Análise biomecânica de próteses implantossuportadas variando a conexão, o sistema de retenção, material restaurador, tipo e o nível do tecido ósseo. Estudo pelo método dos elementos finitos tridimensionais
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Data
2019-03-07
Autores
Lemos, Cleidiel Aparecido Araujo [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Este projeto teve como objetivo analisar as tensões geradas em próteses implantossuportadas fixa unitária variando o sistema de conexão implante/prótese, o sistema de retenção, material restaurador, tipo ósseo, e o nível de tecido ósseo ao redor do implante através do método dos elementos finitos tridimensionais, e realizar uma revisão sistemática com meta-análise sobre o tema osteoporose em relação a taxa de sobrevivência e perda óssea marginal ao redor dos implantes dentários. Em relação à metodologia experimental, foram simulados 24 modelos tridimensionais com ajuda dos programas de desenho assistido Rhinoceros 3D 4.0 (NURBS Modeling for Windows, USA) e SolidWorks 2011 (SolidWorks Corp, USA), e para confecção da porção óssea será utilizado o programa InVesalius (CTI, São Paulo, Brasil). Cada modelo representou uma secção de osso da região posterior maxilar, na forma de um bloco ósseo tipo IV (normal e osteoporótico), variando o nível de reabsorção do tecido ósseo (a nível do pescoço do implante; perda de 1,5 mm; perda de 3,0 mm; e perda de 4,5 mm) com a presença de um implante de 4,0 mm de diâmetro e 10 mm de comprimento com diferentes tipos de conexão (hexágono externo e cone morse), restaurado com coroas (metalocerâmicas e/ou metal free) com diferentes sistemas de retenção (cimentada e/ou parafusada). Os desenhos tridimensionais foram exportados ao programa de pré e pós processamento FEMAP v.11.2 (Siemens Product Lifecycle Management Software Inc. USA) para geração da malha e aplicação de uma carga de 200N axial e 100N oblíqua (45°) simulando um carregamento nas vertentes internas de cada cúspide da coroa. A análise foi realizada no programa de elementos finitos NEiNastran 11 (Noran Engineering, Inc., EUA) e os resultados serão visualizados através de mapas de tensão von Mises e deslocamento para avaliação das tensões sobre os implantes/componentes e tensão máxima principal, microdeformação e deslocamento para avaliação das tensões no tecido ósseo no tecido ósseo em cada modelo proposto no programa FEMAP v.11.2. Os resultados do capítulo 1, verificaram que a perda do tecido ósseo progressiva apresentou influência na distribuição das tensões na região do tecido ósseo, implantes e componentes. A qualidade do osso afetou apenas os valores de microdeformação, principalmente, no tecido ósseo trabeculado. Os implantes cone Morse apresentaram menores concentrações de tensões na região de tecido ósseo comparado aos implantes de hexágono externo, somente para os modelos sem perda óssea. Os implantes de hexágono externo apresentaram pior comportamento biomecânico nos implantes e parafuso de fixação, principalmente no carregamento oblíquo. Em relação ao capítulo 2 foi possível verificar que os implantes do tipo cone Morse apresentam melhor comportamento biomecânico na região de tecido ósseo cortical e parafuso de fixação em relação aos implantes de hexágono externo em relação as próteses fixas implantossuportadas parafusadas. As próteses cimentadas apresentam uma ligeira redução no tecido ósseo cortical, porém, com maior sobrecarga no parafuso de fixação dos implantes de hexágono externo. Os diferentes materiais restauradores não influenciam no comportamento biomecânico das estruturas. No capítulo 3 após a condução sistematizada das buscas, um total de cinco estudos foram incluídos para tabulação dos resultados. Após a realização da meta-análise foi observado que os implantes dentários devem ser considerados uma alternativa de tratamento viável para a reabilitação de pacientes com osteoporose, porém, cuidados clínicos são necessários aos profissionais para garantir a manutenção da estabilidade óssea periimplantar.
The aim of this thesis was to perform the analysis on the stress distribution for implant-supported fixed prostheses varying the implant-abutment connection system, the fixation system, restorative material, bone type, and the level of bone tissue around the dental implant using the finite element method. Furthermore, the aim was to perform a systematic review and meta-analysis about the effect of osteoporosis in terms of implants survival rate and marginal bone loss. In relation to the experimental methodology, 24 three-dimensional models were simulated with the aid of the Rhinoceros 3D 4.0 (NURBS Modeling for Windows, USA), SolidWorks 2011, and InVesalius (CTI, São Paulo, Brazil) softwares. Each model represented a bone section of the maxillary posterior area (bone type IV) (normal and osteoporotic), varying the level of bone resorption (at the level of the implant, loss of bone tissue in 1.5 mm, loss of bone tissue in 3.0 mm and loss of bone tissue in 4.5 mm). All models containing the presence of a dental implant with 4.0 mm in diameter and 10 mm in length with two different abutment-implant connection (external hexagon and Morse taper), restored with crowns (metaloceramic and/or monolithic) with different fixation system (cemented and/or screwed). The designs were exported to FEMAP v.11.2 pre-and postprocessing software (Siemens Product Lifecycle Management Software Inc. USA) for mesh generation and loading application of 200N axial and 100N oblique (45° in the long axis of implant, suppressing lingual cusps) in the slopes each cusp of the crown. The analysis was performed in the NEiNastran 11 (Noran Engineering, Inc., USA) and the results will be imported to FEMAP 11.2 through von Mises stress maps (implants and components) and maximum principal stress and microdeformation (bone tissue). The results of chapter 1 showed that the progressive loss of the bone tissue showed an influence on the stress distribution in the bone tissue, implants and components. The quality of the bone tissue (osteoporosis) affected only the microdeformation, mainly in the trabecular bone tissue. Morse taper implants showed lower stress concentrations in the bone tissue compared to external hexagon implants, only for models without bone loss. The external hexagon implants presented worse biomechanical behavior in the implants and screw fixation, especially in oblique loading. Regarding to chapter 2, it was possible to verify that Morse taper implants showed better biomechanical behavior area of cortical bone tissue and screw fixation compared to external hexagon implants for screwed prostheses. The cemented prostheses showed a slight reduction of stress in the cortical bone tissue; however, with greater stress in the fixation screw for the external hexagon implants. The type of restorative materials (metalceramic and/or monolithic) did not affect the biomechanical behavior of the structures. In chapter 3 after systematic review, a total of five studies were included for tabulation of the data. After performing the metaanalysis it was observed that dental implants should be considered as a viable treatment alternative for the rehabilitation of patients with osteoporosis; however, clinical care is necessary to guarantee the maintenance of peri-implant bone stability, due to high marginal bone loss was observed for patients with osteoporosis.
The aim of this thesis was to perform the analysis on the stress distribution for implant-supported fixed prostheses varying the implant-abutment connection system, the fixation system, restorative material, bone type, and the level of bone tissue around the dental implant using the finite element method. Furthermore, the aim was to perform a systematic review and meta-analysis about the effect of osteoporosis in terms of implants survival rate and marginal bone loss. In relation to the experimental methodology, 24 three-dimensional models were simulated with the aid of the Rhinoceros 3D 4.0 (NURBS Modeling for Windows, USA), SolidWorks 2011, and InVesalius (CTI, São Paulo, Brazil) softwares. Each model represented a bone section of the maxillary posterior area (bone type IV) (normal and osteoporotic), varying the level of bone resorption (at the level of the implant, loss of bone tissue in 1.5 mm, loss of bone tissue in 3.0 mm and loss of bone tissue in 4.5 mm). All models containing the presence of a dental implant with 4.0 mm in diameter and 10 mm in length with two different abutment-implant connection (external hexagon and Morse taper), restored with crowns (metaloceramic and/or monolithic) with different fixation system (cemented and/or screwed). The designs were exported to FEMAP v.11.2 pre-and postprocessing software (Siemens Product Lifecycle Management Software Inc. USA) for mesh generation and loading application of 200N axial and 100N oblique (45° in the long axis of implant, suppressing lingual cusps) in the slopes each cusp of the crown. The analysis was performed in the NEiNastran 11 (Noran Engineering, Inc., USA) and the results will be imported to FEMAP 11.2 through von Mises stress maps (implants and components) and maximum principal stress and microdeformation (bone tissue). The results of chapter 1 showed that the progressive loss of the bone tissue showed an influence on the stress distribution in the bone tissue, implants and components. The quality of the bone tissue (osteoporosis) affected only the microdeformation, mainly in the trabecular bone tissue. Morse taper implants showed lower stress concentrations in the bone tissue compared to external hexagon implants, only for models without bone loss. The external hexagon implants presented worse biomechanical behavior in the implants and screw fixation, especially in oblique loading. Regarding to chapter 2, it was possible to verify that Morse taper implants showed better biomechanical behavior area of cortical bone tissue and screw fixation compared to external hexagon implants for screwed prostheses. The cemented prostheses showed a slight reduction of stress in the cortical bone tissue; however, with greater stress in the fixation screw for the external hexagon implants. The type of restorative materials (metalceramic and/or monolithic) did not affect the biomechanical behavior of the structures. In chapter 3 after systematic review, a total of five studies were included for tabulation of the data. After performing the metaanalysis it was observed that dental implants should be considered as a viable treatment alternative for the rehabilitation of patients with osteoporosis; however, clinical care is necessary to guarantee the maintenance of peri-implant bone stability, due to high marginal bone loss was observed for patients with osteoporosis.
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Palavras-chave
Prótese dentária, Implantes dentários, Análise de elementos finitos, Revisão, Dental prosthesis, Dental implants, Finite element analysis, Review