Peri-implantitis is an inflammatory disease-causing bone loss around dental implants, often requiring reconstructive surgical therapies to reduce probing depth and regenerate bone. However, such surgeries are frequently complicated by postoperative issues. This retrospective case series aimed to identify the main postoperative complications following the reconstructive treatment of peri-implant bone defects in peri-implantitis patients. Data from 14 patients with 21 affected implants were analyzed, including demographics, oral hygiene, surgical techniques, and complications such as wound dehiscence, membrane exposure, and infections. Wound dehiscence was measured using Image J^® software version 1.54. Descriptive and bivariate analyses were performed. The results showed that 11 implants (52.4%; 95% confidence interval (95%CI): 29% to 76%) in nine patients (57.1%; 95%CI = 27% to 87%) developed soft tissue dehiscence after one week, with membrane exposure observed in 4 implants. Dehiscence was significantly associated with mandibular implant location (p = 0.003), poor interproximal hygiene (p = 0.008), and membrane exposure (p = 0.034). No postoperative infections were recorded. In conclusion, more than half of peri-implantitis patients undergoing reconstructive surgery experience wound dehiscence, particularly in cases involving mandible, poor hygiene, and membrane exposure. This complication might compromise bone regeneration and reduce the treatment success rate. These results should be interpreted cautiously due to study design limitations (retrospective design, lack of a control group, and small sample size).

To determine the proportion of patients with peri‑implant mucositis who develop peri‑implantitis over a 1- to 10-year follow-up period, and to identify the variables associated with this progression. A retrospective cohort study was conducted including 97 patients with 204 dental implants diagnosed with peri‑implant mucositis. Clinical and radiographic examinations were performed, and compliance with supportive peri‑implant care (SPIC) was recorded. A multilevel multinomial logistic regression model was developed to identify the predictors of disease progression. After a mean follow-up of 49.8 months, 23.7% of patients initially diagnosed with peri‑implant mucositis became healthy, 57.7% showed no change and remained with peri‑implant mucositis, while 18.5% progressed to peri‑implantitis. A history of periodontitis significantly increased the odds of presenting peri‑implant disease at the last follow-up appointment (p < 0.001). Conversely, regular compliance with SPIC, prostheses with an adequate design, and single-unit restorations significantly reduced the risk of progression (p < 0.001). Almost one fifth of patients with dental implants with peri‑implant mucositis are likely to develop peri‑implantitis after a mean follow-up of 4 years. A history of periodontitis, irregular supportive peri‑implant care and inadequate prosthetic design increase the likelihood of bone loss and progression to peri‑implantitis. This study emphasizes the importance of regular supportive peri‑implant care and appropriate prosthetic design to prevent progression from peri‑implant mucositis to peri‑implantitis, especially in patients with a history of periodontitis.