3D-printed full-arch denture teeth: impact of printing orientation on the trueness and precision in vitro

BACKGROUND: 3D-printed dentures can be fabricated by bonding two separately printed units; a base and a full-arch denture teeth. The accuracy of 3D-printed resin can be influenced by print orientation. While previous studies explored the accuracy of denture bases, no studies evaluated the accuracy of printed denture teeth in a full-arch form or the accuracy when printed at different print orientations. Therefore, this in vitro study aimed to evaluate and compare the trueness and precision of 3D-printed full-arch denture teeth fabricated with different printing orientations. METHODS: A digitally designed full-arch denture teeth model was printed using two types of 3D-printed teeth resin (ASIGA DentaTOOTH and NextDent C&B MFH) at three printing orientations (0°, 45°, and 90°). The printed specimens were scanned and compared to the original CAD design to assess trueness. Precision was evaluated by superimposing scans of identical prints. Root mean square (RMS) values were calculated to quantify deviations. Statistical analysis was conducted using ANOVA and Tukeys' post hoc tests (α = 0.05). RESULTS: Trueness was significantly influenced by printing orientation (P < 0.05). Both resins showed the highest trueness at 0°, with significantly higher accuracy in ridge-lap and axial areas (P < 0.05). Precision remained relatively stable across orientations for NextDent; however, significantly higher precision was observed at 0° orientation for ASIGA resin (P < 0.05). CONCLUSION: Printing orientation and material type influenced the accuracy of 3D‑printed full‑arch denture teeth. The 0° orientation showed the lowest deviations, with trueness ranging from 51 to 92 μm and precision from 25 to 98 μm, depending on material and region. Higher deviations were observed at 45° and 90° (up to 171-299 μm for trueness and 201-217 μm for precision), yet all values remained within laboratory‑based acceptable ranges.