title: A randomized controlled trial of home tooth-whitening products.
abstract: OBJECTIVE
  To evaluate the effectiveness of two marketed home tooth-whitening products.
  
  
  METHODS
  A randomized controlled clinical trial involving 87 adults who were randomly allocated into one of three groups: (1) 6% hydrogen peroxide whitening strips, (2) 18% carbamide peroxide whitening gel, and (3) a placebo (fluoride toothpaste) control group. Subjects were instructed individually and then used the given product daily for 2 consecutive weeks. Color was determined in brightness (L*), yellowness (b*) and redness (a*) [color space] at baseline and 8 weeks after dispensing the product by employing a high resolution digital camera (Fuji HC1000 CCD) to image the subject's anterior maxillary teeth under standard polarized lighting conditions. The subjects also completed a questionnaire on self-satisfaction with the treatment outcome.
  
  
  RESULTS
  One-way ANOVA (Bonferroni test) demonstrated significant differences in color between the three groups with changes in brightness (L*, P< 0.001), yellowness (b*, P< 0.001) and redness (a*, P < 0.001). Changes in L* a* b* was greatest among those who used the 6% hydrogen peroxide whitening strips. Subjects in the whitening strip group also rated that product significantly (P < 0.01) more favorably than other groups with respect to the amount of whiteness improvement, as well as whitening satisfaction and overall impression while there is no significant difference between the whitening gel and the placebo groups.
authors.affiliation: Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong. edward-lo@hku.hk
authors.forename: Edward C M
authors.initials: EC
authors.lastname: Lo
authors.forename: Anthony H H
authors.initials: AH
authors.lastname: Wong
authors.forename: Colman
authors.initials: C
authors.lastname: McGrath
mesh_terms: D000328:Adult; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000627:therapeutic use; D003116:Color; D045424:Complex Mixtures / Q000627:therapeutic use; D003742:Dental Devices, Home Care; D004311:Double-Blind Method; D004338:Drug Combinations; D005459:Fluorides / Q000627:therapeutic use; D006801:Humans; D006861:Hydrogen Peroxide / Q000627:therapeutic use; D016877:Oxidants / Q000627:therapeutic use; D017060:Patient Satisfaction; D010545:Peroxides / Q000627:therapeutic use; D023861:Photography, Dental; D010919:Placebos; D014070:Tooth / Q000473:pathology; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000628:therapy; D014100:Toothpastes / Q000627:therapeutic use; D016896:Treatment Outcome; D014508:Urea / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D002327:Cariostatic Agents; C475021:Colgate Simply White Clear Whitening Gel; D045424:Complex Mixtures; C488279:Crest whitestrips; D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D010919:Placebos; D014100:Toothpastes; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide; D005459:Fluorides