THE EFFECT OF COLOR DIFFERENCE OF ZIRCONIUM COPING ON THE FINAL COLOR OF ZIRCONIA RESTORATIONS

Aim: Closely shade matching of restoration with natural teeth is one of the most challenging clinical procedures in dentistry. The aim of the present study was to compare the effect of color difference of zirconium coping on the final color of zirconia restorations. Materials & Method: A total of 15 ceramic discs of 16 mm in diameter with minimum core/veneer thickness of three groups of ceramics, VITA In-Ceram YZ, IPS e.max ZirPress, and IPS e.max ZirCAD were selected for the study. The discs were then veneered with veneering porcelain. Shade matching was performed using Vita Easyshade and Gretag Macbeth spectrophotometers. The colorimetric parameters L*a*b* were analyzed using One-Way Analysis of Variance (ANOVA) and Tukey's test. The Delta E of the specimens was compared with the Delta E of 2M2 shade (control group). Results: The type of zirconia had a significant effect on the final color of zirconia restorations. The consistency of the Ivoclar Zirpress samples with the Delta E of 2M2 shade was within clinically acceptable limits (Delta E=2.8). The least AF for the shade-matching tabs was observed in VITA In-Ceram YZ (Delta E=5.8). Conclusion: The type of zirconia has a significant effect on the final color of zirconia restorations and the minimum thickness of a core/veneer (1mm) in Vita and Ivoclar blocs cannot produce a clinically acceptable match.