Surface remineralization potential of nano-hydroxyapatite, sodium monofluorophosphate, and amine fluoride containing dentifrices on primary and permanent enamel surfaces: An in vitro study.

BACKGROUND: Organic amine fluorides and nano-hydroxyapatite dentifrices have shown remineralization potential in various studies. However, there is a lack of direct comparison between amine fluoride and nano-hydroxyapatite with conventional inorganic fluorides as sodium monofluorophosphate. AIM: The aim of the study is to evaluate remineralizing efficacy of the three dentifrices on both primary and permanent enamel surfaces. METHODS: Enamel sections were obtained from 40 sound molars - 20 primary and 20 permanent molars. Five enamel slabs were prepared from these extracted molars stored in artificial saliva, wherein one slab acted as control, second as demineralized (negative control), and other three slabs were brushed with sodium monofluorophosphate, amine fluoride, and nano-hydroxyapatite dentifrices, respectively, twice daily for 21 days. Scanning electron microscopy- Energy dispersive spectroscopy (SEM-EDS) analysis for surface morphology and calcium and phosphorus content and Vickers surface microhardness (SMH) values were evaluated at baseline, after demineralization, and postapplication of the experimental agents. RESULTS: Highly significant changes in calcium phosphorus ratio and SMH values were seen in enamel slabs treated with nano-hydroxyapatite and amine fluoride dentifrice as compared to sodium monofluorophosphate in both primary and permanent teeth. Surface morphology of enamel slabs treated with amine fluoride most closely resembled natural enamel morphology, while sodium monofluorophosphate-treated surfaces showed globular pattern of remineralization. Deposition of a separate highly mineralized layer over existing surface was seen in nano-hydroxyapatite-treated surfaces. CONCLUSIONS: Nano-hydroxyapatite exhibited highest remineralization potential in terms of mineral gain followed by amine fluoride and sodium monofluorophosphate dentifrice.