title: Sensitivity of digital dental photo CIE L*a*b* analysis compared to spectrophotometer clinical assessments over 6 months.
abstract: OBJECTIVE
  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 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 deltaE to deltaE2 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.
authors.affiliation: Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: Ariel
authors.initials: A
authors.lastname: Sluzker
authors.forename: Michael
authors.initials: M
authors.lastname: Knösel
authors.forename: Athanasios E
authors.initials: AE
authors.lastname: Athanasiou
mesh_terms: D000328:Adult; D003116:Color / Q000592:standards; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor; D015588:Observer Variation; D023861:Photography, Dental; D015203:Reproducibility of Results; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D013997:Time Factors; D055815:Young Adult