Effects of 3D printing systems and orientations on the accuracy of denture bases

This study evaluated the effects of two additive manufacturing technologies and three orientations on the accuracy of three-dimensional (3D)-printed complete dentures. Additionally, we examined whether resin differences affected the accuracy of the denture bases under varying printing systems and orientations.

We printed denture bases using digital light processing (DLP) and a liquid crystal display (LCD) in three orientations (0°, 45°, and 90°) with two photopolymer resins (n = 6). Intaglio surfaces were scanned to obtain experimental data. We evaluated trueness by superimposing experimental data onto master data, and assessed precision by pairing and superimposing two of the six datasets. Deviation was evaluated using root mean square (RMS) and color map data. Statistical analysis was conducted using the Kruskal-Wallis method and Mann-Whitney U test (α = 0.05).

The DLP printer achieved the highest trueness at an orientation of 90°, whereas the precision was minimally affected by the orientation or printing systems. DLP printers performed well with both recommended and non-recommended resins; however, LCD printers demonstrated better accuracy with the recommended resins. At 0° orientation, the trueness color map for both printers showed negative deviation patterns over the entire palatal surface. Across all manufacturing methods, the precision color maps indicated high reproducibility.

Printing system and orientation affect the trueness of 3D-printed dentures. DLP printers set at 90° demonstrated superior trueness for clinical applications. The accuracy was affected by resin, printer, and orientation.