Avaliação das propriedades térmicas, químicas e mecânica relacionando dente bovino e dente humano
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Data
2005
Autores
Dutra-Corrêa, Maristela [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Dentes bovinos são amplamente utilizados substituindo dentes humanos em pesquisas in vitro, para avaliar o comportamento dos materiais odontológicos. Utilizaram-se sessenta dentes bovinos e sessenta humanos. Esmalte e dentina foram avaliados individualmente em Análises Termodiferencial, Termogravimétrica e Condutividade Térmica. A Dissolução foi avaliada em diferentes tempos e concentrações de ácido. No teste de Desidratação os fragmentos foram colocados em estufa por tempos diferentes. Na Incorporação de Água, após a retirada dos fragmentos da estufa, foram resfriados e depois imersos em água destilada. Verificou-se o quanto o tecido incorporou de água em sua massa. A Penetrabilidade de Corante foi avaliada pela Espectroscopia de Fluorescência. Para avaliar a Microdureza Vickers os dentes foram incluídos em resina de poliéster e polidos até expor esmalte ou dentina. No termodiferencial as dentinas comportaram-se semelhantemente. O esmalte bovino absorveu mais energia, indicando mudanças estruturais e apresentando comportamento estável a partir de 450ºC, enquanto que o humano continuou instável. No Termogravimétrico a dentina humana foi duas vezes mais susceptível à perda de massa. Os esmaltes apresentaram Condutividades Térmicas semelhantes. A dentina humana foi mais condutora do que a bovina. Na Dissolução a perda de massa foi mais lenta no dente humano. Na Desidratação o esmalte bovino perdeu aproximadamente 25% e o humano perdeu 2,5%. No esmalte humano houve menor Penetrabilidade de Corante, porém semelhante nas dentinas. Assim, não se deve extrapolar resultados para dente humano em relação à incorporação de água, à penetrabilidade de corante, à dissolução e ao comportamento térmico.
Bovine teeth are widely required in substitution of human teeth in in vitro researches to evaluate the behavior of dental materials. Sixth human teeth and sixth bovine teeth were used. Enamel and dentin were individually evaluated under Differential Thermal Analysis, Thermogravimetry and Thermal Conductivity. The dissolution was evaluated for different periods of time and different concentrations of acid. In the dehydration test, the fragments were placed inside a stove for different periods of time. In sorption of water, after the fragments were removed from stove, cooled and immersed in distilled water. It was weighted how much water mass the tissues absorbed. The dyeing penetrability was evaluated under Fluorescence Spectroscopy. To evaluate Vickers Micro hardness, the teeth were placed in polyester resin and polished until enamel or dentin was exposed. In the Differential Thermal the dentin behaved similarly. The bovine enamel absorbed more energy, showing structural changes and reaching stability for temperatures up to 450ºC, while human teeth remained unstable. In the Thermogravimetry, the human dentin was two times more susceptible to mass loss. Both enamels presented similar thermal conductivity. Human dentin presented better conductivity than bovine. In the dissolution, mass loss was slower for human teeth. In the dehydration, bovine enamel lost approximately 25 % while human lost 2.5%. There was smaller dyeing penetrability for human enamel however similar in dentins. Therefore, the results for human teeth may not be extrapolated when related to water absorbing, dyeing penetrability, dissolution and thermal behavior.
Bovine teeth are widely required in substitution of human teeth in in vitro researches to evaluate the behavior of dental materials. Sixth human teeth and sixth bovine teeth were used. Enamel and dentin were individually evaluated under Differential Thermal Analysis, Thermogravimetry and Thermal Conductivity. The dissolution was evaluated for different periods of time and different concentrations of acid. In the dehydration test, the fragments were placed inside a stove for different periods of time. In sorption of water, after the fragments were removed from stove, cooled and immersed in distilled water. It was weighted how much water mass the tissues absorbed. The dyeing penetrability was evaluated under Fluorescence Spectroscopy. To evaluate Vickers Micro hardness, the teeth were placed in polyester resin and polished until enamel or dentin was exposed. In the Differential Thermal the dentin behaved similarly. The bovine enamel absorbed more energy, showing structural changes and reaching stability for temperatures up to 450ºC, while human teeth remained unstable. In the Thermogravimetry, the human dentin was two times more susceptible to mass loss. Both enamels presented similar thermal conductivity. Human dentin presented better conductivity than bovine. In the dissolution, mass loss was slower for human teeth. In the dehydration, bovine enamel lost approximately 25 % while human lost 2.5%. There was smaller dyeing penetrability for human enamel however similar in dentins. Therefore, the results for human teeth may not be extrapolated when related to water absorbing, dyeing penetrability, dissolution and thermal behavior.
Descrição
Palavras-chave
Materiais dentários, Esmalte dentário, Dentina
Como citar
DUTRA-CORRÊA, Maristela. Avaliação das propriedades térmicas, químicas e mecânica relacionando dente bovino e dente humano. 2005. 170 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de São José dos Campos, 2005.