Regenerative Surgical Treatment of Peri-Implantitis: A Systematic Review and Meta-Analysis

Background/Objectives: This systematic review and meta-analysis evaluated the clinical effectiveness of regenerative surgical treatments compared with open flap debridement (OFD) in the management of peri-implantitis and, secondarily, assessed whether more advanced regenerative approaches, including guided bone regeneration (GBR), platelet-rich fibrin (PRF), and hyaluronic acid (HA), provide additional clinical benefit compared with bone grafting alone. Methods: A comprehensive search of PubMed, Scopus, and Web of Science was conducted in accordance with PRISMA guidelines and the PICO model, covering the period from 1993 to 2024. From 2119 identified articles, 63 full-text papers were reviewed, and 12 studies met all inclusion criteria. These studies compared regenerative treatments with OFD and bone grafting using clinical outcomes of probing pocket depth (PPD), radiographic bone level (RBL), bleeding on probing (BOP), suppuration (SUP), mucosal recession (REC), and clinical attachment level (CAL). Meta-analysis was performed using a random-effects model. Results: Regenerative treatments demonstrated superior outcomes in radiographic bone level gain compared with OFD (p < 0.001), while no statistically significant differences were observed for PPD (p = 0.77), BOP (p = 0.13), SUP (p = 0.42), REC (p = 0.14), or CAL (p = 0.96). Comparisons between bone grafting and other regenerative materials also showed no statistically significant differences. Conclusions: Regenerative procedures improved radiographic bone outcomes but did not consistently outperform OFD in soft tissue parameters, and no advanced regenerative modality demonstrated clear clinical superiority over bone grafting alone. Further high-quality randomized controlled trials with standardized methodologies are needed to establish clinical guidelines for peri-implantitis surgery.