Toothbrush Wear and Plaque Removal Efficacy Over Time

Objectives: The first aim was to determine the efficacy of toothbrushes in removing artificial plaque over a four month period using a stationary bristle technique (a modification of the Bass technique) or a scrub technique.

The second aim was to determine the amount of wear on a toothbrush when brushing with a stationary bristle technique or a scrub technique, over a four month period on a typodont.

Methods: At baseline and at each two week interval, each brush was photographed from the top down in three sections under 40X magnification. At the same intervals, artificial plaque was applied to the buccal/lingual surfaces of the “Ramfjord” teeth. The typodonts were photographed buccal/lingually and brushed for two minutes, then photographed again.
The scrub (N=2) and stationary bristle (N=2) techniques, with dentifrice and water, were used. Each model was brushed on all surfaces for two minutes per brushing session. This was repeated to simulate brushing twice a day for four months.
Technique and temporal indicators were removed from all photographs, and each was assigned a randomized identification number. Two blind evaluators measured the length and width of each toothbrush section to analyze wear and assessed plaque removal using the Sillness and Loe plaque score.

Results: The scrub technique removed significantly (p=0.0004) more supragingival plaque than the stationary bristle technique. Toothbrush length and width measurements increase over time for both techniques; scrub technique deforms width more than stationary bristle technique, but not length.

Conclusions: Although toothbrushes wear down over time using either the scrub or the stationary bristle technique, neither had a definitive effect on removing artificial plaque as time progressed. These results on artificial plaque provide merit for a clinical study looking at plaque removal, as it implies that toothbrushes may not need to be replaced as frequently as recommended.