## 4 Discussion
Regarding prosthetic complications, a significant association was observed concerning the implant site, with a higher incidence in posterior regions, and rehabilitation type, with a greater frequency of complications in bridges compared to single implants. No statistically significant correlation was found between complications and smoking or the presence of systemic conditions. The higher rate of complications in posterior regions can be attributed to specific biomechanical factors. Previous studies have demonstrated that the greater intensity of occlusal forces in the posterior regions, combined with the generally lower bone quality compared to anterior regions, may increase the risk of ceramic fractures, prosthetic screw loosening, and wear of restorative components [31; 32]. In a systematic review, [PERSON] et al. analyzed the influence of prosthetic design and material selection on complications in implant-supported bridges in posterior regions, reporting a significantly higher incidence of fractures and mechanical failures compared to single-unit fixed prostheses [33]. The increased incidence of complications in bridges compared to single implants has been further confirmed by [PERSON] et al., who, in a literature review, highlighted that multiple-unit fixed prostheses tend to be more vulnerable to complications than single implant crowns. This phenomenon is attributable to the distribution of masticatory forces across multiple units, which can lead to increased mechanical stress on the prosthetic structure and implant connections. Additionally, the complexity of implant bridge design implies a higher risk of ceramic material fractures and prosthetic screw loosening over time [34]. [PERSON] et al. conducted a retrospective study on complications associated with fixed implant-supported prostheses, concluding that the primary cause of long-term failure is represented by technical complications, including ceramic fractures and wear of prosthetic components. The high frequency of these events in posterior restorations suggests that the biomechanical design of implant-supported fixed prostheses should carefully consider the type of material used, the distribution of occlusal forces, and the quality of the supporting bone [35]. [PERSON] emphasized the importance of considering biomechanical forces in implant treatment planning. Excessive loading can induce micromovements at the implant level, contributing to the onset of prosthetic complications, particularly in posterior regions. The author suggests that proper occlusal load distribution and the use of high-strength materials can reduce the risk of implant rehabilitation failure [36]. In the current study, the placement of the implants was performed through basal bone, without biomaterials for bone regeneration. Any gaps between the implant surface and the buccal cortex were filled exclusively by collagen hemostatic sponges, according to a minimally invasive approach geared towards the preservation of hard and soft tissues. The results obtained in terms of implant survival rate contained marginal bone loss, and the incidences of surgical and prosthetic complications are equal to, if not superior to, other studies in the literature in which biomaterials were used to fill post-extraction sockets. In a prospective study conducted by [PERSON] et al. using hydroxyapatite and collagen-based biomaterials in immediately loaded post-extractive implants, a survival rate of 94.4% at 12 months was reported, with an average marginal bone resorption of 0.78 mm [31]. Similarly, [PERSON] et al. clinically compared alveolar filling with an autologous bone versus xenogeneic graft in post-extractive implants, finding similar survival rates but with more frequent peri-implant inflammation in sites treated with heterologous materials [37].