## 4 Discussion
The surgical treatment techniques described in the studies published to date are very heterogeneous and may justify the different reported incidences. In our sample, non-submerged healing that allowed for the immediate placement of the prosthesis was employed and periosteal releasing incisions were performed to reduce flap tension. One of the main advantages of this option is that the patient recovers their chewing ability and quality of life immediately after surgery. A study published by our team [55] found that regenerative peri-implant surgery negatively affected the patients' quality of life. Thus, the immediate placement of the prosthesis may improve this outcome. It is unclear if a submerged approach provides better regenerative outcomes, and the literature on this topic is space [54; 56; 57; 58]. On the one hand, a submerged approach may be more beneficial in terms of radiographic bone fill, but other variables such as comfort and impact on the patient's quality of life should also be considered. In our sample, patients undergoing mandibular surgeries (\(p\) = 0.003) and that did not use interdental brushes (50% vs. 7.1%; \(p\) = 0.008) were significantly more prone to this complication. Mandibular sites seem to be anatomically susceptible to soft tissue dehikences, probably due to the presence of a thinner keratinized mucosa, and restricted vascularization, all of which might affect wound stability and healing [59]. Furthermore, the absence of interdental hygiene promotes biofilm buildup and prolonged inflammation, which may contribute to mucosal recession [60]. [PERSON] et al. [61] and [PERSON] et al. [23] emphasized that adequate oral hygiene, including the interproximal areas, is paramount for the success of peri-implant reconstructive therapy. Other variables that might affect the complication rate, such as operation time, flap design, or prosthetic configurations, were not assessed in the present study and should be evaluated in future research. Mechanical debridement with instruments such as titanium curettes and ultrasonic scalers may significantly modify implant surface topography [62; 63]. These surface alterations might damage guided bone regeneration outcomes, as indicated by [PERSON] et al. (2024) [64] and [PERSON] et al. (2025) [65], illustrating the necessity for careful instrument selection and procedural control. In patients with a thin gingival biotype, particularly in the mandible, a staged approach that includes an initial soft tissue graft (e.g., CTG or tunnel method) followed by delayed bone augmentation might improve wound stability and the esthetic results [66]. [PERSON] et al. (2023) [67] observed that connective tissue grafting prior to implant placement resulted in a stable increase in tissue thickness, promoting long-term peri-implant health. The absence of an association between the occurrence of complications and several factors traditionally considered risk factors is also noteworthy. In our sample, tobacco consumption, systemic conditions, and history of periodontitis were not related to an increased risk of complications. This is probably related to the small sample size. Indeed, previous reports have suggested that smoking negatively affects wound healing and increases the risk of postoperative complications by 2.1 to 2.6 times [68]. Similarly, systemic conditions such as poorly controlled diabetes mellitus can significantly impair wound healing in regenerative procedures [69]. Thus, the results of the present study should be interpreted with caution. The high prevalence of periodontal disease (92.9%) in advanced stages (46.2% in stage 3 and 38.5% in stage 4) in our sample suggests that the included patients had a significant involvement of the periodontal tissues. The scientific literature has established that the history of severe periodontitis is a predictor for the development and progression of peri-implantitis, with an odds ratio of 4.7 [5]. This study has several limitations that should be considered.