RESUMO
PURPOSE: The present study evaluated the displacement and strain generated in an implant- supported fixed prosthesis under axial and non-axial loads using two methods. MATERIALS AND METHODS: Three implants were inserted in a resin block. The Digital Image Correlation (DIC) was used to measure displacement and strain generated on the surface of the resin blocks for the different load applications (500N, 1 image/second). A 3-dimensional model was constructed and a load of 500 N was applied at an axial point and a non-axial point through finite element analysis (FEA). RESULTS: Both methods gave similar trends for the strains, and both gave slightly higher strains with non-axial loading. FEA predicted higher strain magnitude (±11%) in comparison with DIC, but with the same mechanical behavior. According to ANOVA, the loading influenced the strain concentration. Higher strain was generated for non-axial loading around the implant nearest to the loading. CONCLUSIONS: For implant-retained cantilever fixed prosthesis, the same load applied in the lever arm induces higher strain in the cervical area of the last implant, which suggests more damaging potential than a load applied at the center of the prosthesis.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Fenômenos Biomecânicos , Planejamento de Prótese Dentária , Análise do Estresse Dentário , Análise de Elementos Finitos , Estresse MecânicoRESUMO
PURPOSE: This study evaluated the stress distribution in different cement-retained implant-supported prostheses with a hybrid abutment. MATERIALS AND METHODS: Two factors were evaluated: restorative material for the crown and hybrid abutment - zirconia, lithium disilicate and hybrid ceramic, yielding 9 combinations. For finite element analysis, a monolithic crown cemented on a hybrid abutment was modeled and cemented on a titanium base (Ti base). An oblique load (45°, 300 N) was applied to the fossa bottom and system fixation occurred on the bone's base. RESULTS: Each structure was evaluated separately to find the possible weaknesses in geometry and failure criteria. In this context, results demonstrated a significant decrease of maximum principal and von-Mises stresses concentration when crowns with high elastic modulus are cemented onto a hybrid abutment with lower elastic modulus. CONCLUSIONS: Considering this theoretical study for a Morse taper implant, the association of a rigid crown with a more resilient hybrid abutment reduces the tensile stress concentration in the restoration cervical region.