Avaliação de propriedades físicas de uma resina composta fotopolimerizada com diferentes fotopolimerizadores do tipo led utilizados na clínica da faculdade de Odontologia da UFC-Sobral

Abstract

The aim of the present study was to evaluate the effectiveness of light curing of LEDs used in the clinic of the Faculty of Dentistry of UFC Sobral when compared to a third generation LED, on the physical properties of a nanoparticulate composite resin commonly used in this University. Three LED-type light curing units were evaluated: two of the second generation, one wireless (F1) and one wired (F2), and one third generation (F3) used as a standard control. The irradiation of the three different devices was measured at three moments. Samples were made using nanoparticulate composite resin (Z350 XT 3M/ESPE) in color A1B. For the three-point bending test and modulus of elasticity, resin bars (n=10) with dimensions of 2mm X 2mm X 12mm were made. Specimens with 2mm thick and 5mm in diameter were prepared for the Knoop microhardness test (n=8). Results were analyzed to one-way ANOVA and Tukey's post-test. In relation to irradiance, F3>F2>F1 (p<0.001). There was no statistically significant difference in relation to the elastic modulus (p=0.56) neither microhardness (p=0.35) in the comparison between the groups. As for the miniflexural strength, F3 did not present a significant difference when compared to F1 (p=0.88) and F2 (p=0.13). However, F2 showed greater flexural strength than F1 (p=0.04). The light curing units studied showed an adequate irradiance value to perform the light curing of the composite resin used, and there were no statistical differences between the second generation light curing units in relation to the third generation for any of the tests evaluated.