Mechanical Complications of Posterior Implant Restorations using CAD/CAM Titanium Customized Abutments: A Retrospective Study

Abstract

The purpose of this retrospective study was to evaluate the incidence of mechanical complications of the posterior implant-supported fixed dental prosthesis (p-ISFDP) using computeraided design and computer-aided manufacturing (CAD/CAM) titanium customized abutments and to evaluate the influencing factors on complications. Material and Methods:The incidence and consequences of mechanical complications in p-ISFDPs over a mean follow up period of 54.43 ± 6.24 months were assessed based on electronic documentations f rom 138 patients with 266 implants. All p-ISFDP utilized CAD/CAM titanium customized abutments, and were fabricated with cement-retained prostheses with occlusal screw access holes. Statistical analyses were performed to identify the risk factors of mechanical complications.Results: During the observation period (3 -5 years), implant survival rates were 100%. Major mechanical complications were 8 abutment fractures (3.01%), 8 screw loosenings (3.01%), 2 screw fractures (0.75%), 11 chipping or fractures of veneering materials (5.58%), 23 decementations of the superstructure (11.68%). The relationship between the incidence of mechanical complications and the possible factors were not statistically significant(p > .05). Conclusion:There is no significant difference between each mechanical complication and the risk factors. P-ISFDP fabricated with CAD/CAM titanium abutments is a clinically acceptable treatment.