Comparative evaluation of qualitative and quantitative wear of 3D-printing materials and zirconia against primary tooth enamel: An in vitro study

Aim: This study aimed to address the gap in existing literature by evaluating the qualitative and quantitative wear of two three-dimensional (3D) printing materials against primary tooth enamel, in comparison with zirconia, a widely used esthetic crown material. Methods: Eighteen extracted primary canines were used as antagonists, and six blocks each of two 3D printing resins (Shining 3D and NextDent) and zirconia were fabricated. Wear testing was performed using a reciprocating tribometer under a 40 N load at 1.5 Hz with a 4 mm stroke length for 60,000 cycles. Pre- and post-test digital scans were analyzed in Geomagic Software using a superimposition technique to calculate volumetric wear, and surface changes were examined using scanning electron microscopy. Statistical analysis was conducted using one-way ANOVA for quantitative comparison. Results: Shining 3D demonstrated the greatest material wear (0.51 mm³), followed by NextDent (0.27 mm³), while zirconia exhibited the least (0.13 mm³). Conversely, zirconia caused the highest antagonist wear (0.25 mm³), followed by NextDent (0.17 mm³) and Shining 3D (0.12 mm³), although these differences were not statistically significant. Distinct wear patterns were observed for each material. Conclusions: Within the limitations of this in vitro study, NextDent exhibited greater wear resistance than Shining 3D. Both 3D-printing resins produced less antagonist enamel wear than zirconia, underscoring their potential as promising alternatives in pediatric restorative dentistry. Further studies employing diverse materials and standardized protocols are required to validate these findings and enhance clinical translation.