Color and translucency of zirconia ceramics, human dentine and bovine dentine

Objectives: Evaluate color and translucency of both non-colored and colored zirconia ceramics and compare them with corresponding properties of human dentine. Methods: 0.5 mm thick samples of human (MSHD) and bovine (MSBD) dentine were obtained from 5 extracted human anterior maxillary teeth and 5 bovine incisors, respectively. The zirconia systems evaluated (0.5 mm samples) were: (1) IPS e.max (R) ZirCAD sintered samples: (a) regular (ZC1); (b) colored - coloring liquid CL2 (ZC2); (2) LAVA (TM) Zirconia sintered samples: (a) regular (LV1); (b) colored - coloring liquid FS3 (LV2). Translucency parameter (TP) and Delta E*(ab) and Delta E-00 color differences (with respect to the MSHD) were calculated. Spectral reflectance curves were compared using the VAF coefficient. Results: Reflectance spectral behaviour of MSBD and MSHD were similar (VAF = 99.3%). All zirconia samples showed higher spectral reflectance values than the MSHD. Lightness values obtained for all zirconia ceramics (especially LV) were higher than MSHD and MSBD. The range of color differences, with respect to MSHD, was 6.9-20.5 for Delta E*(ab) and 4.9-15.6 for Delta E-00. Colored samples showed lower color differences with respect to MSHD. The highest TP values were found for IPS e.max (R) ZirCAD system and the lowest for LAVA (TM) Zirconia system. In terms of translucency, MSHD, MSBD and zirconia ceramics showed no statistically significant differences. Conclusions: In terms of translucency, the studied zirconia systems could satisfactorily replace the human dentine within a dental restoration but, in order to produce a clinically acceptable match, it is necessary to carefully adjust the color of these systems. (C) 2012 Elsevier Ltd. All rights reserved.