Effect of laser-assisted reconstructive surgical therapy of peri-implantitis on protein biomarkers and bacterial load

Objectives: This randomized clinical trial assessed changes in protein biomarker levels and bacterial profiles after surgical reconstructive therapy of peri-implantitis and investigated whether the adjunctive use of Er:YAG laser impacts protein biomarker and microbial outcomes. Materials and Methods: Twenty-four patients received surgical reconstructive therapy for peri-implantitis with guided bone regeneration following mechanical debridement with (test) or without (control) the adjunctive irradiation of Er:YAG laser. Bacterial and peri-implant crevicular fluid (PICF) samples were collected over 6 months and analyzed with bacterial qPCR and luminex multiplex assays. Results: Surgical reconstructive treatment significantly affected the concentration of PICF protein biomarkers, including a 50% reduction in IL-1β between 2 and 4 weeks (p <.0001). Both MMP-9 (p <.001) and VEGF (p <.05) levels steadily decreased after treatment. In the laser group, the peak increase in IL-1β was attenuated at 2 weeks, followed by significant reduction in MMP-9 (p <.01) and VEGF (p <.05) across all follow-up appointments compared with the control nonlaser group. The total bacterial load was reduced 2 weeks after treatment, especially in the laser group, but recolonized to presurgical levels after 4 weeks in both groups (p <.01). The composition of selective pathogens varied significantly over the follow-up, but recolonization patterns did not differ between groups. Conclusions: Reconstructive therapy of peri-implantitis significantly altered PICF protein biomarker and microbial levels during the healing process. The adjunctive use of Er:YAG laser significantly modulated the inflammatory response through reduced levels of MMP-9 and VEGF during the postsurgical period. The bacterial load was reduced immediately after therapy, but recolonization was observed by 4 weeks in both groups.