Toothbrush abrasivity in a long-term simulation on human dentin depends on brushing mode and bristle arrangement

Abstract

Objective: The aim of this study was to evaluate the susceptibility of dentin to brushing abrasion using four different toothbrushes (rotating-oscillating, sonic and two types of manual toothbrushes) with the same brushing forces.

Methods: Dentin samples (n = 72) were selected from 72 impacted third molars. Half of the surface of dentin samples was covered with an adhesive tape, creating a protected and a freely exposed area in the same specimen. Brushing was performed with either a: sonic (Sonicare PowerUp, Philips GmbH, Hamburg, Germany), b: oscillating-rotating (Oral B Vitality Precisions Clean, Procter & Gamble, Schwalbach am Taunus, Germany) or two different manual toothbrushes c: flat trim brush head toothbrush (Dr. Best: Original, Glaxo-Smith-Kline, Bühl, Germany) and d: rippled-shaped brush head toothbrush (Blend-a-Dent, Complete V-Interdental, Blend-a-med, Schwalbach, Germany) in a custom made automatic brushing machine. The brushing force was set to 2 N and a whitening toothpaste (RDA = 150) was used. The simulation period was performed over a calculated period to mimic a brushing behavior of two times a day brushing for eight years and six months. Dentin loss was quantitatively determined by profilometry and statistically analyzed by Wilcoxon and Mann-Whitney-U Test (p < 0.05).

Results: The mean (standard deviation) surface loss was 21.03 (±1.26) μm for the sonic toothbrush, 15.71 (±0.85) μm for the oscillating-rotating toothbrush, 6.13 (±1.24) μm for the manual toothbrush with flat trim brush head and 2.50 (±0.43) μm for the manual toothbrush with rippled-shaped brush head. Differences between all groups were statistically significant at p<0.05.

Conclusion: Using the same brushing force and a highly abrasive toothpaste, manual toothbrushes are significantly less abrasive compared to power toothbrushes for an 8.5-year simulation.

Fig 1. DentTest, Department of Operative and Preventive Dentistry, Witten/Herdecke University and Ingpuls GmbH Bochum, German.

Fig 2. Study design.

Fig 3. 3D image of profilometry.

Frontal view of a scan with the reference area on top and the brushed area on the bottom.

Fig 4. Measurement of dentin loss using profilometry for different toothbrushes for different toothbrushes.

(A) Sonic toothbrush, (B) Oscillating-rotating toothbrush, (C) Flat trim manual toothbrush (D) Rippled-shaped manual toothbrush.

Fig 5. Scatterplot of the relationship between dentin loss and toothbrushes.

Mean and standard deviation change of dentin loss (μm) after brushing with different toothbrushes and different strokes (***p<0.001). Horizontal bars indicate statistically significant differences between groups for power and manual toothbrushes, *** p < 0.001, one-way ANOVA with post hoc.