Design-Efficacy Relationship of some Electric Toothbrush Heads

The relative efficacy of powered toothbrush designs is of great importance, especially given the desirability of keeping them light, unobtrusive, and economical. Objectives: Laboratory tests designed to evaluate interproximal access and artificial plaque removal were carried out to compare the relative efficiency of eight new powered brush-head designs, which differed in profile and stiffness of the bristles. Methods: and Materials: Interproximal access efficacy (IAE) was assessed for eight powered toothbrushes of new design, and a manual toothbrush (Oral-B Indicator 40) as a benchmark using a standardized method (J Dent Res 74:49, 1995). Twenty-four replicates were run on each design, using vertical and horizontal brushing. IAE was determined as the maximum width of artificial plaque removed around simulated anterior and posterior teeth. Significance of the differences between designs was determined by t-test. Results: All electric brushes had IAE numbers much higher than the manual control. Overall, in the immobile sections of the head, bristles of irregular length yielded better (p<0.05) IAE means than flat-profile brushes, and thinner bristles were better than thicker bristles (p<0.05). Designs with moving bristles had IAE means that were not significantly different (p>0.05). Conclusion: The interproximal cleaning efficacy of the powered toothbrushes tested favors softer bristles arranged in irregular vertical arrays.