title: Effect of Whitening Toothpastes on Dentin Abrasion: An In Vitro Study.
abstract: OBJECTIVE
  To compare the effect of toothbrushing abrasion with hydrated silica-based whitening and regular toothpastes on root dentin using contact profilometry.
  
  
  METHODS
  Ninety dentin specimens (4 x 4 x 2 mm) were randomly divided into five experimental groups (n = 18) according to the toothpaste: three whitening (W1, W2 and W3) and two regular toothpastes (R1 and R2) produced by two different manufacturers. Using a brushing machine, each specimen was brushed with a constant load of 300 g for 2500 cycles (4.5 cycles/s). The toothpastes were diluted at a ratio of 1:3 w/w (dentifrice:distilled water). The brush diamond tip of the profilometer moved at a constant speed of 0.05 mm/s with a force of 0.7 mN.
  
  
  RESULTS
  The average value of brushing abrasion in μm (mean ± SD) was obtained from five consecutive measurements of each specimen: W1 = 8.86 ± 1.58, W2 = 7.59 ± 1.04, W3 = 8.27 ± 2.39, R1 = 2.89 ± 1.05 and R2= 2.94 ± 1.29. There was a significant difference between groups (ANOVA, p<0.0001). Post-hoc Tukey's test for multiple comparisons showed differences between all the whitening and regular toothpastes, but not among the whitening nor among the regular toothpastes.
  
  
  CONCLUSIONS
  The whitening toothpastes tested can cause more dentin abrasion than the regular ones.
authors.forename: Gustavo Henrique Apolinario
authors.initials: GHA
authors.lastname: Vieira
authors.forename: Marcia Bessa
authors.initials: MB
authors.lastname: Nogueira
authors.forename: Eduardo Jose
authors.initials: EJ
authors.lastname: Gaio
authors.forename: Cassiano Kuchenbecker
authors.initials: CK
authors.lastname: Rosing
authors.forename: Sergio Lima
authors.initials: SL
authors.lastname: Santiago
authors.forename: Rodrigo Otavio
authors.initials: RO
authors.lastname: Rego
mesh_terms: D006801:Humans; D066298:In Vitro Techniques; D011897:Random Allocation; D014072:Tooth Abrasion / Q000139:chemically induced*; D058205:Tooth Bleaching Agents / Q000009:adverse effects*; D014100:Toothpastes
chemical_list: D058205:Tooth Bleaching Agents; D014100:Toothpastes