This clinical study reports on the results of a new method in the treatment of peri-implantitis. The surfaces of 24 plasma flame-sprayed cylindric implants in 17 patients who were diagnosed with peri-implantitis were decontaminated with a combination of toluidine blue (100 µg/mL) and laser irradiation at a wavelength of 906 nm. Bone defects were filled with autogenous bone using e-PTFE membranes for retention of the grafting material. Premature membrane exposure occurred in all patients after an average of 3 weeks (± 10 days), which required immediate removal of the exposed membrane in 1 patient. Since the soft tissue showed minimal signs of inflammation, the membranes were left in situ for another 6 weeks in all other patients. The mean radiographic peri-implant bone gain was 2 mm ± 1.90 mm after 9.5 months (maxilla 2.5 mm ± 2.38 mm; mandible 1.9 mm ± 1.87 mm). Two implants around which the initial bone defect had already reached the basket had to be removed after 10 months and 35 months, respectively, despite radiographic evidence of improvement of the peri-implant defect. The longer the membrane stayed in situ, the more bone was gained, as long as the membrane was covered by soft tissue (P = .01). However, the longer an exposed membrane was left in place, the smaller the resultant bone gain (P = .0001). Therefore, despite the absence of clinical signs of inflammation, exposed membranes should be removed immediately. The short-term results of this study corroborate the efficacy of the applied treatment method in prolonging the service time of dental implants involved with peri-implantitis. Schlagwörter: autogenous bone, endosseous dental implantation, guided tissue regeneration, laser therapy