Survival Rate of Implants and Mechanical Complications of 64 Implant-Supported Complete Arch Prostheses in Maxillary Edentulous Patients with a Follow-Up of up to 12 years: A Cross Sectional Analytical Study.

PURPOSE: This study aimed to identify the technical complications associated with maxillary complete-arch implant-supported fixed prostheses (ISFPs) and to evaluate the survival rates of both implants and prostheses. Additionally, we sought to analyze the impact of the presence of cantilevers, the type of prosthetic abutment, and the number of implants on the occurrence of complications.

MATERIALS AND METHODS: Data were obtained from standardized clinical assessments carried out in a single appointment by two calibrated professionals using information from dental records.

RESULTS: The sample consisted of 64 patients rehabilitated with ISFPs classified as hybrid prostheses (metal-resin). The survival rate for implants was 98.6% after 1 to 12 years (5.2 years ± 36.6 months) and was 100% for the prostheses after a follow-up period of 12 to 144 months (mean 48.1 ± 33.94 months). The most frequent complications were occlusal wear (82.8% of patients) and loosening of prosthetic screws (16.6%) and abutments (8.1%). Screw loosening frequency was significantly greater in 30-degree abutments compared with straight abutments (P=0.008), but no significant difference was found between 17-degree and 30-degree abutments. Prostheses with a higher occurrence of screw loosening had a greater average CL/AP spread ratios (0.9 􀀀 0.5). In addition, abutments installed on distal implants were more likely to loosen (P<0.001). The absence of mutually protected occlusion did not significantly influence the loosening of screws and prosthetic abutments.

CONCLUSIONS: Implantsupported fixed maxillary complete-arch rehabilitations have high survival rates but are subject to technical complications.