Articles on the prevalence of peri-implant diseases showed that 90% of peri-implant tissues had some form of inflammatory response and a prevalence of peri-implantitis from 28% to 51% according to various publications. Objective: To provide an overview of how risk factors can be related with peri-implantitis. Methods: A retrospective longitudinal study including 555 implants placed in 132 patients was evaluated based on the presence of peri-implantitis following the criteria of Renvert et al. 2018. Results: In total, 21 patients (15.9%) suffered peri-implantitis (PPG) and 111 patients (84.1%) did not suffer peri-implantitis (NPG). The results reveal that smokers have a high incidence of peri-implantitis (72.7%) compared to non-smokers (27.3%) (p < 0.0005). Another variable with significant results (p < 0.01) was periodontitis: 50% PPG and 23.9% NPG suffered advanced periodontitis. Systemic diseases such as arterial hypertension, diabetes mellitus, osteoporosis, and cardiovascular diseases do not show a statistically significant influence on the incidence of peri-implantitis. Patients who did not attend their maintenance therapy appointment had an incidence of peri-implantitis of 61.4%, compared to 27.3% in those who attend (p < 0.0001). From the results obtained, we can conclude that relevant factors affect peri-implantitis, such as tobacco habits, moderate and severe periodontitis, and attendance in maintenance therapy.

Purpose: The aim of this retrospective study was to compare the influence of removing or not removing a prosthesis after regenerative surgery on peri-implant defects. Methods: Two different groups were compared (Group 1: removing the prosthesis; Group 2: maintaining the prosthesis), analyzing radiographic bone filling (n = 32 implants) after regenerative treatment in periapical radiographs. The peri-implant defects were measured before and after regenerative treatment using Bio-Oss® (Geistlich Pharma, Wohhusen, Switzerland) and a reabsorbable collagen membrane (Jason®, Botis, Berlin, Germany), the healing period was two years after peri-implant regenerative surgery. Statistical analysis was performed, and a Chi square test was carried out. To determine the groups that made the difference, corrected standardized Haberman residuals were used, and previously a normality test had been applied; therefore, an ANOVA or Mann–Whitney U test was used for the crossover with the non-normal variables in Group 1 and Group 2. Results: The results obtained suggest that a regenerative procedure with xenograft, resorbable membrane, and detoxifying the implant surface with hydrogen peroxide form a reliable technique to achieve medium-term results, obtaining an average bone gain at a radiographic level of 2.84 mm (±1.78 mm) in patients whose prosthesis was not removed after peri-implant bone regenerative therapy and 2.18 mm (±1.41 mm) in patients whose prosthesis was removed during the healing period. Conclusions: There are no statistically significant differences in the response to treatment when removing or keeping the prosthesis after regenerative surgery in peri-implant defects.