title: Color and translucency of in vivo natural central incisors.
abstract: BACKGROUND
  The range of shades in shade guides is not consistent with natural teeth, and there is no information on the color and translucency of the natural tooth for all age groups. Therefore, it is important to obtain a database of the characteristics of the natural tooth from a wide age group.
  
  
  OBJECTIVE
  This study obtained information on color and translucency of natural teeth for all age groups, and attempted to clarify the difference of the color and translucency between natural teeth and VITA Lumin Vacuum shade guide.
  
  
  METHODS
  Natural central incisors of 87 subjects (42 men and 45 women; age range from 13 to 84 years) and 16 shades of VITA Lumin Vacuum shade guide were evaluated. Color and translucency of 5 sites, each 1.0 mm in diameter, on the surfaces of individual teeth were measured for L*, a*, and b*, using a color computer according to CIELAB color spaces.
  
  
  RESULTS
  At the center site, negative correlation was found between age and L*, with positive correlation between age and b*. Both a* and b* of the natural tooth increased when moving in the direction of the cervical site, but translucency decreased in the direction of the root. The a* value for the natural tooth was significantly higher than those for VITA Lumin Vacuum shade guide.
  
  
  CONCLUSIONS
  This study found that the older the subject, the darker and more yellow the color at the center site of the natural tooth. Both reddish and yellowish colors of natural teeth tend to increase from the incisal to cervical, whereas translucency decreases. Red-green chromaticity of VITA Lumin Vacuum shade guide was not distributed to cover the natural tooth.
authors.affiliation: GC Dental Products Corporation, Kasugai, Japan. akira_hasegawa@mb.gcdental.co.jp
authors.forename: A
authors.initials: A
authors.lastname: Hasegawa
authors.forename: I
authors.initials: I
authors.lastname: Ikeda
authors.forename: S
authors.initials: S
authors.lastname: Kawaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003116:Color; D003124:Colorimetry; D019992:Databases as Topic; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor / Q000033:anatomy & histology*; D008027:Light; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011874:Radiometry