Influence of Tapered-End and Round-End Bristle Designs on the Abrasive Enamel Wear Using Toothpastes With High...

The aim of this in vitro study was to investigate the influence of bristle end design of toothbrushes and the relative enamel abrasivity (REA) of used toothpaste on the resulting abrasive enamel wear.

A total of 160 bovine enamel samples were allocated into eight groups (n = 20) and surface topography was recorded profilometrically. Samples of groups A-D were brushed with a toothbrush with a tapered-end bristle design, and samples of groups E-H with a round-end bristle design. Brushing was performed in an automatic brushing machine with a frequency of 60 brushing cycles per minute, with reciprocating movements at a constant brushing force of 2.5 N for a total of 6 h. In groups A and E, toothpaste Colgate Total (CT; REA 4); in groups B and F, toothpaste Candida White Diamond (CWD; REA 244); in groups C and G, toothpaste Swiss Smile Diamond Glow (SSDG; REA 177); and in groups D and H, toothpaste Emoform F Diamond (EFD; REA 51) were used. Surface topography was recorded after 6 h of brushing again, and the abrasive enamel wear was calculated.

For all three diamond-based toothpastes (CWD, SSDG and EFD), brushing with the round-end toothbrush caused statistically significantly more wear than with the tapered-end toothbrush (p < 0.05). For both toothbrushes, SSDG caused the highest abrasive wear (51.36/6.34 μm resp. 29.71/15.35 μm), followed by CWD (47.61/18.66 μm resp. 7.16/2.23 μm) and EFD (16.91/2.86 μm resp. 5.27/2.11 μm), with the respective differences being statistically significant (median/interquartile range IQR).

In combination with diamond-based toothpastes, tapered-end toothbrushes cause less abrasive enamel wear compared to round-end toothbrushes.