title: Effects of tooth bleaching on the color and translucency properties of enamel.
abstract: OBJECTIVE
  To investigate the changes in color and translucency properties of enamel following 14 days treatment with carbamide peroxide.
  
  
  METHODS
  24 extracted premolars were used in this study. Two enamel-dentin specimens were prepared from each tooth and randomly assigned to be bleached with carbamide peroxide for 14 days or stored in artificial saliva as control. A spectrophotometer (Spectrascan PR650) was employed to measure the color of specimens according to the CIELab system. Color measurement of enamel-dentin specimens was performed prior to and after bleaching. After 14 days bleaching, enamel slabs were prepared by removing dentin parts using a low-speed saw. Then the color and translucency parameter (TP) of enamel slabs was measured over a black and a white background. Data between the experimental group and the control group were analyzed by paired t-test.
  
  
  RESULTS
  After bleaching, the color of enamel slabs and controls differed significantly both over the black and white background in L* and b* values (all P < 0.001). The translucency parameter (TP) of bleached enamel slabs was significantly lower than that of controls (P < 0.01). Both the deltaE values of enamel on the two backgrounds were significantly correlated to that of enamel-dentin specimens (P = 0.003; P = 0.012).
authors.affiliation: Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Lili
authors.initials: L
authors.lastname: Sun
authors.forename: Zhejun
authors.initials: Z
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yining
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000077463:Carbamide Peroxide; D003116:Color; D003743:Dental Enamel / Q000033:anatomy & histology* / Q000187:drug effects; D003804:Dentin / Q000033:anatomy & histology / Q000187:drug effects; D004338:Drug Combinations; D006801:Humans; D008027:Light; D008422:Materials Testing; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use; D010545:Peroxides / Q000008:administration & dosage / Q000627:therapeutic use; D012464:Saliva, Artificial; D013053:Spectrophotometry; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D012464:Saliva, Artificial; D000077463:Carbamide Peroxide; D014508:Urea