Effect of print orientation on the dimensional accuracy of three-dimensional-printed complete denture models: A comparative analysis of VAT photopolymerization and fused deposition modeling technologies

AIM: To evaluate the effect of print orientation (0°, 45°, and 90°) on the dimensional accuracy, precision, and production parameters of three-dimensional (3D) printed complete denture models fabricated using VAT photopolymerization and fused deposition modeling (FDM) technologies. SETTINGS AND DESIGN: An in-vitro experimental comparative study was conducted to analyze orientation-dependent variations in dimensional trueness and precision among denture models fabricated with two additive manufacturing systems. MATERIALS AND METHODS: A complete denture prosthesis STL file was fabricated in 60 samples using VAT photopolymerization and FDM technologies across three orientations (0°, 45°, and 90°). Printed models underwent postprocessing, followed by digital superimposition to evaluate trueness and precision. STATISTICAL ANALYSIS USED: Statistical analyses were performed using one-way ANOVA with post hoc Tukey's honestly significant difference tests and independent t-tests for intertechnology comparison. RESULTS: VAT prints demonstrated higher average accuracy (mean deviation: 0.1106 mm) but greater variability (standard deviation [SD] =0.2448 mm) than FDM (mean deviation: 0.0316 mm, SD = 0.1558 mm). Across both technologies, the 0° orientation showed the least deviation (VAT: 0.1106 mm and FDM: 0.0316 mm). ANOVA indicated no significant differences among orientations (P = 0.109), whereas t-tests revealed substantial differences between technologies (t = 16.46, P < 0.00001). FDM at 90° exhibited the lowest variability (SD = 0.1163 mm), suggesting a trend toward improved consistency, though this did not reach statistical significance. CONCLUSION: Print orientation influenced dimensional accuracy trends, but only technology type showed statistically significant differences. VAT photopolymerization is suitable for high-precision applications.