title: Bleaching efficacy of whitening agents activated by xenon lamp and 960-nm diode radiation.
abstract: OBJECTIVE
  This in vitro study examines the efficacy of two different dental whitening agents, Opalescence Xtra and Opus White, by analyzing the change in color achieved by the treatment and the temperature increase induced in the pulpal chamber.
  
  
  BACKGROUND
  Bleaching techniques achieved significant advances with the use of coherent or incoherent radiation sources to activate the bleaching chemicals.
  
  
  METHODS
  The bleaching agents, containing 35% of hydrogen peroxide, were stimulated with 0.9 W of xenon arc lamp and 0.9 W or 2 W of a 960-nm diode laser during 60 sec (0.9 W) and 30 sec (2 W) on 33 extracted human teeth. During irradiation, the temperature in the pulpal cavity was monitored. The color change was evaluated using the CIE L*a*b* color space measurement system.
  
  
  RESULTS
  The treated groups showed an increase in color saturation (DeltaC*) of 3-32% and a change in whiteness (DeltaL*) of 0-8%. This study found that only some of the irradiated groups show statistically significant difference (p < 0.05) in the effectiveness of their treatment when compared to the control, whereas no significant statistical difference was obtained in between the irradiated groups. Temperature increase was 2-4 degrees C when using the xenon arc lamp, 2-8 degrees C and 4-12 degrees C when using the diode laser at 0.9 W and 2 W, respectively.
  
  
  CONCLUSIONS
  The results of this study suggest that Opalescence Extra and Opus White are both effective to provide brighter teeth. However, according to the conditions used in this study, only the xenon arc lamp induced a safer temperature increase.
authors.affiliation: Centro de Lasers e Aplicaçôes, IPEN/SP, University of São Paulo, São Paulo, Brazil. nuwetter@net.ipen.br
authors.forename: Niklaus Ursus
authors.initials: NU
authors.lastname: Wetter
authors.forename: Déboraayala
authors.initials: D
authors.lastname: Walverde
authors.forename: Ilka Tiemy
authors.initials: IT
authors.lastname: Kato
authors.forename: Carlos de Paula
authors.initials: Cde P
authors.lastname: Eduardo
mesh_terms: D001831:Body Temperature; D003116:Color; D003782:Dental Pulp; D004338:Drug Combinations; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D053685:Laser Therapy; D010545:Peroxides / Q000528:radiation effects*; D011145:Polyvinyls / Q000528:radiation effects*; D014073:Tooth Bleaching / Q000379:methods; D014508:Urea / Q000031:analogs & derivatives* / Q000528:radiation effects*; D014978:Xenon
chemical_list: D004338:Drug Combinations; D010545:Peroxides; D011145:Polyvinyls; C093177:tooth-bleaching agent, Opalescence; D014978:Xenon; D014508:Urea