Comparação da distribuição de tensão em três modelos de instalação de implantes em mandíbulas edêntulas através do método de elementos finitos

• Autor(a) principal: Pereira Filho, Júlio
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USC
• Texto Completo: http://localhost:8080/tede/handle/tede/62
• topic: ELEMENTOS FINITOS; IMPLANTES DENTAIS; MANDÍBULA; BIOMECÂNICA; FINITE ELEMENT; DENTAL IMPLANTS; MANDIBLE; BIOMECHANICS; CIENCIAS DA SAUDE::ODONTOLOGIA

Purpose: The appropriate distribution of stress to implants and it`s structures of support has been defined as one of the most essential requirements for the maintenance of the implants, since several studies have shown that oclusal overload can lead to peri-implant boné loss. The aim of this study was to compare the stress distribution of three models of installation of implants in edentulous jaws through a three-dimensional finite element study. Materials and method: The model of the mandible was obtained through that database of C.T.I. (São Paulo, Brazil), using software InVesalius (C.T.I., SP, Brazil) and models of prosthetic components and implants were provided by the company P.I. Brånemark Philosophy (São Paulo, Brazil). The models were mounted in software Biocad Rhinoceros V4.0 as follows: 1) Installation of four parallels implants with straight abutments; 2) Two central parallels implants and two distal implants inclined 15o, with the use of straight abutments; 3) Two central parallels implants and two distal implants inclined 45o, with the use of straight abutments in the central implants and 30o angled abutment in the distal implants. The models were prepared for finite element analysis in software FEMAP (Siemens PLM Software Inc., USA), it was applied a load of 150N over the entire bar and were processed in NeiNastran (Noran Engineering, Inc., USA). Results: The results observed in the models of mandible exhibited superior values for vertical and posterior translation in the bar for model 2, followed by the model 3, with the smaller values for model 1. When the jaw was observed, the models with tilted implant showed almost no displacement, while the model 1 showed a low translation distributed in the mandible. The evaluation of von Mises stress in the bar presented that the progressive angulation of the posterior implant and consequent reduction of the cantlever leads to a reduction in the stress over the bar, especially in the cantlever region. Moreover, the configuration 2 exhibited a different behavior from the other models, with tendency of sliding in the posterior direction. Conclusions: The results obtained showed that the higher von Mises stress concentrations in the bar were observed in the model 1, and the higher vertical and posterior translation was observed for the model 2. The model 3, with the least cantlever extension, showed the least von Mises stress in the bar, and the values of vertical and posterior translation intermediate between the values of model 1 and 2.