Nano-hydroxyapatite toothpastes show high enamel and dentine remineralization, a study

In this study, researchers demineralized specimens and randomly divided into five groups, and exposed to an aqueous remineralizing solution for two and five weeks (37 °C). Brushing procedures were performed with the respective toothpaste/storage solution slurry twice daily (2 × 5 s; total contact time of the slurries 2 × 120 s/d): storage in remineralizing solution only (0); additional brushing with B (20 wt% zinc carbonate nano-hydroxyapatite, ZnCO₃/n-HAp); BS (24 wt% ZnCO₃/n-HAp); E (0.14 wt% amine fluoride); or A (7 wt% pure n-HAp). Differences in mineral loss (ΔΔZ) before and after storage/treatment were microradiographically evaluated.

Dentine groups 0, B, BS, and A showed significantly higher ΔΔZ values compared to E. Enamel ΔΔZ values of group A were significantly higher compared to group E, whilst no significant differences of these groups could be observed compared to 0, B, and BS.

The authors concluded that with the in vitro conditions chosen, toothpastes containing n-HAp revealed higher remineralizing effects compared to amine fluoride toothpastes with bovine dentine, and comparable trends were obtained for enamel.