Comparison of color stability and wear resistance of different 3D printed definitive restorative resins

Subtractive manufacturing in computer-aided design and computer-aided manufacturing (CAD-CAM) systems has been extensively studied, but additive manufacturing materials, particularly those used for definitive restorations, are relatively new and data regarding their clinical performance remain limited.

This in vitro study aimed to evaluate the color stability of 3 different 3-dimensionally (3D) printed definitive restorative materials under 5 different Commission Internationale de l'Eclairage illuminants and to compare their metameric color differences. In addition, the mechanical wear resistance of these materials was evaluated independently.

A total of 135 specimens with thicknesses of 1.0, 1.5, and 2.0 mm were 3D printed according to the manufacturers' protocols. Color was evaluated before and after thermocycling under 5 illumination conditions (D65, D50, A, F11, F2). ΔE₀₀ values were analyzed using mixed-design analysis of variance (α=.05). Wear was evaluated in 2.0-mm specimens using simulated mastication and volumetric analysis, and the wear data were analyzed using the Kruskal-Wallis test (α=.05) RESULTS: All specimens exposed to illuminant A exhibited clinically unacceptable color changes, regardless of material type or thickness. Under illuminants D50, F11, and F2, color changes were perceptible but remained within clinically acceptable limits. Thermal aging significantly reduced ΔE₀₀ values (P=.001). Although wear was observed in all groups, no significant differences were found in volumetric loss (P=.139).

Illuminants significantly influenced color stability across all resin types and thicknesses, whereas increased restoration thickness was associated with reduced color change perceptibility. In addition, no significant differences in wear volume were found among the tested 3D printed definitive restorative materials.