Effect of layer thickness, build angle, and viscosity on the mechanical properties and manufacturing trueness of denture base resin for digital light processing

To investigate effects of layer thickness, build angle, and viscosity on the mechanical properties and trueness of denture base resins used for digital light processing (DLP). Two denture base resins for DLP in different viscosity (high and low) were tested by using two manufacturing parameters:1) layer thickness (LT) (50- or 100-μm) and 2) build angle (BA) (0-, 45-, and 90-degree). disk- and bar-shaped specimens were used to evaluate hardness and flexural strength, respectively. Denture base specimens were used to examine trueness, and the deviation was calculated as the root mean square. Three-way analysis of variance (ANOVA) was conducted to determine the interaction among the three factors (viscosity, LT, and BA). Statistical significance was set at P < .05. Effects of LT and BA on hardness differed according to viscosity, with significant interactions among three factors (P=.027). Regardless of LT or BA, the low-viscosity group had higher hardness than the high-viscosity group (P