Three-dimensional finite element analysis of 3 shear bond test devices

Objective: the aim of this study was to compare three differents devices for shear test. The three-dimensional Finite Element Analysis (FEA) was carried out to determine qualitatively the stress distribution for the three device configurations. Methods: Three different devices were analyzed: GI - ISO 11405, GII - strip method and GIII - mechanical device developed in the Dentistry College (UNESP-SJC). Because of the knowledge of the loading and the fixing conditions of the structures, the most requested regions of the specimens were determined. The calculations of the stress distribution were performed with the NASTRAN (MSC Software) finite element program with a cylinder model (9 mm length X 4 mm diameter) simulating a metalceramic restoration. Results: Stress calculations using three-dimensional finite element analysis confirmed the presence of large stress concentration effects in GI followed by GII and with almost homogeneous stress distribution in GIII. Conclusion: the present study showed that the mechanical device developed in Dentistry College (UNESP-SJC) obtained better performance than the conventional method ISO 11405 and the strip. Because the geometry system was simplified with known testing and loading conditions, an exact solution for the analysis problem could be reached .