Wear resistance of 3D printed denture teeth: Influence of printing technology and build orientation

Computer-aided design and computer-aided manufacturing (CAD-CAM) technologies, including additive manufacturing (3-dimensional printing), have been increasingly applied in dentistry. Assessments of the wear resistance and optimized parameters of 3-dimensionally (3D) printed denture teeth are lacking.

The purpose of this in vitro study was to compare the wear resistance of denture teeth fabricated using stereolithography (SLA) and digital light processing (DLP) at 0-, 45-, and 90-degree build orientations with prefabricated acrylic resin denture teeth.

Rectangular cuboid specimens (n=10 per subgroup) were fabricated using SLA and DLP in 3 build orientations (0-, 45-, and 90-degree). A separate control group of prefabricated acrylic resin teeth, which had no orientation levels, served as an independent comparator. After thermocycling, all specimens underwent 2-body wear testing against zirconia antagonists for 120 000 cycles. Wear depth and volume loss were quantified with a contact profilometer, and scanning electron microscopy (SEM) was used for surface morphology analysis. Statistical analysis of technology and orientations was performed using 2-way ANOVA. For overall comparison including the control, a separate 1-way ANOVA with Tukey post hoc tests (α=.05) was conducted.

No significant interaction between printing technology and orientation was found for wear volume loss (P=.179) or wear depth (P=.494). Printing technology significantly influenced wear depth and volume loss (P<.001); orientation had an effect on volume loss (P=.049) but not on wear depth (P=.611). Post hoc analysis showed DLP groups had lower wear than SLA and control. The control group exhibited intermediate wear resistance. The SEM images showed that DLP surfaces had narrow scratches with occasional cracking, SLA surfaces had smoother wear with shallow plowing, and the control group showed rougher textures with more pronounced cracks.

Printing technology significantly affected wear resistance, with DLP outperforming SLA. Orientation had minimal effect. Filler-containing 3D printed resins may enhance wear resistance.