Estudo da dureza e do grau de conversão de resinas compostas: efeito de fonte de luz e material
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Data
2010-03-23
Autores
Ribeiro, Benícia Carolina Iaskieviscz [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A evolução dos materiais odontológicos, a interação de resinas compostas e aparelhos fotopolimerizadores motivaram a realização deste estudo. Foram selecionadas quatro resinas compostas fotopolimerizáveis indicadas para restaurações diretas, sendo três microhíbridas: Vit-l-escenceTM (Ultradent®), Amelogen® Plus (Ultradent®) e Opallis (FGM) e outra de nanopartículas: FiltekTM Z350 (3M ESPE Dental Products), todas indicadas para dentina e na cor A2. Construiram-se corpos-de-prova com dimensões de 4 mm de diâmetro e 2 mm de profundidade (ISO 4049), os quais foram polimerizados por diferentes aparelhos fotoativadores. Para o primeiro estudo, utilizou-se o Led Ultra Lume Led 2 (Ultradent®) e uma luz halógena (Ultralux - Dabi Atlante), esta com diferentes ponteiras condutoras de luz. Decorridas 24 horas, os corpos-de-prova foram submetidos ao ensaio de dureza utilizando-se um aparelho MMTT-3 Microhardness Tester (Buehler Lake Bluff, Illinois USA), com o qual foram realizadas quatro aferições na superfície do topo da amostra (dureza 1) e mais quatro na superfície de base (dureza 2) oposta à fonte de luz. Para o segundo estudo, novos corpos-de-prova foram confeccionados da mesma maneira, utilizando-se a luz halógena (Ultralux Dabi Atlante) com ponteira de vidro, um LED de terceira geração (Ultra Lume Led 5 Ultradent®) e dois leds de segunda geração: Radii-Cal (SDI) e Elipar Free LightTM 2 da 3M ESPETM. Os corpos-deprova foram submetidos ao mesmo teste, em dois tempos: imediato e após 24 horas. Para a terceira pesquisa, pela qual se avaliou o grau de conversão por FT-IR, empregando-se o espectrofotômetro Nexus FT- IR, confeccionou-se do mesmo modo outros corpos-de-prova e, decorridas 24 horas, estes foram triturados e misturados com KBr para a obtenção de pastilhas. Como parâmetro, confeccionou-se mais 20 pastilhas com resinas não curadas...
Our study was motivated by the evolution of dental materials, and the interaction between composite resin and light curing units. We selected four light-curing composite resins suitable for direct restorations, in shade A2, three microhybrid (Vit-l-escenceTM - Ultradent®) (Amelogen® Plus - Ultradent ®) (Opallis - FGM) and one nanoparticles (FiltekTM Z350 - 3M ESPE Dental Products), all indicated for dentin. All specimens were built with dimensions of 4mm diameter and 2mm deep, (ISO 4049) which were irradiated by different light-curing units. For the first study, we used the Led Ultra Lume Led 2 (Ultradent®), and a halogen light (Ultralux - Dabi Atlante) with the last having different conductive tips of light. At 24 hours, samples were tested in microhardness through the device MMTT-3 Microhardness Tester (Buehler Lake Bluff, Illinois USA) where 4 measurements were performed in the top surface (hardness 1) and 4 more in the base area (hardness 2), opposite to the source of light. For the second study, new specimens were prepared in the same way, using the Light Halogen (Ultralux Dabi Atlante) with a glass pipette, a third-generation led (Ultra Lume Led 5 Ultradent®) and two second-generation LEDs: Radii-Cal (SDI) and Elipar Free LigthTM 2 (3M ESPETM). The samples were subjected to the same test in two stages: immediate and after 24 hours. For the third study, which evaluated the degree of conversion by FT-IR, using the spectrophotometer Nexus FT-IR, samples were built in the same manner and after 24 hours they were powdered and mixed with KBr, to obtain tablets. As a parameter, 20 more tablets were prepared with uncured resin. Data were collected and subjected to statistical analysis. In the first study, it was concluded that the led device (second generation) allowed polymerization and the resulting hardness values were equivalent to the halogen unit for three of the four... (Complete abstract click electronic access below)
Our study was motivated by the evolution of dental materials, and the interaction between composite resin and light curing units. We selected four light-curing composite resins suitable for direct restorations, in shade A2, three microhybrid (Vit-l-escenceTM - Ultradent®) (Amelogen® Plus - Ultradent ®) (Opallis - FGM) and one nanoparticles (FiltekTM Z350 - 3M ESPE Dental Products), all indicated for dentin. All specimens were built with dimensions of 4mm diameter and 2mm deep, (ISO 4049) which were irradiated by different light-curing units. For the first study, we used the Led Ultra Lume Led 2 (Ultradent®), and a halogen light (Ultralux - Dabi Atlante) with the last having different conductive tips of light. At 24 hours, samples were tested in microhardness through the device MMTT-3 Microhardness Tester (Buehler Lake Bluff, Illinois USA) where 4 measurements were performed in the top surface (hardness 1) and 4 more in the base area (hardness 2), opposite to the source of light. For the second study, new specimens were prepared in the same way, using the Light Halogen (Ultralux Dabi Atlante) with a glass pipette, a third-generation led (Ultra Lume Led 5 Ultradent®) and two second-generation LEDs: Radii-Cal (SDI) and Elipar Free LigthTM 2 (3M ESPETM). The samples were subjected to the same test in two stages: immediate and after 24 hours. For the third study, which evaluated the degree of conversion by FT-IR, using the spectrophotometer Nexus FT-IR, samples were built in the same manner and after 24 hours they were powdered and mixed with KBr, to obtain tablets. As a parameter, 20 more tablets were prepared with uncured resin. Data were collected and subjected to statistical analysis. In the first study, it was concluded that the led device (second generation) allowed polymerization and the resulting hardness values were equivalent to the halogen unit for three of the four... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Nanotecnologia, Análise espectral, Luz, Resinas compostas, Dureza, Composite resins, Nanotechnology, Spectrum analysis, Hardness, Light
Como citar
RIBEIRO, Benícia Carolina Iaskieviscz. Estudo da dureza e do grau de conversão de resinas compostas: efeito de fonte de luz e material. 2010. 223 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, 2010.