The outcomes of the present study suggest that both regenerative approaches yielded significant improvements in both clinical and radiographic assessments. The procedure using a collagen membrane in combination with a bone substitute showed better results at 12 months in RST of peri-implantitis.

Objectives To compare the 3-year clinical and radiographic outcomes of two different reconstructive surgical management of peri-implantitis using a bone substitute in combination with either concentrated growth factor (CGF) or collagen membrane (CM). Material and methods Fifty-one patients who had at least one implant presenting peri-implantitis with an intrabony defect were filled with a xenogenic bone grafting material and covered either CGF or CM. Clinical and radiographic assessments were carried out at baseline and postoperative years 1 and 3. Three different composite outcomes were defined to evaluate treatment success at a 3-year follow-up. The effects of possible prognostic indicators on treatment success were identified by using multilevel regression analysis. Results The changes in probing depth (PD) and radiographic vertical defect depth (VDD) between baseline and year 1 and baseline and year 3 presented significantly greater decreases for the CM group in comparison with the CGF group (p < 0.05). No significant differences between the two treatment modalities were demonstrated regarding treatment success outcomes. History of periodontitis, VDD at baseline, and the number of intrabony defect walls revealed significant impacts on treatment success (p = 0.033; OR = 3.50, p = 0.039; OR = 0.975, and p = 0.024; OR = 7.0 and p = 0.019;OR = 6.0, respectively). Conclusions CM in combination with a bone substitute seems to have slightly better outcomes compared to the CGF membranes in reconstructive surgical therapy of peri-implantitis. The history of periodontitis, baseline VDD, and peri-implant bone defect configuration could be possible predictors influencing treatment success. Trial registration ClinicalTrials.gov NCT04769609. Clinical relevance For the reconstruction of peri-implant bone defects, using a bone substitute in combination with a collagen membrane may show more favorable outcomes.

Background: Various treatment protocols of peri-implantitis involving surgical therapies with open flap debridement procedures, resective or reconstructive modalities have been documented to achieve variable success. Surgical NO-reconstructive approaches have been suggested to have limited effectiveness in terms of the resolution of inflammation in the long term. Therefore, much more interest has been intensified regarding the efficacy of biomaterials used in reconstructive approaches. Aim/Hypothesis: The aim of this study was to investigate the 3-year clinical/radiographic outcomes of reconstructive surgical therapy of peri-implantitis using a bone substitute combined with two different bioresorbable barrier membranes, either collagen membrane (CM) or concentrated growth factor (CGF). Materials and Methods: A total of 72 patients who had at least one implant diagnosed with peri-implantitis and needed to be scheduled for reconstructive therapy of a peri-implant intrabony defect were included. Peri-implantitis case was defined as increased probing depth (PD) compared to previous examinations with bleeding on probing (BOP) and/or suppuration and radiographic evidence of peri-implant bone loss beyond crestal bone level changes resulting from initial bone remodeling. The patients were randomly assigned to receive a bone substitute filling in combination with either CM or CGF. Intrabony components were filled with a bone substitute (BioOss spongiosa granules; Geistlich, Wolhusen, Switzerland) and covered with a CM (Bio-Guide, Geistlich Biomaterials) or CGF membrane. The plaque INDIAx (PI), gingival INDIAx (GI), BOP, PD, clinical attachment level (CAL), mucosal recession (MR) and radiographic vertical defect depth (VDD) values were evaluated at 1 and 3 years postoperatively. Results: One patient from the CM group and two patients from CGF group were discontinued from the study due to severe pus formation during the study time periods. At 1 year, the mean PD, CAL and vertical defect depth (VDD) values were statistically significant in favor of the CM group. However, at the 3-year follow-up, both CM and CGF groups revealed comparable mean VDD values. Moreover, the mean values of defect fill (DF) at both 1 year and 3 years follow-up in the CM group were not statistically significantly different from that observed in the CCF group. Conclusions and Clinical Implications: Both reconstructive surgical treatment modalities yielded improved clinical and radiographic outcomes at both 1 year and 3 years postoperatively compared to baseline conditions. Despite the fact that the clinical significance may be considered as weak, the procedure using a collagen membrane in combination with a bone substitute seems to have favorable clinical outcomes compared to the CGF membranes combined with bone substitute filling.