Surgical versus non‐surgical endodontic re‐treatment for periradicular lesions
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To assess the effects of surgical versus non‐surgical endodontic therapy for the re‐treatment of teeth with periapical pathosis.
The following null hypothesis will be tested:
There is no difference in outcome between surgical and non‐surgical therapy for endodontic re‐treatment of teeth with periapical disease.
Background
In recent years the number of people seeking endodontic treatment has dramatically increased because of conservative tendency towards root canal treatment over tooth extraction (Ruddle 2002). The aim of root canal treatment is to clean and disinfect the root canal system in order to reduce the number of micro‐organisms, remove necrotic tissue, and finally seal the system to prevent recontamination. Success rates up to 97% have been reported for endodontic initial treatment (Friedman 2004) but failure may occur after treatment. The persistence of micro‐organisms within the root canal system may induce an inflammatory and immune response within the periradicular (periapical) tissues resulting in local bone destruction. Furthermore, contamination of the periradicular tissues by micro‐organisms and root filling material 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 diseases can exceed 30% of all root‐filled teeth population (Boucher 2002; Dugas 2003; Eriksen 2002; Friedman 2002). These data suggest a considerable need for treatment of this condition. Re‐treatment planning must include a careful evaluation of periapical condition, so that a decision can be made among non‐surgical (orthograde) re‐treatment, surgical (retrograde) procedure or tooth extraction (Ruddle 2002).
Some studies reported that once the disease is addressed, extraction is the first‐choice treatment (Hoen 2002). However, this trend is disappointing, in view of the possibility to conservatively treat the disease by orthograde retreatment or apical surgery (Friedman 2002). Surveys among general practitioners and endodontists have shown considerable variability in selecting between orthograde re‐treatment and surgery, suggesting that the procedure selection process is subjective and inconsistent (Friedman 2002; Friedman 2004; Hoen 2002; Hulsmann 1994; Kvist 2002; Smith 1981). To a large extent, this variability may depend not only on individual differences in the assessment of disease severity, but also on the ambiguity of information found in the literature regarding the outcome of endodontic re‐treatment (Farzaneh 2004; Kvist 1999; Mead 2005; Paik 2004).
According to the current concepts of evidence‐based health care, selection between alternative treatments is based on the assessment of their respective benefits and risks from studies consistent with a high level of evidence (Friedman 2002; Sackett 1997). Such studies are those that conform to rigorous designs and well‐defined methodology (Fletcher 1988; Sackett 1997). The main benefit considered in evaluating the outcome of both surgical and non‐surgical procedures for the re‐treatment is the probability of healing (Friedman 2002). The success of re‐treatment can be assessed by histological, clinical or radiographic evaluation of healing (or a combination of the above), after a given follow‐up period, as reported in many clinical studies.
The outcome of endodontic therapy is generally assessed 1 year after treatment and is categorized as follows: (a) 'success', that includes two subcategories: 'complete healing' (radiographic and clinical normalcy) and 'incomplete healing' (clinical normalcy combined with reduced radiolucency and scar formation); (b) 'uncertain healing' (persistence of radiolucency in the absence of clinical signs and symptoms, or presence of clinical signs/symptoms (clinical questionable) associated with a not complete radiographic healing); (c) 'failure' (presence of clinical signs and symptoms combined with reduced or persistent radiolucency) (Gutmann 1991; Molven 1987; Rud 1972). Jesslen and coworkers determined that the validity of a 1‐year follow up is predictable in over 95% of the cases (Jesslen 1995). When the 1‐year outcome is recorded as 'uncertain healing', the tooth should be re‐evaluated yearly up to 4 years after treatment and then recorded as success or failure (Molven 1996).
This review aims at comparing the success rates of surgical versus non‐surgical endodontic therapy for the re‐treatment of periapical lesions, based on the reports of randomized controlled clinical trials, in order to provide clinicians with the best evidence‐based information for their decision making process.
Objectives
To assess the effects of surgical versus non‐surgical endodontic therapy for the re‐treatment of teeth with periapical pathosis.
The following null hypothesis will be tested:
There is no difference in outcome between surgical and non‐surgical therapy for endodontic re‐treatment of teeth with periapical disease.
Methods
Criteria for considering studies for this review
Types of studies
All randomized controlled clinical trials (RCTs) about re‐treatment of teeth with periapical pathosis in which both surgical and non‐surgical approach were used.
Types of participants
Patients with one or more teeth endodontically treated that present with a periapical condition requiring endodontic re‐treatment.
Types of interventions
(1) Surgical procedure (endodontic surgery, periradicular surgery, apicectomy, retrograde therapy) and (2) non‐surgical procedure (orthograde therapy) for the re‐treatment of teeth with periapical pathosis.
Types of outcome measures
The main outcome sought in this systematic review will be the success of the re‐treatment at 1‐year follow up, as determined by clinical assessment of signs and symptoms, combined with examination of periapical radiographs to evaluate radiographical healing.
The outcome will be recorded when available at the following time points:
‐ one year after re‐treatment;
‐ between 1 and 4 years after re‐treatment;
‐ more than 4 years after re‐treatment.
Unexpected events/outcomes will be documented if identified in included RCTs.
Search methods for identification of studies
The search strategy aims at identifying all published randomized controlled clinical trials dealing with the subject of this review. For the identification of studies to be included in, or considered for this review, detailed search strategies will be developed for each database searched. These will be based on the search strategy developed for MEDLINE (OVID) but revised appropriately for each database, to take account of differences in controlled vocabulary and syntax rules. The MEDLINE search strategy will combine a sensitive search strategy for RCTs revised from phases one and two of the Cochrane Sensitive Search Strategy for RCTs (as published in Appendix 5c in the Cochrane Handbook for Systematic Reviews of Interventions). The subject search will use a combination of controlled vocabulary and free text terms based on the following search strategy for searching MEDLINE via OVID:
#1 randomized controlled trial.pt.
#2 controlled clinical trial.pt.
#3 randomized controlled trials.sh.
#4 random allocation.sh.
#5 double blind method.sh.
#6 single blind method.sh.
#7 or/1‐6
#8 (ANIMALS not HUMAN).sh.
#9 7 not 8
#10 clinical trial.pt.
#11 exp clinical trials/
#12 (clin$ adj25 trial$).ti,ab.
#13 ((singl$ or doubl$ or trebl$ or tripl$) adj25 (blind$ or mask$)).ti,ab.
#14 placebos.sh.
#15 placebo$.ti,ab.
#16 random$.ti,ab.
#17 research design.sh.
#18 or/10‐17
#19 18 not 8
#20 19 not 9
#21 9 or 19
#22 exp "Tooth Root"/
#23 exp Periapical Diseases/
#24 Tooth Apex/
#25 (((tooth adj root$) or (root$ adj6 teeth) or (tooth adj6 apex$) or (teeth adj6 apex$) or (teeth adj6 apices) or periapical$ or peri‐apical$ or periradicular or peri‐radicular) and (disease$ or periodontiti$ or abscess$ or granuloma$ or lesion$ or cyst$ or infect$ or inflamm$ or pathosis)).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#26 or/22‐25
#27 Apicoectomy/
#28 (endodontic$ and (treat$ or therap$ or surgery or surgical$)).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#29 (apical$ and (surgery or surgical$)).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#30 (surgery or surgical$ or non‐surgical$).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#31 (apicectom$ or apicoectom$).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#32 ((orthograd$ adj6 fill$) or (retrograd$ adj6 fill$)).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#33 ((root adj6 treat$) or (root adj6 therap$) or (root‐end adj6 resect$) or (root‐end adj6 fill$)).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#34 endodontics/
#35 or/27‐34
#36 retreatment/
#37 (re‐treat$ or retreat$).mp. [mp=title, original title, abstract, name of substance word, subject heading word]
#38 or/36‐37
#39 26 and 35 and 38
#40 21 and 39
Databases to be searched
The following electronic databases will be searched:
Cochrane Oral Health Group Trials Register
Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, current issue)
MEDLINE (1966 to present)
EMBASE (1974 to present).
Language
No language restriction will be placed. In case of the need for translations, these will be provided by appropriate Departments of our University.
Unpublished studies
Seven manufacturers of instruments for either orthograde therapy and/or endodontic surgery, and the authors of the identified RCTs will be contacted in order to identify unpublished or ongoing RCTs.
Handsearching
All issues of the following journals are of particular importance to this review:
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International Endodontic Journal
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Journal of Endodontics
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Dental Traumatology (formerly Dental Traumatology and Endodontics)
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Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics
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International Journal of Oral and Maxillofacial Surgery
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Journal of Oral and Maxillofacial Surgery
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British Dental Journal
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Endodontic Topics.
Where these journals have not already been searched as part of the Cochrane Journal Handsearching Programme, the journals will be handsearched by two authors (Massimo Del Fabbro (MDF), Silvio Taschieri (ST)).
The bibliographies of all identified RCTs and relevant review articles will be searched for identification of studies outside the handsearched journals.
Data collection and analysis
The titles and abstracts (when available) of all reports identified through the searches will be scanned independently by two authors (MDF and ST). Full reports will be obtained for trials appearing to meet the inclusion criteria or for which there is insufficient information in the title and abstract to make a clear decision. The full reports obtained from all the electronic and other methods of searching will be assessed independently, in duplicate, by two authors to establish whether the trials meet the inclusion criteria or not. Disagreements will be resolved by discussion. Where resolution is not possible, a third author will be consulted. All studies meeting the inclusion criteria will undergo validity assessment and data extraction. All studies rejected at this or subsequent stages will be recorded in the table of excluded studies and reasons for exclusion will be recorded.
Quality assessment
The quality assessment of included trials will be undertaken independently and in duplicate by two authors as part of the data extraction process.
Included trials will be assessed on three main quality criteria:
(1) concealed allocation of treatment, recorded as: (a) adequate, (b) unclear, (c) inadequate, (d) not used, as described in the Cochrane Handbook for Systematic Reviews of Interventions;
(2) completeness of information on reasons for withdrawal by trial group, recorded as (a) adequate, (b) unclear, (c) inadequate, (d) not used, as described in the Cochrane Handbook for Systematic Reviews of Interventions;
(3) further quality assessment will be carried out to assess the randomization method, sample size calculations, definition of exclusion/inclusion criteria, adequate definition of success criteria, comparability of control and treatment groups at entry, calibration of evaluator(s).
Authors of the RCTs will be contacted for clarification or to provide missing information whenever possible.
In order to summarise the validity of studies, they will be grouped into the following categories.
(A) Low risk of bias (plausible bias unlikely to seriously alter the results) if all of the criteria are met.
(B) Moderate risk of bias (plausible bias that raises some doubt about the results) if one or more criteria are partly met (e.g. if authors respond that they had made some attempts to conceal the allocation of patients or to give an explanation for withdrawals, but these attempts are not judged to be ideal, these criteria will be categorized as 'partly').
(C) High risk of bias (plausible bias that seriously weakens confidence in the results) if one or more criteria are not met, as described in the Cochrane Handbook for Systematic Reviews of Interventions.
Blind outcome assessment will not be assessed as a quality criteria. In fact, the outcome evaluators cannot be blinded to treatment when evaluating radiographs, that disclose if one or the other treatment has been applied (in surgical treatment root‐end is resected). Evaluators can be blinded only to patients.
The quality assessment criteria will be pilot tested using several articles.
Data extraction
Data will be extracted by two authors (MDF, ST) independently using properly designed data extraction forms. The data extraction forms will be piloted on several papers and modified as needed before use. Any disagreement will be resolved by discussion and a third author will be consulted where necessary. If agreement cannot be reached data will be excluded until further clarification is provided.
For each trial the following data will be recorded:
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Date of the study, year of publication, country of origin and source of study funding.
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Details of the participants including demographic characteristics, criteria for inclusion, type and location of teeth, type and size of periapical lesion, presence or absence of a post in the canal, type of materials and instruments used for root canal system management.
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Details on the type of intervention.
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Details of the outcomes reported, including method of assessment and time intervals after intervention.
Data synthesis
In order to standardize statistical calculations using RevMan, the outcomes will be dichotomized. All cases classified as complete or incomplete healing plus cases classified as uncertain healing in the absence of clinical signs and symptoms will be considered as 'successful'. Those cases classified as failures plus those classified as uncertain healing in the presence of signs and symptoms will be considered as 'unsuccessful'. Both patient based and tooth based analysis will be performed.
The Cochrane Oral Health Group statistical guidelines will be followed and, for each trial, risk ratios along with 95% confidence intervals will be calculated to estimate the effect of the interventions.
Clinical heterogeneity will be assessed by examining the types of participants, interventions and outcomes in each study. Only if studies of similar comparisons reporting the same outcome measures will a meta‐analysis be attempted. Risk ratios will be combined for dichotomous data using a fixed‐effect model. The significance of discrepancies in the estimates of the treatment effects from different trials will be assessed by means of Cochran's test for heterogeneity. Where significant heterogeneity (P < 0.1) is detected, the significance of the treatment effects will be re‐assessed using a random‐effects model.
Sensitivity analysis will be undertaken to examine the effect of randomization and concealed allocation on the overall estimates of effect.
