Avaliação das propriedades físico-químicas de uma resina composta de alta opacidade fotopolimerizada com diferentes LEDs

Abstract

Photopolymerizable composite resins (RCFs) are among the most commonly used restorative materials in the dental field. Opaque RCFs are commonly used in posterior tooth restorations. This study evaluated the physicochemical properties of a high-opacity microhybrid composite resin in the shade DA3.5, polymerized with different LED-type devices. The groups were composed based on the LED photopolymerizers (FT) used, two second-generation devices, F1 (FT, Kondentech) and F2 (FT Radii-Cal), and one thirdgeneration device, F3 (FT Valo Cordless Grand). The irradiance measurement of the three devices was performed using a radiometer, obtaining the mean of three measurements. The physical properties of the restorative material were evaluated through analysis of the modulus of elasticity and flexural strength, using the three-point bending test, for which resin bars (n=10) were fabricated according to each experimental group. Additionally, a Knoop microhardness test was conducted, creating cylindrical specimens (n=8). Regarding the chemical properties, water sorption and solubility were assessed through disk-shaped specimens (n=8). The data were subjected to one-way analysis of variance (ANOVA) (p<0.05) and Tukey's post hoc test. All FTs exhibited irradiance values above 1000 mW/cm². Regarding the modulus of elasticity, there was no statistically significant difference among the evaluated groups. For the flexural strength tests, there was a statistical difference only between groups F2 and F1 (p=0.001). Concerning F1, there was no statistical difference either compared to F2 (p=0.17) or F3 (p=0.11). Regarding microhardness, a statistically significant difference was observed only between groups F3 and F1 (p=0.019). For water sorption (p=0.26) and solubility (p=0.414), there was no statistical difference among the groups. It is concluded that, for the high-opacity composite resin used in this study, the evaluated FTs presented adequate results within the assessed laboratory parameters, with statistically significant differences found only between second and third-generation devices in the flexural strength and microhardness tests.