Influência de pilares angulados e ponto de aplicaçao de carga em proteses tipo protocolo branemark : análise de elemento finito não linear com modelo tridimensional

Abstract

The aim of this study was to analyse the use of angled abutments and the loading region on the stress generated at the implant-bone interface, the abutment screws and the prosthetic screws of a full-arch implant supported prosthesis. A nonlinear finite element analysis was performed on models simulating a mandibular fixed prosthesis supported by five implants, with the distal ones tilted 27 degrees distally. Applying a force of 100N, four situations were tested: region of loading on the second premolar using straight abutments on all implants (RP) and using angled abutments on the distal implants (AP); and applying the load on the first molar region with straight abutments (RM); and angled abutments on the distal implants (AM). The resulting Von Mises strains were evaluated by a qualitative method in the three regions of interest. The results showed that the utilization of angled abutments on the distal implants generated lower tensions on the periimplant bone, at the same time that they presented higher strains on the abutment and prosthetic screws. The tensions were always reduced when the load was applied on the second premolar region. Within the limitations of this study, it was possible to conclude the the used of angled abutments may increase the risk of biomechanical failures on a full-arch implant supported prosthesis, although its use may also result on lower strains in the bone interface. Also, that reduced cantilevers are more favorable because of the generation of lower stresses on the bone and the protsthetic components.