Sensitivity of digital dental photo CIE L a b analysis compared to spectrophotometer clinical assessments over 6 months

Purpose: To assess the sensitivity of digital dental photo CIE L a b analysis compared to clinical spectrophotometer assessments over 6 months. Methods: CIE L a b values for the upper right central incisors of 14 predoctoral dental students subjected to certain color-relevant exclusion criteria were recorded at baseline (TO), after 6 months (T1), and 1 week later (T2), using (Method 1) a spectrophotometer and (Method 2) a method of digital photo analysis. Statistical analysis of color and lightness data between both methods and time points were assessed using the Shapiro-Wilk test, Pearson's correlation coefficient (r), Dahlberg's formula for method error calculation, and paired samples t-tests, adopting a level of significance alpha= 0.05. Results: Between T0 - T1, the spectrophotometer recorded significant changes in lightness (75.51 > 77.75) and color values (a : 3.25 > 2.38; b : 18.47 > 17.31), whereas significant changes with Method 2 were only seen for b (21.51 > 20.57). No significant changes for overall color and lightness changes Delta E to Delta E2 were found for either of the methods. The error of the method (T1-T2) and corresponding correlation coefficients r for values L a b were found to be 1.44 / 0.43 / 0.62 (r: 0.69; P= 0.007/0.64; P= 0.14/0.9; P< 0.001) for Method 1 and 0.97/0.67/1.25 (r : 0.87; P< 0.001/0.63; P= 0.17/0.57, P= 0.04) for Method 2, respectively. (Am J Dent 2011;24:300-304).