title: Influence of chemical or physical catalysts on high concentration bleaching agents.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the bleaching efficacy of high concentration bleaching agents activated by chemical or physical catalysts.
  
  
  METHODS
  This study was divided into two parts. Part 1 evaluated the efficacy of tooth whitening after treatment with 35% hydrogen peroxide (Whiteness HP Maxx) that was activated by different light-curing units: halogen lamp (conventional and bleach mode) (Optilux 501C, Demetron/Kerr), LED first generation (Ultrablue IV, DMC), LED/diode laser (Ultrablue IV, DMC), LED second generation (Bluephase 16i, Ivoclar Vivadent), and no light source (control group). Part 2 provided an analysis of the effect of chemical and physical catalysts on high concentration bleaching agents: 35% hydrogen peroxide (Whiteness HP Maxx) + 20% sodium hydroxide; 35% hydrogen peroxide + 7% sodium bicarbonate; 38% hydrogen peroxide (Opalescence Xtra Boost); 35% hydrogen peroxide + halogen lamp; 35% hydrogen peroxide + 20% sodium hydroxide + halogen lamp; 35% hydrogen peroxide + 7% sodium bicarbonate + halogen lamp; 38% hydrogen peroxide + halogen lamp; and 35% hydrogen peroxide. Blocks obtained from human molars were randomly divided into groups (n = 5) in accordance with bleaching treatments. The efficacy of bleaching was measured using a spectrophotometer. Three bleaching sessions were performed. The results were submitted to ANOVA followed by the Tukey test (5%).
  
  
  RESULTS
  For both parts of the study, activated vs. non-activated bleaching did not differ significantly for all sessions tested.
  
  
  CONCLUSIONS
  Activating systems did not improve the whitening effectiveness of high concentration bleaching agents.
authors.affiliation: Department of Restorative Dentistry, Piracicaba School of Dentistry, Campinas State University, SP, Brazil. deboralima@fop.unicamp.br
authors.forename: Débora Alves Nunes Leite
authors.initials: DA
authors.lastname: Lima
authors.forename: Flávio Henrique Baggio
authors.initials: FH
authors.lastname: Aguiar
authors.forename: Priscila C Suzy
authors.initials: PC
authors.lastname: Liporoni
authors.forename: Egberto
authors.initials: E
authors.lastname: Munin
authors.forename: Gláucia Maria Bovi
authors.initials: GM
authors.lastname: Ambrosano
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Lovadino
mesh_terms: D000328:Adult; D002384:Catalysis; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D058205:Tooth Bleaching Agents; D014075:Tooth Discoloration / Q000628:therapy*
chemical_list: D058205:Tooth Bleaching Agents