Stability of peri-implantitis surgical reconstructive therapy—a (> 2 years) follow-up of a randomized clinical trial

Objectives This follow-up study aimed to report the 24- and 30-month outcomes of a cohort previously enrolled in a randomized clinical trial on surgical reconstructive treatment of peri-implantitis. Methods Twenty-four patients were diagnosed with peri-implantitis and treated with surgical reconstructive therapy with or without the adjunctive use of Er:YAG laser. Within-group and between-group comparisons were tested with mixed model with repeated measures. Results Regarding peri-implant pocket depth (PPD) reduction (control vs. laser test group) between 6 months (− 1.85 vs. − 2.65 mm) and 30 months (− 1.84 vs. − 3.04 mm), the laser group showed statistically significant changes but not the control group. In terms of radiographic marginal bone loss (RMBL) at 6 months (− 1.1 vs. − 1.46 mm) to 24 months (− 1.96 vs. − 2.82 mm), both groups showed statistical difference compared to baseline. The six explanted implants all were featured by severe peri-implantitis and mostly with no or limited keratinized tissue (< 2 mm) at baseline and membrane exposure after surgery. Among the 15 retained cases, eight cases achieved more than 50% peri-implant bone level gain. Conclusions Within the limitation and follow-up time frame of this trial, the outcome of the surgical reconstructive therapy sustained or improved in most of the cases. However, 25% of the implants with severe peri-implantitis failed 2 years after the surgical reconstructive therapy. The use of Er:YAG laser favors PPD reduction in the longer term up to 30 months. Clinical relevance Longer-term follow-up on reconstructive therapy of peri-implantitis revealed sustained or improved stability in certain cases, but the survival of implants with severe peri-implantitis has its limitation, especially when there is limited keratinized tissue (< 2 mm or no KT). Trial registration Clinical Trials Registration Number: NCT03127228 and HUM00160290.