Análise da distribuição das tensões em restaurações cerâmicas sobre dente natural e implante por meio do método dos elementos finitos
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Data
2008-01-21
Autores
Freitas Júnior, Amilcar Chagas [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As restaurações cerâmicas têm proporcionado resultados satisfatórios estética e biomecanicamente. Porém, a comparação dos dados sobre a distribuição das tensões nos casos de diferentes restaurações suportadas por dente ou por implante é inconclusiva. O objetivo desse estudo foi avaliar, através da análise de elementos finitos bidimensional, a distribuição interna das tensões nos materiais e estruturas de suporte em função de duas possibilidades restauradoras em cerâmica (faceta laminada e coroa total) e dois tipos de suportes (dente natural e implante). Foram confeccionados 8 (oito) modelos (M) no programa AutoCad 2006, variando o tipo de suporte e restauração: MA (controle) – representação do incisivo central maxilar, hígido, seccionado sagitalmente; MB1, MB2 e MB3 – semelhantes ao MA, restaurados com faceta laminada pelo sistema IPS Empress, IPS Empress Esthetic e Laminado Procera, respectivamente; MC1 e MC2 – semelhantes ao MA, com coroa total pelo sistema IPS Empress 2 (MC1) e Procera AllCeram (MC2); MD1 e MD2 – porção coronária semelhante ao MC1 e MC2, respectivamente, com a presença de um implante osseointegrado (Sistema Bränemark - 4,3 X 15,0 mm) e pilar em zircônia. Para análise numérica (Ansys 10.0), os modelos foram carregados (C) sob duas condições (50N): C1 - 45º de inclinação com o longo eixo dental, no terço médio da face palatina; C2 – perpendicular à borda incisal. Adicionalmente, uma terceira condição foi adotada para o MA: C3 – 50N na borda incisal paralelo ao longo eixo dental. Foram obtidas a tensão equivalente de von Mises (σvM) e a máxima tensão principal em tensão (σmax.t) e compressão (σmax.c). Observou-se que C3 proporcionou a menor variação de svM no dente e estruturas de suporte quando comparada à C1 e C2.
The ceramics restorations have provided excellent aesthetic and biomechanical clinical results. However, the data about the stress distribution in tooth and implant-supported restorations are inconclusive. Using two-dimensional finite element analysis, the purpose of this study was to evaluate the stress distribution in the materials and support structures based on two ceramics restorative possibilities (laminate veneer and ceramic crown) and two support structures (tooth and implant). 8 models (M) were built in the program AutoCAD 2006, varying the restorations and their support structures: MA (control) – an intact maxillary central incisor in sagittal cut; MB1, MB2 and MB3 – similar to MA, with laminate veneers of IPS Empress, IPS Empress Esthetic and Procera veneer, respectively; MC1 and MC2 – similar to MA, with a full crown of IPS Empress 2 (MC1) and Procera AllCeram (MC2); MD1 and MD2 – coronary portion similar to MC, with an osseointegrated implant (Bränemark System - 4.3 X 15.0 mm) and zircon abutment. To the numerical analysis (Ansys 10.0), the following loadings (L) were performed (50N): L1 - on the medium third of the lingual face, in 45º with the dental long axis; L2 – perpendicular to the incisal edge; L3 – 50N in the incisal edge parallel to the tooth long axis (only for the natural tooth). The von Mises equivalent stress (σvM) and maximum principal stress in tension (σmax.t) and compression (σmax.c) were obtained. It was observed that L3 provided the smallest variation of σvM in the tooth and support structures in comparison with L1 and L2. The beam3 elements used for the periodontal ligament modeling showed an appropriate behavior for parallel loading. In the MB and MC, the ceramics increased the σvM in the adhesive interface, mainly for Procera. In the models with implant, the IPS Empress2 showed higher σvM than that for Procera AllCeram.
The ceramics restorations have provided excellent aesthetic and biomechanical clinical results. However, the data about the stress distribution in tooth and implant-supported restorations are inconclusive. Using two-dimensional finite element analysis, the purpose of this study was to evaluate the stress distribution in the materials and support structures based on two ceramics restorative possibilities (laminate veneer and ceramic crown) and two support structures (tooth and implant). 8 models (M) were built in the program AutoCAD 2006, varying the restorations and their support structures: MA (control) – an intact maxillary central incisor in sagittal cut; MB1, MB2 and MB3 – similar to MA, with laminate veneers of IPS Empress, IPS Empress Esthetic and Procera veneer, respectively; MC1 and MC2 – similar to MA, with a full crown of IPS Empress 2 (MC1) and Procera AllCeram (MC2); MD1 and MD2 – coronary portion similar to MC, with an osseointegrated implant (Bränemark System - 4.3 X 15.0 mm) and zircon abutment. To the numerical analysis (Ansys 10.0), the following loadings (L) were performed (50N): L1 - on the medium third of the lingual face, in 45º with the dental long axis; L2 – perpendicular to the incisal edge; L3 – 50N in the incisal edge parallel to the tooth long axis (only for the natural tooth). The von Mises equivalent stress (σvM) and maximum principal stress in tension (σmax.t) and compression (σmax.c) were obtained. It was observed that L3 provided the smallest variation of σvM in the tooth and support structures in comparison with L1 and L2. The beam3 elements used for the periodontal ligament modeling showed an appropriate behavior for parallel loading. In the MB and MC, the ceramics increased the σvM in the adhesive interface, mainly for Procera. In the models with implant, the IPS Empress2 showed higher σvM than that for Procera AllCeram.
Descrição
Palavras-chave
Ceramica, Cerâmica odontológica, Implantes dentarios endoosseos, Método dos elementos finitos, Prótese dentária, Biomimética, Análise de elemento finito, Biomimetics, Ceramics, Dental Implantation, Endosseous, Finite element analysis, Dental prosthesis
Como citar
FREITAS JÚNIOR, Amilcar Chagas. Análise da distribuição das tensões em restaurações cerâmicas sobre dente natural e implante por meio do método dos elementos finitos. 2008. 232 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araçatuba, 2008.