройств или процедур при проведении хирургического лечения улучшить заживление поражения или уменьшить дискомфорт пациента после операции. Этот обзор обновляет опубликованный в 2008 году.

Актуальность

При лечении корневого канала удаляют зараженную пульпу зуба, и дезинфицируют корневую полость и заполняют её герметизирующим материалом. Однако, если микроорганизмы, которые вызвали инфекцию, не полностью удалены, через какое-то время они могут вызывать болезнь верхушки корня, называемую пери-апикальным поражением. Лечение этого требует второго вмешательства, которое может быть выполнено таким же образом, как и при первичном лечении, от коронки внутрь корневого канала, чтобы удалить имеющийся там наполнитель, очистить и продезинфицировать канал наилучшим возможным образом, прежде чем вновь его герметизировать. В качестве альтернативы, если эта процедура не получится, или, если это не представляется возможным, можно использовать хирургическое вмешательство.

Характеристика исследований

Мы провели широкий поиск медицинской и стоматологической литературы по 10 февраля 2016. Мы выявили 20 исследований, в которых участников рандомизировали в группы (распределяли в группы случайным образом); участники в разных группах получали различные формы повторного лечения периапикальных поражений. В этих исследования оценивали девять различных сравнений: хирургического и не-хирургического лечения (два исследования, в одном участников наблюдали в течение 10 лет); двух диагностических рентгенологических метода (одно исследование); возникновение послеоперационной инфекции при использовании антибиотиков или без них (одно исследование); использование различных устройств для улучшения обзора (видимости) для хирурга во время самых критических этапов хирургической процедуры (одно исследование); эстетический вид десен рядом с обработанными зубами и боль после операции, когда использовались два различных типа десневого разреза (два исследования); использование минимально инвазивных ультразвуковых устройств или традиционных вращающихся боров для работы с верхушкой корня (одно исследование); использование различных материалов для заполнения корневого конца (семь исследований); заполнение полостей периапикальных поражений трансплантационным материалом (четыре исследования); и воздействие лазером низкого уровня энергии на участок хирургического вмешательства для уменьшения боли (одно исследование).

Основные результаты

Нет доказательств, что хирургический подход приводит к лучшим результатам по сравнению с нехирургическим лечением при сроке наблюдения в один год (или от четырех до 10 лет) после вмешательства. Однако, люди, подвергнувшиеся к хирургическому лечению, сообщили о большей боли и отеке в течение первой недели после лечения.

Были оценены различные хирургические методы (техники). Заживление за один год наблюдения, казалось, было улучшено при использовании ультразвуковых устройств, вместо традиционного бура, для подготовки корневого конца. Имелись некоторые доказательства лучшего заживления за один год наблюдения, когда корневые концы были заполнены минеральным агрегатом триоксида по сравнению с заполнением их гуттаперчей.

Использование трансплантата, состоящего из геля, обогащенного собственными тромбоцитами пациента, для заполнения дефекта во время хирургической процедуры, значительно уменьшило послеоперационную боль. Воздействие лазера низкого уровня энергии по-видимому, не уменьшало боль в месте операции.

Небольшой десневой надрез может сохранить десну между двумя соседними зубами, улучшая эстетический вид и вызывает меньше боли после операции.

Не было каких-либо доказательств, что применение антибиотиков снижает возникновение послеоперационных инфекций (хотя, когда процедура хорошо выполнена, инфекция является чрезвычайно редким событием).

Различные способы повышения обзора (видимости) для хирурга не приводят к разным результатам, по крайней мере за один год после операции, и результаты повторного лечения не зависели от рентгенографического метода, используемого для постановки диагноза.

Качество доказательств

Мы решили, что качество доказательств было плохим; поэтому мы не можем полагаться на эти результаты. Только одно исследование было с низким риском смещения, мы оценили большинство исследований как имеющих высокий риск смещения.

Выводы авторов

Трудно сделать выводы, поскольку имеющиеся в настоящее время доказательства - все низкого или очень низкого качества. Необходимо больше рандомизированных контролируемых испытаний, проведенных в соответствии с высокими стандартами, чтобы выяснить влияние хирургического по сравнению с не-хирургическим подходом и, когда используется хирургическое вмешательство, какие материалы, устройства или оперативные протоколы являются предпочтительными для улучшения заживления поражения и уменьшения дискомфорта пациента.

Заметки по переводу

Перевод: Гараева Айзяра Фаниловна. Редактирование: Зиганшина Лилия Евгеньевна. Координация проекта по переводу на русский язык: Cochrane Russia - Кокрейн Россия (филиал Северного Кокрейновского Центра на базе Казанского федерального университета). По вопросам, связанным с этим переводом, пожалуйста, обращайтесь к нам по адресу: cochrane.russia.kpfu@gmail.com; cochranerussia@kpfu.ru

Resumen en términos sencillos

Procedimientos para el retratamiento del conducto radicular luego del fracaso del tratamiento

Pregunta de la revisión

Se procuraba determinar la mejor forma de tratar de nuevo a los pacientes en los que ha fallado el tratamiento del conducto radicular. Se deseaba saber si es mejor el retratamiento quirúrgico o no quirúrgico, y si el uso de materiales, dispositivos o procedimientos específicos en la intervención quirúrgica podría mejorar la cicatrización de la lesión o reducir el malestar del paciente después de la cirugía. Esta revisión actualiza una publicada en 2008.

Antecedentes

En el tratamiento del conducto radicular, se retira la pulpa infectada del diente, y la cavidad de la raíz se desinfecta y se rellena con un material de sellado. Sin embargo, si los microorganismos que causaron la infección no se eliminan completamente, después de algún tiempo pueden causar una enfermedad en el final de la raíz, llamada lesión periapical. El tratamiento para esta afección requiere una segunda intervención, que puede realizarse de la misma manera que el primer tratamiento, desde la corona en el conducto radicular, para eliminar el excipiente existente y limpiar y desinfectar lo mejor posible antes de sellarlo nuevamente. Como alternativa, si este procedimiento fracasara, o si no fuese factible, puede utilizarse una intervención quirúrgica.

Características de los estudios

Se realizó una amplia búsqueda de la literatura médica y dental hasta el 10 de febrero de 2016. Se identificaron 20 estudios que asignaron al azar a los participantes a grupos que recibieron diferentes formas de retratamiento de las lesiones periapicales. Estos estudios evaluaron nueve comparaciones diferentes: tratamiento quirúrgico versus no quirúrgico (dos estudios, uno controló a los participantes por hasta diez años); dos técnicas radiográficas de diagnóstico (un estudio); la aparición de infección postoperatoria con o sin antibióticos (un estudio); uso de diferentes dispositivos para la mejoría del criterio del cirujano durante los pasos más críticos del procedimiento quirúrgico (un estudio); la apariencia estética de la encía próxima al diente tratado y el dolor después de la cirugía cuando se utilizaron dos tipos diferentes de incisión gingival (dos estudios); el uso de dispositivos ultrasónicos mínimamente invasivos o fresas rotatorias tradicionales para tratar el final de la raíz (un estudio); el uso de diferentes materiales para rellenar el final de la raíz (siete estudios); el relleno de la lesión periapical con un material de injerto (cuatro estudios); y la exposición del sitio quirúrgico a un láser de bajo nivel de energía para aliviar el dolor (un estudio).

Resultados clave

No existen pruebas de que un abordaje quirúrgico dé lugar a mejores resultados en comparación con el retratamiento no quirúrgico un año más tarde (o a los cuatro o diez años) después de la intervención. Sin embargo, los pacientes tratados quirúrgicamente informaron más dolor y edema durante la primera semana después del tratamiento.

Se evaluaron diferentes técnicas quirúrgicas. La cicatrización al año de seguimiento pareció mejorar con el uso de dispositivos ultrasónicos, en lugar de la fresa tradicional, para la preparación del final de la raíz. Hubo algunas pruebas de una mejor cicatrización al año de seguimiento cuando el final de la raíz se rellenó con agregado de trióxido mineral en comparación con tratamiento con alisamiento del relleno ortógrado de la raíz con gutapercha.

El uso de un injerto compuesto de un gel enriquecido con las propias plaquetas del paciente aplicado al defecto durante el procedimiento quirúrgico alivió significativamente el dolor posoperatorio. La exposición a un láser de bajo nivel de energía aparentemente no alivió el dolor en el sitio quirúrgico.

Una incisión gingival pequeña puede preservar la encía entre dos dientes adyacentes, mejorando la apariencia estética y causando menos dolor después de la intervención quirúrgica.

No hubo pruebas de que la administración de antibióticos redujera la aparición de infección posoperatoria (aunque cuando el procedimiento se realiza de forma adecuada, la infección es un evento sumamente raro).

Las diferentes formas de mejorar el criterio del cirujano no dieron lugar a diferentes resultados al menos un año después de la cirugía, y los resultados del retratamiento fueron independientes de la técnica radiográfica utilizada para hacer el diagnóstico.

Calidad de la evidencia

Se consideró que la calidad de las pruebas fue deficiente; por lo tanto no es posible basarse en los hallazgos. Sólo un estudio estuvo en bajo riesgo de sesgo; la mayoría se consideró en alto riesgo de sesgo.

Conclusiones de los autores

Es difícil establecer conclusiones, debido a que las pruebas disponibles actualmente son de calidad baja a muy baja. Se necesitan más ensayos controlados aleatorios, realizados con un estándar alto, para determinar los efectos del enfoque quirúrgico versus no quirúrgico y, cuando se utiliza la intervención quirúrgica, qué materiales, dispositivos o protocolos quirúrgicos son mejores para optimizar la cicatrización de la lesión y reducir el malestar del paciente.

Notas de traducción

La traducción y edición de las revisiones Cochrane han sido realizadas bajo la responsabilidad del Centro Cochrane Iberoamericano, gracias a la suscripción efectuada por el Ministerio de Sanidad, Servicios Sociales e Igualdad del Gobierno español. Si detecta algún problema con la traducción, por favor, contacte con Infoglobal Suport, cochrane@infoglobal-suport.com.

Summary of findings(Explanation)

Summary of findings for the main comparison. Root-end resection versus root canal retreatment
  1. aQuality of evidence was downgraded owing to heterogeneity (inconsistency).

    bQuality of evidence was downgraded owing to imprecision (CI includes RR of 1.0).

    cQuality of evidence was downgraded because both studies had high risk of bias.

    dQuality of evidence was downgraded because it was based on a single small study at high risk of bias.

Root-end resection versus root canal retreatment

Patient or population: people requiring retreatment of periapical lesions
Setting: university clinics
Intervention: root-end resection (with root-end filling)

Comparison: root canal retreatment

OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with root canal retreatmentRisk with root-end resection and filling
Healing - 1 year726 per 1000835 per 1000
(704 to 980)
RR 1.15
(0.97 to 1.35)
126
(2 RCTs)
⊕⊝⊝⊝
very low a,b,c

RR after 4 years was 1.03 (0.89 to 1.20) (1 study, 82 participants)

RR after 10 years was 1.11 (0.88 to 1.41) (1 study, 95 participants)

Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 day279 out of 1000932 out of 1000 (572 to 1515)RR 3.34 (2.05 to 5.43)

87

(1 study)

⊕⊕⊝⊝
low d
Number of participants reporting pain each day in the first postoperative week was significantly higher in the surgical group than in the non-surgical group.
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

Summary of findings 2 Cone beam computed tomography (CBCT) versus periapical radiography

Summary of findings 2. Cone beam computed tomography (CBCT) versus periapical radiography
  1. aQuality of evidence was downgraded because it was derived from a single study at high risk of bias with imprecise results.

CBCT versus periapical radiography
Patient or population: people requiring retreatment of periapical lesions
Setting: university
Interventions: CBCT vs periapical radiography
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with periapical radiographyRisk with CBCT
Healing - 1 year737 per 1000752 per 1000
(516 to 1000)
RR 1.02
(0.70 to 1.47)
39
(1 RCT)
⊕⊝⊝⊝
very low a
 
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 3 Preoperative antibiotic prophylaxis versus placebo

Summary of findings 3. Preoperative antibiotic prophylaxis versus placebo
  1. aQuality of evidence was downgraded because it was derived from a single study at unclear risk of bias with very imprecise results.

Preoperative antibiotic prophylaxis versus placebo
Patient or population: people requiring retreatment of periapical lesions
Setting: university
Interventions: preoperative antibiotic prophylaxis vs placebo
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with placeboRisk with antibiotic prophylaxis
Healing - 1 yearNot assessed
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeks32 per 100016 per 1000
(3 to 85)
RR 0.49
(0.09 to 2.64)
250
(1 RCT)
⊕⊝⊝⊝
very low a
 
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 4 Magnification devices

Summary of findings 4. Magnification devices
  1. aQuality of evidence was downgraded because it was derived from a single study at high risk of bias.

Different types of magnification devices
Patient or population: people requiring retreatment of periapical lesions
Setting: university
Interventions: magnification devices
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with loupes or microscopeRisk with endoscope
Loupes vs endoscope - healing at 1 year906 per 1000952 per 1000
(834 to 1000)
RR 1.05
(0.92 to 1.20)
62 (71 teeth)
(1 RCT)
⊕⊕⊝⊝
low a
 
Microscope vs endoscope - healing at 2 years902 per 1000911 per 1000
(803 to 1000)
RR 1.01
(0.89 to 1.15)
70 (100 teeth)
(1 RCT)
⊕⊕⊝⊝
low a
 
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

Summary of findings 5 Papilla base incision (PBI) incision versus complete mobilisation

Summary of findings 5. Papilla base incision (PBI) incision versus complete mobilisation
  1. aQuality of evidence was downgraded because it was derived from a single small study at unclear risk of bias with very imprecise results.

    bQuality of evidence was downgraded because it was derived from one small split-mouth study at high risk of bias.

Papilla base incision (PBI) versus complete mobilisation
Patient or population: people requiring retreatment of periapical lesions
Setting: university
Intervention: PBI vs complete mobilisation
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with complete mobilisationRisk with PBI
Healing - 1 yearNot assessed
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayMean pain was 90 mmMean pain in the intervention group was 2.25 lower (7.17 lower to 2.67 higher).-38
(1 RCT)
⊕⊝⊝⊝
very low a
 
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papilla - 1 yearMean height loss of interdental papilla was 0.98 mm.Mean height loss of interdental papilla in the intervention group was 1.04 mm lower (1.48 lower to 0.60 lower).-12
(1 RCT)
⊕⊝⊝⊝
very low b
 
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 6 Ultrasonic instruments versus bur

Summary of findings 6. Ultrasonic instruments versus bur
  1. aQuality of evidence downgraded because it was derived from one study at high risk of bias (attrition bias).

Ultrasonic instruments versus bur
Patient or population: people requiring retreatment of periapical lesions
Setting: university
Intervention: ultrasonic instruments vs bur
OutcomesAnticipated absolute effects* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Risk with burRisk with ultrasonic
Healing - 1 year709 per 1000809 per 1000
(709 to 922)
RR 1.14
(1.00 to 1.30)
290
(1 RCT)
⊕⊕⊝⊝
low a
There was inconclusive evidence that use of ultrasonic devices could produce a better success rate after 1-year follow-up.
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 7 Root end fillings

Summary of findings 7. Root end fillings
  1. aQuality of evidence was downgraded owing to imprecision (CI includes RR of 1.0).

    bQuality of evidence was downgraded because one study had high risk of bias (attrition bias).

    cQuality of evidence was downgraded because it was based on a single study and because of imprecision.

    dQuality of evidence was downgraded because it was based on a single study that had high risk of bias.

Different types of root end fillings

Patient or population: people requiring retreatment of periapical lesions

Settings: university hospital

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
Number of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
  Intermediate restorative material (IRM) Mineral trioxide aggregate (MTA)    
Healing - 1 year806 per 1000878 per 1000
(781 to 975)
RR 1.09 (0.97 to 1.21)222
(2 RCTs)
⊕⊕⊝⊝
low a,b
RR after 2 years as computed on 108 participants (1 study) was 1.05 (95% CI 0.92 to 1.20).
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 day815 per 1000823 per 1000
(684 to 994)
RR 1.01 (0.84 to 1.22)100
(1 RCT)
⊕⊕⊝⊝
low a,b
RR after 2 days as computed on 100 participants (1 study) was 0.94 (95% CI 0.73 to 1.20).
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
  MTA SuperEBA    
Healing - 1 year956 per 1000927 per 1000
(870 to 994)
RR 0.97 (0.91 to 1.04)192
(1 RCT)
⊕⊕⊝⊝
low c
There was no evidence of a difference in success rate after 1-year follow-up when MTA or SuperEBA was used as root-end filler.
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
  Gutta-percha MTA    
Healing - 1 year619 per 1000990 per 1000
(706 to 1000)
RR 1.60 (1.14 to 2.24)

46

(1 RCT)

⊕⊕⊝⊝
low c
There was evidence of better healing rate after 1-year follow-up when MTA as compared with gutta-percha was used.
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayMean pain in the control group was 21.Mean pain in the intervention groups was 4 units lower
(-16.69 to 8.69).
 

42

(1 RCT)

⊕⊕⊝⊝
low c
After 2 days, mean difference in pain was 2.00 (-6.22 to 10.22); after 3 days, mean difference in pain was 5.00 (-4.37 to 14.37).
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
  Amalgam Glass ionomer cement    
Healing - 1 year904 per 1000886 per 1000
(777 to 1000)
RR 0.98 (0.86 to 1.12)

105

(1 RCT)

⊕⊝⊝⊝
very low a,d
RR after 5 years as computed on 82 participants (1 study) was 1.00 (95% CI 0.84 to 1.20).
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
  Gutta-percha IRM    
Healing - 1 year (or longer)885 per 1000

814 per 1000

(708 to 929)

RR 0.92 (0.80 to 1.05)

147

(1 RCT)

⊕⊝⊝⊝
very low a,d
There is no evidence of a difference in success rate after 1-year follow-up when gutta-percha or IRM was used as root-end filler.
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
  IRM SuperEBA    
Healing - 1 year (or longer)816 per 1000

906 per 1000

(808 per 1000)

RR 1.11

(0.99 to 1.24)

194

(1 RCT)

⊕⊝⊝⊝
very low a,d
There was no evidence of a difference in success rate after 1-year follow-up when SuperEBA or IRM was used as root-end filler.
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 8 Grafting versus no grafting

Summary of findings 8. Grafting versus no grafting
  1. aQuality of evidence was downgraded two levels because it was based on a single study and because of imprecision.

Grafting versus no grafting

Patient or population: people requiring retreatment of periapical lesions

Settings: university

Intervention: grafting

Control: no grafting

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
No graftingGrafting
Healing - 1 year  Calcium sulphate    
889 per 1000

996 per 1000

(738 per 1000)

RR 1.12

(0.83 to 1.50)

18

(1 RCT)

⊕⊕⊝⊝
low a
There was no evidence that grafting the periapical lesion with calcium sulphate may improve healing of the lesion after 1-year follow-up.
  GTR + Bovine bone    
743 per 1000

832 per 1000

(639 per 1000)

RR 1.12

(0.86 to 1.46)

59

(1 RCT)

⊕⊕⊝⊝
low a
There was no evidence that guided tissue regeneration improves healing of the lesion after 1-year follow-up.
   PRGF gel    
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayMean pain was 73.3.Mean pain in the intervention group was 51.6 lower (63.43 lower to 39.77 lower).-

36

(1 RCT)

⊕⊕⊝⊝
low a
There was evidence that using plasma rich in growth factors may decrease postoperative pain in the early days after surgery. After 2 days, mean pain in the intervention group was 41.7 lower than in the control group (-52.09 to -31.31); after 3 days, mean pain in the intervention group was 45 lower than in the control group (-59.71 to -30.29).
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papillaNot assessed
Maximum pain assessed with verbal rating scale (VRS)Not assessed
*The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Summary of findings 9 Low energy level laser therapy versus placebo versus control

Summary of findings 9. Low energy level laser therapy versus placebo versus control
  1. aQuality of evidence was downgraded three levels because it is based on a single study at high risk of bias.

Low energy level laser therapy compared with placebo for surgical retreatment of periapical lesions

Patient or population: people requiring retreatment of periapical lesions
Setting: university
Intervention: low energy level laser therapy (LLLT)

Control: placebo

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
Number of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
PlaceboLLLT
Healing - 1 yearNot assessed
Pain assessed with visual analogue scale (VAS) from 0 to 100 - 1 dayNot assessed
Prevalence of pain - 1 dayNot assessed
Occurrence of postoperative infection - 4 weeksNot assessed
Height loss of interdental papilla - 1 yearNot assessed
  Placebo LLLT    
Maximum pain assessed with verbal rating scale (VRS) 0 per 1000 0 per 1000Not estimable52
(1) RCT
⊕⊝⊝⊝
very low a
 
  Control LLLT    
Maximum pain assessed with verbal rating scale (VRS) 300 per 1000 0 per 1000Not estimable44
(1) RCT
⊕⊝⊝⊝
very low a
 
*The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval; RR: risk ratio.
GRADE Working Group grades of evidence
High quality: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

Background

Description of the condition

Root canal treatment for the infected pulp of a tooth aims to eradicate pathological microbiota and prevent future infection within the root canals. Root canal treatment should obtain proper root canal shape, so an efficient cleaning can be performed before three-dimensional filling (Wesselink 2010). In recent years, the number of people seeking root canal treatment has dramatically increased because a conservative approach is preferred over tooth extraction (Azarpazhooh 2013a; Azarpazhooh 2013b).

Even when an adequate standard of treatment is performed, failures may occur, owing to the anatomical characteristics of the root canal system and to the presence of peculiar noxious factors within the inflamed tissue (Nair 2004; Nair 2006). The persistence of micro-organisms in the root canal system may induce an inflammatory and immune response in the periradicular (periapical) tissues, resulting in local bone destruction. Furthermore, contamination of the periradicular tissues and of the filling material by micro-organisms may initiate a foreign body reaction, thereby impairing tissue healing.

Large cross-sectional studies from different countries have reported that the prevalence of apical periodontitis and other post-treatment periradicular disease can exceed 30% of all root-filled teeth (Boucher 2002; Friedman 2002; Peters 2011; Tavares 2009), suggesting a considerable need for treatment of this condition.

Although two-dimensional imaging techniques have been used in the past, it has been proposed that three-dimensional imaging delineates greater detail, especially in the periradicular tissues. This may impact the diagnosis of periapical lesions requiring treatment, although robust evidence is lacking (Horner 2013; Petersson 2012).

Furthermore, the presence of cysts, extraradicular infections or other conditions not properly related to a dental pathosis, such as foreign body reactions, could be an indication for root-end resection.

Description of the intervention

Although success rates up to 97% have been reported for the initial root canal treatment (Friedman 2002), failure may occur after treatment, mainly owing to incomplete removal of the pathogenic microbiota. In cases of persistent apical periodontitis or another post-treatment periapical disease in a previously treated tooth, as a consequence of the failure of primary root canal treatment to permanently eradicate the infection, two possible treatment alternatives exist to preserve the tooth: root canal retreatment and root-end resection.

Root canal retreatment has the same aim as primary treatment of infected root canals: complete elimination of micro-organisms and hermetic sealing with biocompatible materials. This is accomplished by removal of root canal filling material, disinfection of the root canal system and sealing of root canals (Machtou 2010).

However, when root canal retreatment is not feasible, when it fails, when it is unlikely that it can improve on the previous result or when biopsy of the periapical lesion is necessary, a surgical intervention consisting of root-end resection with or without root-end filling might be indicated and represents the last chance for avoiding tooth extraction.

Root-end resection (also named endodontic surgery, periradicular surgery, periapical/apical surgery or apicoectomy) consists of surgical removal of a periapical lesion, resection of the apical portion of the root, disinfection and sealing of the apical portion of the remaining root canal (Gutmann 1991).

Standard root-end resection is performed through an osteotomy to make the site of the lesion accessible. Then, the technique includes surgical debridement of the pathological periradicular tissue, bevel resection of the apex with a bur, root-end preparation and placement of root-end filling material to seal the root canal. In the past, amalgam was generally used as the root filling material (Gutmann 1991).

A modern approach to root-end resection involves the use of magnification to allow a smaller osteotomy. In addition, the apex is resected with minimal or no bevel and the root-end is treated with ultrasonic tips, then is sealed with modern root-end filling materials other than amalgam (Kim 2006; Tsesis 2006). This approach combines modern ultrasonic preparation and filling materials with use of microsurgical instruments, high-power magnification and illumination to overcome the limitations associated with standard root-end resection, achieving a higher probability of success (Setzer 2010). The microscopic approach to root-end resection ensures easier root apex identification; also, the resected root apices can disclose, under magnification and illumination, complicated anatomical characteristics, intricate details of the apical ramifications, and isthmuses, microfractures and additional canals, allowing proper disinfection and filling of all root canals. Furthermore, the ultrasonic instruments used together with the microscope ensure that root-end preparation may be performed in a conservative, deep and coaxial way, and that the root-end filling may be precisely accomplished (Kim 2006; Setzer 2010). Various protocols have been proposed to optimise the results of root-end resection and to reduce patient discomfort. For example, guided tissue regeneration with the use of membranes has been applied, different root-end fillers have been used and different bone substitutes for enhancing bone regeneration have been adopted (Gutmann 2014).

Soft tissue management during root-end resection was improved by the introduction of microsurgical instruments. Adequate soft tissue preservation has a beneficial impact on patient-related outcomes during the early postoperative period, on postsurgical aesthetic outcomes and on healing (Kim 2006; Taschieri 2014; Taschieri 2016; Velvart 2005).

In a small segment of failed root canal cases, root canal retreatment or root-end resection is not feasible or impractical. One alternative is intentional replantation, which is a procedure in which the tooth is gently extracted, curettage of the apical lesion (when present) is performed, the apicoectomy and root-end filling procedure are performed extraorally and the tooth is replanted in its alveolar socket. Minimal extraction trauma and very short extraoral time (less than 10 minutes) are the most critical factors contributing to the success of this procedure, which has strict selection criteria for applicability. Its success rate, however, has been reported to be far lower than that of root canal retreatment or root-end resection (Bender 1993; Rouhani 2011).

Another alternative to performing any kind of immediate operative treatment is to just observe and recall for further assessment. The possibility always exists that a periapical lesion that emerges or persists following root canal treatment may heal spontaneously. This option requires the patient agrees with the plan to not intervene and accepts undergoing an observation period of unpredictable duration to follow the natural history of the lesion. Of course, in case of painful exacerbation of the disease (flare-ups), a decision to treat can be made, although it has been reported that the risk of flare-ups among persistent lesions is very rare, and that they have minimal impact on daily activities (Yu 2012).

How the intervention might work

Root canal retreatment has the main aim of removing resident bacteria from the root canal systems and avoiding recurrence of intracanal infection.

After the root canal is accessed through an opening in the crown, and crowns, bridges or posts are removed, the root filling material has to be removed. Root canals then are reshaped, irrigated with antimicrobial solution to ensure complete eradication of micro-organisms and closed with proper root canal filling material. Finally, the access hole is sealed (Machtou 2010; Ruddle 2004).

Root-end resection with or without root-end filling aims to regenerate damaged periapical tissues, confine intracanal bacteria and excise the lesion itself (Nair 2006; Von Arx 2001).

Complete surgical removal of the periapical lesion, adequate resection of the apex, root-end preparation and three-dimensional retrograde filling and sealing of the so-created root-end cavity are necessary to allow periapical tissue healing, which consists of neo-osteogenesis in the cavity created by the lesion (Gutmann 1991).

Why it is important to do this review

Cochrane Oral Health undertook an extensive prioritisation exercise in 2014 to identify a core portfolio of clinically important titles to be maintained in The Cochrane Library (Worthington 2015). The operative and prosthodontic dentistry expert panel identified this review as a priority title (Cochrane OHG priority review portfolio).

Evidence of whether to use root canal retreatment or root-end resection, in the case of a primary root canal treatment failure, is scarce and is now out of date (Del Fabbro 2007; Torabinejad 2009). Therefore, assessment of clinical and radiographic outcomes of these two treatment options is necessary to compare their success rates and to determine whether differences between them can be identified, with the final aim of providing clinicians with up-to-date information about current RCT evidence.

Furthermore, owing to variability in proposed techniques and heterogeneity in study design evident in the available literature, we seek to understand how root-end resection protocols work, and which variables may affect clinical outcomes (Setzer 2010; Setzer 2012). We will systematically evaluate the efficacy of modern techniques to justify their use as a reliable alternative to standard surgical protocols.

Objectives

To assess effects of surgical and non-surgical therapy for retreatment of teeth with apical periodontitis.

To assess effects of surgical root-end resection under various conditions, for example, when different materials, devices or techniques are used.

Methods

Criteria for considering studies for this review

Types of studies

Randomised controlled trials dealing with root canal retreatment of teeth presenting periapical pathosis.

Types of participants

People who have had endodontic treatment of root canals of one or more teeth and who were diagnosed with a periapical condition requiring retreatment.

Types of interventions

Interventions for retreatment of teeth with periapical pathosis, consisting of one of the following.

  • Root canal retreatment.

  • Root-end resection following a standard protocol (i.e. without magnification devices and with a bur for apex resection and root-end preparation, a long bevel and amalgam as filling material).

  • Root-end resection following a modern protocol (i.e. use of magnification devices with root-end preparation through ultrasonic tips, a short bevel and modern sealing materials).

Types of outcome measures

We were interested in the healing of the periapical lesion (assessed clinically and radiologically), the occurrence of adverse effects and the impact of the intervention on postoperative quality of life.

Primary outcomes
  • One-year healing of periapical pathosis evaluated by assessment of clinical signs and symptoms (absence of pain, suppuration, swelling) and through two-dimensional or three-dimensional radiological examination

  • Absence or presence of adverse effects or unexpected sequelae after endodontic surgery (tooth loss, mobility, soft tissue recession, abscess, infection, neurological damage, loss of root sealing material evaluated through radiographs)

  • Patient-reported outcomes such as postoperative pain and discomfort or completion of an appropriate quality of life measurement during the first week after surgery

Secondary outcomes
  • Longer than one-year healing of the periapical pathosis evaluated by assessment of clinical signs and symptoms (absence of pain, suppuration, swelling) and through radiological examination.

Search methods for identification of studies

To identify studies for this review, we developed detailed search strategies for each database searched. These were based on the search strategy developed for MEDLINE (Ovid) and were revised appropriately for each database. The search strategy used a combination of controlled vocabulary and free-text terms and was linked with the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying RCTs in MEDLINE: sensitivity-maximising version (2008 revision), as referenced in Chapter 6.4.11.1 and detailed in Box 6.4.c of the Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011) (Lefebvre 2011). We provide details of the MEDLINE search in Appendix 1. The search of Embase was linked to the Cochrane Oral Health filter for identifying RCTs.

Electronic searches

We searched the following electronic databases.

  • Cochrane Oral Health Trials Register (searched 10 February 2016) (see Appendix 2).

  • Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1), in The Cochrane Library (searched 10 February 2016) (see Appendix 3).

  • MEDLINE Ovid (1946 to 10 February 2016) (see Appendix 1).

  • Embase Ovid (1980 to 10 February 2016) (see Appendix 4).

We applied no restrictions on language or date of publication in our searches of electronic databases.

Searching other resources

We searched the following trial registries for ongoing studies.

  • US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (http://clinicaltrials.gov/; searched 10 February 2016).

  • World Health Organization International Clinical Trials Registry Platform (apps.who.int/trialsearch; searched 10 February 2016).

We searched the reference lists of included studies and of relevant systematic reviews for additional studies.

Moreover, we performed a handsearch of all issues (from 1960 to February 2016) of the following journals.

  • British Journal of Oral and Maxillofacial Surgery.

  • International Endodontic Journal.

  • Journal of Endodontics.

  • Dental Traumatology (formerly Dental Traumatology and Endodontics).

  • Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics.

  • International Journal of Oral and Maxillofacial Surgery.

  • Journal of Oral and Maxillofacial Surgery.

  • Australian Endodontic Journal.

  • British Dental Journal.

  • Australian Dental Journal.

  • Journal of Dentistry.

To identify additional unpublished and ongoing RCTs, we contacted manufacturers of instruments for root canal treatment and for endodontic surgery, along with the authors of selected RCTs.

Data collection and analysis

Selection of studies

Two review authors (SC, MDF) independently screened titles and abstracts of the retrieved studies and discarded non-relevant articles. We obtained the full text of all studies that we considered relevant, or for which we did not have sufficient information, and two review authors (SC, MDF) independently evaluated these to check whether they met the inclusion criteria. The two review authors resolved disagreements by discussion and consultation with a third review author. We collated multiple publications of the same study. For all studies rejected at this stage, we recorded reasons for exclusion in the Characteristics of excluded studies tables.

Data extraction and management

Two review authors (SC, IT) independently extracted data and resolved disagreements through discussion and consultation with a third review author. In cases of missing information, we contacted authors of the included studies through email. In cases of missing or incomplete data and absence of further clarification by study authors, we excluded these reports from the analysis.

We recorded the following data for each included study.

  • Demographic characteristics of the study population.

  • Setting, country, year, study design.

  • Funding source.

  • Number of surgeons involved.

  • Characteristics of the intervention.

  • Outcome characteristics (how outcomes were assessed, time intervals, results).

Assessment of risk of bias in included studies

Two review authors (IT, PSB) independently assessed the risk of bias of included studies. If papers to be assessed listed one or more review authors on the byline, review authors not involved in the trial independently evaluated these studies. We resolved disagreements by discussion.

We conducted the risk of bias assessment according to instructions provided in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We considered five items for each study: selection bias, performance bias, detection bias, attrition bias and reporting bias. For each domain, we judged the risk as low, unclear or high. If a study had low risk for each item, we judged that study to have low risk of bias. If a study had unclear risk for at least one domain but no items scored at high risk, we judged that study to have unclear risk of bias. If a study had high risk of bias for at least one domain, we judged that study to be at high risk of bias.

Measures of treatment effect

For dichotomous outcomes, we calculated estimates of effects of interventions as risk ratios (RRs) with 95% confidence intervals (CIs). For continuous variables, we calculated estimates of effects of interventions as mean differences (MDs) with 95% CIs.

Unit of analysis issues

In parallel-group studies, the statistical unit of analysis was usually the participant - not the lesion or the tooth. We undertook a tooth-based meta-analysis if only tooth-based data - instead of participant-based data - were available for all studies addressing a given comparison. In split-mouth studies, the tooth was considered as the unit of analysis.

Dealing with missing data

When necessary, we contacted corresponding authors of study articles through email to request missing data regarding specific items considered in the risk of bias assessment. If these authors did not respond, we sent the same email again, copying in coauthors, a maximum of three times. If no answer was obtained, and no sufficient outcome data were available for the analysis, we did not include the data in the analysis and considered the relative item at high risk of bias.

Assessment of heterogeneity

We assessed heterogeneity among studies using the Chi2 test, considering significance at P < 0.1. We quantified heterogeneity by calculating I2 statistics. If I2 was over 50%, we considered it significant (Higgins 2011).

Assessment of reporting biases

We assessed publication bias by testing for funnel plot asymmetry, as described in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). If asymmetry was evident, we investigated this and described possible causes.

Data synthesis

We performed meta-analysis for studies with comparable outcomes, calculating RRs for dichotomous data ('success' or 'non-success' of retreatment) and MDs for continuous data (self-reported pain on a visual analogue scale). As in the previous version of this review, we dichotomised data regarding healing of the periapical lesion that are usually expressed as four scores (complete, incomplete, uncertain, unsatisfactory healing) into success (complete plus incomplete healing data) and non-success (uncertain plus unsatisfactory healing data). Similarly, for other outcomes expressed as scores composed of four or five items, we grouped those that were similar in order to express data in a dichotomous form and allow meta-analysis. We used the fixed-effect model, as each meta-analysis included fewer than four studies. For data from split-mouth studies, we used the generic inverse variance method. We had planned to calculate numbers needed to treat for the primary outcome. When meta-analysis was not appropriate, we described individual study data in the text.

We used the software Review Manager for meta-analysis computations (RevMan 5.3).

Subgroup analysis and investigation of heterogeneity

We had planned to perform subgroup analysis when we identified a sufficient number of included studies. We had planned subgroups based on:

  • whether root-end resection was performed with a standard or a modern technique;

  • whether or not guided bone regeneration (GBR) techniques were applied;

  • use of different magnification devices (surgical microscope, loupes, endoscope); and

  • use of different root-end fillers (such as mineral trioxide aggregate (MTA), ethoxy benzoic acid (EBA) cement and intermediate restorative material (IRM)).

Sensitivity analysis

We had planned to perform sensitivity analysis by excluding studies at high risk of bias to evaluate the effect of study risk of bias on overall effects.

Assessment of quality of the evidence

We assessed the quality of the body of evidence using GRADE criteria, with reference to the overall risk of bias of included studies, directness of the evidence, consistency of the results, precision of the estimates and risk of publication bias. We graded the quality of the body of evidence for each primary outcome as high, moderate, low or very low.

Presentation of main results

We developed a 'Summary of findings' table for each comparison and for the primary outcomes of this review using GRADEPro software. We reported the following outcomes.

  • Healing at one year.

  • Pain (visual analogue scale 0 to 100) on day 1.

  • Prevalence of pain.

  • Occurrence of postoperative infection.

  • Loss of interdental papilla height.

Results

Description of studies

See Characteristics of included studies and Characteristics of excluded studies.

Results of the search

We present the flow of the article screening process in Figure 1. The electronic search yielded a total of 1716 records. After deduplication, 1018 records remained. After screening of titles and abstracts, we considered 26 articles potentially eligible for inclusion. We selected 10 additional articles by journal handsearching or by searching through the references of the selected articles. After full-text evaluation, we excluded nine studies (Bader 1998; Dhiman 2015; Garrett 2002; Goyal 2011; Huumonen 2003; Kim 2008; Marin-Botero 2006; Shearer 2009; Von Arx 2010a) and included 20 studies (27 publications) (Angerame 2015; Chong 2003; Christiansen 2009; Danin 1996; De Lange 2007; Del Fabbro 2009; Del Fabbro 2012; Kurt 2014; Kvist 1999; Lindeboom 2005a; Lindeboom 2005b; Payer 2005; Pecora 2001; Song 2012; Taschieri 2007; Taschieri 2008; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991). Seven of the included studies (Chong 2003; Christiansen 2009; Kvist 1999; Taschieri 2007; Taschieri 2008; Velvart 2004; Zetterqvist 1991) were reported in multiple articles.

Figure 1.

Study flow diagram

Included studies

Of the 20 included studies, five were performed in Sweden (Danin 1996; Kvist 1999; Walivaara 2009; Walivaara 2011; Zetterqvist 1991), six in Italy (Angerame 2015; Del Fabbro 2009; Del Fabbro 2012; Pecora 2001; Taschieri 2007; Taschieri 2008), three in The Netherlands (De Lange 2007; Lindeboom 2005a; Lindeboom 2005b) and one each in Austria (Payer 2005), Denmark (Christiansen 2009), Korea (Song 2012), Switzerland (Velvart 2004), Turkey (Kurt 2014) and United Kingdom (Chong 2003).

Characteristics of study design, trial setting and investigators

All studies except Velvart 2004 used a parallel-group study design. Velvart 2004, the only split-mouth study, evaluated the height of interdental papilla after root-end resection, comparing two different approaches for incision: papilla base incision (PBI) versus complete papilla mobilisation, involving the two papillae adjacent to the tooth undergoing endodontic surgery.

One trial declared that support was received from industry directly involved in the product being tested, along with free material (De Lange 2007). For four studies, funding was provided by the author's institution (Chong 2003; Christiansen 2009; Danin 1996; Lindeboom 2005a). Six studies declared that no specific funding was received for performing the study (Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005b; Taschieri 2007; Taschieri 2008). For the remaining nine studies (Angerame 2015; Kurt 2014; Payer 2005; Pecora 2001; Song 2012; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991), study authors did not state the source of funding (if any) and provided no information.

Seven studies included only one surgeon (Angerame 2015; Christiansen 2009; Del Fabbro 2009; Del Fabbro 2012; Kurt 2014; Kvist 1999; Song 2012); 10 studies included two surgeons (Chong 2003; Danin 1996; Lindeboom 2005a; Pecora 2001; Taschieri 2007; Taschieri 2008; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991); one study had three surgeons (Lindeboom 2005b); one study had four surgeons Payer 2005; and one study had seven surgeons (five oral and maxillofacial surgeons and two endodontic surgeons) (De Lange 2007).

Eight studies reported an a priori sample size calculation (Chong 2003; De Lange 2007; Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005b; Song 2012; Taschieri 2008).

Nine studies did not specify the lesion size (Angerame 2015; Chong 2003; Christiansen 2009; De Lange 2007; Kurt 2014; Song 2012; Velvart 2004; Walivaara 2009; Zetterqvist 1991), although two of these (Christiansen 2009; Kurt 2014) reported that they estimated the lesion condition by using the periapical index (PAI). The other studies reported lesion sizes smaller than 5 mm (Payer 2005); smaller than 5 mm and 5 mm or larger (Danin 1996; Kvist 1999); smaller than 5 mm, 5 to 9 mm and larger than 9 mm (Walivaara 2011); 3 to 19 mm (Taschieri 2008); 8 to 12 mm (Del Fabbro 2012); smaller than 10 mm (Del Fabbro 2009; Lindeboom 2005a; Lindeboom 2005b); and larger than 10 mm (Pecora 2001; Taschieri 2007).

Characteristics of the interventions

The included studies evaluated the following comparisons of different aspects of endodontic surgery.

  • Root-end resection with root-end filling versus root canal retreatment of periapical lesions (Danin 1996; Kvist 1999).

  • Type of preoperative evaluation: cone beam computed tomography (CBCT) versus conventional periapical radiography (Kurt 2014).

  • Prophylactic antibiotic versus placebo (Lindeboom 2005a).

  • Incision type: papilla base incision (PBI) versus complete papilla mobilisation (Velvart 2004); PBI versus sulcular incision (Del Fabbro 2009).

  • Magnification type: surgical microscope versus endoscope versus surgical loupes (Taschieri 2008).

  • Ultrasonic device versus conventional bur for root-end preparation (De Lange 2007).

  • Root-end filling material: glass ionomer cement versus amalgam (Zetterqvist 1991); MTA versus IRM (Chong 2003; Lindeboom 2005b); MTA versus gutta-percha smoothing (Christiansen 2009); MTA versus SuperEBA (Song 2012); IRM versus gutta-percha (Walivaara 2009); and IRM versus SuperEBA (Walivaara 2011).

  • Grafting versus no grafting: calcium sulphate versus no grafting (Pecora 2001); guided tissue regeneration (GTR) using bovine bone mineral and resorbable collagen membrane versus no GTR (Taschieri 2007); plasma rich in growth factors versus no grafting (Del Fabbro 2012); and platelet-rich fibrin versus no grafting (Angerame 2015).

  • Low energy level laser therapy (LLLT) versus placebo versus control (Payer 2005).

Characteristics of outcome measures

The included studies used the following outcomes to assess treatments.

Duration of follow-up

Follow-ups up to one week were adopted only in studies that aimed to assess postsurgical pain and discomfort and were as follows.

Studies assessing healing of periapical lesions reported outcome measures at the following time points.

Two studies that evaluated healing of periapical lesions reported results in follow-up ranges with a minimum follow-up of 12 months and mean values of 15.6 months (Walivaara 2009) and 13.1 months (Walivaara 2011).

One study evaluated the efficacy of prophylactic antibiotic administration by recording the occurrence of postoperative infection and had a follow-up of four weeks (Lindeboom 2005a).

One study evaluated the height of the interproximal papilla after one-year follow-up (Velvart 2004).

Excluded studies

We excluded two studies because they were not actually randomised to treatment (Bader 1998; Von Arx 2010a). We excluded one study because healing was evaluated after too short a follow-up period (Shearer 2009). We excluded four studies because they treated apicomarginal defects (Dhiman 2015; Goyal 2011; Kim 2008; Marin-Botero 2006); one of which specifically compared the outcome of endodontic microsurgery for apical versus apicomarginal defects (Kim 2008). In the present review, we considered only lesions confined to the periapical region, not endoperiodontal lesions. We excluded one studybecause it dealt only with orthograde endodontic retreatment - not apical surger (Huumonen 2003), and another study because recruitment was defective and the dropout rate was extremely high (Garrett 2002). In that study, recruitment of 60 participants was planned, but only 25 were actually treated and only 13 could be evaluated at the scheduled follow-up.

Risk of bias in included studies

Overall, we judged only one study to be at low risk of bias (Lindeboom 2005b), and four studies to be at unclear risk of bias (Del Fabbro 2009; Lindeboom 2005a; Pecora 2001; Taschieri 2008). We considered all other studies to be at high risk of bias (Angerame 2015; Chong 2003; Christiansen 2009; Danin 1996; Del Fabbro 2012; De Lange 2007; Kurt 2014; Kvist 1999; Payer 2005; Song 2012; Taschieri 2007; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991). See Figure 2 and Figure 3.

Figure 2.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies

Figure 3.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study

Allocation

Random sequence generation

We deemed the randomisation method to be appropriate in 17 studies, and we assessed these studies to be at low risk of bias. Payer 2005 and Velvart 2004 reported no details on the randomisation procedure, and study authors provided no information; we therefore assessed these studies as being at unclear risk of bias. In the study by Walivaara 2009, participants were allocated into two groups according to their date of birth, which meant that we judged this study to be at high risk of bias.

Allocation concealment

When assessing information reported in the trials, we considered allocation concealment as adequate for eight studies (Chong 2003; Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005a; Lindeboom 2005b; Pecora 2001; Taschieri 2008). We considered five trials to have unclear concealment of allocation, even after receiving study authors' replies (Christiansen 2009; De Lange 2007; Kurt 2014; Payer 2005; Song 2012). In seven studies (Angerame 2015; Danin 1996; Taschieri 2007; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991), allocation concealment, as stated in the article or confirmed by some of the authors, was not attempted and so we assessed these studies as having high risk of bias.

Blinding

Blinding of participants and personnel (performance bias)

In some cases (Danin 1996; Kvist 1999), blinding of treatment to operators or to participants was not feasible, as surgical and non-surgical procedures were compared. In these cases, we classified risk of bias as high. On the basis of information present in the articles and the replies of study authors, we considered the risk of performance bias to be low in five studies (De Lange 2007; Lindeboom 2005a; Lindeboom 2005b; Payer 2005; Pecora 2001), unclear in two studies (Chong 2003; Del Fabbro 2009) and high in 13 studies (Angerame 2015; Christiansen 2009; Danin 1996; Del Fabbro 2012; Kurt 2014; Kvist 1999; Song 2012; Taschieri 2007; Taschieri 2008; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991).

Blinding of outcome assessment (detection bias)

On the basis of information present in the articles and the replies of trial authors, we judged the risk of detection bias to be low in 13 studies (Angerame 2015; Chong 2003; Christiansen 2009; De Lange 2007; Del Fabbro 2009; Del Fabbro 2012; Lindeboom 2005a; Lindeboom 2005b; Payer 2005; Pecora 2001; Song 2012; Taschieri 2007; Taschieri 2008), unclear in one study (Kurt 2014) and high in six studies (Danin 1996; Kvist 1999; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991).

Incomplete outcome data

In the study articles, investigators clearly presented adequate information on all participants treated (including reasons for dropout) in nine trials (Angerame 2015; Christiansen 2009; Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005a; Lindeboom 2005b; Pecora 2001; Velvart 2004). This information was only partially reported and remained unclear after the trial author's reply for seven studies (Danin 1996; Kurt 2014; Taschieri 2007; Taschieri 2008; Walivaara 2009; Walivaara 2011; Zetterqvist 1991). For three studies, there was no information at all on dropouts and missing data, which put them at high risk of bias for this item (Chong 2003; Payer 2005; Song 2012). In two studies (De Lange 2007; Zetterqvist 1991), the dropout rate was rather high (> 20%), although investigators provided an explanation for dropouts.

Selective reporting

Thirteen studies reported full information on outcome measures, and we considered these trials to be at low risk of bias (Angerame 2015; Chong 2003; Christiansen 2009; Danin 1996; De Lange 2007; Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005a; Lindeboom 2005b; Pecora 2001; Song 2012; Velvart 2004). Seven studies reported partial or doubtful information on data of outcome measures that were assessed, though they reported the primary outcome healing of the periapical lesion in a satisfactory manner, hence we assessed these studies as being at unclear risk of bias (Kurt 2014; Payer 2005; Taschieri 2007; Taschieri 2008; Walivaara 2009; Walivaara 2011; Zetterqvist 1991). Another reason for the 'unclear' assessment for Payer 2005 was that only diagrams were provided for several variables, making obtaining actual numbers impossible and hence preventing meta-analysis.

Other potential sources of bias

We considered eight studies to be at low risk of any other potential source of bias (Christiansen 2009; Del Fabbro 2009; Del Fabbro 2012; Kvist 1999; Lindeboom 2005b; Payer 2005; Taschieri 2007; Taschieri 2008). Twelve studies did not perform an a priori sample size calculation (Angerame 2015; Christiansen 2009; Danin 1996; Kurt 2014; Lindeboom 2005a; Payer 2005; Pecora 2001; Taschieri 2007; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991), although this was not per se considered a possible source of bias; we assigned a judgement of 'unclear risk' only when missing sample size calculation was associated with other possible sources of bias. Lindeboom 2005b performed sample size calculation, although investigators did not clearly report the details. In one study (De Lange 2007), comparing two different devices for root-end preparation (ultrasonic device versus round dental bur), seven operators performed surgical procedures; the experience and comparability of the seven operators was not specified, and it was not clear each of them performed interventions in both groups equally; therefore, we judged this study to be at high risk of bias. Other studies failed to give a complete description of the characteristics of the study setting and of participant population (Angerame 2015; Chong 2003; Danin 1996; De Lange 2007; Kurt 2014; Lindeboom 2005a; Payer 2005; Pecora 2001; Song 2012; Velvart 2004; Walivaara 2009; Walivaara 2011; Zetterqvist 1991). We did not consider missing information about study characteristics, such as the recruitment period, sources of funding or participant characteristics including proportion of smokers, age and gender per se as a source of bias, but only as imprecision in reporting. On the other hand, missing information about lesion size and the type of teeth treated (as in Angerame 2015; Chong 2003; De Lange 2007; Pecora 2001; Song 2012; Velvart 2004; Walivaara 2009; and Zetterqvist 1991) may be more relevant as these parameters might affect the treatment outcome and it is important they are equally distributed among groups. In Zetterqvist 1991, which reported one-year and five-year follow-up evaluations, periapical healing was assessed using personal criteria instead of the conventional criteria adopted by most studies. Investigators in the two studies by Walivaara (Walivaara 2009; Walivaara 2011) did not assess participants at a given follow-up time but reviewed them clinically and radiographically after a minimum of one year (12 to 38 months in Walivaara 2009, and 12 to 21 months in Walivaara 2011). Therefore periapical lesion healing was evaluated at a follow-up duration not equal for all teeth. For the quantitative analysis, it was as if all participants were assessed at one year, which was likely to lead to underestimation of the results because some lesions may take longer than one year to heal. We considered the two studies at high risk of bias for this item.

Effects of interventions

See: Summary of findings for the main comparison Root-end resection versus root canal retreatment; Summary of findings 2 Cone beam computed tomography (CBCT) versus periapical radiography; Summary of findings 3 Preoperative antibiotic prophylaxis versus placebo; Summary of findings 4 Magnification devices; Summary of findings 5 Papilla base incision (PBI) incision versus complete mobilisation; Summary of findings 6 Ultrasonic instruments versus bur; Summary of findings 7 Root end fillings; Summary of findings 8 Grafting versus no grafting; Summary of findings 9 Low energy level laser therapy versus placebo versus control

See Summary of findings for the main comparison; Summary of findings 2; Summary of findings 3; Summary of findings 4; Summary of findings 5; Summary of findings 6; Summary of findings 7; and Summary of findings 8.

1. Root-end resection with or without root-end filling versus root canal retreatment for secondary treatment of periapical lesions (two trials, 126 participants)

Two studies at high risk of bias addressed this comparison (Danin 1996; Kvist 1999). Kvist 1999 compared surgical and non-surgical treatments at six-month and one-, two- and four-year follow-up periods. The results in the article were summarised only by a diagram but the main author provided us with numerical data that we considered for the present analysis. Danin 1996 provided results for healing at one-year follow-up only. Data from these two studies were dichotomised as described in the Data synthesis section of this review.

We found no clear evidence that surgical intervention had a higher healing rate than non-surgical intervention after one-year follow-up (risk ratio (RR) 1.15, 95% confidence interval (CI) 0.97 to 1.35; Analysis 1.1; Figure 4). We noted heterogeneity between study results (P = 0.02). Similarly, Kvist 1999 found no evidence of a difference in healing rates between root-end resection and root canal retreatment after four years (RR 1.03, 95% CI 0.89 to 1.20; Analysis 1.2; Figure 5). The study author reported that four surgically retreated cases that had been classified as healed at one-year follow-up did show a relapse of the apical radiolucency or presented with clinical symptoms at a later follow-up. The author of the latter study provided us with data recorded at a longer follow-up (10 years, personal communication), which confirmed there was no evidence of a difference between groups (RR 1.11, 95% CI 0.88 to 1.41; Analysis 1.3; Figure 6).

Figure 4.

Forest plot of comparison: 1 Root-end resection versus root canal retreatment, outcome: 1.1 Healing - one year

Figure 5.

Forest plot of comparison: 6 Ultrasonic versus Bur, outcome: 6.1 Healing - one year

Evaluation of self-reported pain and swelling in the first seven days after secondary treatment showed a significantly higher number of participants reporting pain and swelling in the root-end resection group as compared with the root canal retreatment group (Analysis 1.4; Analysis 1.5).

2. Type of preoperative evaluation: cone beam computed tomography (CBCT) versus conventional periapical radiography (one trial, 39 participants)

One study at high risk of bias addressed this question (Kurt 2014). There was no evidence that use of CBCT in the preoperative evaluation was advantageous, in terms of one-year clinical and radiographic healing, as shown in Analysis 2.1 (RR 1.02, 95% CI 0.70 to 1.47).

3. Antibiotic prophylaxis versus placebo (one trial, 250 participants)

One study at unclear risk of bias addressed this question (Lindeboom 2005a). There was no evidence that use of preoperative antibiotics reduced the incidence of postoperative infection after four weeks compared with placebo, as shown in Analysis 3.1 (RR 0.49, 95% CI 0.09 to 2.64).

4. Magnification devices: surgical microscope versus endoscope versus surgical loupes (one trial, 98 participants/150 teeth)

One study at high risk of bias addressed whether use of magnification devices could bring advantages in clinical and radiographic healing up to two years of follow-up (Taschieri 2008). Results of this three-arm trial were presented in two articles - one reporting the comparison between surgical loupes and endoscope, after one-year of follow-up, and the other reporting the comparison between surgical microscope and endoscope, at two years of follow-up. Both analyses were tooth-based and showed no evidence of a difference in healing with one or the other magnification device, as shown in Analysis 4.1 (loupes versus endoscope on 71 teeth followed up to one year (RR 1.05, 95% CI 0.92 to 1.20)) and Analysis 4.2 (microscope versus endoscope on 100 teeth followed up to two years (RR 1.01, 95% CI 0.89 to 1.15)).

5. Incision type (two trials, 52 participants)

Two studies addressed the question of whether the type of incision could lead to better results in terms of aesthetics or postoperative quality of life.

One split-mouth study at high risk of bias evaluated the height of interdental papilla after papilla base incision (PBI) versus complete papilla mobilisation techniques (Velvart 2004) at follow-up of one year (12 participants). Results show weak evidence of a lower papilla height reduction with the PBI technique as compared with complete papilla mobilisation after one year (Analysis 5.1; mean difference (MD) -1.04, 95% CI -2.10 to 0.02).

The other study (Del Fabbro 2009), which was at unclear risk of bias, had a parallel design and evaluated pain and postoperative symptoms in participants undergoing PBI versus sulcular incision (complete papilla mobilisation) with follow-up of one week (38 participants). Results showed no evidence of a difference in reported pain on a VAS scale at day one (Analysis 5.2; MD -2.25, 95% CI -7.17 to 2.67; P = 0.37) or day two (MD -1.50, 95% CI -6.34 to 3.34; P = 0.54). On the other hand, there was evidence of less pain in the PBI group than in the sulcular incision group at day 3 (MD -22.00, 95% CI -26.81 to -17.19; P < 0.00001).

6. Ultrasonic device versus conventional bur for root-end preparation (one trial, 290 participants)

One study at high risk of bias addressed this question, evaluating treatment success at one-year follow-up (De Lange 2007). Use of ultrasonic devices for root-end preparation provided weak evidence of an advantage when compared with the traditional bur, as shown by Analysis 6.1 (RR 1.14, 95% CI 1.00 to 1.30). This study adopted the radiographic evaluation criteria of Rud 1972. See Figure 5.

7. Root-end filling material (seven trials, 846 participants)

Seven studies each compared two different materials for root-end filling.

MTA (mineral trioxide aggregate) versus IRM (intermediate restorative material) was evaluated by two studies that involved 222 participants (Chong 2003; Lindeboom 2005b). After one-year follow-up, there was no evidence of a difference between groups in clinical and radiographic success, as shown in Analysis 7.1 (RR 1.09, 95% CI 0.97 to 1.21). There was no heterogeneity between the two studies' results (P value = 0.72). Only one study provided healing outcomes at two-year follow-up (Chong 2003), showing no evidence of a difference between groups, as shown in Analysis 7.2 (RR 1.05, 95% CI 0.92 to 1.20; P = 0.45).

Only one study evaluated postoperative pain (Chong 2003). The comparison up to two days post surgery was based on the proportion of participants experiencing postoperative pain and found no evidence of a difference at one day (RR 0.99, 95% CI 0.82 to 1.19; P = 0.88) or at two days (RR 1.06, 95% CI 0.83 to 1.36; P = 0.62) (Analysis 7.3).

MTA versus SuperEBA was evaluated by one study that involved 192 participants (Song 2012). After one-year follow-up, there was no evidence of a difference in clinical and radiographic success, as shown in Analysis 7.4 (RR 0.97, 95% CI 0.91 to 1.04).

MTA versus gutta-percha smoothing was evaluated by one study at high risk of bias that involved 44 participants (Christiansen 2009). . There was evidence of better healing when the root-end was filled with MTA as compared with treatment of the root-end by smoothing of the orthograde GP root filling, after one-year follow-up, as shown in Analysis 7.5 (RR 1.60, 95% CI 1.14 to 2.24).

The study assessed postoperative pain using a VAS scale and showed no evidence of a difference in pain evaluated at one day (MD -4.00, 95% CI -16.69 to 8.69; P = 0.54), 2 days (MD 2.00, 95% CI -6.22 to 10.22; P = 0.63) and three days post surgery (MD 5.00, 95% CI -4.37 to 14.37; P = 0.30), as shown in Analysis 7.6.

Glass ionomer cement versus amalgam was evaluated in one study a high risk of bias that involved 85 participants/105 teeth (Zetterqvist 1991); the analysis was tooth-based. After one-year follow-up, there was no evidence of a difference in clinical and radiographic success (P = 0.78), as shown in Analysis 7.7 (RR 0.98, 95% CI 0.86 to 1.12). After five years of follow-up, some participants dropped out and the population was reduced to 64 participants/67 teeth. Results showed no evidence of a difference in clinical and radiographic success at the five-year follow-up (P = 1.00), as shown in Analysis 7.8 (RR 1.00, 95% CI 0.84 to 1.20).

IRM versus gutta-percha was evaluated by one study at high risk of bias that involved 139 participants/160 teeth (Walivaara 2009); 147 teeth in 131 participants were evaluated at the one-year follow-up. Fractured teeth at one-year follow-up (three in the IRM group and one in the gutta-percha group) were considered as failures instead of being excluded as in the Walivaara 2011 study. After one-year follow-up, results showed no evidence of a difference in clinical and radiographic success (P = 0.22) between the two groups, as shown in Analysis 7.9 (RR 0.92, 95% CI 0.80 to 1.05).

IRM versus SuperEBA was evaluated by one study at high risk of bias that involved 164 participants/206 teeth (Walivaara 2011); 194 teeth in 153 participants were assessed at the one-year follow-up. After one-year follow-up, in spite of a tendency in favour of IRM group, there was no clear evidence of a difference in clinical and radiographic success, as shown in Analysis 7.10 (RR 1.11, 95% CI 0.99 to 1.24; P = 0.07).

8. Grafting versus no grafting (four trials, 106 participants)

One study at unclear risk of bias that involved 18 participants/18 teeth evaluated calcium sulphate versus no grafting (Pecora 2001). After one-year follow-up, there was no evidence of better healing when calcium sulphate was used (P = 0.46), as shown in Analysis 8.1 (RR 1.12, 95% CI 0.83 to 1.50).

One study at high risk of bias (Taschieri 2007), which involved 41 participants/59 teeth, assessed guided tissue regeneration (GTR) using bovine bone mineral and resorbable collagen membrane versus no GTR. The analysis was tooth-based. After one-year follow-up, results showed no evidence of better healing when GTR was used (P = 0.39), as shown in Analysis 8.2 (RR 1.12, 95% CI 0.86 to 1.46).

Plasma rich in growth factors (PRGF) versus no grafting was evaluated in one study at high risk of bias (Del Fabbro 2012), which assessed postoperative pain and symptoms up to one week in 36 participants. There was evidence of less pain among participants treated with the adjunct of PRGF, as shown in Analysis 8.3 (one day: MD -51.60, 95% CI -63.43 to -39.77; P < 0.001; two days: MD -41.70, 95% CI -52.09 to -31.31; P < 0.001; three days: MD -45.00, 95% CI -59.7 to -30.29; P < 0.001).

Platelet-rich fibrin versus no grafting was evaluated in one study at high risk of bias (Angerame 2015), which assessed radiographic healing up to one year after surgery, pain and swelling up to seven days postoperatively, and the occurrence of complications such as sinus tract apicomarginal communication and infection with tenderness to palpation or percussion. This study claimed to be preliminary and had a small sample size (only seven participants in the test group and four in the control group), which prevented a robust analysis. Study authors reported that after one-year follow-up, they found no significant difference in healing of the lesion between test and control groups, and they were able to observe a significant difference only at two-month and three-month follow-up. The article included no report of complications, and the study authors replied that none occurred throughout the observation period. Pain was not assessed by means of a VAS scale, so we could not compare these findings with those of other studies. Pain was reported to be significantly less among participants treated with PRF adjunct at two time points only, two and six hours after surgery. Swelling was reported to be significantly less in the PRF group up to five days postoperatively.

9. Low energy level laser therapy (LLLT) versus placebo versus control (one study, 72 participants)

One study at high risk of bias evaluated the effects of LLLT irradiation performed intraoperatively at one, three and seven days after surgery (Payer 2005). There was no evidence of a difference between participants treated with LLLT and those in the placebo group (irradiation without laser activation) or control group (no use of the laser device) in terms of swelling, wound healing and pain, as evaluated at one, three and seven days post surgery. Pain evaluated by VAS (0 to 100 scale) and a numerical rating scale (NRS; 1 to 10 scale) was reported only in graphic form, and study authors were not able to provide actual means and standard deviations to allow a quantitative evaluation. Pain evaluated by a verbal rating scale (VRS; scored as no pain or slight, moderate, strong and very strong pain) represented the maximum pain levels experienced by participants in the first postoperative week. In all cases, maximum pain occurred on the first day after surgery (Payer 2005). For this analysis, we aggregated data from "moderate" + "minor" scores (low pain) and from "strong" and "very strong" scores (high pain) and considered the latter as events in Analysis 9.1 (LLLT versus control: RR 0.04, 95% CI 0.00 to 0.71; placebo versus control: RR 0.04, 95% CI 0.00 to 0.61).

Discussion

Summary of main results

We performed this review to update a previous Cochrane review, published in 2007 (Del Fabbro 2007), which addressed the comparison between surgical and root canal retreatment for periapical lesions. The present version expanded the initial aim to include an evaluation of different aspects of surgical root canal treatment.

We identified two studies that compared a surgical and a non-surgical approach, both of which were included in the previous version of this review. Thomas Kvist, the author of the study with four-year follow-up (Kvist 1999), kindly provided us with results of treatment after 10 years of follow-up. These results indicate the absence of a difference between the two groups.

We identified 18 studies comparing different surgical approaches.

One study evaluated the importance of modern radiographic diagnostic tools in the preoperative phase, finding no significant advantage of using preoperative CBCT instead of periapical radiographs in terms of healing of the lesion after one-year follow-up (Kurt 2014).

One study evaluated the value of antibiotic prophylaxis for reducing postoperative infection in a cohort of 256 participants up to four weeks post surgery, but found no evidence of a difference between groups for the incidence of infective episodes (Lindeboom 2005a).

Two studies addressed the hypothesis that a minimally invasive incision like the papilla base incision (PBI) could have beneficial results in root-end resection as compared with a traditional flap (complete papilla mobilisation). One parallel-design study found that the PBI led to reduced postoperative pain and discomfort (Del Fabbro 2009). The other study, which used a split-mouth design (Velvart 2004), found inconclusive evidence that PBI produced a better aesthetic outcome in terms of interdental papilla height after one year of healing. Both of these trials had a limited sample size, and their suggested benefits need to be confirmed by further evidence.

The benefit of magnification devices was explored in a three-arm trial that, unfortunately, did not include a control group without magnification (Taschieri 2008). Therefore, the true efficacy of a given magnification device could not be evaluated. The only conclusion of this tooth-based study was that there is no evidence of a difference in healing of the lesion after one year or after two years, using microscope, endoscope or loupes during the surgical procedure. Technical and practical advantages of magnification devices in enhancing the view of the surgical field and consequently improving precision and surgeon comfort during the operation have been claimed often but never quantified.

One trial evaluated use of an ultrasonic device versus a conventional handpiece bur for root-end preparation (De Lange 2007). The analysis showed inconclusive evidence of an advantage of the ultrasonic device, supporting the benefits claimed for this technology for bone surgery and many surgical applications in the oral field.

Seven of the included trials compared different retro-filling materials, evaluating healing after one year (Christiansen 2009; Lindeboom 2005b; Song 2012; Walivaara 2009; Walivaara 2011) or longer (Chong 2003; Zetterqvist 1991). Two of these studies also assessed postoperative pain and symptoms (Chong 2003; Christiansen 2009). Only one comparison showed evidence of a difference between groups in terms of periapical healing at one year, with the group having root-end filled with mineral trioxide aggregate (MTA) displaying better results than the group treated with gutta-percha (Christiansen 2009). The other six studies showed no evidence of differences in outcomes between materials tested, suggesting that the effect of root-end filling material per se might be considered of minor importance to the success of retreatment. It should be noted that the type of material used in filling the retrograde cavity did not represent the only difference in the protocols adopted for root-end resection in these seven studies. For example, in Zetterqvist 1991, investigators used a traditional technique, without magnification devices and with an inverted cone bur in preparing the retrograde cavity. The other studies adopted a modern technique, with microsurgical ultrasonic instruments for retrograde cavity preparation; investigators used a surgical microscope (Chong 2003; Christiansen 2009; Song 2012) or loupes (Lindeboom 2005b; Walivaara 2009; Walivaara 2011) to enhance root-end visualisation.

Another question in endodontic surgery is whether filling the periapical lesion with a graft material improves healing of the lesion. Four studies addressed this question, but their protocols were too different to allow meta-analysis. Pecora 2001 found no evidence of benefit derived from grafting the lesion with calcium sulphate when evaluating healing of the lesion after one-year follow-up. Taschieri 2007 failed to demonstrate evidence of an advantage of guided tissue regeneration (GTR) for the treatment of large periapical lesions of strict endodontic origin. Del Fabbro 2012 found evidence of a benefit of plasma rich in growth factors in reducing postoperative pain during the first three days after surgery. Unfortunately, no data are currently available regarding healing of the lesion at one-year follow-up, thereby preventing any comparison with other studies evaluating the effects of grafting the lesion. Angerame 2015 reported a significant benefit of platelet-rich fibrin in reducing both postoperative pain and swelling. The study reported significantly better healing of the lesion two and three months after surgery but not at 12-month follow-up. This preliminary study had a very small sample size, so results should be interpreted cautiously.

One study addressed the efficacy of low energy level laser therapy (LLLT) for reducing postoperative pain and swelling in root-end resection, showing no evidence of differences in outcomes between LLLT and placebo (irradiation without laser activation), although both caused less pain as compared with the control (without use of the laser device) (Payer 2005). This suggests that LLLT is ineffective in preventing postoperative pain and confirms the importance of the placebo group for outcomes based on subjective evaluation.

Overall completeness and applicability of evidence

Most studies were performed in university clinics or in non-academic specialised clinical centres, by experienced operators. Therefore, generalisation of results from the present review to different clinical settings, such as general daily practice, should be made with caution. Studies comparing the same interventions were insufficient to enable robust conclusions to be drawn via meta-analysis. We found several indications of possible advantages of some procedures or materials over others, but no definitive evidence for almost any of the topics addressed.

In most cases, outcomes were restricted to the one-year follow-up period. Although this does allow comparison of results from different studies after the same observation period, it does not consider the fact that in surgical procedures, risk of emerging post-treatment disease might increase over time. This fact was underlined only by Kvist 1999, which reported relapses in four surgically treated participants at between one and four years of follow-up, but no recurrence for participants who underwent root canal retreatment. Thus, outcomes at one year may not actually reflect the longer-term outcomes of which both clinicians and patients need to be aware.

Quality of the evidence

Most of the studies included in this review provided data on assessment of the primary outcome of this review, that is, they investigated the efficacy of different endodontic surgical protocols by performing clinical and radiographic evaluations of healing of periapical pathosis after at least one year of follow-up. Other outcomes addressed were the effects of different surgical protocols on postoperative pain and symptoms. The quality of the available evidence quality is low to very low. The risk of bias in most of the included studies was unclear, with most possible sources of bias due to lack of allocation concealment and blinding of operators, participants and evaluators, especially in Walivaara 2009, Walivaara 2011 and Zetterqvist 1991, which also omitted most information regarding the source of funding, the characteristics of participants, the teeth and the lesions. Zetterqvist 1991 had a dropout rate higher than 20% at five-year follow-up, thereby reducing the statistical power of the analysis and the robustness of the outcomes provided. Furthermore, in these three studies, some participants had more than one tooth treated and data were provided with only the tooth - not the participant - considered as the analysis unit. Finally, in the two studies by Walivaara (Walivaara 2009; Walivaara 2011), investigators reported no specific follow-up time, but they followed teeth for at least 12 months, in a range between 12 and 38 months (Walivaara 2009) and 12 to 21 months (Walivaara 2011). This raises some concerns about the way these trials were conducted and the reliability of results reported by these investigators.

The size of the lesion, which is an important parameter often correlated with the likelihood of healing, was not the same across all included studies, ranging from smaller than 5 mm (small lesions) to larger than 10 mm (large lesions), and nine out of 20 included studies did not even report the lesion size (Angerame 2015; Chong 2003; Christiansen 2009; De Lange 2007; Kurt 2014; Song 2012; Velvart 2004; Walivaara 2009; Zetterqvist 1991). This could be a concern when the trials are compared.

Sample size was variable among studies, ranging from 11 participants (Angerame 2015) to 260 participants (Song 2012). Only eight out of 19 studies reported a sample size calculation, and in most cases, the sample size appeared underpowered to detect a significant difference.

Potential biases in the review process

This review did not consider studies performed with the traditional root-end resection technique (e.g. Kvist 1999; Zetterqvist 1991) separately from studies performed using a modern root-end resection technique, which represent the majority of included trials. This means that potentially important differences in the protocols might not be fully accounted for. Indeed, several studies sought to compare specific aspects of the traditional technique versus the modern one, but in general, standardisation among these studies was poor, which might hinder any comparison and limit the precision of the success estimate.

Some authors of the present review (MDF, ST) are also among the authors of some of the included studies (Del Fabbro 2009; Del Fabbro 2012; Taschieri 2007; Taschieri 2008). We addressed this bias by excluding these authors from any evaluation concerning the studies in which they were involved.

Furthermore, some of the parameters accounted for are patient-based outcomes, such as pain, aesthetics and satisfaction, which are subjective. The individual judgement of patients may depend on factors such as their expectations and their previous experience. However, as we found no clear evidence suggesting that apical periodontitis is a life-threatening disease, such patient-based outcomes may represent a sensible contribution to assessment of treatment success.

Agreements and disagreements with other studies or reviews

Other systematic reviews and meta-analyses have addressed some aspects of root-end resection, such as outcomes of modern techniques (Tsesis 2009; Tsesis 2013), comparison of traditional root-end surgery and root-end microsurgery (Setzer 2010), effects of using guided tissue regeneration (Tsesis 2011), use of regenerative techniques (Von Arx 2011), comparison of root-end microsurgery with and without the use of higher magnification (Setzer 2012) and factors affecting prognosis (Von Arx 2010b). However, because the findings of these reviews were not based on the most reliable clinical studies owing to less restrictive inclusion criteria with respect to the present review, direct comparison with the present findings could be inappropriate and difficult to interpret.

Authors' conclusions

Implications for practice

The review found that neither root-end resection nor root canal retreatment was superior for healing at one year; however, root canal retreatment produced less postoperative pain and swelling than root-end resection with root-end filling.

The surgical approach to retreatment of periapical lesions through root-end resection with or without root-end filling has changed considerably since its inception because of the introduction of various materials, devices and techniques that aim to improve success rates of treatment, reduce recurrence of disease and lessen patient discomfort in the postsurgical phase. Although the studies included in this review addressed many different aspects of the surgical procedure, unfortunately, the overall evidence emerging from the included trials is limited and incomplete; for most of the comparisons considered, only one study provided data.

The only surgical technique that significantly increased clinical and radiographic healing of the periapical lesion after at least one year of follow-up was the use of ultrasonic devices instead of the conventional handpiece bur for root-end preparation.

This review also found that antibiotic prophylaxis does not seem to reduce the incidence of postoperative infection; use of platelet concentrates as an adjunct to the surgical procedure may markedly reduce postoperative pain; and use of a papilla base incision may help to preserve the interdental papilla.

Overall, none of the review findings can be assumed to be conclusive, as the quality of the evidence was low to very low. Information is still insufficient to inform clinicians whether root canal retreatment or root-end resection should be used, and which procedures for root-end resection should be followed to achieve the best results for patients.

Implications for research

The review authors are aware of the difficulties of carrying out large-scale, long-term randomised studies, especially regarding the financial resources needed to perform appropriate well-designed studies; however, without consistent results from such studies, no reliable answers to pending questions can be found. All questions addressed in this review need further investigation if we are to understand whether a surgical or a non-surgical approach should be used, and which surgical procedures may provide the best and most predictable results, in terms of healing of periapical lesions and quality of life of the patient in the postoperative period. Future studies should use standardised techniques and success criteria, precisely defined outcomes and specific features of the periapical lesion. Investigators should use the participant - not the tooth - as the analysis unit, if possible, and should follow the CONSORT recommendations for reporting (www.consort-statement.org).

Acknowledgements

The review authors are indebted to Anne Littlewood for invaluable help in reviewing and finalising the search strategy for the present review. We also acknowledge the help of Helen Wakeford, Helen Worthington and Laura MacDonald.

Data and analyses

Download statistical data

Comparison 1. Root-end resection versus root canal retreatment
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Healing - 1 year2126Risk Ratio (M-H, Fixed, 95% CI)1.15 [0.97, 1.35]
2 Healing - 4 years1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
3 Healing - 10 years1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
4 Participants reporting pain1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
4.1 day 11 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.2 day 21 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.3 day 31 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.4 day 41 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.5 day 51 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.6 day 61 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4.7 day 71 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5 Participants reporting swelling1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
5.1 day 11 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.2 day 21 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.3 day 31 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.4 day 41 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.5 day 51 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.6 day 61 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
5.7 day 71 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 1.1.

Comparison 1 Root-end resection versus root canal retreatment, Outcome 1 Healing - 1 year.

Analysis 1.2.

Comparison 1 Root-end resection versus root canal retreatment, Outcome 2 Healing - 4 years.

Analysis 1.3.

Comparison 1 Root-end resection versus root canal retreatment, Outcome 3 Healing - 10 years.

Analysis 1.4.

Comparison 1 Root-end resection versus root canal retreatment, Outcome 4 Participants reporting pain.

Analysis 1.5.

Comparison 1 Root-end resection versus root canal retreatment, Outcome 5 Participants reporting swelling.

Comparison 2. CBCT versus periapical radiography
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Healing - 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
Analysis 2.1.

Comparison 2 CBCT versus periapical radiography, Outcome 1 Healing - 1 year.

Comparison 3. Antibiotic prophylaxis versus placebo
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Occurrence of postoperative infection - 4 weeks1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
Analysis 3.1.

Comparison 3 Antibiotic prophylaxis versus placebo, Outcome 1 Occurrence of postoperative infection - 4 weeks.

Comparison 4. Magnification devices
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Loupes versus endoscope - healing at 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
2 Microscope versus endoscope - healing at 2 years1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
Analysis 4.1.

Comparison 4 Magnification devices, Outcome 1 Loupes versus endoscope - healing at 1 year.

Analysis 4.2.

Comparison 4 Magnification devices, Outcome 2 Microscope versus endoscope - healing at 2 years.

Comparison 5. Type of incision
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 PBI versus complete mobilisation - papilla height1 Mean Difference (Fixed, 95% CI)Totals not selected
2 PBI versus complete mobilisation - pain1 Mean Difference (IV, Fixed, 95% CI)Totals not selected
2.1 1 day1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2.2 2 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
2.3 3 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 5.1.

Comparison 5 Type of incision, Outcome 1 PBI versus complete mobilisation - papilla height.

Analysis 5.2.

Comparison 5 Type of incision, Outcome 2 PBI versus complete mobilisation - pain.

Comparison 6. Ultrasonic versus bur
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Healing - 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
Analysis 6.1.

Comparison 6 Ultrasonic versus bur, Outcome 1 Healing - 1 year.

Comparison 7. Root-end filling material
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 MTA versus IRM - healing at 1 year2222Risk Ratio (M-H, Fixed, 95% CI)1.09 [0.97, 1.22]
2 MTA versus IRM - healing at 2 years1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
3 MTA versus IRM - pain1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
3.1 1 day1 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
3.2 2 days1 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
4 SuperEBA versus MTA - healing at 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
5 MTA versus gutta-percha - healing at 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
6 MTA versus gutta-percha - pain1 Mean Difference (IV, Fixed, 95% CI)Totals not selected
6.1 1 day1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
6.2 2 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
6.3 3 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
7 Glass ionomer cement (GIC) vs amalgam - healing at 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
8 Glass ionomer cement (GIC) vs amalgam - healing at 5 years1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
9 IRM vs Gutta-percha - healing > 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
10 IRM vs SuperEBA - healing > 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
Analysis 7.1.

Comparison 7 Root-end filling material, Outcome 1 MTA versus IRM - healing at 1 year.

Analysis 7.2.

Comparison 7 Root-end filling material, Outcome 2 MTA versus IRM - healing at 2 years.

Analysis 7.3.

Comparison 7 Root-end filling material, Outcome 3 MTA versus IRM - pain.

Analysis 7.4.

Comparison 7 Root-end filling material, Outcome 4 SuperEBA versus MTA - healing at 1 year.

Analysis 7.5.

Comparison 7 Root-end filling material, Outcome 5 MTA versus gutta-percha - healing at 1 year.

Analysis 7.6.

Comparison 7 Root-end filling material, Outcome 6 MTA versus gutta-percha - pain.

Analysis 7.7.

Comparison 7 Root-end filling material, Outcome 7 Glass ionomer cement (GIC) vs amalgam - healing at 1 year.

Analysis 7.8.

Comparison 7 Root-end filling material, Outcome 8 Glass ionomer cement (GIC) vs amalgam - healing at 5 years.

Analysis 7.9.

Comparison 7 Root-end filling material, Outcome 9 IRM vs Gutta-percha - healing > 1 year.

Analysis 7.10.

Comparison 7 Root-end filling material, Outcome 10 IRM vs SuperEBA - healing > 1 year.

Comparison 8. Grafting versus no grafting
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Calcium sulphate (CaS) versus no grafting - healing at 1 year1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
2 GTR with bovine bone vs no grafting - healing at 1 year - TB1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
3 PRGF versus no grafting - pain (VAS)1 Mean Difference (IV, Fixed, 95% CI)Totals not selected
3.1 1 day1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
3.2 2 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
3.3 3 days1 Mean Difference (IV, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 8.1.

Comparison 8 Grafting versus no grafting, Outcome 1 Calcium sulphate (CaS) versus no grafting - healing at 1 year.

Analysis 8.2.

Comparison 8 Grafting versus no grafting, Outcome 2 GTR with bovine bone vs no grafting - healing at 1 year - TB.

Analysis 8.3.

Comparison 8 Grafting versus no grafting, Outcome 3 PRGF versus no grafting - pain (VAS).

Comparison 9. Low energy level laser therapy (LLLT) versus placebo versus control
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Maximum pain (VRS)1 Risk Ratio (M-H, Fixed, 95% CI)Totals not selected
1.1 LLLT vs control1 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
1.2 LLLT vs placebo1 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
1.3 placebo vs control1 Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]
Analysis 9.1.

Comparison 9 Low energy level laser therapy (LLLT) versus placebo versus control, Outcome 1 Maximum pain (VRS).

Appendices

Appendix 1. MEDLINE Ovid search strategy

1. exp Periapical diseases/
2. ((“tooth root$” or (root$ adj3 teeth) or (tooth adj3 apex) or (teeth adj3 apex) or (teeth adj3 apices) or periapical$ or periradicular or peri-radicular) and (disease$ or periodont$ or abscess$ or granuloma$ or lesion$ or cyst$ or infect$ or inflam$ or pathosis)).ti,ab.
3. 1 or 2
4. exp Endodontics
5. endodontic$.ti,ab.
6. (apical$ and (surgical or surgery)).ti,ab.
7. (apicectom$ or apicoectom$).ti,ab.
8. (retrograd$ adj6 fill$).ti,ab.
9. ((root$ adj6 treat$) or (root$ adj6 therap$) or (root-end adj6 resect$) or (root-end adj6 fill$)).ti,ab.
10. (retrograd$ or orthograd$).ti,ab.
11. or/4-10
12. 3 and 11

The subject search was linked to the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying randomised trials in MEDLINE: sensitivity maximising version (2008 revision) as referenced in Chapter 6.4.11.1 and detailed in box 6.4.c of The Cochrane Handbook for Systematic Reviews of Interventions, Version 5.1.0 [updated March 2011] (Lefebvre 2011).

1. randomized controlled trial.pt.
2. controlled clinical trial.pt.
3. randomized.ab.
4. placebo.ab.
5. drug therapy.fs.
6. randomly.ab.
7. trial.ab.
8. groups.ab.
9. or/1-8
10. exp animals/ not humans.sh.
11. 9 not 10

Appendix 2. Cochrane Oral Health Trials Register search strategy

1 (("tooth root*" or (tooth and apex) or (teeth and apex) or (teeth and apices) or periapical* or periradicular or peri-radicular)):ti,ab
2 (disease* or periodont* or abscess* or granuloma* or lesion* or cyst* or infect* or inflam* or pathosis):ti,ab.
3 #1 and #2
4 endodontic*:ti,ab
5 (apical* and (surgical or surgery)):ti,ab
6 (apicectom* or apicoectom*):ti,ab
7 ((root* and treat*) or (root* and therap*) or (root-end and resect*) or (root-end and fill*)) :ti,ab
8 (retrograd* or orthograd*):ti,ab
9 (#4 or #5 or #6 or #7 or #8)
10 (#3 and #9) AND (INREGISTER)

Appendix 3. Cochrane Central Register of Controlled Trials (CENTRAL) search strategy

#1 TOOTH ROOT explode all trees (MeSH)
#2 PERIAPICAL DISEASES explode all trees (MeSH)
#3 APICOECTOMY single term (MeSH)
#4 TOOTH APEX single term (MeSH)
#5 ENDODONTICS single term (MeSH)
#6 RETREATMENT single term (MeSH)
#7 (#1 or #2 or #3 or #4 or #5 or #6)
#8 (tooth near root*) or (teeth near root*) or (tooth near apex*) or (teeth near apex*) or (teeth near apices) or periodical* or periradicular or peri-radicular
#9 disease* or periodontitis or abscess* or granuloma* or lesion* or cyst* or infect* or inflame* or pathosis
#10 (#8 and #9)
#11 endodontic* and (treat* or therapy or surger* or surgical*)
#12 apical* and (surger* or surgical*)
#13 apicectom* or apicoectom*
#14 retrograd* near fill*
#15 (root near treat*) or (root near therap*) or (root-end near resect*) or (root-end near fill*)
#16 (#11 or #12 or #13 or #14 or #15)
#17 re-treat* or retreat*
#18 (#10 and #16 and #17)

Appendix 4. Embase Ovid search strategy

1. exp Periapical diseases/
2. (("tooth root$" or (root$ adj3 teeth) or (tooth adj3 apex) or (teeth adj3 apex) or (teeth adj3 apices) or periapical$ or periradicular or peri-radicular) and (disease$ or periodont$ or abscess$ or granuloma$ or lesion$ or cyst$ or infect$ or inflam$ or pathosis)).ti,ab.
3. 1 or 2
4. exp Endodontics/
5. endodontic$.ti,ab.
6. (apical$ and (surgical or surgery)).ti,ab.
7. (apicectom$ or apicoectom$).ti,ab.
8. (retrograd$ adj6 fill$).ti,ab.
9. ((root$ adj6 treat$) or (root$ adj6 therap$) or (root-end adj6 resect$) or (root-end adj6 fill$)).ti,ab.
10. (retrograd$ or orthograd$).ti,ab.
11. or/4-10
12. 3 and 11

The above subject search was linked to the Cochrane Oral Health Group filter for identifying RCTs in EMBASE via OVID:

1. random$.ti,ab.
2. factorial$.ti,ab.
3. (crossover$ or cross over$ or cross-over$).ti,ab.
4. placebo$.ti,ab.
5. (doubl$ adj blind$).ti,ab.
6. (singl$ adj blind$).ti,ab.
7. assign$.ti,ab.
8. allocat$.ti,ab.
9. volunteer$.ti,ab.
10. CROSSOVER PROCEDURE.sh.
11. DOUBLE-BLIND PROCEDURE.sh.
12. RANDOMIZED CONTROLLED TRIAL.sh.
13. SINGLE BLIND PROCEDURE.sh.
14. or/1-13
15. (exp animal/ or animal.hw. or nonhuman/) not (exp human/ or human cell/ or (human or humans).ti.)
16. 14 NOT 15

Appendix 5. US National Institutes of Health Trials Registry (ClinicalTrials.gov) and WHO International Clinical Trials Registry Platform search strategy

periradicular
periapical and retreat

What's new

DateEventDescription
7 December 2016AmendedMinor correction: magnification devices were not used in the De Lange 2007 study. The reference to a microscope having been used in the ultrasonic group has been corrected in the 'Other potential risks of bias' section and the relevant 'Characteristics of included studies' table. Risk of bias and quality assessments are unaffected.

History

DateEventDescription
16 August 2016New citation required and conclusions have changed

Evidence for root-end resection versus root canal retreatment is inconclusive.

This update includes evidence from eight comparisons of different aspects of the root-end section procedure: cone beam computed tomography versus periapical radiography for preoperative assessment; antibiotic prophylaxis versus placebo; different magnification devices; different types of incision; ultrasonic devices versus handpiece burs; different types of root-end filling material; grafting versus no grafting; low energy level laser therapy versus placebo versus control (no use of the laser device).

10 February 2016New search has been performedReview has been expanded to include comparisons of different surgical approaches to retreatment of periapical lesions.
Title has been changed.
New search was conducted.
17 new studies have been included.
Unpublished data on longer-term follow-up were received from 1 trial author.
31 July 2008AmendedConverted to new review format

Contributions of authors

Conceiving of the review: Silvio Taschieri (ST), Massimo Del Fabbro (MDF).
Designing and co-ordinating the review: MDF.
Developing search strategies and undertaking searches: Stefano Corbella (SC), Eyal Rosen (ER).
Screening search results and retrieved papers against inclusion criteria: SC, MDF.
Writing to study authors for additional information: MDF, SC.
Appraising the quality of papers: Igor Tsesis (IT), Alessandra Lolato (AL), Patrick Sequeira-Byron (PSB).
Extracting data from papers: SC, AL, IT.
Screening data on unpublished studies: SC, IT.
Analysing data: SC, PSB, MDF.
Interpreting data: MDF, ST, ER.
Writing the review: MDF, SC.
Providing general advice on the review: ST, ER, IT.
Addressing referee comments: MDF, SC, PSB, AL.

Declarations of interest

The review authors declare that they are free from any commercial conflict of interest. Massimo Del Fabbro and Silvio Taschieri are investigators on studies included in the review; therefore, they were not involved in any assessment regarding those studies (quality appraisal, data extraction, analysis, interpretation).

Sources of support

Internal sources

  • No sources of support supplied

External sources

  • National Institute for Health Research (NIHR), UK.

    This project was supported by the NIHR, via Cochrane Infrastructure funding to Cochrane Oral Health. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Systematic Reviews Programme, NIHR, NHS or the Department of Health

  • Cochrane Oral Health Global Alliance, Other.

    The production of Cochrane Oral Health reviews has been supported financially by our Global Alliance since 2011 (ohg.cochrane.org/partnerships-alliances). Contributors over the past year have been the British Association for the Study of Community Dentistry, UK; the British Society of Paediatric Dentistry, UK; the Canadian Dental Hygienists Association, Canada, the Centre for Dental Education and Research at All India Institute of Medical Sciences, India; the National Center for Dental Hygiene Research & Practice, USA; New York University College of Dentistry, USA; NHS Education for Scotland, UK

  • School of Dentistry, The University of Manchester, UK.

Differences between protocol and review

We changed the title to reflect the change in scope.

We added a few sentences in the Background section, at the beginning of 'Description of the condition' and 'Description of the intervention', to better explain the aim of root canal therapy and the main differences between orthograde and surgical endodontic retreatment.

We included patient-reported outcomes such as postoperative pain and discomfort, as well as the follow-up time for such outcomes (first week after surgery).

We added the method of analysing studies with paired data (trials with split-mouth design) (generic inverse variance) in the 'Data synthesis' section.

Some review authors (MDF, ST) were among the authors of some of the included studies; therefore, only those review authors not involved in the trials (IT, PSB) performed the risk of bias assessment for these studies.

We included some parallel-group studies presenting data only on a tooth basis because the review authors agreed that these results were worth reporting, and we undertook meta-analysis if only tooth-based data, instead of patient-based data, were available for all studies addressing a given comparison. In split-mouth studies, the tooth was considered as the unit of analysis.

We dichotomised data regarding healing of the periapical lesion, which usually are expressed in four scores (complete, incomplete, uncertain, unsatisfactory healing), into 'healing' (complete plus incomplete healing data) and 'failure' (uncertain plus unsatisfactory healing data). In our previous version, we had included 'uncertain' results under 'healing'. For outcomes reported as continuous variables (e.g. pain, as expressed with VAS), we calculated the estimates of effects of interventions as mean differences (MDs).

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Angerame 2015

Methods

Trial design: randomised, parallel-group trial

Location: Trieste, Italy

Study centres: Dental Clinic, University Clinical Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy

Recruitment period: not stated

Source of funding: none

Ethical approval: not stated

Number of surgeons: 1

Participants

Inclusion criteria: adults presenting a tooth with persisting periapical radiolucency, the presence of fistula and symptoms after orthograde root canal retreatment and a high risk of jeopardising the root integrity by the orthograde approach
Exclusion criteria: severe systemic disorders (i.e. non-controlled diabetes, immunological disease, malignant neoplastic process), thrombocytopenia, insufficient compliance
Age at baseline: 46.8 ± 11.6 years (range 28 to 72 years)
Gender: W6/M5
Smokers: not specified
Teeth treated: various types
Number randomised (participants/teeth): 11/11
Number evaluated (participants/teeth): 11/11 at 12 months

Size of lesion: unspecified

Interventions

Comparison: apical surgery by leaving the cavity empty vs filling with platelet-rich fibrin (PRF)

Test group: apical surgery plus PRF (participants/teeth): 7/7

Control group: only apical surgery (participants/teeth): 4/4

Surgical technique: root-end resection; in both groups, the microscope was used for root-end management; root-end preparation was made by ultrasonic instruments; SuperEba cement was used as root-end filler

Follow-up duration: 12 months

Outcomes

Periapical healing assessed by clinical and radiographic evaluation according to the criteria of Molven 1987 at 1, 2, 3, 4, 5, 6, 12 months:

  • Presence of postoperative complications at each follow-up visit

  • Pain and swelling evaluated on a 0 to 3 scale by a questionnaire filled out by participants at 2, 6 and 12 hours and each day during the first postoperative week

NotesSample size calculation was not performed; radiographs were blindly examined twice at interval ≥ 30 days; no detail on lesion size was provided.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskSimple computerised randomisation procedure was performed.
Allocation concealment (selection bias)High riskThis was not done.
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind the operator using PRF and participants from whom blood was drawn for PRF preparation.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskThe 2 evaluators of radiographs were blinded.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll randomised participants were included in the final analysis.
Selective reporting (reporting bias)Unclear riskAll outcomes were adequately reported, except for complications. Study authors replied that no complications occurred.
Other biasHigh riskNo details on recruitment period, smoking or lesion size were provided. It is unclear how sample size was decided.

Chong 2003

Methods

Trial design: randomised, parallel-group trial

Location: London, UK

Study centres: Dept. of Conservative Dentistry, GKT Dental Institute, King's College London, Guy's Hospital London, UK

Recruitment period: not stated

Source of funding: DHSC London, Research & Development, Responsive Funding Programme

Ethical approval: yes (local ethical committee)

Number of surgeons: 2

Participants

Inclusion criteria: adult patients with periapical lesions diagnosed radiographically. The involved teeth had adequate root canal filling and crown. Periodontal probing depth < 4 mm, except for unilocular sinus tract
Exclusion criteria: failure to satisfy entry criteria
Age at baseline: not specified
Gender: not specified
Smokers: not specified
Teeth treated: single-rooted anterior teeth, 1 root of premolar teeth, mesio-buccal root of maxillary molars
Number randomised (participants/teeth): 183/183
Number evaluated (participants/teeth): 122/122 at 12 months, 108/108 at 24 months; in Chong 2005: n = 100 participants (54 questionnaires in IRM group and 46 in MTA group were deemed correctly completed)

Size of lesion: unspecified

Interventions

Comparison: mineral trioxide aggregate (MTA) vs intermediate restorative material (IRM) as root-end filler in root-end resection

Test group: MTA (Loma Linda University, Loma Linda, CA, USA) (n = 64 participants/64 teeth after 12 months and n = 61 participants/61 teeth after 24 months)

Control group: IRM (Dentsply, Konstanz, Germany) (n = 58 participants/58 teeth after 12 months and n = 47 participants/47 teeth after 24 months)

Surgical technique: root-end resection with ultrasonic instrument used for root-end preparation Operating microscope was used to check root-end filling adaptation

Follow-up duration: 24 months (48 hours in Chong 2005)

Outcomes

Periapical healing assessed by clinical and radiographic evaluation according to the criteria of Molven 1987

Postoperative pain assessed by VAS and counts of analgesics at 3 to 5 hours, 24 hours and 48 hours after surgery (in Chong 2005)

Notes

Sample size calculation was performed. Radiographs were reassessed after 2 to 3 months to ensure reproducibility. Intraobserver and interobserver agreement was assessed by Cohen's kappa statistics.

Questionnaires not evaluated were not returned or were excluded if the writing was illegible or the information entered was incomplete (Chong 2005). Scarce details were provided about participant demographics, defect characteristics and tooth type distribution in the 2 groups.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandomisation process was carried out on the day of surgery.
Allocation concealment (selection bias)Low riskOne of the research team members picked a sealed envelope from a pack to learn which material should be used.
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskThis was not specified.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskPostoperative radiographs were assessed by independent trained observers.
Incomplete outcome data (attrition bias)
All outcomes
High risk

34% of participants failed to return, and no reasons were given for dropouts ("patients failed to attend"). However, it is stated, "All reasonable methods were used to encourage and pursue all review patients including the offer to reimburse their travel costs."

Only 100 questionnaires were evaluated.

Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasUnclear riskNo details on recruitment period, participant age, gender, smoking or lesion size were provided.

Christiansen 2009

Methods

Trial design: randomised, parallel-group trial (18 participants per group); 8 more patients had 2 teeth treated (split-mouth); another article (Christiansen 2008) reported on a subgroup of participants in the same trial.

Location: Aarhus, Denmark

Study centres: 1; University of Aarhus, Denmark

Recruitment period: June 2005 to October 2006

Source of funding: "research stipend from the Faculty of Health Sciences, University of Aarhus, Denmark" (Christiansen 2008); the Danish Dental Association (Calcinfonden) was acknowledged for support (Grant No. FORSKU 2005).

Ethical approval: yes (regional Committee of Ethics; N.reg. clinicaltrials.gov: ID: NCT00228280)

Number of surgeons: 1

Participants

Inclusion criteria: incisor, canine or premolar with sufficient orthograde root filling regarding length and density, and with a periapical lesion, which was unchanged in size or had progressed during at least a 2-year period. Marginal bone level around the tooth in question should be reduced by no more than 50%.
Exclusion criteria: presence of visible gaps between root filling and dentin wall; severe periodontitis
Age at baseline: 54.6 ± 11.9 years (range 30 to 77 years); in Christiansen 2008, average 54.4 years (range 30 to 68 years)
Gender: W24/M20; in Christiansen 2008, W23/M19
Smokers: 16/44; in Christiansen 2008, 6/18 control group; 7/24 test group
Teeth treated: 17 incisors/24 maxillary canines and premolars, 11 mandibular canines and premolars
Number randomised (participants/teeth): 44/52 (8 participants contributed with 2 teeth each: 1 tooth per group); in Christiansen 2008, 42/42
Number evaluated (participants/teeth): 39/46; in Christiansen 2008, 42/42

Size of lesion: not specified (PAI score evaluated)

Interventions

Comparison: MTA vs smoothening of orthograde gutta-percha root filling

Test group: MTA as root-end filler (mineral trioxide aggregate, n = 26 participants/26 teeth)

Control group: smoothening of orthograde gutta-percha (n = 26 participants/26 teeth)

Surgical technique: root-end resection; in MTA group, root-end cavity was prepared with the use of diamond-coated Surgical Endo Tips mounted in an ultrasonic scaler. The root-end surface was visualised under a surgical microscope.

Follow-up duration: 12 months

OutcomesPeriapical healing assessed by clinical and radiographic evaluation (Molven 1987, Rud 1972) by blinded observers; in Christiansen 2008, a visual analogue scale (VAS) and a questionnaire used to assess postoperative pain, swelling and discomfort the first 3 days after surgery
NotesSample size calculation was not reported.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandomisation was performed at participant level, by drawing lots at the time of treatment delivery. Eight participants had 2 teeth; the first was randomised and the second underwent the opposite treatment, in the same surgical session.
Allocation concealment (selection bias)Unclear riskThis was not done because treatment was allocated at the time of delivery.
Blinding of participants and personnel (performance bias)
All outcomes
High riskThis was not stated.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskQuote: "Each radiograph...was blinded to treatment method by masking apical root filling."
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll data were provided for all participants evaluated. All dropouts (5 participants/6 teeth) were accounted for, and reasons were explained.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasLow riskNone was detected.

Danin 1996

Methods

Trial design: randomised, parallel-group trial

Location: Stockholm, Sweden

Study centres: Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden

Recruitment period: not stated

Source of funding: grants from the Swedish Dental Association and Praktikertjănst AB

Ethical approval: not stated

Number of operators: 1 surgeon for test group (apicoectomy), 1 experienced endodontist for control group (endodontic retreatment)

1-Year follow-up parallel-group randomised trial with 38 participants. 1 participant initially assigned to root canal retreatment group was later excluded because of uncertainty as to whether the periradicular lesion was associated with the tooth in question.

Participants

Inclusion criteria: periradicular pathoses with root canal filled incisors, canines and premolars, referred for specialist treatment at the Department of Endodontics, Karolinska Institutet, Stockholm, Sweden. Only 1 tooth per participant and only teeth for which both retreatment and periradicular surgery were technically feasible were included.
Exclusion criteria: patients not meeting inclusion criteria
Age at baseline: 52 years (range 24 to 80 years)
Gender: W17/M20
Smokers: not specified
Teeth treated: 28 teeth were single-rooted; 9 were double-rooted
Number randomised (participants/teeth): 38/38
Number evaluated (participants/teeth): 37/37 (1 participant in control group was excluded later because of uncertainty as to whether the periradicular lesion was associated with the tooth in question)

Size of lesion: ≤ 5 mm: 12 control/13 test; > 5 mm: 6 control/6 test

Interventions

Comparison: root-end resection vs root canal retreatment

Test group: root-end resection (n = 19 participants/19 teeth)

Control group: root canal retreatment (n = 18 participants/18 teeth)

Surgical technique: root-end resection according to the standard, old technique (round bur, apex resected at 45°, no magnificators used, cavity filled with glass ionomer cement)

Follow-up duration: 12 months

OutcomesClinical and radiographic healing 1 year after retreatment. Radiographs were examined by 2 different calibrated observers. Treatment outcome was assessed according to the criteria of Rud 1972: complete healing, incomplete healing, uncertain healing, unsatisfactory healing (failure). All cases with symptoms were referred to the 'failure' group. In teeth with 2 treated canals, the result of the less successfully treated root was recorded. At 1 year, the success rate for surgical and root canal retreatment was, respectively, 58% (11/19) and 28% (5/18).
NotesSample size calculation was not reported.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskParticipants were randomly allocated to treatments.
Allocation concealment (selection bias)High riskStudy authors replied that no allocation concealment was attempted.
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind treatments (surgical vs non-surgical).
Blinding of outcome assessment (detection bias)
All outcomes
High riskBlinding to treatment was impossible for radiographic assessment; the 2 calibrated observers were independent.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskOne participant in the control group was excluded. We believe this did not significantly affect the analysis. All data are presented for all remaining participants.
Selective reporting (reporting bias)Low riskHealing data were adequately reported.
Other biasUnclear riskSample size calculation was missing; no details on recruitment period, ethics approval or smokers were provided.

De Lange 2007

Methods

Trial design: randomised, parallel-group trial

Location: Zwolle, Gronngen, The Netherlands

Study centres: Isala Klinieken and University Medical Centre in Zwolle, The Netherlands

Recruitment period: not stated (duration of recruitment: 14 months)

Source of funding: All ultrasonic devices were provided by the Satalec Company, Merignac, France.

Ethical approval: not stated

Number of surgeons: 5 oral and maxillofacial surgeons and 2 residents

Participants

Inclusion criteria: periapical lesion on 1 of the teeth, confirmed on radiograph, previous endodontic treatment more than 6 months earlier
Exclusion criteria: root fracture, periodontal origin of apical infection or absence of marginal buccal bone after flap elevation, root perforation, no previous endodontic treatment, previous endodontic surgery
Age at baseline: average 42.7 years (range 9 to 79 years)
Gender: W173/M117
Smoker: not stated
Teeth treated: 58 anterior, 97 premolar, 135 molar
Number randomised (participants/teeth): 399/399
Number evaluated ( participants/teeth): 290/290

Size of lesion: not stated

Interventions

Comparison: ultrasonic device vs bur for root-end preparation

Test group: ultrasonic device (P-Max Newtron, Satelec, Merignac, France) ( n = 149 participants/149 teeth)

Control group: round dental bur (Hager & Meisinger GmbH, Neuss, Germany) (n = 141 participants/141 teeth)

Surgical technique: endodontic surgery. No magnification devices were used in either group.

Follow-up duration: 1 year

OutcomesClinical and radiographic healing 1 year after retreatment
NotesSample size calculation was performed. 24.4% and 30.2% of participants in test and control groups, respectively, were lost to follow-up.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskEach participant was randomised by a number drawn from a closed box.
Allocation concealment (selection bias)Unclear riskThis was not stated.
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind the operator, as he had to use different instruments for root-end preparation.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskAll radiographs were assessed by 2 oral and maxillofacial surgeons blinded to the applied therapy. The randomisation code was broken 1 year after the last participant was included.
Incomplete outcome data (attrition bias)
All outcomes
High risk

24.4% and 30.2% of randomised participants in test and control groups, respectively, were lost to follow-up.

Quote: "The relatively large number of patients who were lost to follow-up was categorized as “missing at random” with no relation to the outcome of treatment."

All data were reported for all remaining participants evaluated after the scheduled follow-up.

Selective reporting (reporting bias)Low riskTreatment outcomes were reported adequately. Outcomes were provided according to tooth type and the number of roots treated.
Other biasHigh riskSeven operators performed surgical procedures; the experience and comparability of the seven operators was not specified; it was not mentionet if each operator performed a comparable number of interventions in both treatment groups; no information on smokers and lesion size was provided.

Del Fabbro 2009

Methods

Trial design: randomised, parallel-group trial

Location: Milano, Italy

Study centres: a University clinic (Università degli Studi di Milano, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy) and a private centre (Milano, Italy)

Recruitment period: December 2004 to December 2006

Source of funding: none

Ethical approval: Institutional Review Board of Milan University

Number of surgeons: 1 experienced surgeon

Participants

Inclusion criteria: no general medical contraindications were known for oral surgical procedures (ASA-1 or ASA-2); only 1 tooth required periradicular surgery; tooth treated surgically had a periradicular lesion of strictly endodontic origin (chronic apical periodontitis) not exceeding 10 mm; non-surgical re-treatment was judged not feasible or had previously failed; tooth had an adequate final restoration with no clinical evidence of coronal leakage; apical root canal was devoid of the presence of a post for ≥ 6 mm; no acute symptoms were present
Exclusion criteria: presence of any kind of pathosis associated with vertical root fracture; perforation of the furcation area or lateral canal walls; presence of traumatic injury; periodontal bone loss, detected with a periodontal probe (> 4 mm probing depth); bone defects involving buccal and lingual cortical bone; presence of a thin gingival biotype
Age at baseline: 36.4 years (range 22 to 59 years) in SI group and 33.7 years (29 to 56 years) in PBI group
Gender: W23/M17
Smokers: 15 (6 in SI group, 9 in PBI group)
Teeth treated: 40 (31 anterior, 9 premolar)
Number randomised (participants/teeth): 40/40
Number evaluated (participants/teeth): 38/38

Size of lesion: < 10 mm

Interventions

Comparison: SI vs PBI

Test group: PBI: papilla base incision (participants/teeth): 20/20

Control group: SI: sulcular incision (participants/teeth): 20/20 treated with complete mobilisation of the papilla

Surgical technique: root-end resection; in both groups, microscope was used for root-end management; root-end preparation was made by ultrasonic instruments; zinc oxide EBA-reinforced cement was used as root-end filler

Follow-up duration: 7 days

OutcomesPain assessment assessed by VAS, quality of life assessed by a questionnaire
NotesDropout reasons provided; sample size calculation performed; total time needed for each procedure recorded
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskA computer-generated randomised table was used.
Allocation concealment (selection bias)Low riskA closed opaque envelope containing the indication of which surgical flap had to be used was opened before the start of each surgical operation.
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskIt was impossible to blind the operator performing the incision. Participants were unaware of the type of incision they received.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskNo evaluator blinding was provided because outcomes were self-assessed by participants, who completed questionnaires. The statistician was blinded to groups.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll randomised participants were included in the final analysis.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasLow riskNone was detected.

Del Fabbro 2012

Methods

Trial design: randomised, parallel-group trial

Location: Milano, Italy

Study centres: a University clinic (Università degli Studi di Milano, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy) and a private centre (Milano, Italy)

Recruitment period: April 2010 to April 2011

Source of funding: none

Ethical approval: Institutional Review Board of Milan University

Number of surgeons: 1 experienced surgeon

Participants

Inclusion criteria: no general medical contraindications were known for oral surgical procedures (ASA-1 or ASA-2); patients had only 1 maxillary tooth requiring periradicular surgery; tooth had a periradicular lesion of strictly endodontic origin (chronic apical periodontitis); minimum diameter of the bone defect, as determined from periapical radiographs, was ≥ 8 mm and ≤ 12 mm; root canal re-treatment was judged unfeasible or had previously failed; tooth had an adequate final restoration without clinical evidence of coronal leakage; apical root canal was devoid of the presence of a post for ≥ 6 mm; no spontaneous pain or swelling was present
Exclusion criteria: presence of any kind of pathosis associated with vertical root fracture; presence of through-and-through lesions, diagnosed preoperatively by periapical radiographs, finger palpation and bone probing; perforation of the furcation area or lateral canal walls; known history of traumatic injury; moderate to severe periodontal bone loss, detected with a periodontal probe (probing depth > 5 mm). Patients with neuropsychiatric disorders were also excluded.
Age at baseline: 42.4 years (range 34 to 56 years) in test group; 44.8 years (31 to 62 years) in control group
Gender: W20/M16
Smokers: 15 (9 in test group, 6 in control group)
Teeth treated: 36 (9 lateral incisors, 8 cuspids, 10 premolars, 9 molars)
Number randomised (participants/teeth): 18/18
Number evaluated (participants/teeth): 18/18

Size of lesion: 8 to 12 mm

Interventions

Comparison: PRGF adjunct vs modern microsurgery alone

Test group: plasma rich in growth factors (PRGF) used to fill the defect and applied on the root-end surface and over the suture (n = 18 participants/18 teeth treated)

Control group: no PRGF used (n = 18 participants/18 teeth treated)

Surgical technique: root-end resection; in both groups, microscope was used for hard and soft tissue management, and an endoscope was used for root-end management; root-end preparation was performed with ultrasonic instruments; MTA was used as root-end filler.

Follow-up duration: 7 days

OutcomesPain assessed by VAS, quality of life assessed by a questionnaire
NotesSample size calculation was performed
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskThe decision to use PRGF was made by a computer-generated randomised table for each participant.
Allocation concealment (selection bias)Low riskA closed opaque envelope containing the indication of group allocation was opened before the start of each surgical operation.
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind the operator using PRGF and participants from whom blood was drawn for PRGF preparation.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskNo operator blinding was needed because the data (filled questionnaires) were provided by participants. The statistician was blinded to groups.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll randomised participants were included in the final analysis.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasLow riskNone was detected.

Kurt 2014

Methods

Trial design: randomised, parallel-group trial

Location: Adana, Turkey

Study centres: Department of Oral and Maxillofacial Surgery, Cukurova University Faculty of Dentistry, Adana, Turkey

Recruitment period: not stated

Source of funding: not stated

Ethical approval: yes: The ethical committee of Cukurova University approved the present study (ethical committee report no. 21.05.2009:5:13).

Number of surgeons: 1

Participants

Inclusion criteria: patients referred for periradicular surgery of an upper first molar tooth because of an unhealed periradicular lesion despite conventional root canal treatment, a retained root canal instrument fragment, overflow of root canal filling material, or any other idiopathic reason; American Society of Anesthesiologists (ASA) class 1 or ASA class 2; older than 18 years; periodontally healthy adjacent teeth
Exclusion criteria: significant systemic medical status (ASA class 3 or higher), acute sinusitis, pregnancy or risk of pregnancy, large lesions that affected the neighbouring teeth, presence of periodontal pathological features, radiolucency at the bifurcation region, smoking habit, a history of radiotherapy at the maxillofacial region, osteoporosis requiring medical therapy, metastatic cancer, alcoholism or drug abuse, physical or mental disability that prevented co-operation
Age at baseline: not stated
Gender: W18/M22
Smokers: excluded from the study
Teeth treated: maxillary first molars
Number randomised (participants/teeth): 40/40
Number evaluated (participants/teeth): 39/39 (1 participant from control group was excluded for extensive lesion involvement detected during the procedure. In another participant, the tooth had to be extracted at 6 months because of recurrent infection; the latter was considered a failure concerning treatment outcome, but some parameters could not be assessed at 12 months)

Size of lesion: assessed by periodontal probe and CBCT PAI

Interventions

Comparison: preoperative evaluation with cone beam computed tomography (CBCT) vs conventional (panoramic and periapical) radiography

Test group: CBCT (n = 19 participants/19 teeth)

Control group: conventional radiography (n = 21 participants/21 teeth)

Surgical technique: root-end resection was performed with surgical loupe (3.5× magnification); root-end preparation was done with ultrasonic instruments; root-end cavity was filled with MTA.

Follow-up duration: 12 months

OutcomesClinical and radiographic healing according to Zetterqvist 1991 and Jesslen 1995 criteria; pain, tenderness on apical palpation of buccal and palatal aspects of the tooth; tenderness on horizontal and vertical percussion (all measured on VAS). The presence of swelling, sinus tracts, fluctuation, erythema or abscess was noted, and mobility index and periodontal index of the tooth, as well as perioperative time, were measured.
NotesNo sample size calculation was reported; sinus membrane elevation was performed in 92.3% of all participants. Sinus membrane perforation occurred in 20% of participants in group 1 and in 36.8% of participants in group 2.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskA block randomisation technique was used.
Allocation concealment (selection bias)Unclear riskThis was not specified.
Blinding of participants and personnel (performance bias)
All outcomes
High riskOperators were not blinded.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskAll radiographs were evaluated by the same person (no double assessment).
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskDropout rate was low. 1 participant was excluded from the control group for a lesion detected during treatment. In another participant in the test group, the treated tooth had to be extracted owing to infection. All outcomes were reported for remaining participants.
Selective reporting (reporting bias)Unclear risk

Data were reported adequately and in detail for most outcomes, except for VAS scores, which were not presented.

Quote: "The VAS scores of pain, tenderness on palpation, and tenderness on percussion in any of the vertical or horizontal directions showed no statistically significant difference between the 2 groups at any of the follow-up sessions (P > .05)."

So it was not possible to consider these data for meta-analysis.

Other biasHigh riskSample size calculation was missing; no details on recruitment dates, source of funding or participants' age at baseline were provided; demographic information was limited. It is unclear if and how sinus membrane elevation and sinus membrane perforations reported could have affected outcomes. No specific analysis was done to investigate a possible relationship.

Kvist 1999

Methods

Trial design: randomised, parallel-group trial

Location: Göteborg, Sweden

Study centres: Clinics of Endodontics, Faculty of Odontology, Göteborg University, Sweden

Recruitment period: 1989 to 1992

Source of funding: none (information provided by study author)

Ethical approval: yes: committee for research on human participants at Göteborg University, Göteborg, Sweden (information provided by study author)

Number of surgeons: 1

Participants

Inclusion criteria: Patients with periapical disease ("endodontically failed cases") who were in need of endodontic retreatment; an apical radiolucency was clearly visible; root canal treatment was performed more than 4 years ago, or patient presented with clinical symptoms; no apical-marginal communication was observed; randomisation of retreatment options was considered medically and economically feasible; patient consent was obtained.
Exclusion criteria: not meeting inclusion criteria
Age at baseline: mean 52 years; test: 53 years (range 28 to 75 years), control: 52 years (17 to 74 years)
Gender: test: W29/M16, control: W25/M22
Smokers: not stated
Teeth treated: maxillary and mandibular incisors and canines
Number randomised (participants/teeth): 92/95
Number evaluated (participants/teeth): 87/90 (at 4-year examination, 3 patients were deceased and 2 withdrawn from the study); in Kvist 2000: 92/95 at 1 week post retreatment

Size of lesion: ≤ 5 mm (n = 54) /> 5 mm (n = 41)

Interventions

Comparison: root-end resection vs root canal retreatment

Test group: root-end resection (n = 45 participants/47 teeth)

Control group: root canal retreatment (n = 47 participants/48 teeth); 2 weeks elapsed between first phase (preparation of the root canal) and the second phase (root canal filling with resin chloroform and softened gutta-percha))

Surgical technique: standard root-end resection

Follow-up duration: 4 years (1 week in Kvist 2000). Study author provided unpublished data on treatment healing at longer follow-up (10 years).

OutcomesPatients were clinically and radiographically examined 6, 12, 24 and 48 months after retreatment. Radiographs were evaluated independently by 2 examiners. Observers used a strict definition of periapical disease and reported a positive finding (healing) only when absolutely certain. In Kvist 2000, postoperative discomfort was assessed by means of a questionnaire evaluating pain and swelling by VAS, analgesics intake and time off work resulting from participants' discomfort.
NotesSample size calculation was performed before the start of the study (information provided by study author); in Kvist 2000, 88 questionnaires could be evaluated.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskCases were randomised to surgical or root canal retreatment by the "minimization method," as described by Pocock 1983. Three randomisation factors were considered: size of the periapical radiolucency, the apical position and technical quality of the root filling.
Allocation concealment (selection bias)Low riskClosed envelopes were open soon before treatment (information provided by study author).
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind operators and participants to treatment (surgery vs non-surgery).
Blinding of outcome assessment (detection bias)
All outcomes
High riskBlinding to treatment was impossible for radiographic assessment; 2 examiners independently evaluated the radiographs.
Incomplete outcome data (attrition bias)
All outcomes
Low risk87 of the 92 randomised participants were included in the 4-year analysis; reasons were provided for all dropouts.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasLow riskNone was detected.

Lindeboom 2005a

Methods

Trial design: randomised, parallel-group trial

Location: Amsterdam, The Netherlands

Study centres: (affiliation) Department of Oral and Maxillofacial Surgery, Academic Medical Centre Amsterdam, University of Amsterdam, Amsterdam, The Netherlands

Recruitment period: not specified ("over a period of 28 months")

Source of funding: none declared

Ethical approval: yes: medical ethical committee of the Academic Medical Centre of Amsterdam

Number of surgeons: 2

Participants

Inclusion criteria: tooth with apical periodontitis with an adequate root filling and coronal restoration
Exclusion criteria: teeth with perforations of the lateral canal walls, periodontal attachment loss (pocket depth > 5 mm), vertical fractures and teeth exhibiting radiographic lesions exceeding 1 cm. Patients with acute symptoms of endodontic infection such as submucosal swelling and erythema were also excluded from the study, as were patients who had received antibiotics before surgery. Other exclusion criteria were hypersensitivity for clindamycin, systemic disease and a medical condition that required prophylactic antibiotics.
Age at baseline: average 44.4 ± 11.4 (range 18 to 82 years) (data also provided per group)
Gender: W147/M109 (data also provided per group)
Smokers: not reported
Teeth treated: all types, detailed in a table (data also provided per group)
Number randomised (participants/teeth): 256/256
Number evaluated (participants/teeth): 256/256

Size of lesion: ≤ 10 mm

Interventions

Comparison: prophylactic antibiotic administration vs placebo

Test group: antibiotic (n = 128 participants/128 teeth)

Control group: placebo (n = 128 participants/128 teeth)

Surgical technique: root-end resection: root apex bevelled 10 to 25°; apical preparation performed with ultrasonic instruments; IRM used as root-end filler

Follow-up duration: 4 weeks

OutcomesAssessment of wound healing for signs of infection
NotesSample size calculation not performed
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskSealed envelopes with a study ID number were picked up by an assisting nurse before treatment administration.
Allocation concealment (selection bias)Low riskParticipants, oral and maxillofacial surgeons and investigators were blinded to random allocation throughout the study.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskEnvelopes contained a study-identification number with two capsules of placebo or clindamycin. Blind administration of study drugs was ensured through the use of labelled sets of identical looking tablets.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskOperators were blinded to group.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll randomised participants were included in the final analysis.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasUnclear riskSample size calculation was missing, although the study population appears adequate; no details on smokers, recruitment dates and sources of funding were provided.

Lindeboom 2005b

Methods

Trial design: randomised, parallel-group trial

Location: Amsterdam, The Netherlands

Study centres: Oral and Maxillofacial Surgery Department of the Academic Medical Center of Amsterdam

Recruitment period: 1 July 2000 to December 2002 (info provided by study author)

Source of funding: not funded; the department paid the costs (info provided by study author)

Ethical approval: approved by the Medical Ethical Committee of the Academic Medical Center in Amsterdam (info provided by study author)

Number of surgeons: 3 (info provided by study author)

Participants

Inclusion criteria: Patients had to undergo a surgical periapical endodontic procedure under local anaesthesia; tooth to be treated had a dental history of a root canal treatment and demonstrated a periradicular lesion of strictly endodontic origin with or without clinical signs or symptoms; only single-rooted teeth were included.
Exclusion criteria: teeth with perforations of the lateral canal walls, periodontal attachment loss (pocket depth > 5 mm), teeth with vertical fractures, teeth exhibiting radiographic lesions exceeding 1 cm
Age at baseline: average 43.4 ± 11.1 years (range 17 to 64 years)
Gender: W57/M33 (2 teeth in 10 participants were treated - 8 female and 2 male)
Smokers: not reported
Teeth treated: anterior maxillary or mandibular teeth and maxillary and mandibular single-rooted premolars
Number randomised (participants/teeth): 90/100 (In Methods, it is first stated that 100 consecutive patients were included, and is later stated that 57 female + 33 male = 90 patients, of whom 10 patients with two teeth were treated, each in separate surgical sessions; the unit of randomisation was the tooth (info provided by study author))
Number evaluated (participants/teeth): 90/100

Size of lesion: not exceeding 10 mm

Interventions

Comparison: MTA (mineral trioxide aggregate) vs IRM (intermediate restorative material) as root-end filling material

Test group: MTA (n = 50 participants/50 teeth)

Control group: IRM (n = 50 participants/50 teeth)

Surgical technique: root-end resection: root apex bevelled 10 to 25°; apical preparation performed with ultrasonic instruments, visualised under surgical loupes

Follow-up duration: 1 year

OutcomesClinical and radiographic healing
NotesInterobserver agreement by kappa statistics was done and reported; sample size calculation was performed but was not presented in detail.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk

Randomisation was done on a tooth basis (info provided by study author).

"Randomization was carried out by a nurse who picked a sealed envelope and opened it at the time of placement of the retrograde filling."

Consecutive participants were randomised. Study authors explained that in the 10 participants who had 2 teeth treated, the second tooth underwent independent randomisation and was treated in a separate surgical session.

Allocation concealment (selection bias)Low riskThe envelope was opened at the time of placement of the root-end filling. On a label, the name of the filling material was written.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskParticipants were blinded to treatment.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskThe outcome of the healing process was evaluated by 2 independent assessors, who were not involved in the surgical procedure.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll data were provided for all randomised participants.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasLow riskSample size calculation details were not clearly reported; no details on smokers were provided.

Payer 2005

Methods

Trial design: randomised, parallel-group trial (3 arms)

Location: Graz, Austria

Study centres: Department for Oral Surgery and Radiology, Dental School, Medical University Graz

Recruitment period: not reported

Source of funding: not stated

Ethical approval: not stated

Number of surgeons: 4 oral surgeons

Participants

Inclusion criteria: healthy dental and periodontal status before and after surgery (Community Periodontal Index of Treatment Needs (CPITN) 0 to 2)
Exclusion criteria: smokers of > 5 cigarettes/d
Age at baseline: average 45 years (range 20 to 79 years)
Gender: W38/M34
Smokers: 15/72 (all up to 5 cigarettes/d) (4 in test, 5 in placebo, 6 in control groups)
Teeth treated: upper and lower incisors and premolars
Number randomised (participants/teeth): 72/72
Number evaluated (participants/teeth): 72/72

Size of lesion: < 5 mm

Interventions

Comparison: low energy level laser therapy (LLLT) vs placebo vs control

Test group: irradiation performed intraoperatively and postoperatively 1, 3 and 7 days after surgery (n = 24 participants/24 teeth)

Placebo group: irradiation without laser activation (n = 28 participants/28 teeth)

Control group: Neither LLLT nor placebo therapy was used (n = 20 participants/20 teeth).

Surgical technique: Root-end resection was performed; the root tip was exposed with round burs, and a fissure bur was used for root resection; retrograde root canal preparation was accomplished with diamond-coated ultrasonic instruments (Piezon Master 400, EMS GmbH, Munich, Germany) under apical magnification. The root-end filling was performed with IRM.

Follow-up duration: 7 days post surgery

OutcomesSwelling, inflammation, bleeding, disturbance of sensitiveness, dehiscences, oral hygiene and pain. Pain was assessed by a visual analogue scale (VAS), a numerical rating scale (NRS) and a verbal rating scale (VRS).
NotesSample size calculation was not reported.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNo details on the randomisation procedure ("patients were split randomly in the three groups") were provided.
Allocation concealment (selection bias)Unclear riskIt was not mentioned if allocation was concealed until treatment delivery. No reply was received from study authors.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskParticipants in the placebo group were not aware that the laser was not activated during irradiation. Control participants were informed of participating in a study on the outcome of endodontic surgery but did not know what treatment was given to the other 2 groups.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskA separate completely blinded investigator evaluated the parameters at 1, 3, 7 days post-op; the statistician was not involved in the clinical nor the operative part of the study.
Incomplete outcome data (attrition bias)
All outcomes
High riskQuote: "Four patients had to be excluded from the study for lack of oral hygiene after surgery," but it was not specified to which group(s) these participants belonged.
Selective reporting (reporting bias)Unclear riskAll outcomes were reported, although for pain measured through NRS and VAS, only diagrams were provided, and it was not possible to obtain data for meta-analysis.
Other biasLow riskSample size calculation was not reported; no details on recruitment period, source of funding or ethical approval were provided.

Pecora 2001

Methods

Trial design: randomised, parallel-group trial

Location: Rome, Italy

Study centres: 1 centre (private practice, Rome)

Recruitment period: not reported

Source of funding: not reported

Ethical approval: not stated

Number of surgeons: 1 operator performed all surgeries; another operator prepared and placed the calcium sulphate

Participants

Inclusion criteria: previous root canal treatment and retreatment (except 2 cases) with persistence of a bony lesion; presence of a periapical bone defect > 10 mm with lack of both buccal and lingual plates diagnosed preoperatively by periapical radiographs, finger palpation and bone probing; all patients presented with fistula tracts and recurrent episodes of purulent discharge; all cases (except 2) received conventional root canal retreatment. After a minimum follow-up of 3 months, if the lesion had remained unchanged, the patient was scheduled for periradicular surgery and was included in the present study.
Exclusion criteria: failure to satisfy inclusion criteria
Age at baseline: average 48 years (range 30 to 60 years)
Gender: not stated
Smokers: none
Teeth treated: not reported
Number randomised (participants/teeth): 20/20
Number evaluated (participants/teeth): 18/18 (1 tooth per group had to be extracted)

Size of lesion: > 10 mm

Interventions

Comparison: grafting with calcium sulphate vs no grafting

Test group: grafting of the bone defect with calcium sulphate (Surgiplaster, Class Implant, Rome, Italy) (n = 10 participants/10 teeth)

Control group: no grafting (n = 10 participants/10 teeth)

Surgical technique: root-end resection; root-end filling with SuperEBA cement under magnification with a surgical microscope

Follow-up duration: 12 months

OutcomesRadiographic healing (according to the criteria provided by Rud 1972)
NotesNo sample size calculation was performed.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskCases were randomly assigned by flipping a coin.
Allocation concealment (selection bias)Low riskThe coin was flipped before surgery. After performing the conventional surgical technique (i.e. apicoectomy and root-end filling), operators were given an envelope, which disclosed to which group the participant they were operating on belonged.
Blinding of participants and personnel (performance bias)
All outcomes
Low riskTwo operators, both unaware of the group to which operating sites belonged, performed all surgeries.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskQuote: "The outcome of the healing process was radiologically evaluated by three independent examiners who were not involved in the surgical procedure and blind with respect to the test or control group."
Incomplete outcome data (attrition bias)
All outcomes
Low riskOther than the 2 participants who had to undergo extraction of the treated tooth, all randomised participants were included in the final analysis.
Selective reporting (reporting bias)Low riskAll outcomes were reported in detail.
Other biasUnclear riskSample size calculation was missing; no details on recruitment dates, source of funding, ethical approval, gender, smokers or teeth treated were provided.

Song 2012

Methods

Trial design: randomised, parallel-group trial

Location: Seoul, Korea

Study centres: Department of Conservative Dentistry at the Dental College, Yonsei University, Seoul, Korea

Recruitment period: February 2003 to October 2010

Source of funding: not stated

Ethical approval: obtained from the Yonsei University Committee for Research on Human Subjects

Number of surgeons: 1

Participants

Inclusion criteria: All root-filled cases with symptomatic or asymptomatic apical periodontitis were included.
Exclusion criteria: Teeth with class II or greater mobility, horizontal and vertical fractures and perforations were excluded from the study. Through endodontic microsurgery, teeth with a through-and-through lesion and/or a lesion of combined periodontal endodontic origin were also excluded.
Age at baseline: presented only as frequencies per age range
Gender: W69/M123
Smokers: not stated
Teeth treated: 73 maxillary anterior, 31 maxillary premolar, 28 maxillary molar; 21 mandibular anterior, 11 mandibular premolar, 28 mandibular molar
Number randomised (participants/teeth): 260/260

Number evaluated (participants/teeth): 192/192

Size of lesion: not stated

Interventions

Comparison: mineral trioxide aggregate (MTA) vs super ethoxy–benzoic acid (SuperEBA)

Test group: MTA (participants/teeth): 90/90

Control group: SuperEBA (participants/teeth): 102/102

Surgical technique: root-end resection, With the exception of incisions, flap elevation and suturing, all surgical procedures were performed with an operating microscope. The root tip was sectioned with a tapered fissure bur under copious sterile distilled water irrigation. The root-end preparation was made with KIS ultrasonic tips driven by a Piezoelectric ultrasonic unit. The root-end filling material used was SuperEBA or ProRoot MTA, which was selected according to the randomisation.

Follow-up duration: 12 months

OutcomesThe primary outcome measure for this study was the change in apical bone density at 12 months. Radiographic findings, which were taken from 3 angles (straight and 20° mesial and distal), were evaluated blindly and independently by 2 examiners, who used the same criteria as those used by Molven 1987. Secondary outcome measures included the presence of clinical symptoms or abnormal findings at 12 months, such as any pain and/or swelling or loss of function, tenderness to percussion or palpation, subjective discomfort, mobility, sinus tract formation and periodontal pocket formation. Criteria for failure included any clinical signs and/or symptoms or radiographic evidence of uncertain or unsatisfactory healing.
NotesSample size calculation was performed. The 2 examiners standardised the evaluation criteria before they performed case analyses, so that their results were based on the same evaluation methods and conditions. Cohen kappa statistical analysis was used to measure interexaminer variability.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskTeeth were randomly assigned to groups by the Pocock ‘‘minimization method.’’ The random allocation sequence was generated by an assistant. The following 3 randomisation factors were considered: sex, age and tooth type.
Allocation concealment (selection bias)Unclear riskThis was not stated. We received no reply from study authors.
Blinding of participants and personnel (performance bias)
All outcomes
High riskBlinding of participants was not clearly stated. Operators could not be blinded to treatment.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskRadiographs were evaluated blindly and independently by 2 examiners.
Incomplete outcome data (attrition bias)
All outcomes
High riskThe study had a 26% dropout at 1-year follow-up, which is rather high; in 63/68 cases, the reason was "fail to attend" with no attempt to explain why participants did not attend. All data were reported for all randomised participants completing the trial.
Selective reporting (reporting bias)Low riskOutcomes were adequately reported.
Other biasUnclear riskNo details on source of funding, smokers or lesion size were reported.

Taschieri 2007

Methods

Trial design: randomised, parallel-group trial

Location: Milano, Italy

Study centres: Istituto Ortopedico Galeazzi, Department of Health Technologies, Dental Clinic, Università degli Studi di Milano, and private practice, Milano, Italy

Recruitment period: 24 months (dates not specified)

Source of funding: none (information provided by study author)

Ethical approval: The study protocol was evaluated and approved by the Review Board of the University of Milano, Italy.

Number of surgeons: 2

Participants

Inclusion criteria: The tooth treated surgically showed a periradicular lesion of strictly endodontic origin, and root canal retreatment was considered unfeasible or had previously failed. The minimum diameter of the bone defect, as determined from periapical radiographs, was at least 10 mm. The tooth treated surgically exhibited adequate final restoration with no clinical evidence of coronal leakage. Patients had no general medical contraindications for oral surgical procedures (ASA-1 or ASA-2 rating).
Exclusion criteria: teeth with any kind of pathoses associated with vertical root fracture, teeth with perforation of the furcation area or lateral canal walls; teeth with traumatic injury; severe periodontal bone loss detected with a periodontal probe (≥ 5 mm probing depth)
Age at baseline: 36 years for women, 43 years for men
Gender: W29/M15 (evaluated: W28/M13)
Smokers: 10/44 participants were smokers of fewer than 15 cigarettes/d (information provided by study authors).
Teeth treated: 2 participants (accounting for 3 teeth) did not return at follow-up; 1 tooth was extracted because of intraoperative root perforation; teeth evaluated at 1 year included 39 in the maxilla (16 anterior, 14 premolars, 9 molars) and 20 in the mandible (10 anterior, 6 premolars, 4 molars).

Number randomised (participants/teeth): 44/63
Number evaluated (participants/teeth): 41/59

Size of lesion: ≥ 10 mm

Interventions

Comparison: GTR (bone grafting and resorbable membrane) vs no GTR for surgical treatment of large periapical lesions

Test group (GTR group): grafting (anorganic bovine bone, Bio-Oss, Geistlich Pharma, Wolhusen, Switzerland) (participants/teeth) and resorbable collagen membrane (BioGide, Geistlich Pharma): 16/24

Control group: no grafting (participants/teeth): 25/35

Four-wall defects and through-and-through lesions were also compared.

Surgical technique: root-end resection. Surgical access to the root was attained through the cortical bone with a round bur. The periradicular lesion was removed with sharp bone curettes and angled periodontal curettes. After exposure of the root-end, a straight fissure bur in a handpiece was used to cut 2.5 to 3 mm of the root-end. Root-end cavities were prepared with zirconium nitrate retro-tips driven by an ultrasonic device unit. Zinc oxide EBA-reinforced cement was used as the root-end filling material. In cases allocated to the GTR group, the bone defect was filled with bovine bone mineral, then was covered with a resorbable collagen membrane. No grafting nor membrane was used in the control group.

Follow-up duration: 1 year

OutcomesRadiographic healing according to Molven 1987 criteria
NotesSample size calculation was missing; the study was tooth-based - not participant-based.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskTreatment was assigned through a computer-generated randomised table.
Allocation concealment (selection bias)High riskThis was not performed (information provided by study authors).
Blinding of participants and personnel (performance bias)
All outcomes
High riskSurgeons could not be blinded to treatment, and participants were informed of the treatment received.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskTwo blinded examiners independently evaluated all radiographs at 4.3× magnification with the use of surgical magnification loupes.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThree participants could not be evaluated at follow-up (reasons were provided). All data were reported for all randomised participants completing the trial.
Selective reporting (reporting bias)Unclear riskAll outcomes were adequately reported, although on a tooth basis.
Other biasLow riskSample size calculation was not performed.

Taschieri 2008

Methods

Trial design: randomised, parallel-group trial with 3 arms

Location: Milano, Italy

Study centres: Istituto Ortopedico Galeazzi, Department of Health Technologies, Dental Clinic, Università degli Studi di Milano, and private practice, Milano, Italy

Recruitment period: 22 months, from December 2001 to December 2004

Source of funding: none (information provided by study author)

Ethical approval: Institutional Review Board of Galeazzi Orthopedic Institute, Milano, Italy (information provided by study author)

Number of surgeons: 2

Participants

Inclusion criteria: A periradicular lesion of strictly endodontic origin was present; root canal retreatment was considered unfeasible or had previously failed; the tooth treated surgically exhibited an adequate final restoration with no clinical evidence of coronal leakage; the apical root canal had 6 mm or more without the presence of a post; acute symptoms were absent; patient had no general medical contraindications for oral surgical procedures (ASA-1 or ASA-2).
Exclusion criteria: teeth with any kind of pathoses associated with vertical root fracture; teeth with perforation of the furcation area or lateral canal walls; teeth with traumatic injuries; molars; severe periodontal bone loss detected with a periodontal probe (≥ 5 mm probing depth); bone defect involving both buccal and lingual cortical bone
Age at baseline: average 38 years for women and 41 years for men. In Taschieri 2008, mean age was 43 years (women) and 37 years (men) in the microscope group, and 41 years (women) and 40 years (men) in the endoscope group.
Gender: W53/M45
Smokers: 18/98 participants were smokers of fewer than 15 cigarettes/d; 2 smoked more than 15 cigarettes/d (information provided by study authors).
Teeth treated: 34 in maxilla and 37 in mandible; both single- and multi-rooted teeth; 45 anterior teeth and 21 premolars
Number randomised (participants/teeth): 98/150
Number evaluated (participants/teeth): 85/132

Size of lesion: Maximum size ranged between 3 mm and 19 mm

Interventions

Comparison: magnification loupes vs endoscope in root-end management (Taschieri 2006); surgical microscope vs endoscope (Taschieri 2008)

Test group: endoscope (Hopkins Tele-Otoscope 70°; Karl Storz GmbH) (patients/teeth): 34/50

Test group: microscope (patients/teeth): 36/63

Control group: magnification loupes (patients/teeth): 28/37

Surgical technique: Root-end resection was performed. Surgical access to the root was made through the cortical bone with a round bur. The periradicular lesion was removed with sharp bone curettes and angled periodontal curettes. After exposure of the root-end, a straight fissure bur in a handpiece was used to cut 2.5 to 3 mm of the root-end. All of these procedures were performed with magnification loupes (4.3×) with a headlight. After root-end resection, surgical procedures were performed with the same loupes or with an endoscope or a microscope. Root-end cavities were prepared with zirconium nitrate retro-tips driven by an ultrasonic device unit. Zinc oxide EBA-reinforced cement was used as the root-end filling material.

Follow-up duration: 24 months (Taschieri 2008)

OutcomesRadiographic criteria established by Molven 1987 were used for outcome assessment: complete healing, incomplete healing, uncertain healing or unsatisfactory outcome. Clinically, any evidence of signs and/or symptoms was recorded, according to the guidelines of Gutmann 1991. All clinical records were supplied to the observers.
NotesSample size calculation was performed before enrolment. To reduce the effect of evaluator fatigue as a confounding variable, 10 radiographs were viewed consecutively; then a 15-minute break was taken before the next evaluation session.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskA computer-generated randomised table was used; the participant - not the tooth - was randomised.
Allocation concealment (selection bias)Low riskA closed, opaque envelope containing the indication for which the magnification device was to be used was opened before the start of each surgical operation.
Blinding of participants and personnel (performance bias)
All outcomes
High riskParticipants were blinded, and the operator could not be blinded to magnificator type.
Blinding of outcome assessment (detection bias)
All outcomes
Low riskTwo blinded examiners independently evaluated radiographs at 4.3× magnification with magnification loupes.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThirteen participants (18 teeth) could not be evaluated at follow-up (reasons were provided). All data were reported for all randomised participants completing the trial.
Selective reporting (reporting bias)Unclear riskAll outcomes were adequately reported, although on a tooth basis.
Other biasLow riskNone was detected.

Velvart 2004

Methods

Trial design: randomised, split-mouth trial

Location: Zurich, Switzerland

Study centres: University of Basel, University of Geneva, Switzerland

Recruitment period: not stated

Source of funding: not stated

Ethical approval: not stated

Number of surgeons: not specified (probably 2)

Participants

Inclusion criteria: root-filled teeth failing with persisting symptoms and/or apical radiolucency; conventional retreatment failed or unfeasible; no signs of periodontal disease (absence of bleeding on probing, no more than 3 mm probing depth in involved teeth); interdental papillae occupying the interproximal space below the contact area
Exclusion criteria: failure to satisfy entry criteria
Age at baseline: average 45 ± 9.4 years (range 36 to 63 years)
Gender: W6/M6
Smokers: not stated
Teeth treated: 6 anterior teeth, 4 premolars, 3 molars (both jaws)
Number randomised (participants/teeth): 12/12
Number evaluated (participants/teeth): 12/12

Size of lesion: not stated

Interventions

Comparison: papilla base incision (PBI) vs complete papilla mobilisation

Test group: complete base incision (n = 12 participants/12 teeth)

Control group: standard papilla mobilisation (n = 12 participants/12 teeth)

Surgical technique: Root-end resection was performed. The entire surgical procedure was performed with microsurgical instruments and magnified vision of at least 4.3× with loupes and an operating microscope. Only details of the incision/flaps are reported; no details of the apical surgery procedure are provided.

Follow-up duration: 12 months

OutcomesHeight of interdental papilla with plaster replicas and laser scanner
NotesSample size calculation was not reported. No details about smokers, lesion size, source of funding, recruitment period, ethical approval or number of surgeons were given.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskRandomisation method was not specified. The paper reports: "The incision technique applied to the mesial or distal interproximal space was randomly selected."
Allocation concealment (selection bias)High riskAllocation concealment was not applicable in this split-mouth study.
Blinding of participants and personnel (performance bias)
All outcomes
High riskIt was impossible to blind the operator.
Blinding of outcome assessment (detection bias)
All outcomes
High riskNo assessor blinding was reported.
Incomplete outcome data (attrition bias)
All outcomes
Low riskAll data were reported for all randomised participants.
Selective reporting (reporting bias)Low riskAll outcomes were adequately reported.
Other biasHigh riskSample size calculation was missing.No details about smokers, lesion size, source of funding, recruitment period, ethical approval or number of surgeons were given.

Walivaara 2009

Methods

Trial design: randomised, parallel-group trial

Location: Halmstad, Sweden
Study centres: Maxillofacial Unit, Halmstad Hospital, Sweden

Recruitment period: not specified

Source of funding: not stated

Ethical approval: not stated

Number of surgeons: 2

Participants

Inclusion criteria: all referred patients for periapical surgery living a maximum of 40 kilometres from the hospital
Exclusion criteria: advanced periodontal disease with apical marginal communications and obvious root fractures

Age at baseline: average 58.5 years
Gender: W81/M58
Smokers: not stated
Teeth treated: 46 incisors, 10 canines, 42 premolars, 49 molars
Number randomised (participants/teeth): 139/160
Number evaluated (participants/teeth): 131/147

Size of lesion: not stated

Interventions

Comparison: ultrafill thermoplasticised gutta-percha vs IRM as root-end fillings

Test group: IRM (n = 68 participants/X teeth): 77 teeth

Control group: ultrafill thermoplasticised gutta-percha (n = 71 participants/X teeth): 83 teeth

Surgical technique: Root-end resection was performed with 2.3x magnification operating loupes. The bony periapical area was exposed with a round bur. Enucleation of the granuloma or cyst was followed by a slightly oblique resection of the root with a fissure bur. The root canal was prepared and cleaned with ultrasonic root-end cavity preparation.

Follow-up duration: 12 to 38 months, average 15.6 months

OutcomesThe clinical evaluation was performed by 1 of 5 independent surgeons. Molven 1987 and Rud 1972 criteria were adopted. Any clinical findings such as tenderness on percussion, tenderness on palpation on the crown and/or in the apical area, gingival swelling and presence of fistula or apicomarginal communication were registered as a failure.
NotesSample size calculation was not reported. No details about smokers, lesion size, source of funding, recruitment period or ethical approval were given.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskParticipants were randomly allocated to 2 groups according to date of birth.
Allocation concealment (selection bias)High riskThis was not stated.
Blinding of participants and personnel (performance bias)
All outcomes
High riskBlinding of participants was not clearly stated. Operators could not be blinded to treatment.
Blinding of outcome assessment (detection bias)
All outcomes
High riskRadiographic assessment was made by 3 independent operators (2 operating surgeons and a maxillofacial radiologist), but no blinding to treatment was mentioned. Before the assessment, all met to calibrate for a consensus.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskEight participants (13 teeth) could not be evaluated (reasons were provided). For all other randomised participants, only tooth-based data were provided.
Selective reporting (reporting bias)Unclear riskOutcomes on success and failure were reported in detail, although only on a tooth basis; data per participant were not reported.
Other biasHigh riskSample size calculation was missing. No details about smokers, lesion size, source of funding, recruitment period or ethical approval were given. Follow-up was not the same for all participants.

Walivaara 2011

Methods

Trial design: randomised, parallel-group trial

Location: Halmstad, Sweden
Study centres: Maxillofacial Unit, Halmstad Hospital, Sweden

Recruitment period: September 2006 to December 2008

Source of funding: not stated

Ethical approval: yes, approved by the human ethical committee at the University of Lund, Sweden

Number of surgeons: 2

Participants

Inclusion criteria: consecutive patients referred to the department for an apical surgery procedure on all types of teeth
Exclusion criteria: teeth with obvious root fracture or advanced periodontal disease
Age at baseline: not stated
Gender: W99/M65
Smokers: not stated
Teeth treated: 40 incisors, 16 canines, 57 premolars and 81 molars in both jaws
Number randomised (participants/teeth): 164/206
Number evaluated (participants/teeth):153/194

Size of lesion: Distribution of lesion size and lesion type amongst the 194 followed teeth was reported in a table.

Interventions

Comparison: 2 different root-end filling materials: IRM vs SuperEBA

Test group: IRM (participants/teeth): not specified/96 teeth

Control group: SuperEBA (participants/teeth): not specified/98 teeth

Surgical technique: Root-end resection was performed with 2.3x magnification operating loupes. The bony periapical area was exposed with a round bur. The root canal was prepared and cleaned with ultrasonic root-end cavity preparation.

Follow-up duration: range 12 to 21 months, average 13.1 months

OutcomesRegistration of clinical findings such as tenderness on percussion, tenderness on palpation of the crown and/or in the apical area, gingival swelling and presence of a fistula or an apicomarginal communication was recorded as a failure. Clinical and radiographic healing was assessed according to the Molven 1987 and Rud 1972 criteria.
NotesSample size calculation was not reported.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskA standard randomisation table was used.
Allocation concealment (selection bias)High riskThis was not stated.
Blinding of participants and personnel (performance bias)
All outcomes
High riskBlinding of participants was not clearly stated. Operators could not be blinded to treatment.
Blinding of outcome assessment (detection bias)
All outcomes
High riskClinical and radiographic assessment was made by independent operators (2 operating surgeons and a maxillofacial radiologist), but no blinding to treatment was mentioned.
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskEleven participants (12 teeth) could not be evaluated (reasons were provided). For all other randomised participants, only tooth-based data were provided.
Selective reporting (reporting bias)Unclear riskOutcomes on success and failure were reported in detail, although only on a tooth basis; data per participant were not reported.
Other biasHigh riskSample size calculation was missing; no details on source of funding, participants' age at baseline or smokers were provided. Follow-up was not the same for all participants.

Zetterqvist 1991

  1. a

    ASA: American Society of Anesthesiologists.

    CBCT: cone beam computed tomography.

    CPITN: Community Periodontal Index of Treatment Needs.

    GC: glass ionomer cement.

    GTR: bone grafting and resorbable membrane.

    IRM: intermediate restorative material.

    MTA: mineral trioxide aggregate.

    NRS: numerical rating scale.

    PAI: periapical index.

    PBI: papilla base incision.

    PRF: platelet-rich fibrin.

    PRGF: plasma rich in growth factors.

    SI: sulcular incision.

    VAS: visual analogue scale.

Methods

Trial design: randomised, parallel-group trial

Location: Stockholm, Sweden

Study centres: Department of Oral Surgery, Karolinska Institute, Stockholm

Recruitment period: not stated

Source of funding: not stated

Ethical approval: The study was approved by the local ethical committee of Huddinge Hospital (information taken from Jesslen 1995).

Number of surgeons: 2

Participants

Inclusion criteria: presence of teeth with periapical lesions not accessible to conventional endodontic treatment
Exclusion criteria: not stated
Age at baseline: not stated
Gender: not stated
Smokers: not stated
Teeth treated: not stated
Number randomised (participants/teeth): 85/105
Number evaluated (participants/teeth): 85/105 (67/82 in Jesslen 1995)

Size of lesion: not stated

Interventions

Comparison: glass ionomer cement (GC) vs amalgam

Test group: glass ionomer cement (53 teeth)

Control group: amalgam (52 teeth)

Surgical technique: Root-end resection was performed. Any bone covering the apical area and any granulation tissue were removed. Apicoectomy was performed, and the root canal was prepared in a box-type manner with an inverted cone bur. Each tooth was filled with amalgam or GC.

Follow-up duration: 1 year; 5 years (Jesslen 1995)

OutcomesClinical and radiographic healing. Standardised radiographs were obtained and interpreted by one of the study authors trained in oral radiology. The following 4 classifications were used: complete healing, improvement, no improvement, failure.
NotesSample size calculation was not reported; participant dropout was 21.2% at 5 years (Jesslen 1995). Periapical healing was assessed by personal criteria instead of conventional criteria.
Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskTreatment was allocated "in accordance with a randomisation form."
Allocation concealment (selection bias)High riskThis was not stated.
Blinding of participants and personnel (performance bias)
All outcomes
High riskThis was not stated.
Blinding of outcome assessment (detection bias)
All outcomes
High riskThe investigator was aware of the treatment that each participant had received because GC shows no radiographic contrast; at 5 years, the 2 investigators were not independent (Jesslen 1995).
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskAll participants were seen at 1-year follow-up, and all outcomes were reported; 18 participants (23 teeth) could not be included in the 5-year follow-up and were considered dropouts (21% participants) (Jesslen 1995).
Selective reporting (reporting bias)Unclear riskHealing data were provided on a tooth basis only.
Other biasHigh riskNo sample size calculation was reported; no details of participant demographics (age, gender, smokers), tooth type, lesion size, source of funding, recruitment period or exact numbers of participants allocated to test and control groups were given. Personal criteria instead of conventional criteria were used in evaluating periapical healing.

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
Bader 1998Participants were not actually randomised to treatment.
Dhiman 2015This study examined apicomarginal defects (in the present review, only lesions confined to the periapical region were to be considered).
Garrett 2002Recruitment was defective, and the dropout rate was extremely high. Of the 60 participants planned to be recruited according to the sample size calculation, only 25 were indeed treated and, of these, only 13 were evaluated at the scheduled follow-up.
Goyal 2011This study examined apicomarginal defects (in the present review, only lesions confined to the periapical region were to be considered).
Huumonen 2003This was not a study on endodontic surgery. Researchers evaluated only orthograde retreatment.
Kim 2008This study on endodontic microsurgery compared a group with apical lesions and a group with apicomarginal defects (in the present review, only lesions confined to the periapical region were to be considered).
Marin-Botero 2006This study examined apicomarginal defects (in the present review, only lesions confined to the periapical region were to be considered).
Shearer 2009Follow-up for this study was too short (6 months).
Von Arx 2010aParticipants were not actually randomised to treatment.

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