An In Vitro Model to Evaluate the Accuracy of Guided Implant Placement Based on the Surgeon's Experience.

PURPOSE: To evaluate whether there are differences in the accuracy of guided implant placement based on the surgeon's experience level. MATERIALS AND METHODS: Fifteen surgeons, divided into three groups based on experience level (group I, expert; group II, intermediate; group III, novice), placed six implants in five identical mandibles (75 mandibles and 450 implants). A planning and stereolithographic guide was generated using cone beam computed tomography (CBCT) images and implant planning software (Nemoscan, Nemotec) and was used in all cases. After the implants were placed in each mandible, another scan was taken, and the three-dimensional (3D) images of each scan were blended with the images in the planning guide to evaluate any deviations. Any differences in platform and apex position and the angle of the implant were measured. The differences between each surgeon and each group were compared using multivariate analysis of variance (MANOVA). RESULTS: There were significant differences in the implant angles among the three groups (P = .001). Group III (novices) presented the greatest angle deviation and showed more deviations than group I (experts) (P = .024) and group II (intermediate) (P = .001) did. There were no significant differences between groups I and II (P = .368). There were no significant differences among the groups in terms of platform (P = .135) and apex position (P = .092). CONCLUSION: Some degree of deviation can occur between the planned placement of the implant and its definitive placement, and this deviation may be influenced by the surgeon's experience. Expert surgeons show less angle deviation than novice surgeons. Although these differences (less than 0.5 degrees) are statistically significant, they may be considered clinically irrelevant.

Complication rate in 200 consecutive sinus lift procedures: guidelines for prevention and treatment.

PURPOSE: Maxillary sinus grafting is a predictable and reliable procedure that has been routinely performed for more than 30 years. The complication rate is low, but some cases may require additional surgery, and the outcome of oral rehabilitation may be affected. The purpose of the present study was to evaluate the early and late complications after sinus lift procedures performed in the authors' center, with special attention to risk factors and their connection to the principles of prevention and treatment. MATERIALS AND METHODS: A retrospective analysis of 127 patients was performed. During an 8-year period, patients underwent preprosthetic surgery with implants and a maxillary sinus lift procedure because of maxillary atrophy. In total, 202 sinus lift procedures were performed and 364 implants were placed (117 simultaneously and 247 delayed). Clinical data, local or systemic disease, risk factors, type of surgery, intraoperative and postoperative complications, and the evolution of the implant zone were recorded. RESULTS: The most common intraoperative complication was damage to the Schneiderian membrane (25.7%), which did not show any connection to postoperative complications. Thirty patients (14.9%) developed postoperative complications, including wound infection, abscess, or dehiscence with drainage (9 cases), maxillary sinusitis of the operated area (6 cases), partial exposure of the simultaneous onlay graft (6 cases), and loss of the graft (2 cases). CONCLUSION: Sinus lift surgery is a proven and reliable technique because of the low observed rate of postoperative complications and the success rate of implants placed into the grafted area. To minimize risk, care must be taken with all technical details and risk factors that can lead to fatality.