Avaliação da biomecânica óssea de implantes com diferentes estruturas protéticas na reabilitação de mandíbula atrófica por análise de elementos finitos

Abstract

Successful results of dental implant treatment are associated with the transfer of stress to the peri-implant bone. The materials used in the prosthesis play an important role in distributing loads to implants and bone. The present work aimed to evaluate the effect of the material used to make an implant-supported prosthesis on the distribution of tension in the implants and bone tissue in an atrophic mandible. Virtual models of the jaw, implants and prosthetic components were modeled from existing data. Two models were created with 4 implants inserted in the region between the mental foramina in parallel. The metalloplastic model consisted of a prosthesis with a nickel-chromium support bar and acrylic resin for the teeth. The zirconia model was a single prosthetic piece in monolithic zirconia. Each model was simulated to evaluate the stress distributions in the implants and bone using the finite element method (FEM), using a load of 150 N applied to each tooth (premolars and molars). The principal stresses in bone and resin, and von Mises equivalent stresses for zirconia, implants, support bars and components were evaluated. The metalloplastic model presented greater stresses distributed to the implants and prosthetic system, and cortical bone. Greater compressive stress was observed in the zirconia model in the medullary bone. The variation in the prosthesis material caused different biomechanical behaviors. Biomechanically, zirconia proved to be a suitable material for the manufacture of prostheses for the rehabilitation of atrophic jaws.