OBJECTIVES: A comparison of different treatment modalities of peri-implantitis can lead to the development and application of more effective and efficient methods of therapy in clinical practice. This study compares the effectiveness of open flap debridement used alone, with an approach employing the additional use of a diode laser for the treatment of peri-implantitis.MATERIALS AND METHODS: Nineteen patients were divided into two groups and treated for peri-implantitis. In the control group (C group), the therapy utilized access flaps, plastic curettes, and sterilized gauzes soaked in saline. The test group (L group) was treated similarly but with additional irradiation using a diode laser. The parameters studied were pocket depth (PD) as the primary outcome variable, clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI) as secondary variables. Measurements were performed at three different time points, baseline (BSL), 3 months, and 6 months after treatment. Three months after treatment, a mean PD reduction of 1.19 mm for the control group and 1.38 mm for the laser group was recorded. The corresponding BOP changes were 72.9 and 66.7%, respectively. These changes were significant and remained at the same levels at the 6-month examination (p < 0.05). CAL was reduced significantly only in group L from 5.25 mm at baseline to 4.54 mm at 3 months, remaining at this level at 6 months (p < 0.05). PI was reduced significantly in group C at 3 months from 37.5 to 6.3%. The 6-month data showed no statistically significant difference (p < 0.05) from the 3-month measurements.RESULTS: The two methods of therapy for peri-implantitis examined seemed to be equally efficient in the reduction of the PD and BOP 3 months after surgery, with the results sustained at the same levels after 6 months. CAL significantly improved only in the test group after 3 months. PI was reduced and maintained at low levels in both groups.CONCLUSIONS: Surgical treatment of peri-implantitis by access flaps leads to improvement of all clinical parameters studied while the additional use of diode laser does not seem to have an extra beneficiary effect.CLINICAL RELEVANCE: The additional use of a diode laser in the surgical treatment of peri-implantitis offers a limited clinical benefit.