Estudo de fatores influentes na dureza superficial de um composito fotoativado

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Adequate resin composite polymerization is a crucial factor in obtaining optimal physical performance of these materials. Several variables can affect the amount of light energy received at the top and bottom surfaces of a resin composite increment, such as, distance of the light guide tip from the resin composite, power density, light energy mode, exposure duration, shade and opacity of the resin composite and increment thickness. Thus, the aim of this study composed of four manuscripts was to evaluate the influence: 1) of the resin composite thickness on top and bottom microhardness, in a clinical simulation when the light curing tip was 2, 4, 6 and 8mm distant from the resin composite top surface; 2) of the resin composite shade on top and bottom microhardness, in a clinical simulation when the light curing tip was 2, 4, and 8mm distant from the resin composite top surface; 3) of light curing modes and light curing time on top and bottom microhardness, in a clinical simulation when the light curing tip was 8mm distant from the resin composite top surface; 4) of light curing modes and resin composite sample thickness on top and bottom microhardness, in a clinical simulation when the light curing tip was 2, 4, and 8mm distant from the resin composite top surface. Based on the results, within the experimental limits of this study, it can be concluded that: 1) the top surface microhardness was a little affected by the experimental factors, and it was not an adequate parameter to show the polymerization effectiveness of the resin composite, mainly of the bottom surface. However, the bottom surface microhardness was substantially affected by the studied factors; 2) the distance between of the light guide tip and the resin composite top surface is a factor that must be carefully analyzed, because as higher was the distance, as lower was the microhardness of the resin composite bottom surface; 3) resin composite has the capacity of reducing the light energy penetration, and consequently, the polymerization effectiveness of the bottom surface of the sample, independent of the others factors studied; 4) when the distance between of the light guide tip and the resin composite top surface is superior to 4mm, it should increase the light curing time at least three times; use light resin composite shades, since they do not have any esthetic involvement; and use efficient light curing devices; 5) when the distance between of the light guide tip and the resin composite top surface is superior or equal to 2mm, it should use resin composite increments of 1mm thick.

ASSUNTO(S)

fotopolimeros dentisitica resinas compostas

ACESSO AO ARTIGO

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