Color Masking of 3D Printed Resins and One Feldspathic Ceramic

Objectives: This study aimed to investigate the color differences (ΔE) of 3D printed resin crowns and feldspathic ceramic across various fabrication stages, comparing their values over black and white preparations.
Methods: Two 3D printed crowns (Formlabs Permanent Crown and SprintRay Ceramic Crown) and a CAD-CAM feldspathic ceramic (VITA Triluxe Forte), a control group, were evaluated. A maxillary right central incisor from a typodont model was prepared and scanned. Forty specimens were fabricated for each group: Formlabs and SprintRay (n=20 per group) and fifteen for VITA Triluxe Forte (n=15). The crowns underwent color measurements (L*, a*, and b*) after each fabrication step using a spectrophotometer (Vita Easyshade V), and the ΔE values were calculated using the CIEDE2000 formula after each step (Milling/Printing, Polishing, Glazing, and Try-in cement) over black and white substrates. Statistical analysis was performed using one-way ANOVA and LSD post hoc tests (p < 0.05).
Results: ΔE value ranged from 0.5628 (Glazing vs.Try-in Cement, SprintRay Ceramic Crown, white) to 8.027 (Printed vs.Try-in cement, Formlabs Permanent Crown, black). ΔE values were highest when crowns were placed on black preparations. Formlabs Permanent Crown overall showed the highest ΔE values, indicating noticeable color differences, followed by SprintRay Ceramic Crown. VITA Triluxe Forte demonstrated the best color stability compared to both 3D printed crowns.
Conclusions: The study showed that the color stability of 3D printed crowns is affected by different fabrication steps. Formlabs Permanent Crown and SprintRay Ceramic Crown offer acceptable outcomes according to various fabrication steps, but VITA Triluxe Forte suggests more color stability and retention. The higher propensity to change colors, especially over darker backgrounds, highlights a limitation in the application of 3D printed crowns.