Surgical therapy of peri-implant disease: A 3-year follow-up study of cases treated with 3 different techniques of bone regeneration

Background: Advanced peri-implant intrabony defects require comprehensive surgical treatment regimens different from periodontal therapy strategies. The purpose of this longitudinal trial was to evaluate the peri-implant outcomes following guided bone regeneration with 3 treatment protocols. Methods: In 25 patients, 41 peri-implant defects with supporting bone loss > 50% of the implant length were treated with flap surgery plus autogenous bone grafts alone (FG) (controls, n = 12) plus non-resorbable (FGM) (test 1, n = 20) or bioabsorbable barriers (FGRM) (test 2, n = 9) and supportive antimicrobial therapy. Following submerged healing, the membranes were removed (FGM), and the peri-implant probing depths (PD), probing bone levels (BL), mobility scores (PT), and intrabony defect height (DH) were radiographically evaluated at baseline, 6 months, and 1 and 3 years post-therapy. Results: Non-surgical/anti-infective therapy resulted in a limited improvement of PD scores after 6 months. At the 3-year visit, surgical treatment revealed significant changes from baseline for the controls and both of the test groups for PD: 5.1 +/- 2.7 mm (FG), 5.4 +/- 3.0 mm (FGM), and 2.6 +/- 1.6 mm (FGRM), and for BL: 3.2 +/- 2.4 mm (FG), 3.4 +/- 2.4 mm (FGM), and 2.3 +/- 1.6 mm (FGRM), Mann-Whitney test, P less than or equal to0.05. The changes for DH and PT were significant only for FG- and FGM-treated subjects. The overall improvement for FGRM-treated patients during the 3-year observation was less marked. However, the differences between the 3 surgical treatment protocols did not affect the treatment outcomes after 3 years. Conclusions: Autogenous bone grafting is an appropriate treatment regimen to augment open crater-formed peri-implant defects. Although certain clinical situations require an additional fixation of barrier membranes, their routine application should be approached with caution.