## 1 Introduction  
Implant-prosthetic rehabilitation with immediately loaded post-extraction implants aims to reduce the overall treatment time, preserve both hard and soft tissues, and limit the extent of post-extraction bone remodeling [1]. Alveolar bone loss following tooth extraction remains a significant clinical concern, as it can negatively impact implant integration and compromise long-term prosthetic outcomes [2]. Immediate implant placement within the extraction socket helps to counteract these effects by minimizing bone resorption and supporting tissue stability, especially in the anterior maxilla where aesthetics are critical [3].  
However, the clinical success of immediate post-extraction implant placement depends on several factors, including the quality of the residual bone, the ability to achieve primary stability, and the appropriate biomechanical management of immediate loading [4]. In particular, success is closely linked to the stabilization of the implant within the alveolar socket and the immediate placement of a prosthesis with a controlled and well-distributed occlusal load [5]. Primary stability is considered a critical condition for successful osseogeintegration, as it reduces micromovements that may interfere with the healing process [6].  
Numerous clinical investigations have demonstrated that the measurement of the implant stability quotient (ISQ) represents a reliable parameter for predicting implant prognosis in immediate loading protocols [7]. Furthermore, comparative studies between immediately loaded and delayed implants have suggested that, when performed under optimal conditions, the long-term survival rates of both approaches are comparable [8]. This supports the predictability and safety of immediate protocols when case selection and surgical execution are carefully managed.  
Patient selection remains one of the most crucial elements in the predictability of this technique. As reported by [PERSON] et al., several risk factors for implant failure must be considered, including the quantity and quality of the residual bone, the presence of preexisting infections, and the proper management of the gap between the implant surface and the alveolar walls [9]. The use of biomaterials in these contexts has been shown to enhance bone regeneration and to limit post-extraction ridge resorption [10].  
Additionally, [PERSON] et al., in their retrospective clinical study, reported no statistically significant differences in long-term survival between immediate and delayed implants when standardized surgical and prosthetic protocols were followed [11]. Immediate placement is often preferred in the aesthetic zone, where the preservation of soft tissue contours and bone volume is essential. Conversely, in cases of significant bone dehiscence or active infection, a delayed approach may be more appropriate [12; 13].  
Recent evidence by [PERSON] et al. has demonstrated that alveolar ridge preservation techniques using bone grafts or synthetic substitutes can improve both aesthetic and functional outcomes in immediate post-extraction implants [14]. Furthermore, long-term clinical studies have reported success rates exceeding 95% for immediately loaded implants over follow-up periods longer than five years, supporting the reliability of this approach [15; 16]. Nonetheless, potential complications such as marginal bone resorption and peri-implant soft tissue inflammation may compromise the overall success of the treatment [17; 18].  
Current analyses of soft tissue behavior indicate that immediate loading does not negatively affect the biological stability of the peri-implant environment [19].  
This retrospective clinical cohort study aimed to evaluate, over an 18-month follow-up period, implant survival rates, marginal bone loss, peri-implant parameters, and surgical and prosthetic complications in immediately loaded post-extraction implants used for single or partial implant-prosthetic rehabilitation.