title: Abrasion of human enamel and dentine caused by toothpastes of differing abrasivity determined using an in situ wear model.
abstract: OBJECTIVE
  To determine the rates of enamel and dentine wear in situ during tooth brushing with a range of five toothpastes of differing RDA and REA values.
  
  
  METHODS
  Enamel/dentine inserts were placed in the buccal aspects of full upper dentures of human volunteers. Enamel wear was determined by change in Knoop indent length and dentine wear was determined from the enamel-dentine step height, measured using optical profilometry.
  
  
  RESULTS
  Significant differences between the test products were found for both enamel and dentine (p < 0.05). However for the conventional toothpastes the rate of wear was similar and differences between the products were not generally statistically significant for either enamel or dentine, despite the fact that their RDA values differed by more than a factor of two. The rate of wear was found to decrease throughout the duration of the study.
  
  
  CONCLUSIONS
  The study demonstrated that the methodology used is capable of assessing enamel and dentine wear in situ within a relatively short period of time. The data suggest that whilst in vitro tests have value in understanding differences in abrasivity between products, they cannot be used to predict in vivo effects.
authors: Unilever Oral Care, Port Sunlight Laboratory, Bebington, Wirral, UK. matthew.pickles@unilever.com
authors: M J
authors: MJ
authors: Pickles
authors: A
authors: A
authors: Joiner
authors: E
authors: E
authors: Weader
authors: Y L
authors: YL
authors: Cooper
authors: T F
authors: TF
authors: Cox
mesh_terms: D000328:Adult; D003743:Dental Enamel / Q000473:pathology*; D003804:Dentin / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006244:Hardness; D006801:Humans; D008297:Male; D055095:Optics and Photonics; D000091402:Prohibitins; D016037:Single-Blind Method; D014072:Tooth Abrasion / Q000145:classification / Q000209:etiology*; D014100:Toothpastes / Q000009:adverse effects*
chemical_list: C000717331:PHB2 protein, human; D000091402:Prohibitins; D014100:Toothpastes