Comparison of Translucency Parameter of Enamel and Dentin Using Two Formulas

Objectives: The CIEDE2000 color difference formula is recommended by the Commission Internationale de L’Éclairage (CIE) to correlate better perceived visual findings with computed color differences. The objective is to compare the translucency parameter (TP) values of human enamel and dentin obtained using CIELAB and CIEDE2000 color difference formulas.
Methods: Slices of extracted human teeth, 1-mm and 2-mm thick, were evaluated. Reflection values for three different areas of enamel and dentin were obtained against black and white backgrounds using a non-contact spectroradiometer (1/8° aperture size, D65 illuminant, 2° standard observer). The reflection values were converted into color coordinates and TP was calculated as color difference using CIELAB (TP_ab) and CIEDE2000 (TP₀₀) formula. Means and standard deviations were calculated. The data were analyzed by correlation statistics and paired t-test.
Results: TP₀₀ and TP_ab values were significantly different (p<0.0001). Relationships between TP values for 1-mm and 2-mm thick dentin and enamel are presented in the table. These data include conversion equations (TP_ab to TP₀₀), R² values, and % (s.d.) of numerical value of TP₀₀ compared to TP_ab. TP_ab versus TP₀₀ for all data are presented in the figure. The reduction of numerical value of TP₀₀ compared to TP_ab was 71.5% (4.7%).
Conclusions: Translucency parameters obtained using CIELAB and CIEDE2000 color difference formulas were closely correlated. The conversion equation (TP_ab to TP₀₀) and % (s.d.) of numerical value of TP₀₀ compared to TP_ab can be utilized to convert previous CIELAB findings into respective CIEDE2000 values.