Analise fotoelastica da tensão de contração ocorrida na polimerização de compositos resinosos
Karla Mychellyne Costa Oliveira
DISSERTAÇÃO
Português
T/UNICAMP OL4a
[Photoelastic analysis of polymerization shrinkage stress in resin composites]
Piracicaba, SP : [s.n.], 2009.
117p. : il.
Orientador: Simonides Consani
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Resumo: O objetivo deste trabalho foi comparar a tensão de contração de polimerização gerada por compósitos resinosos em diferentes tempos após a fotoativação, por meio de análise fotoelástica. Três compósitos experimentais com diferentes tipos de fotoiniciadores, e dois compósitos comerciais, sendo...
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Resumo: O objetivo deste trabalho foi comparar a tensão de contração de polimerização gerada por compósitos resinosos em diferentes tempos após a fotoativação, por meio de análise fotoelástica. Três compósitos experimentais com diferentes tipos de fotoiniciadores, e dois compósitos comerciais, sendo um à base de monômeros metacrilatos e o outro à base de siloranos foram comparados. Compósitos experimentais foram fabricados com 40% em massa de matriz orgânica e 60% de partículas de carga inorgânica, canforoquinona (CQ) ou fenil propanodiona (PPD) foram adicionados como sistemas fotoiniciadores. Discos deresina fotoelástica (base: Araldite GY 279/ endurecedor: Aradur 2963) foram confeccionados com perfurações de 6mm de diâmetro e 2mm de espessura no centro de cada disco. A superfície interna da resina fotoelástica foi condicionada com agente adesivo. Os compósitos foram separados em 5 grupos, sendo que os grupos 1 e 2 representaram os compósitos comerciais Filtek Silorane e Filtek Z250, respectivamente. Enquanto que os grupos 3, 4 e 5 constituíam os compósitos experimentais com os sistemas iniciadores CQ/Amina, CQ/PPD/Amina e PPD/Amina, respectivamente. O compósito foi inserido em incremento único no preparo da resina fotoelástica e fotoativado com luz LED (LED Ultralume 5) por 60s. As tensões geradas pelos compósitos foram avaliadas logo após a fotoativação, em 24 horas e 7 dias, por meio de análise fotoelástica com polariscópio plano, diretamente sobre luz branca ou com filtro vermelho resultando em imagens coloridas e monocromáticas, respectivamente. A análise qualitativa das imagens fotoelásticas revelaram que o grupo 1 apresentou a menor tensão de contração de polimerização em todos os tempos avaliados. Comparando os grupos das resinas experimentais, notou-se que o grupo 3 gerou maior tensão na resina fotoelástica em relação aos grupos 4 e 5 imediatamente após a fotoativação. Porém, 24 horas e 7 dias após a fotoativação as tensões geradas se equipararam para os grupos das resinas experimentais. A análise quantitativa realizada com avaliação das imagens monocromáticas mostrou que a tensão gerada pelo compósito Filtek Silorane foi similar à do compósito Filtek Z250 imediatamente após a fotoativação; porém, em 24 horas e 7dias o Filtek Z250 apresentou maiores tensões quando comparado ao Filtek Silorane. Os compósitos experimentais não apresentaram diferença estatisticamente significativa entre eles em nenhum dos tempos avaliados. Em geral, as tensões geradas aumentaram com o passar do tempo. Concluiu-se que o PPD não foi efetivo para minimizar as tensões geradas durante o processo de polimerização dos compósitos. Compósitos à base de silorano apresentaram os menores valores de tensão de contração de polimerização.
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Abstract: The aim of this study was to compare polymerization shrinkage stresses of dental composites in different moments after light-activation. Three experimental composites with different photoinitiator systems, and two commercial composites, one methacrilate based and the other silorane based...
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Abstract: The aim of this study was to compare polymerization shrinkage stresses of dental composites in different moments after light-activation. Three experimental composites with different photoinitiator systems, and two commercial composites, one methacrilate based and the other silorane based were compared. Experimental composites were fabricated with 40% of organic matrix and 60% of inorganic filler, canforoquinone (CQ) or phenyl propanodione (PPD) were added to the resin as photoinitiator systems. Discs of the photoelastic resin (Araltide GY279/Aralur 2963) were prepared with cylindrical cavities (6mm diameter, 2mm thick) in the center of each disc. Internal surfaces of the photoelastic resin were roughened and prepared with adhesive system application. The composites were
divided into five groups: groups 1 and 2 represented commercial composites Filtek Silorane and Filtek Z250, respectively; groups 3, 4 and 5 represented experimental composites with CQ/Amine, CQ/PPD/Amine and PPD/Amine as initiator system, respectively. A bulk increment of the composite was inserted into the cavity of photoelastic resin and photo-polymerized with a LED light-cure unit (LED Ultralume 5) for 60s. The stresses created by polymerization shrinkage were analyzed immediately after photopolymerization, in 24 hours and 7 days, by photoelastic analysis with a plane polariscope, with white light, with or without a red filter resulting in color and black and white images, respectively. Qualitative analysis of photoelastic images showed that group 1 had the lowest polymerization shrinkage stress in all times evaluated. Comparing experimental composites, it was observed that group 3 created more stress in photoelastic resin than groups 4 and 5 immediately after light-activation. However, 24 hours and 7 days after photopolymerization the stresses had equalized in resin experimental groups. Quantitative analysis showed that shrinkage strain of Filtek Silorane was similar to that of Filtek Z250 immediately after photopolymerization. In 24 hours and 7 days, the Filtek Z250 showed higher strain than Filtek Silorane. Experimental composites didn't differ statistically between each other in all times evaluated. Generally, the tension increased with the time. It was concluded that PPD wasn't capable of decrease the stresses created during polymerization process of composites. Silorane based composites had the lowest stresses during polymerization shrinkage process. Ver menos
divided into five groups: groups 1 and 2 represented commercial composites Filtek Silorane and Filtek Z250, respectively; groups 3, 4 and 5 represented experimental composites with CQ/Amine, CQ/PPD/Amine and PPD/Amine as initiator system, respectively. A bulk increment of the composite was inserted into the cavity of photoelastic resin and photo-polymerized with a LED light-cure unit (LED Ultralume 5) for 60s. The stresses created by polymerization shrinkage were analyzed immediately after photopolymerization, in 24 hours and 7 days, by photoelastic analysis with a plane polariscope, with white light, with or without a red filter resulting in color and black and white images, respectively. Qualitative analysis of photoelastic images showed that group 1 had the lowest polymerization shrinkage stress in all times evaluated. Comparing experimental composites, it was observed that group 3 created more stress in photoelastic resin than groups 4 and 5 immediately after light-activation. However, 24 hours and 7 days after photopolymerization the stresses had equalized in resin experimental groups. Quantitative analysis showed that shrinkage strain of Filtek Silorane was similar to that of Filtek Z250 immediately after photopolymerization. In 24 hours and 7 days, the Filtek Z250 showed higher strain than Filtek Silorane. Experimental composites didn't differ statistically between each other in all times evaluated. Generally, the tension increased with the time. It was concluded that PPD wasn't capable of decrease the stresses created during polymerization process of composites. Silorane based composites had the lowest stresses during polymerization shrinkage process. Ver menos
Analise fotoelastica da tensão de contração ocorrida na polimerização de compositos resinosos
Karla Mychellyne Costa Oliveira
Analise fotoelastica da tensão de contração ocorrida na polimerização de compositos resinosos
Karla Mychellyne Costa Oliveira
Exemplares
Nº de exemplares: 1
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