Evaluation of tapered-end toothbrush bristles regarding efficacy of access to occlusal fissures.

The purpose of this in vitro study was to determine how two toothbrushes, with a combination of a tapered-end and round-end bristle design (Group A), compared to a conventional toothbrush with only rounded-end bristles (Group B) for cleaning in simulated occlusal fissures on a brushing machine. The fissure width at the surface was 200 microns, and then tapered down to the fissure base depths of 230 and 400 microns. The toothbrushes were positioned 90 or 180 degrees to the fissure groove surface on the model, and a 200 g force was applied to the brush head. The fissure model received 190 strokes over one minute by the brushing machine. The removal of an artificial plaque substance in the fissure model was measured by a two-dimensional analyzing system. For each combination of the fissure depth versus bristle angle versus brush head configuration variables, five specimens were measured and means were determined. The results were statistically analyzed using a three-way ANOVA followed by Scheffe's test (alpha = 0.05). The results demonstrated that the combination of tapered and round-end bristles (Group A brush) was statistically significantly (p < 0.01) more effective in removing the artificial plaque material on the fissure area than the Group B brush for specific types and brush stroke directions.