Toothbrush with fluoride-infused bristles: A potential tool to remineralize enamel.

Abstract

Objectives: The aim of this study was to investigate whether toothbrushes with fluoride-infused bristles can have any (re)mineralisation effects on bovine enamel. Methods: Bovine incisors (N=160) were extracted and the buccal side of crown was cut into dimensions of ~5mm x 5mm with a low speed saw. These specimens were randomly allocated into four groups: half of the specimens (ca. 80) were stored in demineralising solution (DM) and half in deionised water (DW) for 96 hours, before brushing with manual toothbrush that have either fluoride-infused (TF) or regular (TR) bristles for ten minutes with a force of 2.0 ± 0.1 N. Micro-hardness (Vickers), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) were used to investigate the surfaces on the bovine enamel specimens before and after the brushing. Two-way ANOVA was used to analyse the hardness data, and the Pairwise comparison method was used to analyse the Ca/P ratio, for each group at α=0.05. Results: Brushing with either of these toothbrushes would increase the Vickers micro-hardness on DM or DW enamel (p<0.001). SEM revealed the “fish-scale” enamel pattern after DM, and a thin layer of deposits was observed after TF. EDS revealed the quantity of fluorine element was be higher in DM or DW enamel after TF, and Ca/P was significantly higher (p<0.05) in DM enamel after TF (before: 1.24; after: 1.50) brushing. However, only hydroxyapatite (HAP) and no fluorapatite (FAP) was observed in all groups from XRD. Conclusions: Fluoride-infused bristle toothbrush might be useful to remineralize enamel, and the mechanism is yet to be determined.