title: Tooth whitening with hydrogen/carbamide peroxides in association with a CPP-ACP paste at different proportions.
abstract: BACKGROUND
  Different enhanced peroxide formulations have been developed to overcome mineral loss during tooth whitening. This study investigated the impact on tooth whitening from combining a CPP-ACP paste with home peroxide agents at several proportions.
  
  
  METHODS
  Ninety bovine incisors were randomly allocated into nine groups (n = 10) and exposed to 7.5% hydrogen peroxide (HP), 16% carbamide peroxide (CP), a CPP-ACP paste (Tooth Mousse/MI Paste, GC Corporation, Tokyo, Japan) and blends of HP/CP:MI at three proportions (1:1, 2:1 and 1:2). Tooth whitening was performed for 14 days and its effectiveness was measured by a spectrophotometer utilizing the CIE L*a*b* system (ΔE, ΔL*, Δa* and Δb*). Colour readings were measured at baseline (T0), 7 days of bleaching (T7), 14 days of bleaching (T14) and 7 days after the end of bleaching (T21). Data were analysed by two-way ANOVA for paired averages followed by the Tukey's test and Pearson's correlation at 5%.
  
  
  RESULTS
  Although CP produced the greatest colour change (ΔE), all whitening protocols were considered to be effective regardless of the CPP-ACP presence. In general, greater changes in ΔE, ΔL*, Δa* and Δb* were detected at T14, with T21 exhibiting similar results to those at T7. A greater number of strong correlations with ΔE values was found for a* (11/15).
  
  
  CONCLUSIONS
  Within the limitations of this study, the results indicate that the CPP-ACP paste did not affect tooth whitening efficacy.
authors.affiliation: School of Dentistry, Potiguar University (Laureate International Universities), Natal, Brazil.
authors.forename: A A M
authors.initials: AA
authors.lastname: de Vasconcelos
authors.forename: A G G
authors.initials: AG
authors.lastname: Cunha
authors.forename: B C D
authors.initials: BC
authors.lastname: Borges
authors.forename: C T
authors.initials: CT
authors.lastname: Machado
authors.forename: A J S
authors.initials: AJ
authors.lastname: dos Santos
mesh_terms: D000818:Animals; D000077463:Carbamide Peroxide; D002364:Caseins / Q000494:pharmacology*; D002417:Cattle; D003124:Colorimetry; D003804:Dentin / Q000187:drug effects; D004336:Drug Antagonism; D004338:Drug Combinations; D006861:Hydrogen Peroxide / Q000008:administration & dosage; D010545:Peroxides / Q000008:administration & dosage; D013053:Spectrophotometry; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000008:administration & dosage*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: D002364:Caseins; D004338:Drug Combinations; D010545:Peroxides; D058205:Tooth Bleaching Agents; C447032:casein phosphopeptide-amorphous calcium phosphate nanocomplex; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide