Efeito da orientação de impressão nas propriedades físicas de resinas impressas 3D utilizadas para base de próteses totais

Abstract

The use of 3D printing in the fabrication of complete dentures is relevant as it minimizes laboratory steps, thereby reducing variables inherent to the conventional process and associated fabrication errors. This study aimed to evaluate the physical properties of four brands of 3D-printed denture base resins (Cosmos Denture [CD], SmartPrint [SP], PriZma 3D Bio Denture [PZB], PrintaX BB Base [PXBB]) at different printing orientation angles (0°, 45°, and 90°), compared to a control group (CG) using heat-polymerized resins. A total of 130 circular specimens were fabricated (n=10), including 120 printed and 10 conventional, with dimensions of 10 mm in diameter and 3 mm in thickness. Color analysis was performed using a benchtop spectrophotometer. Surface roughness was measured with a profilometer to obtain Ra values. Hydrophilicity was assessed using the sessile drop method with a goniometer. Additionally, sorption and solubility analyses were conducted using a desiccator and drying oven. All samples underwent thermocycling for 10,000 cycles to evaluate the influence of thermal aging on the materials. Data were subjected to normality testing. For color, hydrophilicity, and sorption parameters, parametric analysis of variance (ANOVA) followed by Tukey's post hoc test was applied. Non-parametric data for roughness and solubility were analyzed using the Kruskal–Wallis test. The different resins did not significantly affect surface roughness (P=0.576) or hydrophilicity (P=0.217); however, significant differences were found for color (P<0.001), sorption (P<0.001), and solubility (P=0.003). GC and PXBB resins showed greater color change compared to CD, SP, and PZB resins (P<0.001), with no significant differences among the latter (P=0.141). CD resins showed lower sorption and solubility values compared to GC, while GC presented results similar to the other printed resins. Printing orientation did not influence color change (P=0.356), surface roughness (P=0.565), hydrophilicity (P=0.567), sorption (P=0.152), or solubility (P=0.820). Thermocycling significantly increased surface roughness and decreased hydrophilicity of the 3D-printed resins (P<0.001). Therefore, it can be concluded that 3D-printed resins exhibit physical properties comparable to conventional heatpolymerized resins and are not affected by printing orientation. Thermocycling can influence surface roughness and hydrophilicity of the evaluated resins.