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 (T0), 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 = 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 to 2 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). CLINICAL SIGNIFICANCE: This clinical study evaluated the intra-examiner sensitivity of measurements of natural anterior permanent teeth using either a reflectance spectrophotometer or digital photo analysis while conducting a crosssectional assessment under standardized lighting conditions, which has so far not been reported in the literature for these two methods. The spectrophotometer was considered more suitable for detecting slight changes in color and lightness appearance than the digital photo method. : Dr. Athanasios E. Athanasiou, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece. E: aeathan@dent.auth.gr