Abstract
ObjectiveTo compare the brushing abrasion carried out by manual toothbrushes with different bristle types (hard and soft) on normal and demineralized human enamel.
Materials and MethodsThirty enamel blocks (N=30) were prepared and were randomly divided into three main groups: A, teeth kept in artificial saliva with no brushing (control, n=2); B, teeth brushed with toothbrushes with hard bristles (n=14); and C, teeth brushed with toothbrushes with soft bristles (n=14). Seven teeth belonging to groups B and C were brushed normally, and the remaining seven were demineralized before brushing experiments with 6 wt.% citric acid (pH = 2.2) for 5 minutes. The brushing experiments were carried out twice a day for 2 mins for 7days inside a toothbrush simulation machine. The changes in the surface of enamel (prebrushing and post-brushing) were evaluated using non-contact profilometry. The results were analysed statistically using Kruskal-Wallis test and the Wilcoxon signed rank test.
ResultsFor both normal and demineralized enamel, toothbrushes with soft bristles caused more abrasion. The results revealed significant differences (P=.055) in the surface roughness values between the four groups prebrushing. Within each group, the prebrushing and post-brushing surface roughness value differences were all statistically significant (P<.05).
ConclusionsThe results demonstrate that soft bristles caused more abrasion as compared with the hard bristles. These results could have an impact on the toothbrush recommendations for patients.