title: Influence of Bristle Stiffness of Manual Toothbrushes on Eroded and Sound Human Dentin--An In Vitro Study.
abstract: OBJECTIVE
  The aim of this study was to determine the influence of manual toothbrushes with different bristle stiffness on the abrasivity on eroded and sound human dentin.
  
  
  METHODS
  Dentin specimens were made from impacted third molars and attributed to three groups: erosion-abrasion (EA), abrasion (A) and erosion (E). The specimens from EA and E were treated with 1% citric acid (pH 2.3) for 1 min rinsed, and neutralized with artificial saliva for 15 min. This cycle was repeated five times. Thereafter, specimens from EA and A were treated with three toothbrushes types with different bristle stiffness (soft, medium, and hard) in a custom-made toothbrushing machine. The brushing was performed at a load of 3 N with a toothpaste slurry for 630 s. This procedure was repeated five times, in group EA after each erosion cycle. EA and A groups passed through five cycles with a total of 6300 strokes. The abrasivity was analyzed by contact-free profilometry. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis.
  
  
  RESULTS
  With respect to bristle stiffness there was no statistically significant difference in dentin loss within the EA group. In group A, a statistically significantly higher dentin loss was found for the soft in comparison to the hard bristles. No statistically significant differences were measured between soft/medium and medium/hard toothbrushes. The amount of dentin loss from specimens in the EA group was significantly higher than in the A group.
  
  
  CONCLUSIONS
  Within the limitations of this study, the dentin loss in the Abrasion group was higher with soft bristles than with hard ones. This result might have an influence on the toothbrush recommendations for patients with non-carious cervical lesions.
authors.affiliation: Department of Operative and Preventive Dentistry, Witten/Herdecke University, Witten, Germany.
authors.forename: Mozhgan
authors.initials: M
authors.lastname: Bizhang
authors.affiliation: Department of Operative and Preventive Dentistry, Witten/Herdecke University, Witten, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Riemer
authors.affiliation: Department of Biological and Material Sciences in Dentistry, Witten/Herdecke University, Witten, Germany.
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Arnold
authors.affiliation: Department of Operative and Preventive Dentistry, Witten/Herdecke University, Witten, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Domin
authors.affiliation: Department of Operative and Preventive Dentistry, Witten/Herdecke University, Witten, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Zimmer
mesh_terms: D003804:Dentin / Q000293:injuries* / Q000473:pathology; D006244:Hardness; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008964:Molar, Third / Q000293:injuries / Q000473:pathology; D012464:Saliva, Artificial; D013499:Surface Properties; D014072:Tooth Abrasion / Q000209:etiology* / Q000473:pathology*; D014077:Tooth Erosion / Q000209:etiology* / Q000473:pathology*; D014099:Toothbrushing / Q000009:adverse effects* / Q000295:instrumentation*; D014100:Toothpastes
chemical_list: D012464:Saliva, Artificial; D014100:Toothpastes