Influência de duas técnicas de ativação complementar de uma resina composta direta / indireta comparadas a uma resina composta laboratorial na resistência ao dobramento e microdureza Vickers

Abstract

The purpose of this study was to assess the influence of two additional activation techniques on the composite resin Filtek P-60®, comparing it with the laboratorial composite resin Artglass, by means of bending strength and Vickers microhardness tests. The study experimental groups were the following: Group I conventional photoactivation using the photoactivator Optlight Plus®; Group II following the conventional photoactivation, the additional activation in a dry heat oven, at 125±2°C, for 600 seconds was carried out; Group III - after conventional photoactivation, the additional light activation in a laboratorial unit UniXS® for 360 seconds was carried out; Group IV photoactivation in a laboratorial unit UniXS®, for 360 seconds. Groups I, II and III were prepared with Filtek P-60®, and group IV with Artglass. The bending strength tests followed the 1988 ISO 4049 criteria:, and the Vickers microhardness tests followed the criteria of the ASTM E-384: 1999. Following the photoactivation and additional activation procedures, the test bodies were kept in deionized water at 37±1°C for 24 hours, and then stored protected from light. After the statistical analysis of the results it can be concluded that: the additional activation of the composite resin Filtek P-60, in group II and in group III, has provided an increase of the flexural strength. The bending strength values of the composite resin Filtek P-60, in group I, were statistically the same of the bending strength values in group IV. The additional activation in group II and group III has also provided an increase of the Vickers microhardness. The Vickers microhardness values in group I were superior to the Vickers microhardness values in group IV. It can be suggested by the present study the use of the composite resin Filtek P-60® by the indirect technique, subjected to dry heat additional activation with adequate bending strength and Vickers microhardness proprieties. However, it is important to point out the need of other laboratorial tests, in addition to clinical evaluation studies for the indication of this new technique.