###### Abstract  
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\({}^{\circledR}\) 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). p 2025 15 8040  
[PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON]. the Classification of Periodontal and Peri-Implant Diseases and Conditions, peri-implant mucositis is an inflammatory pathological condition of the peri-implant mucosa without accompanying bone loss. Clinical signs include pus formation, redness, swelling, and bleeding on probing (BOP) [4; 5]. On the other hand, in peri-implantitis, inflammation affects soft and hard tissues, causing peri-implant bone loss. This can be observed clinically as increased probing depth (PD), significant progressive bone loss beyond the margin of measurement error (approximately 0.5 mm), and the presence of pus and/or bleeding on probing [5; 6]. This biological complication affects approximately one out of every five patients with dental implants and is one of the most common causes of implant failure [7]. A systematic review with meta-analysis reported subject-based estimated weighted mean prevalences and ranges for peri-implant mucositis and peri-implantitis. According to these authors, peri-implant mucositis has a prevalence of 43% (range from 19% to 65%), while peri-implantitis is slightly less common with a prevalence of 22% (range from 1% to 47%) [8]. Additionally, [PERSON] et al. [9] concluded that the patient-based prevalence of peri-implantitis in a private practice located in Spain was 9.1% (16.3% of implants). In this sample, peri-implant mucositis affected 38.8% of the patients and 21.6% of the implants. The real prevalence may be higher since the available diagnostic tests have limitations and require improvements [10; 11; 12]. Several risk factors for peri-implantitis have been identified [13]. These include the history of periodontitis, inadequate oral hygiene, smoking, diabetes, and lack of regular supportive peri-implant therapy. A comprehensive risk assessment and personalized preventive strategies are important to minimize complications and ensure long-term implant success [14]. Regular dental check-ups and periodontal and peri-implant supportive therapy are also crucial for maintaining health.