earticle

영어

Purpose: This study aims to compare the internal and marginal accuracy of provisional crowns fabricated using the digital light processing (DLP) three-dimensional (3D) printing method, considering build directions of 0° and 90°, as well as layer thicknesses of 50 μm, 75 μm, and 100 μm. Methods: Provisional crowns were fabricated using a DLP 3D printer, and six experimental groups were created, each comprising 10 specimens. Provisional crowns were designed with computer-aided design software and printed using a liquid resin material. Internal and marginal accuracy were assessed using root mean square (RMS) values. Statistical analyses, including two-way ANOVA and Tukey HSD tests (α=0.05), were conducted to evaluate the effects of build direction and layer thickness on RMS values. Results: For the trueness of the internal surface, the lowest RMS value (31.56±4.47 μm) was observed at a 0° build direction with a layer thickness of 100 μm. At 90° with 100 μm, the RMS value was 64.72±4.96 μm (p<0.05). Marginal trueness at a 0° build direction with 75 μm showed the lowest value of 31.88±6.89 μm, while at 90° with 75 μm it was 85.40±22.45 μm (p<0.001). Differences between build direction and layer thickness combinations were confirmed for both internal and marginal trueness (p<0.001). Conclusion: The effects of build directions (0°, 90°) and layer thicknesses (50 μm, 75 μm, 100 μm) on the internal and marginal accuracy of printed crowns were analyzed, revealing a significant interaction in both internal and marginal trueness.