Study of the Variation between CIELAB ΔE^* and CIEDE2000 Color-differences of Resin Composites

This study sought to assess the significance of the corrections introduced in the new CIEDE2000 color difference formula with respect to ΔE*_<ab>. The purpose of which was to provide sounder knowledge, and hence more informed decision-making, about applying this new formula to dental resin composites. With two different hybrid composites, color differences were calculated between unpolymerized and polymerized resin composites, between polymerized resin composites of different thicknesses (1 and 2mm), and between polymerized resin composites cured with halogen and LED light curing units (LCUs). The two formulas differed significantly, with V_<AB>(E) (equal size) values higher than the inter-observer variability (V_<AB>(E)=11%) and V_<AB>(O) (original size) values greater than 25% for each of the data sets analyzed. Results obtained in this study agreed with and thus supported the recent recommendation of the Commission Internationale de l'Eclairage (CIE), whereby the new CIEDE2000 formula should be used to evaluate color differences of resin composites.