Evaluation of the Accuracy of ΔE Value Measured Electronically by VITA Easyshade® Advance 4.0 Device

Abstract

Background and Aim: The purpose of this study was to evaluate the accuracy of ΔE value measured electronically by VITA Easyshade^® Advance 4.0 device as compared to the ΔE value calculated by use of the formula based on the color space system CIELab which was defined by International Commission on Illumination.

Materials and Methods: The sample of the study consisted of 28 patients who received vital bleaching treatment on their upper anterior teeth 4 hours/ 7 days using 20% carbamide peroxide (opalescence) .The color and the color values L, a, b, of the right upper central incisors (11) and the left upper canines (23) were measured using a spectrophotometer (VITA Easyshade^® Advance 4.0) before the application of the bleaching treatment and after one month. The color difference ΔE was calculated after one month of the treatment twice; the first was by using the color space system formula (ΔE=[(ΔL)2+(Δa)2+(Δb)2]^1/2, and the second was electronically using a special icon on the measurement menu of the VITA Easyshade^® Advance 4.0 device for teeth 11 and 23. Results were statistically analyzed by T Student test for dependent samples to study the significance of differences in mean values of ΔE between the two measuring methods used in this study. Cronbach's alpha and Intra-class Correlation Coefficient (ICC) were calculated to study the relation and the level of agreement in ΔE values between the two measuring methods at significance level (p<0.05).

Results: T student test revealed no statistical differences in mean ΔE values between the two measuring methods in teeth 11 group (P=0.334), while significant differences were found in teeth 23 group and the whole sample (P=0.005, 0.004). Cronbach's alpha and Intra-class Correlation Coefficient (ICC) showed no statistical agreement and stability in mean ΔE values between the two measuring methods in teeth 23 group (P=0.( 122,  while there was statistical agreement and stability in mean ΔE values between the two measuring methods in teeth 11 group and the whole sample (P=0.00(.   

Conclusions: This study couldn't prove the accuracy of ΔE value measured electronically using the special icon on the measurement menu of the VITA Easyshade^® Advance 4.0 device when compared to the ΔE value calculated by use of the formula based on the color space system, although it showed a statistical