title: Colorimetric assessment of laser and home bleaching techniques.
abstract: OBJECTIVE
  This study recorded in vitro color change of three tooth bleaching techniques that included laser-activated hydrogen peroxide and two concentrations of carbamide peroxide.
  
  
  METHODS
  Forty extracted human central incisors were exposed to argon laser-activated 35% H2O2, 10% carbamide peroxide, or 20% carbamide peroxide. A fourth group (control) did not receive any bleach treatment (n = 10/group). Commission International de l'Eclariage (CIE) L*a*b* coordinates were recorded prior to bleaching (baseline), at 1 week, and at 2 weeks. The color difference (delta E*ab) between baseline and subsequent measurements was calculated.
  
  
  RESULTS
  The control group did not demonstrate significant color difference over time (p > .05). The laser group was not statistically different from the control group (p > .01). The color difference of the 10% and 20% carbamide peroxide groups was statistically different from the control group (p < .01).
  
  
  CONCLUSIONS
  Exposure to 20% carbamide peroxide produced the greatest perceivable change in color. The recommended one-time application of laser-activated hydrogen peroxide did not demonstrate any perceivable color change. The clinician should be aware that additional or longer applications may be required.
authors.affiliation: University of Iowa, Iowa City, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Jones
authors.forename: A M
authors.initials: AM
authors.lastname: Diaz-Arnold
authors.forename: M A
authors.initials: MA
authors.lastname: Vargas
authors.forename: D S
authors.initials: DS
authors.lastname: Cobb
mesh_terms: D000077463:Carbamide Peroxide; D003124:Colorimetry; D003742:Dental Devices, Home Care; D004338:Drug Combinations; D006801:Humans; D007180:Incisor; D007834:Lasers; D010545:Peroxides / Q000008:administration & dosage; D014073:Tooth Bleaching / Q000295:instrumentation / Q000379:methods*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: D004338:Drug Combinations; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea