LAUSR

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 of IL-1β between 2 and 4 weeks (p<0.0001). Both MMP-9 (p<0.001) and VEGF (p<0.05) levels steadily decreased after treatment. In the laser group, the peak increase of IL-1β was attenuated at 2 weeks, followed by significant reduction of MMP-9 (p<0.01) and VEGF (p<0.05) across all follow-up appointments compared to the control non-laser group. The total bacterial load was reduced two weeks after treatment, especially in the laser group, but recolonized to presurgical levels after four weeks in both groups (p<0.01). 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 post-surgical period. The bacterial load was reduced immediately after therapy, but recolonization was observed by 4 weeks in both groups.