Evaluation of toothbrush-induced dentin substrate wear using an in vitro ridged-configuration model

To measure the dentin substrate wear associated with toothbrush use utilizing an in vitro specimen modeled to simulate the prominences of teeth and thus more closely simulate the clinical situation.

Dentin sections were cast within resin to produce a specimen configuration with three half-round ridges: a central ridge containing dentin (3 x 10 mm) and two similar ridges on each side of the central ridge. The specimens were brushed for the equivalent of the amount of time an individual tooth surface would be brushed in a 2-year period using a machine that simulated typical movement of a toothbrush across the specimen under controlled load and fluid conditions. Brushing was done with either a manual toothbrush (MTB), the Braun Oral-B 3D Excel (PTB1) or the Sonicare Elite (PTB2) and various loads. Dentin substrate loss was measured by profilometry.

Using this ridged specimen configuration, the results showed that the MTB and PTB1 had the highest amount of dentin substrate wear in both average depth and average maximum depth measurements. Increased toothbrush force from 90 g to 150 g increased the dentin substrate wear of both PTBs. PTB1 produced approximately 4-5 times greater average wear than PTB2 (P < 0.05).