title: The effects of different levels of brush end rounding on gingival abrasion: a double-blind randomized clinical trial.
abstract: OBJECTIVE
  The objective of this study was to evaluate the effect of different levels of filament end rounding on gingival abrasions (GAs).
  
  
  METHODS
  The study was a crossover, split-mouth, contra-lateral, double-blinded, randomized design using professional brushing. Three manual toothbrushes, with 0%, 40-50% and >90% end-rounded filaments, were investigated. Participants refrained from all oral hygiene procedures for 48 h prior to each of the three visits. Prior to brushing, oral soft tissue (OST) and GAs were assessed. Based on the randomization, during every visit contra-lateral quadrants were brushed with one of the three test brushes. After brushing, GAs were re-assessed. The means of the GAs prebrushing and post-brushing and differences per brush were calculated. Subanalyses were performed based on the size of the abrasion and its location.
  
  
  RESULTS
  A total of 46 generally healthy participants without periodontitis completed the study and provided a full data set. All brushes had statistically significant increases of abrasions following their use (P < 0.001). Non-end-rounded brushes provided significantly more GAs than did the 40-50% and the >90% brushes (P ≥ 0.001). A subanalysis showed that significantly more small-sized (P ≥ 0.002) abrasions located at the gingival margin (P < 0.001) occurred when a non-end-rounded brush was used. No significant differences were found between the 40-50% and >90% end-rounded brushes in any of the analyses. OST deviations were not observed.
  
  
  CONCLUSIONS
  Based on the results of this experiment involving professional brushing, it can be concluded that 40-50% or greater end-rounded filaments can provide a significant reduction in gingival abrasions compared to non-end-rounded filaments.
authors.affiliation: Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: N L
authors.identifier: http://orcid.org/0000-0002-6740-5657
authors.initials: NL
authors.lastname: Hennequin-Hoenderdos
authors.affiliation: Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: D E
authors.initials: DE
authors.lastname: Slot
authors.affiliation: Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Van der Sluijs
authors.affiliation: Procter & Gamble Service GmbH, Kronberg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Adam
authors.affiliation: Procter & Gamble, Mason, OH, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Grender
authors.affiliation: Department of Periodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: G A
authors.initials: GA
authors.lastname: Van der Weijden
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D005881:Gingiva / Q000293:injuries*; D006801:Humans; D008297:Male; D010518:Periodontitis / Q000517:prevention & control*; D014099:Toothbrushing / Q000009:adverse effects*
keywords: end-rounding; filaments; gingival abrasion; randomized clinical trial; tooth brushing