title: [De-/re-mineralization in deciduous teeth assessed by color value analysis of digital photographs: an in vivo study].
abstract: OBJECTIVE
  The aim of this in vivo study was to detect the different ability of deciduous teeth in absorbing stain after de- or re-mineralization by color value analysis of digital photographs.
  
  
  METHODS
  Fifty-eight children aging from 3.5 to 4.5 years old were recruited in this study. After clinical examination, the labial surface of an incisor was stained with 2% aqueous methylene blue and digitally photographed. Then an area of the deciduous tooth was etched with 37% phosphoric acid gel for 1 min. Immediately after etching, this de-mineralized area was stained and digitally photographed with the same procedures as above. Twenty-four hours and one week later, the re-mineralized area was stained and photographed again respectively. Color values (R,G,B) of the digital photos were analyzed using image analysis software photoshop CS4. The changes of the color values was evaluated. All data were analyzed using one way ANOVA by SPSS 19.0 software package.
  
  
  RESULTS
  Just after etching and 24 hours later, the values of R,G,B were significantly different from the baseline (P<0.05). One week later, only B value was significantly different form the baseline. The difference of the color values between the time point just after etching and 24 hours later was not significant(P<0.05). While the difference of R,G,B between the time points just after etching and 1 week later was significant(P<0.05).
  
  
  CONCLUSIONS
  The results suggest that deciduous de- or re-mineralization may be assessed by color value analysis of digital photographs.
authors: Department of Pediatric and Preventive Dentistry, Shanghai Jiao Tong University School of Medicine, Shanghai, China. jasmineshimin@msn.com
authors: Shi-min
authors: SM
authors: Zhao
authors: Jun
authors: J
authors: Wang
mesh_terms: D002675:Child, Preschool; D003116:Color; D006801:Humans; D007180:Incisor; D010756:Phosphoric Acids; D010781:Photography; D014075:Tooth Discoloration; D014094:Tooth, Deciduous
chemical_list: D010756:Phosphoric Acids; C030242:phosphoric acid