title: [Bleaching of non-vital discolored tooth: clinical analysis of 30 cases].
abstract: OBJECTIVE
  The purpose of this study was to evaluate the bleaching efficacy of non-vital discolored tooth.
  
  
  METHODS
  Thirty-three non-vital discolored anterior teeth with intact crowns from 30 patients were included in this clinical study. Bleaching treatment was performed using a combination of intracoronal and extracoronal applications of 15% carbamide peroxide. Intracoronal bleaching with 30% hydrogen peroxide was used as control group. The effective cases of the experimental group were reexamined one year later. Statistical analysis of all data was performed with SPSS 17.0 software package.
  
  
  RESULTS
  Combined therapy with intracoronal and extracoronal applications of 15% carbamide peroxide presented higher bleaching efficacy than intracoronal applications of 30% hydrogen peroxide alone, the difference was significant. But the color shade change one year later was not significant.
  
  
  CONCLUSIONS
  A combination of intracoronal and extracoronal applications of 15% carbamide peroxide was an effective bleaching technique for non-vital discolored teeth.Supported by Key Research Project of Science and Technology Bureau of Hefei City (Grant No.2007-1016).
authors.affiliation: Department of Endodontics, Hefei Stomatological Hospital, Clinical School of Anhui Medical University, Hefei 230001, Anhui Province, China. 827498481@qq.com
authors.forename: Ai-min
authors.initials: AM
authors.lastname: He
authors.forename: Qi-ling
authors.initials: QL
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000368:Aged; D001881:Borates; D000077463:Carbamide Peroxide; D006801:Humans; D006861:Hydrogen Peroxide; D010545:Peroxides; D014073:Tooth Bleaching; D014075:Tooth Discoloration; D014508:Urea / Q000031:analogs & derivatives
chemical_list: D001881:Borates; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide