Effects of Substructure Color and Restoration Thickness on the Final Color of Ultra-Translucent Zirconia Ceramics

YILMAZ BİÇER E., BANKOĞLU GÜNGÖR M., AYDIN C.

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, 2026 (SCI-Expanded, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2026
  • Doi Number: 10.1111/jerd.70138
  • Journal Name: JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CINAHL, EMBASE, MEDLINE
  • Keywords: masking ability, restoration thickness, shade-gradient zirconia, substructure color
  • Gazi University Affiliated: Yes

Abstract

Objective: This in vitro study aimed to evaluate the effects of substructure color and restoration thickness on the final color of shade-gradient ultra-translucent zirconia ceramics. Material and Methods: A total of 180 flat-shaped ultra-translucent zirconia specimens (5Y-PSZ) with thicknesses of 0.4, 0.6, and 0.8 mm (n = 60) were fabricated and cemented onto composite substructures in six colors (A1, A2, B1, B2, C2, D2). Color parameters were measured before and after cementation, and color differences (Delta E-00) were calculated using the CIEDE2000 formula. The data were evaluated using the two-way repeated measures of ANOVA, Kruskal-Wallis, Tukey HSD, and Bonferroni tests (alpha = 0.05). Results: Substructure color and restoration thickness had significant effects on Delta E-00 (p < 0.001) after cementation, with values exceeding the acceptability threshold (1.8) in all groups. Before and after cementation, A2 remained below the acceptability threshold relative to target color A1 and B2 achieved acceptable color matching with increased thickness. Conclusions: Restoration thickness and substructure color significantly influenced the final color of shade-gradient zirconia ceramics. A2 provided better color matching, while B2 required a minimum thickness of 0.8 mm for acceptable results.