The in vitro Efficacy of Various Manual Toothbrush Parameters

Objectives: Manual toothbrushes have different parameters which may impact their overall efficacy (cleaning function). Therefore, different toothbrushes were evaluated using the laboratory model described below.
The parameters evaluated in the laboratory model were; head size, tuft diameter, stiffness, bristle length and configuration. These represent the most frequently adjusted design parameters during manual toothbrush development.
Methods: A clinically validated, comparative Robot Test used KaVo typodonts with teeth in anatomic positions and coated in simulated plaque to assess toothbrush efficacy (ORMED). All 10 teeth were cleaned with brushing movements horizontally, rotationally and vertically at 3.5N force. Plaque removal at 24 planimetrical fields per tooth was calculated by computer-assisted optical planimetry with differentiation of specific areas.
Results: There are different levels of plaque control efficacy (p <= 0.001, p <= 0.01 and p <= 0.05) at the various tooth fields buccally/lingually, interdentally and along the gum line, in percentages, were measured for the different brush parameters. The removal of simulated plaque overall was better for; compact head size Vs full head size, narrow tuft diameter Vs standard, long filaments Vs shorter lengths, and extra soft variants compared to soft and medium. For brushes with different tuft heights the brush with the greater difference in bristle length showed better results than a brush with small difference between lengths.

Conclusions: The data generated supported those brushes that allow the bending and flexing of bristles, (longer, softer) with smaller parameters (head size, tuft diameter) to remove statistically more simulated plaque than the comparator brushes with short, hard bristles, large tufts and heads. This information can be used to improve the overall toothbrush design prior to clinical evaluation.