title: Comparison of surface abrasion produced on the enamel surface by a standard dentifrice using three different toothbrush bristle designs: A profilometric in vitro study.
abstract: OBJECTIVE
  The aim was to assess, in vitro, the effect on surface abrasivity of enamel surface caused by three different types (flat trim, zig-zag, bi-level) of toothbrush bristle design.
  
  
  METHODS
  Twenty-four freshly extracted, sound, human incisor teeth were collected for this study. The enamel slab was prepared, which were mounted, on separate acrylic bases followed by subjected to profilometric analysis. The surface roughness was measured using the profilometer. The specimen were divided into three groups, each group containing eight mounted specimens, wherein, Group 1 specimens were brushed with flat trim toothbrush; Group 2 brushed with zig-zag and Group 3 with bi-level bristle design. A commercially available dentifrice was used throughout the study. A single specimen was brushed for 2 times daily for 2 min period for 1 week using a customized brushing apparatus. The pre- and post-roughness value change were analyzed and recorded.
  
  
  METHODS
  Kruskal-Wallis test and Mann-Whitney U-test.
  
  
  RESULTS
  The results showed that surface abrasion was produced on each specimen, in all the three groups, which were subjected to brushing cycle. However, the bi-level bristle design (350% increase in roughness, P = 0.021) and zig-zag bristle design (160% increase in roughness, P = 0.050) showed significantly higher surface abrasion when compared with flat trim bristle design toothbrush.
  
  
  CONCLUSIONS
  Flat trim toothbrush bristle produces least surface abrasion and is relatively safe for use.
authors.affiliation: Department of Public Health Dentistry, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Consultant Periodontist, Bengaluru, Karnataka, India.
authors.forename: Minal
authors.initials: M
authors.lastname: Kumari
authors.affiliation: Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal, Karnataka, India.
authors.forename: Shashidhar
authors.initials: S
authors.lastname: Acharya
authors.affiliation: Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal, Karnataka, India.
authors.forename: Ram
authors.initials: R
authors.lastname: Prasad
keywords: Abrasion; bristles; dentifrice; toothbrush