Methods: Stain removal was determined by brushing artificially-stained teeth with 8 marketed power toothbrushes: 4 combination rotary/reciprocating and 2 rotary only (Crest SpinBrush, medium and soft varieties), and 2 vibrating (Oral-B Pulsar, medium and soft). A manual soft toothbrush (Oral-B Indicator 40) was included as a control. Extrinsically-stained bovine tooth specimens (Stookey et al., JDR 61:1236, 1982) were treated on a V-8 mechanical cross-brushing machine, adapted to hold the power toothbrushes. Treatments were performed at 150 grams pressure with a 5:8 dentifrice (Crest Regular) to water slurry for 800 strokes with the power toothbrushes activated (n=16 specimens per brush). Stain color was measured before and after treatment by taking diffuse reflectance absorbance readings (as tristimulus L*a*b* color space) in triplicate with a spectrophotometer equipped with a targeting mask (Minolta CM-503i). Between-treatment comparisons of ΔL* and ΔE were performed by ANOVA and Newman-Keuls test for multiple comparisons.
Results: Compared to the manual control, all power toothbrushes showed numerical improvements in extrinsic stain removal, many of which were statistically significant. The 4 combination rotary/reciprocating and 2 rotary-only brushes were significantly more effective than the 2 vibrating brushes and the manual control. In addition, the 4 combination brushes were statistically more effective than the rotary-only brushes. The 2 vibrating brushes were not significantly different from the control brush.
Conclusions: Under the conditions of this in vitro evaluation, combination rotary/reciprocating toothbrushes were more effective in removing extrinsic tooth stains than rotary-only toothbrushes, which were more effective than vibrating toothbrushes. [Supported by Church & Dwight]