Effect of toothbrush bristle stiffness and toothbrushing force on the abrasive dentine wear.

Abstract

ObjectiveTo investigate the influence of toothbrush bristle stiffness and applied brushing force on the resulting abrasive dentine wear in vitro.MethodsOne hundred sixty bovine dentine samples were randomly allocated in eight groups (n = 20). Groups one to four were brushed with a soft‐bristle toothbrush with soft bristles applying 1, 2, 3 and 4 N brushing force, respectively. Groups five to eight were brushed with a medium‐bristle toothbrush applying the same aforementioned brushing forces (120 strokes/min, abrasive slurry (RDA = 121), 25 min). Profiles were recorded before and after the brushing sequence, and the median and interquartile range of abrasive dentine wear were calculated and compared using two‐way ANOVA and pairwise tests corrected after Tukey (α = 0.05).ResultsAt 1, 2 and 3 N brushing force, the tested toothbrushes caused no significantly different abrasive dentine wear. At 4 N brushing force, the medium‐bristle toothbrush caused statistically significantly higher abrasive force than the soft‐bristle toothbrush. Using the medium‐bristle toothbrush, abrasive dentine wear statistically significantly increased with increasing brushing force from 1 to 3 N. However, increasing the brushing force to 4 N did not result in statistically significantly higher wear. Using the soft‐bristle toothbrush, abrasive dentine wear statistically significantly increased with increasing brushing force from 1 to 2 N. However, increasing the brushing force to 3 or 4 N did not result in statistically significantly higher wear.ConclusionThe soft‐bristle toothbrush tends to cause less abrasive wear with increasing brushing force than the medium‐bristle toothbrush.