title: Spectrophotometric comparison of translucent composites and natural enamel.
abstract: OBJECTIVE
  To compare the optical characters of four translucent composites and natural enamel.
  
  
  METHODS
  Thirty natural enamel slabs and 120 composite replicas (n=30) using four brands of translucent composites (Polofil Supra, Brilliant Esthetic, Gradia Direct, and Vit-l-escence) were evaluated at the thicknesses of 1.0mm and 0.8mm. The colors of the enamel slabs or corresponding composite specimens placed on an A3 shade, white and black backgrounds were measured using a spectrophotometer. Color differences (ΔE*) of the enamel-composite pairs and translucency parameter (TP) of each specimen were calculated. Reflection spectrums were recorded in the wavelength from 380nm to 780nm. Paired-t tests were performed to evaluate the differences of color coordinates (L*, a*, and b*) and TP values between the translucent composites and natural enamel.
  
  
  RESULTS
  There were significant differences of color coordinates (L*, a*, and b*) between the enamel and translucent composites (P<0.05). Although no statistical difference of TP values were found in the enamel-composite pairs with Polofil Supra and Brilliant Esthetic composites. The main peaks of the reflectance spectrums of the enamel are different from the four brands of the translucent composites. A reddish shifting of the main reflection peaks was observed, while the thickness of the composite specimens decreasing from 1.0mm to 0.8mm. Whereas, the main reflection peak was not changed in the teeth enamel.
  
  
  CONCLUSIONS
  The color and the translucency of translucent composites are different from the teeth enamel.
authors.affiliation: Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: B T
authors.initials: BT
authors.lastname: Xu
authors.forename: R
authors.initials: R
authors.lastname: Li
authors.forename: Y N
authors.initials: YN
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003743:Dental Enamel / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D008027:Light; D013053:Spectrophotometry; D055815:Young Adult
chemical_list: C069351:Brilliant Direct-Inlay resin; D003188:Composite Resins; C470230:Gradia; C515948:Vit-l-escence Trans Ice; C100748:Polofil Molar