title: Toothbrush abrasion, simulated tongue friction and attrition of eroded bovine enamel in vitro.
abstract: OBJECTIVE
  Enamel erosion results in the formation of a softened layer that is susceptible to disruption by mechanical factors such as brushing abrasion, tongue friction and attrition. The aim of this study was to investigate the individual contribution of those mechanical insults to the enamel loss caused by dental erosion.
  
  
  METHODS
  Forty two bovine enamel samples were randomly divided into seven groups (n=6 per group) that were submitted to 3cycles of one of the following regimes: erosion and remineralization (er/remin); toothbrush abrasion and remineralization (abr/remin); erosion, toothbrush abrasion and remineralization (er/abr/remin); attrition and remineralization (at/remin); erosion, attrition and remineralization (er/at/remin); simulated tongue friction and remineralization (tg/remin); erosion, simulated tongue friction and remineralization (er/tg/remin). Erosion took place in a demineralization solution (50mM citric acid, pH 3) for 10min under agitation. Brushing abrasion, tongue friction and attrition were simulated for 1min using a home-made wear device. Remineralization was carried out in artificial saliva for 2h. Enamel loss was quantified using optical profilometry.
  
  
  RESULTS
  One-way ANOVA indicated a significant difference between the amounts of enamel lost due to the different wear regimes (p<or=0.001). Multiple comparisons with Bonferroni procedure showed that the wear depths found for the er/at/remin (p<or=0.001) and er/tg/remin (p<or=0.001) were significantly higher than the amount found for the er/remin group (4.4+/-0.7microm). This was not the case for er/abr/remin group (p=0.075).
  
  
  CONCLUSIONS
  The results suggest that the three forms of mechanical insults remove to varying extent the softened layer formed by the erosion challenges.
authors.affiliation: Department of Dentistry and Dental Hygiene, University Medical Centre Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands. a.vieira@med.umcg.nl
authors.forename: A
authors.initials: A
authors.lastname: Vieira
authors.forename: E
authors.initials: E
authors.lastname: Overweg
authors.forename: J L
authors.initials: JL
authors.lastname: Ruben
authors.forename: M C D N J M
authors.initials: MC
authors.lastname: Huysmans
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel / Q000737:chemistry*; D014072:Tooth Abrasion / Q000209:etiology*; D019217:Tooth Attrition / Q000209:etiology*; D014077:Tooth Erosion / Q000209:etiology*; D014099:Toothbrushing / Q000009:adverse effects*