title: Clinical evaluation of 16% and 35% carbamide peroxide as in-office vital tooth whitening agents.
abstract: BACKGROUND
  Tooth bleaching (whitening) is a conservative and cost effective treatment of discoloured teeth.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the clinical efficacy and safety of 16% and 35% carbamide peroxide as in-office bleaching agents.
  
  
  METHODS
  Thirty adult subjects who desired to whiten their discoloured teeth were enrolled in the study. Carbamide bleaching agents, in concentrations of 16% and 35%, were used to whiten their teeth employing the spilt-arch technique/half-mouth design using vacuum formed half-arch matrix seated over the maxillary teeth for a one-hour session per week for two weeks. Outcome was monitored with Vita shade guide and photographs.
  
  
  RESULTS
  Twenty females and ten males, ages 18-43 years, with mean age 27.83 years, participated in the study. Tooth whitening was obtained in all subjects. Shade tab movement of 2-4 shades and 4-6 shades was recorded at first sessions then 3-5 and 5-9 shades at second sessions for 16% and 35% concentrations of carbamide peroxide respectively. The bleaching outcome was significantly better with the 35% concentration of carbamide peroxide while transient tooth sensitivity was observed in both concentrations ofthe bleaching agents.
  
  
  CONCLUSIONS
  Carbamide peroxide in 16% and 35% concentration are effective and safe for bleaching discoloured vital teeth, however, 35% concentration gave significantly more lightening effect without additional side effects compared to 16% concentration.
authors.affiliation: Restorative Dentistry Department, College of Medicine of the University of Lagos, Nigeria.
authors.forename: U V
authors.initials: UV
authors.lastname: Onwudiwe
authors.affiliation: Restorative Dentistry Department, College of Medicine of the University of Lagos, Nigeria.
authors.forename: D C
authors.initials: DC
authors.lastname: Umesi
authors.affiliation: Child Dental Health Department, College of Medicine of the University of Lagos, Nigeria.
authors.forename: O O
authors.initials: OO
authors.lastname: Orenuga
authors.affiliation: Restorative Dentistry Department, College of Medicine of the University of Lagos, Nigeria.
authors.forename: O P
authors.initials: OP
authors.lastname: Shaba
mesh_terms: D000293:Adolescent; D000328:Adult; D000077463:Carbamide Peroxide; D003807:Dentin Sensitivity / Q000139:chemically induced; D005260:Female; D006801:Humans; D008297:Male; D010545:Peroxides / Q000009:adverse effects / Q000737:chemistry* / Q000627:therapeutic use*; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000009:adverse effects / Q000737:chemistry* / Q000627:therapeutic use*; D014508:Urea / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000737:chemistry / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea