Renvert 2004

Methods	Randomised, parallel group. Patients cannot be blind, outcome assessors blind. 2 withdrawals at 3 months from the chlorhexidine group.
Participants	Adults. Age 41 to 75. Implants placed 10 to 12 years before. 32 enrolled and results given for 30.
Interventions	2 groups. Mechanical debridement plus 1 mg minocycline (OraPharma) versus 1 ml 1% chlorhexidine (Corsodyl) inserted submucosally. No brushing for 12 hours and no interdental cleaning for 10 days. Recall 1, 2, 3, 6, 9 and 12 months. Study duration: 12 months.
Outcomes	Full mouth plaque score, full mouth bleeding score, local plaque score (presence), probing pocket depths (mm), bleeding on microbial sampling, microbial sampling at 10 days, 1, 2, 3, 6, 9, 12 months. Side effects: soreness in the gum at 10 days. 1‐year data used.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"The randomisation was done before initiation of the study." Author answer: "Computer generated list".
Allocation concealment (selection bias)	Low risk	Author answer: "Assigned treatment were written in numbered and sealed envelopes. After mechanical treatment were done the envelope with the next number were opened and the treatment indicated performed".
Blinding (performance bias and detection bias) All outcomes	Low risk	"The clinician performing the measurements was unaware of the treatment given".
Incomplete outcome data (attrition bias) All outcomes	Low risk	No data missing. 2 losses to follow‐up.
Selective reporting (reporting bias)	Low risk
Other bias	Unclear risk	"This study was supported by Oralpharma inc. (Warminster, PA,USA)".
Blinding of the patient?	Low risk	Not possible. This was judged to be irrelevant for the risk assessment.