Avaliação da conversão da resina composta polimerizada com luz halógena e LED com espectometria do infravermelho
Data
2004-03-04
Autores
Sarabia Quiroz, Ana María [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O presente estudo avaliou a conversão da polimerização de resinas compostas expostas à luz halógena e LED. Foram realizados corpos de prova e divididos em 64 grupos experimentais, onde variaram o tipo de luz (halógena e LED) utilizada, tempo de exposição à luz (20 e 40 segundos), profundidade do corpo de prova (1,2,3,e 4mm) e tempo de avaliação após a irradiação (0, 24,48 e 168 horas após a irradiação), cada grupo tinha cinco repetições. Os corpos de resina foram cortados e armazenados em ambiente seco e escuro. Foram confeccionadas pastilhas com 5mg de KBr e 50æg de pó de resina e os picos de absorbância foram registrados com o espectrômetro de infravermelho (FTIR). Os valores de conversão foram determinados na proporção das áreas obtidas com Microcal Origin 6.0 de C=O (pico em 1720) / C=C (pico em 1638). Os resultados da conversão foram analisados estatisticamente com os testes de ANOVA e Tukey. Obtendo-se, os seguintes resultados: A luz Halógena dá melhores resultados de polimerização que o LED, 40 segundos de exposição a luz dá melhores resultados de conversão, independente do tipo de luz, a menor profundidade o valor de conversão é melhor as 168 horas, que as observadas as 24 e 0 horas. Concluindo-se, que a conversão de polimerização das resinas compostas está influenciada pela fonte de luz, tempo de exposição à luz, profundidade do corpo de prova e tempo de avaliação.
The purpose of this study was to determine the polymerization conversion of the resin-composites exposed to halogen light and LED. Five specimens were made for each of the 64 groups, varying type of light (halogen and LED), time of exposure (40 and 20 seconds) deepness of the specimen (1, 2, 3 and 4mm) and time of the evaluation (0, 24, 48 and 168 hours after light irradiation) .The specimens were stored in a dry and dark area and were pulverized into a fine powder with a mortar and a pestle. Fifty æg of powder were mixed with approximately 5mg of potassium bromide, and the absorbance peaks were recorded by FTIR. The value of conversion was determined from the ratio of areas obtained with Microcal Origin 6.0 of C=O (peak at 1720) /C=C (peak at 1638). The results were statistically analyzed with ANOVA and Tukey tests. The results observed were the following: i) halogen light gives better polymerization results than LED light, ii) 40 seconds to light exposure give s better results of conversion, iii) as less deepness , more is the conversion (with both types of light) , iv) With 168 hours of observation, the polymerization is better than with 0 or 24 hours of observation. Conclusion: polymerization conversion of the resin composites is influenced by the type of light, time of exposure to light, deepness of the specimen and time of observation.
The purpose of this study was to determine the polymerization conversion of the resin-composites exposed to halogen light and LED. Five specimens were made for each of the 64 groups, varying type of light (halogen and LED), time of exposure (40 and 20 seconds) deepness of the specimen (1, 2, 3 and 4mm) and time of the evaluation (0, 24, 48 and 168 hours after light irradiation) .The specimens were stored in a dry and dark area and were pulverized into a fine powder with a mortar and a pestle. Fifty æg of powder were mixed with approximately 5mg of potassium bromide, and the absorbance peaks were recorded by FTIR. The value of conversion was determined from the ratio of areas obtained with Microcal Origin 6.0 of C=O (peak at 1720) /C=C (peak at 1638). The results were statistically analyzed with ANOVA and Tukey tests. The results observed were the following: i) halogen light gives better polymerization results than LED light, ii) 40 seconds to light exposure give s better results of conversion, iii) as less deepness , more is the conversion (with both types of light) , iv) With 168 hours of observation, the polymerization is better than with 0 or 24 hours of observation. Conclusion: polymerization conversion of the resin composites is influenced by the type of light, time of exposure to light, deepness of the specimen and time of observation.
Descrição
Palavras-chave
Resinas compostas, Espectroscopia infravermelho transformada de Fourier, Polimerização, Composite resins, Polymerization, Spectroscopy, Fourier transform infrared
Como citar
SARABIA QUIROZ, Ana María. Avaliação da conversão da resina composta polimerizada com luz halógena e LED com espectometria do infravermelho. 2004. 128 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, 2004.