Methods

Twelve week follow up, randomised, parallel group study. Unclear whether outcome assessors were blinded. Three withdrawals at 12 weeks for unknown reasons, 1 from the metronidazole group and 2 from the ultrasonic debridement group.

Participants

Patients in good general health having 1 stable implant affected by perimplantitis (bleeding on probing; PPD equal to or < 6 mm; bone loss < 4 mm). Exclusion criteria were assumption of antibiotics over the last 3 months and antimicrobial mouthwashes over the last month. Adults treated at the Centre for Dental Implantation, Peking University, China. Thirty enrolled (15 patients in each group) and results given for 27.

Interventions

Metronidazole gel 25% injected into the pocket at a depth of 3 mm versus ultrasonic debridement with carbon fiber tip inserted 1 to 2 mm into the gingival sulcus at the lowest power for 15 seconds around IMZ or Frialit‐2 implants. Both interventions were repeated a second time 1 week after.

Outcomes

Probing pocket depth, bleeding on probing, plaque index, BANA test for bacterial quantification (Periochek, Sunstar, Japan) and side effects at 1, 2, 6 and 12 weeks. Twelve weeks data used. We could not calculate change data as the standard deviations for these were not present.

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment (selection bias)

Unclear risk

B ‐ Unclear