Influence of implants' inclination on the stress distribution of overdenture-retaining bar with vertical misfit

Abstract

During the surgical procedure of implants placement the concern about the implants' inclination is high, since in some cases the malposition of implants may contraindicate the utilization of determined overdentures retention system, like o'ring attachments. However, the implants' inclinations may also affect the biomechanics of other types of retention system, as the bar-clip system. In this way, the present study aims to evaluate stresses in an overdenture with a bar-clip retention system with: different implant inclinations (-10º, -5º, 0º, +5º, +10º); vertical misfit (10, 50, 100 µm); and bar materials (Au type IV, Ag-Pd, Ti commercialy pure, Co-Cr) through finite element analysis. The tridimensional study models will be made using a 3-D modeling software (SolidWorks 2010, USA) and exported to specific software for analysis (ANSYS Workbench 12, USA). A displacement will be applied to simulate the screw torque. All the analysis will be made in terms of Maximum Principal Stress and von Mises stress, in MPa. Results will be presented in a qualitative way through the figures with the stress distribution in different color gradients, and quantitatively by numerical reading in software of the stresses in certain regions of the models.