The prevalence of surgical complications of the sinus graft procedure and their impact on implant survival

Background: Grafting of the maxillary sinus floor has been performed successfully over the last decade. The ultimate goal of this procedure is to allow surviving implants to support a functional prosthesis. Surgical complications of the procedure are rarely reported and their impact on implant survival has been investigated even to a lesser extent. The purpose of this study was to evaluate the prevalence of surgical complications of the sinus graft procedure and their impact on implant survival. Methods: The study consisted of 70 patients who underwent 81 sinus graft procedures using the lateral wall approach from 1995 to 2000. A total of 212 screw-shaped implants were placed in the grafted sinuses and were restored by fixed prosthesis. Mean follow-up period for the implants was 43.6 months. Intra- and postoperative complications were thoroughly documented regarding clinical signs, times of occurrence, and treatment regimens. Results: Perforation of the Schneiderian membrane was the major intraoperative complication, observed in 36 of the 81 sinuses (44%). Of the 70 patients, seven (10%) suffered from postoperative complications, specifically related to the sinus graft procedure, which included an uncommon cyst formation and an infection. Membrane perforations were strongly associated with the appearance of postoperative complications (specific and non-specific to the procedure) (P <0.001). However, no association was found between membrane perforations or postoperative complications and implant survival. Conclusions: Intraoperative complications may lead to post-operative complications. Surgical complications did not significantly influence implant survival.