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.