Schwarz 2006a.

Methods	1‐year follow‐up, randomised, parallel group study. Blinded outcome assessor. 2 withdrawals in the chlorhexidine group due to persisting pus formation 4 to 12 weeks after treatment. The affected implants received the Er:YAG laser treatment.
Participants	Patients having at least 1 implant affected by peri‐implantitis, showing bone loss, BOP and exudate with PD > 4 mm. Exclusion criteria were assumption of antibiotics over the last 6 months; treatment for peri‐implantitis over the last 12 months; absence of peri‐implant keratinized mucosa; regular smokers, hollow cylinder implants, and any systemic diseases that could influence the outcome of the therapy. Adults treated in various universities and hospitals in Germany and Switzerland. 20 patients enrolled (10 in each group) and results given for 18.
Interventions	Oral hygiene instructions 2 to 4 times and supragingival cleaning with rubber caps and polishing paste were given prior to the initiation of the trial. Er:YAG laser (Key 3, KaVo, Biberach, Germany) emitting a pulsed infrared radiation at a wavelength of 2.94 µm. The laser parameters were set at 100 mJ/pulse, 10 pps, and pulse energy at the tip was approximately 85 mJ/pulse. The laser beam was guided onto the implant surface under water irrigation with a specially designed periodontal handpiece (2061, KaVo, Biberach, Germany) and a cone‐shaped glass fibre tip emitting a radial and axial laser beam. The fibre tip was guided in a circular motion from coronal to apical parallel to the implant surface in contact mode. In the control group manual debridement was performed with plastic curettes followed by pocket irrigation with 0.2% chlorhexidine and subgingival application of 0.2% chlorhexidine gel, followed by 2 weeks of mouthrinses with 0.2% chlorhexidine, twice a day for 2 minutes. For both groups, instrumentation was carried out until the operator felt that the implant surfaces were adequately debrided, on the average 6 minutes per implant. The trial included implants with TPS and SLA surfaces.
Outcomes	Implant failure, recurrence of peri‐implantitis, PAL, PPD, REC, plaque, BOP and complications/side effects at baseline, 3, 6 and 12 months.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The patients were randomly assigned to the following test and the control groups according to a computer‐generated protocol (RandList, DatInf GmbH, Tubingen, Germany)".
Allocation concealment (selection bias)	Unclear risk	No information in the article. Author's reply failed to clarify the issue.
Blinding (performance bias and detection bias) All outcomes	Low risk	No information in the article. The author replied that the assessor was blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Between 4 and 12 weeks following treatment 2 patients (4 implants) of the mechanical debridement group were excluded due to severe pus formation. They were treated with laser as in the other group. No data were presented regarding the outcomes of the their re‐treatments.
Selective reporting (reporting bias)	High risk	Pre and postoperative radiographs at baseline and 12 months were taken and evaluated but there was no description of how they were assessed nor data apart from an approximate subjective quantification. Missing data for the patients excluded by the authors.
Other bias	Low risk	None apparent, though this trial was sponsored by the laser manufacturer.