title: Randomized clinical trial on the efficacy and safety of four professional at-home tooth whitening gels.
abstract: OBJECTIVE
  This randomized clinical trial evaluated the efficacy and safety of four gels of differing concentrations used for at-home vital bleaching.
  
  
  METHODS
  Ninety-six volunteers participated in the study and were divided into four groups of 24 individuals. A gel of differing concentration was used for each group: 10% and 15% carbamide peroxide and 7.5% and 9.5% hydrogen peroxide. The patients used the whitening agent in a tray without reservoirs for one hour per day for two weeks. The measurement of the change in tooth color was made by two observers in the maxillary right central incisor and with a colorimeter in both upper central incisors and canines, using the CIE L*a*b* and CIE L*C*h* values. Sensitivity was evaluated by the participants on a scale with values as follows: 0 = absent, 1 = minor, 2 = moderate, 3 = considerable, 4 = severe.
  
  
  RESULTS
  At the baseline, the observers noted darker colors than the colorimeter (p<0.01), and there were differences between incisors and canines in all the CIE L*a*b* and CIE L*C*h* values (p<0.001). In all of the groups and for all of the CIE L*a*b* and CIE L*C*h* parameters, there were color changes in the assessments made in the four maxillary teeth after treatment (p<0.001). There were no differences in ΔL* and ΔE* between the groups. The number of patients who experienced sensitivity and the intensity of the sensitivity were not significant.
  
  
  CONCLUSIONS
  There were no differences in the degree of whitening among the different products. With all of the products there was an increase in L*, a decrease in chromatic intensity (C*), and an increase in the value (tone) or hue (h*).
authors.forename: V
authors.initials: V
authors.lastname: Alonso de la Peña
authors.forename: M
authors.initials: M
authors.lastname: López Ratón
mesh_terms: D000328:Adult; D000077463:Carbamide Peroxide; D003807:Dentin Sensitivity / Q000139:chemically induced; D005260:Female; D005782:Gels; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D010545:Peroxides / Q000009:adverse effects / Q000627:therapeutic use; D012648:Self Care / Q000009:adverse effects / Q000379:methods; D014073:Tooth Bleaching / Q000009:adverse effects / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014508:Urea / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D005782:Gels; D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide