Long-Term Treatment Outcomes of Peri-Implantitis Reconstructive Therapy: 7-Year Survival and Success of a Randomized Clinical Trial.

OBJECTIVES To report the 7-year outcomes of a randomized clinical trial evaluating a reconstructive surgical procedure of peri-implantitis with a bone substitute in combination with either concentrated growth factor (CGF) or collagen membrane (CM). MATERIALS AND METHODS The original population consisted of 57 patients with at least one implant diagnosed with peri-implantitis exhibiting two-, three-, or four-wall intrabony defects ≥ 3 mm which were filled with a xenogenic bone grafting material and covered with either CGF or CM. Clinical and radiographic parameters, treatment success, and disease recurrence frequencies were evaluated over the 7-year follow-up period of supportive periodontal/peri-implant care. Relationships between prognostic indicators/predictors and treatment success and failure were investigated. RESULTS Sixteen patients (24 implants) (CGF group) and 18 (25 implants) (CM group) completed the 7-year follow-up. Although short-term improvements in clinical and radiographic outcomes were observed, a tendency toward relapse was detected through time. At implant level, CM group demonstrated significantly more favorable outcomes for deepest PPD and radiographic vertical defect depth (p = 0.040 and p = 0.043) compared to CGF group. At 7 years, treatment success was achieved in 23.1% of CGF and 30.8% of CM patients, while disease recurrence occurred in 34.6% and 30.8%, respectively (p > 0.05). The presence of baseline suppuration was the only significant patient-level predictor for treatment failure (OR = 15.45; 95% CI: 1.42-168.5; p = 0.02). CONCLUSION Both protocols led to comparable clinical and radiographic outcomes. Long-term treatment success was limited, with increasing failure rates over time. Baseline suppuration had a significant negative impact on treatment outcomes.