Fatigue resistance and failure mode of CAD/CAM composite resin implant abutments restored with type III composite resin and porcelain veneers.

摘要

OBJECTIVES: This study assessed the fatigue resistance and failure mode of type III porcelain and composite resin veneers bonded to custom composite resin implant abutments. MATERIAL AND METHODS: Using the CEREC 3 machine, 28 composite resin implant abutments (Paradigm MZ100) were fabricated along with non-retentive type III veneers, milled either in ceramic Paradigm C (n=14) or in composite resin Paradigm MZ100 (n=14). The intaglio surfaces of the veneers were hydrofluoric acid etched and silanated (Paradigm C) or airborne-particle abraded and silanated (MZ100). The fitting surface of the abutments was airborne-particle abraded, cleaned, silanated and inserted into a bone level implant (10 mm, BLI RC). All veneers were luted with adhesive resin (Optibond FL) and a preheated light curing composite resin (Filtek Z100). Cyclic isometric chewing (5 Hz, 30 degrees angle) was simulated, starting with a load of 40 N, followed by stages of 80, 120, 160, 200, 240 and 280 N (20,000 cycles each). Samples were loaded until fracture or to a maximum of 140,000 cycles. Groups were compared using the life table survival analysis (Log rank test at P=0.05). Previously published data using same-design zirconia abutments were included for comparison. RESULTS: Paradigm C and MZ100 specimens fractured at an average load of 243 and 206 N (survival rate of 21% and 0%), respectively, with a significant difference in survival probability (P=0.02). Fractured specimens presented mixed failure modes and solely adhesive failures were not observed. The survival of composite resin abutments was similar to that of identical zirconia abutments from a previous study (P=0.76). CONCLUSIONS: Non-retentive porcelain veneers bonded to custom composite resin implant abutments presented a higher survival rate when compared with composite resin veneers. Survival of composite resin abutment did not differ from zirconia ones.