Comparison of CIELAB DeltaE(*) and CIEDE2000 color-differences after polymerization and thermocycling of resin composites.

OBJECTIVES Though instrumental technologies have been widely used for quantifying color of esthetic dental materials, the sizes for the perceptible or acceptable color-difference varied. Instead of the CIELAB DeltaE(*)(DeltaE(ab)(*)) formula, the CIEDE2000 (DeltaE(00)) formula that included weighting and parametric functions was introduced. The objective of this study was to determine the correlation between color-difference values of DeltaE(ab)(*) and DeltaE(00) after polymerization and thermocycling of dental resin composites. METHODS Color-differences were calculated between unpolymerized and polymerized, and between polymerized and thermocycled resin composites. Color was measured relative to the standard illuminant D65 over a white background with SCE geometry. Regression analyses were performed between the color difference values of DeltaE(ab)(*) and DeltaE(00). RESULTS There were significant correlations between DeltaE(ab)(*) values and DeltaE(00) values after polymerization and thermocycling (p<0.01), and the correlation coefficient was 0.99 and 0.98, respectively. SIGNIFICANCE Within the limit of this study, the results suggest that two color-difference formulas can be used interchangeably for the evaluation of the color-difference of resin composites after polymerization and thermocycling. However, for the evaluation of changes in separate color parameters such as lightness, chroma and hue, the DeltaE(00) formula could be considered for the color evaluation of esthetic dental materials after confirming with human observer responses.

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