Efeito de tecnologias de impressão e protocolo de aquecimento nas propriedades físico-mecânicas de resinas impressas 3D para restaurações definitivas

Abstract

Three-dimensional (3D) printing has become widely adopted in the dental workflow. The printing technologies and heating used during printing and postpolymerization can affect the physicomechanical properties of 3D printed resins for definitive indirect restorations. The aim of this in vitro study was to evaluate the physicomechanical performance of 3D printed resins indicated for definitive indirect restorations influenced by different printing technologies and a heating protocol used during printing and postpolymerization. Two commercially available A2-shade 3D printed resins (Voxelprint, FGM; VarseoSmile, BEGO) were printed using digital light processing (DLP) or liquid crystal display (LCD) technologies, for both resins with manufacturer-specified parameters, either at room temperature (24 ±1°C) or with heating during printing (40 ±1°C) and postpolymerization (60 ±1°C). Flexural strength (FS, MPa), elastic modulus (E, GPa), Vickers hardness (VHN, HV), compressive strength (CS, MPa), ultimate tensile strength (UTS, MPa), surface roughness (Ra, μm) before and after simulated brushing, and radiopacity (mmAl) were measured. Scanning electron microscopy was used for topographic analysis before and after simulated brushing. Data were analyzed by 3-way ANOVA and Tukey test (α=.05). Significant differences were found for CS, UTS, FS, E, VHN, and radiopacity values (P<.001). Voxelprint exhibited superior FS, E, VHN, CS, and UTS properties compared to VarseoSmile, with greater gains after heating. Surface roughness was significantly higher after simulated brushing, with no significant difference between groups; however, Ra values remained clinically acceptable (≤0.2 μm). Printing technologies had no significant effect on the physicomechanical properties of the 3D printed resins. VarseoSmile did not meet the radiopacity criteria of ISO 4049.