Efeito do envelhecimento por termociclagem nas propriedades de placas para bruxismo dos métodos convencionais, fresadas CAD/CAM e impresso 3D

Abstract

Clinical Statement: Digital technology has become a valuable ally in dentistry by reducing clinical time and simplifying techniques. However, scientific evidence regarding the surface properties and microbiological adhesion of occlusal splints fabricated using the CAD/CAM system over time remains limited. Objective: To analyze the surface properties and microbial adhesion of resins used in the fabrication of occlusal splints produced by conventional methods (heat-cured, self-cured, and mixed) and by CAD/CAM techniques (milled and 3D-printed). Materials and Methods: Fifty samples were fabricated with dimensions of 10 × 3 mm, according to ISO 20795-1 specifications, and divided according to the material used: heat-cured resin (n=10), self-cured resin, mixed, milled, and 3D-printed. The samples were evaluated at three aging intervals by thermocycling: T0 (start time), T1 ( 5.000 cycle) and T2 (10.000 cycle). The Shapiro–Wilk normality test and two-way ANOVA were applied with a significance level of p < 0.05, considering the factors of group and time. When significant differences were found, Tukey’s post hoc test was used (p<0.05). Results: Comparing times T2 and T0, the heat-cured, mixed, and milled resins showed no significant differences in surface roughness (p > 0.05). Regarding surface microhardness, the heat-cured resin was the only material that exhibited a significant decrease at T2 compared with T0. Conclusion: Heat-cured, mixed, and milled resins demonstrated smoother surface characteristics, while the heat-cured resin exhibited a gradual reduction in surface microhardness over time.