A comparative evaluation of the percent acceptable end-rounded bristles: Butler G.U.M., Colgate Plus, Crest Complete, and Reach

J Clin Dent. 1994;5(2):38-45.


Many researchers have concluded that end-rounded toothbrush bristles reduce the potential of soft tissue trauma. Toothbrushes with a rippled-bristle pattern have been shown to more effectively remove dental plaque from interproximal surfaces than flat-trimmed toothbrushes. Unfortunately, many attempts to utilize rippled-bristle toothbrushes are fraught with difficulty due to poor end-rounding of these bristles in the traditional manufacturing process. In this study, the proportion of acceptably end-rounded bristles has been compared for a rippled bristle design toothbrush (Crest Complete), a traditional flat-trimmed brush (Colgate Plus), a bi-level brush (Reach), and a domeshaped brush (Butler G.U.M. 411). Toothbrush bristles were examined using a stereomicroscope by a grader blind to brush type, and bristle end-rounding was evaluated based on the Silverstone and Featherstone scale used previously in the literature. The results were tabulated for the percent of bristles with acceptable grades, summed, and averaged for five random bristles per tuft, five random tufts per brush, for 30 brushes of each type. Bristles in the Crest Complete toothbrush demonstrated 96.5% acceptable end-rounding. These results were significantly different (p = 0.0001) from those found in the other brushes tested: 34.3% (Reach), 16.1% (Colgate Plus), and 14.0% (Butler G.U.M.) acceptable end-rounding was observed. These results demonstrate that the newly designed rippled-bristle brush (Crest Complete) exhibits excellent bristle end-rounding.

Publication types

  • Comparative Study

MeSH terms

  • Analysis of Variance
  • Equipment Design
  • Toothbrushing / instrumentation*