title: Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study.
abstract: OBJECTIVE
  Bleaching techniques achieved significant advances with the use of coherent or incoherent radiation sources to activate the bleaching agents. This in vitro study compares the whitening efficacy of LED and diode laser irradiation using the two agents Opalescence X-tra and HP Whiteness.
  
  
  METHODS
  A total of 60 bovine incisors were randomly divided into six groups, three for each bleaching agent, receiving only agent, agent and LED (wavelength 470 nm), agent and 1.6 W diode laser (808 nm). The results of the irradiations were characterized using the CIEL*a*b* system.
  
  
  RESULTS
  Significant differences in the chroma value are obtained for the two whitening agents and for the different light sources. In terms of lightness, the association of Laser and Whiteness HP bleaching gel showed significantly better results than when the same agent was used alone or in combination with LED.
  
  
  CONCLUSIONS
  Best overall results are obtained with the Whiteness HP and Laser association.
authors.affiliation: Centro de Lasers e Aplicações, IPEN/SP, University of São Paulo, Av. Prof. Lineo Prestes 2242, CEP 05508-000, São Paulo, Brazil. nuwetter@ipen.br
authors.forename: Niklaus Ursus
authors.initials: NU
authors.lastname: Wetter
authors.forename: Márcia C S
authors.initials: MC
authors.lastname: Barroso
authors.forename: José E P
authors.initials: JE
authors.lastname: Pelino
mesh_terms: D000818:Animals; D002417:Cattle; D007834:Lasers; D008027:Light; D014073:Tooth Bleaching / Q000379:methods*