Distribuição de tensões entre parafusos protéticos de implante cone morse e hexágono externo: análise de elementos finitos

Abstract

This three-dimensional finite element study observed the stress distribution characteristics of prosthetic screws on External Hexagon Implant (HE) and Morse Taper Implant (CM) with different preloads. Using two models for the study: MHE - HE implant model, and MCM -CM implant model, compounds by implant, abutment and abutment screw. In each model was evaluated two situations: preload value using the torque recommended by the manufacturer for the prosthetic screw (MHE1 and MCM1); and 10 Ncm above the recommended torque (MHE2 and MCM2). Finding the preload values respectively 243,18N, 229,71N, 324,24N and 344.57. The regions with the highest von Mises stress results were at the bottom of the initial two threads in contact of all models, however the maximum stress on MCM2 model were higher than the yield strength of abutment screw material. In conclusion, the use of torques above the recommended can cause plastic deformation in the threads of morse taper implant. Elevated torques are harmful to morse taper implant than to external hexagon implant.