Objective To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri‐implantitis. Methods In this multicenter randomized clinical trial, 138 patients (147 implants) with peri‐implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra‐oral radiographs, and patient‐reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD ≤5 mm at all aspects and (iv) ≤1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient‐reported outcomes. Results During follow‐up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted. Conclusions Surgical therapy of peri‐implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.

Objective The aim of the present study was to assess interventions and their consequences with regard to further bone loss at sites diagnosed with peri‐implantitis. Materials and Methods In 2017, records of 70 patients diagnosed with moderate/severe peri‐implantitis at ≥1 implant sites 4 years earlier were obtained. Changes of marginal bone levels during the study period assessed on radiographs and predictors of disease progression were identified by Cox regression and mixed linear modelling. Patient files were analysed for professional interventions related to the treatment of peri‐implantitis. Results Mean bone loss (±SD) at implants diagnosed with moderate/severe peri‐implantitis was 1.1 ± 2.0 mm over the observation period of 3.3 years. While non‐surgical measures including submucosal and/or supra‐mucosal cleaning of implants were provided to almost all patients, surgical treatment of peri‐implantitis was limited to a subgroup (17 subjects). Surgically treated implant sites demonstrated a mean bone loss of 1.4 ± 2.4 mm prior to surgical intervention, while only minor changes (0.2 ± 1.0 mm) occurred after therapy. Clinical parameters (bleeding/suppuration on probing and probing depth) assessed at diagnosis were statistically significant predictors of disease progression. Conclusions Non‐surgical procedures were insufficient to prevent further bone loss at implant sites affected by moderate/severe peri‐implantitis. Surgical treatment of peri‐implantitis markedly diminished the progression of bone loss. Clinical assessments of bleeding on probing and probing depth at diagnosis predicted further bone loss.

Over a 5-year period, technical complications in implant-supported restorative therapy occurred frequently and their management required professional intervention.