Efeito de líquidos modeladores na dureza, rugosidade e estabilidade de cor de resinas compostas: estudo in vitro

Abstract

Being used since the middle of the 20th century, composite resins have been studied and improved since then. In this context, modeling liquids began to be introduced in the market to facilitate using composites within the oral cavity. Thus, the present work aimed to evaluate, in vitro, the effect of modeling liquids on the hardness, roughness, and color stability of nanohybrid and nanoparticulate composite resins. For this purpose, 60 samples were made, 10 for each studied group, using a Z100™ resin and a Z350™ resin, which received FGM universal amber adhesive or BISCO® modeling liquid as a modeling agent. The samples were submitted to a color evaluation and microhardness and roughness tests, before and after immersion in coffee solution for seven days. The Shapiro-Wilk test was used to determine the homogeneity of the data. Based on the uniformity of the sample, it underwent the ANOVA test for roughness, initial/final hardness, and color change, followed by the Tukey post-test. The analysis of the difference between the initial and final hardness for each modeling liquid was evaluated using the paired T-test, and the significance level adopted was 5%. The results showed that the color stability of the resins, as well as the roughness, was not affected by the use of modeling liquids. On the other hand, the microhardness was strongly influenced, by the modeling liquid showing reduced values even before immersion in the coffee solution. However, further studies are needed to understand better the interaction of the modeling resin on the surface of the resins and the effect of an additional polishing step on the results found.