Three-dimensional Finite Element Stress Analysis of a Cuneiform-Geometry Implant

Purpose: The biomechanical behavior of an osseointegrated dental implant plays an important role in its functional longevity inside the bone. Studies of this aspect of dental implants by the finite element method are ongoing. In the present study, a cuneiform-geometry implant was considered with a 3- dimensional model that had a mesh that was finer than in the models commonly found in the literature. Materials and Methods: A mechanical model of an edentulous mandible was generated from computerized tomography, with the implant placed in the left first premolar region. A 100-N axial load was applied at the implant abutment, and the mandibular boundary conditions were modeled considering the real geometry of its muscle supporting system. The cortical and trabecular bone was assumed to be homogeneous, isotropic, and linearly elastic. Results: The stress analysis provided results that were used to plot global and detailed graphics of normal maximum (S1), minimum (S3), and von Mises stress fields. The results obtained were analyzed and compared qualitatively with the literature. Discussion: Quantitative comparisons were not performed because of basic differences between the model adopted here and those used by other authors. The stress distribution pattern for the studied geometry was similar to those found in the current literature, but insignificant apical stress concentration occurred. The stress concentration occurred at the neck of the implant, ie, in the cortical bone, which was similar to results for other implant shapes reported in the literature. Conclusion: The studied geometry showed a smooth stress pattern, with stress concentrated in the cervical region. The values, however, were within the range of values found in the cortical layer far from the implant, caused by the muscular action. No significant stress concentration was found in the apical area. (More than 50 references.)