Effect of build position on the accuracy and flexural properties of resin model materials for three-dimensional printing technologies

AIM: This study aimed to evaluate the effects of build position (rows or columns) on the accuracy and flexural properties of three-dimensional printing resin model materials. SETTINGS AND DESIGN: This was a comparative experimental study. MATERIALS AND METHODS: Three additive manufacturing technologies - digital light processing (DLP), stereolithography (SLA), and polymer jetting printing (PJP) - were employed to fabricate resin model specimens (2 mm × 2 mm × 25 mm), arranged evenly in 7 rows and 7 columns on the build platform. Dimensional trueness was assessed by measuring deviations in length (X-axis), width (Y-axis), and height (Z-axis) using a digital micrometer. Triplicate printing runs were performed to determine precision, quantified using intraclass correlation coefficient analysis. Flexural properties were evaluated through three-point bending tests. STATISTICAL ANALYSIS USED: Data were analyzed using one-way ANOVA followed by Tukey post hoc tests. RESULTS: The PJP group exhibited deviations in length (0.18-0.25 mm) and height (0.18-0.22 mm) at several column positions, exceeding 0.1 mm, whereas the DLP and SLA groups showed deviations in all dimensions within 0.1 mm. At different row positions, PJP length (0.20-0.24 mm) and height (0.17-0.22 mm) deviations also exceeded 0.1 mm. Precision in height was lower than in length or width across both rows and columns (P = 0.000). Compared with the DLP and PJP groups, the SLA group demonstrated larger deviations in flexural modulus at column positions (P = 0.003, H = 19.730) and greater variations (95% confidence interval) in flexural strength and modulus at column and row positions. CONCLUSION: Build position had a greater influence on trueness in the PJP group, while precision was lowest for height across all three groups. Furthermore, the flexural strength and modulus of the SLA group varied more significantly with build position. Thus, meticulous selection of the build position is essential to achieve improved accuracy and flexural properties in resin models.