Variations in the Shades of Contemporary Dental Ceramics: An In Vitro Analysis

Background: To identify and compare the shade variations of various commonly used esthetic dental ceramics by calculating their total-color-difference (& UDelta;E) and translucency parameter (TP) using a spectrophotometer. Methods: In total, 165 disc specimens from three shades (A1, B1, and C1) of five ceramic materials (N = 55/shade; n = 11/ceramic material group) were prepared (Metal-ceramic (MC), IPS e.max press (Emax-P), IPS e.max layer (Emax-L), Layered Zirconia (Zr-L) and Monolithic zirconia (Zr-M)). With a spectrophotometer, the L* a* b* values were obtained. Total color differences (& UDelta;E = [(& UDelta;L*)2 + (& UDelta;a*)2 + (& UDelta;b*)2](1/2)) and translucency parameter (TP = [(L*B - L*W)(2) + (a*B - a*W)(2) + (b*B - b*W)(2)](1/2)) were calculated. The statistical tests included ANOVA and Post hoc Tukey's analysis (p < 0.05). Results: Significant differences (p = 0.000) were found between the groups for & UDelta;E. Highest & UDelta;E (A1) were found for Zr-L (80.18 & PLUSMN; 20) and lowest for Zr-M (62.97 & PLUSMN; 1.28). For B1, highest & UDelta;E values were noted for MC (76.85 + 0.78) and lowest for the Emax-L (62.13 & PLUSMN; 1.49). For C1, highest & UDelta;E values were found for the MC group (73.96 & PLUSMN; 0 67) and lowest for Emax-P (55.09 & PLUSMN; 1.76). Translucency variations between tested ceramics were revealed (p < 0.05). Highest TP values (A1) were found for Emax-L (2.99 & PLUSMN; 1.64) and lowest for Zr-L (0.35 & PLUSMN; 0.16). For B1, highest TP values were noted for Emax-P (3.50 & PLUSMN; 1.74) and lowest for MC (0.57 & PLUSMN; 0.40). For C1, highest TP values were found for Emax-P (4.46 & PLUSMN; 2.42) and lowest for MC (0.58 & PLUSMN; 0 48). Conclusions: Significant differences in & UDelta;E and TP were found for tested ceramic groups. The color differences of the tested materials varied according to clinical acceptability, even with the selection of same color/shade. The color/shades of the various dental ceramics do not match with the vita shade guide tabs, to which they are compared most often. Shade differences are present between different lots of ceramic materials from the same or different brands.

Automated summary

By using a spectrophotometer to measure the color differences and translucency parameters of commonly used esthetic dental ceramics, significant variations in color differences and translucency were found among different ceramics, even with the same color/shade.