Prevention of enamel demineralization with a novel fluoride strip: enamel surface composition and depth profile.

Bor-Shiunn Lee,Hua-Yang Liao,Shu-Yu Chen,Che-Chen Chang,Po-Hung Chou

doi:10.1038/srep13352

Bor-Shiunn Lee, Hua-Yang Liao + Show 3 more

Open Access

https://doi.org/10.1038/srep13352

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Abstract

There is no topically applicable low concentration fluoride delivery device available for caries prevention. This study was aimed to assess the use of a low concentration (1450 ppm) fluoride strip as an effective fluoride delivery system against enamel demineralization. The enamel surface composition and calcium-deficient hydroxyapatite or toothpaste treatments were investigated using X-ray photoelectron spectroscopy. In vitro enamel demineralization was assayed using a pH cycling model and the dissolution of calcium ions from the treated specimens was quantified using ion chromatography. After 24-hr fluoride-strip treatment, the enamel was covered with a CaF2 layer which showed a granular morphology of 1 μm in size. Below the CaF2 layer was a region of mixed fluorapatite and CaF2. Fluoride infiltrated extensively in enamel to produce highly fluorinated fluorohydroxyapatite. In comparison, low-fluoride-level fluorinated fluorohydroxyapatite was formed on the enamel specimen exposed to toothpaste. The treatments with the fluoride strip as short as 1 hr significantly inhibited enamel demineralization. The fluoride strip was effective for topical fluoride delivery and inhibited in vitro demineralization of enamel by forming CaF2 and fluoride-containing apatites at the enamel surface. It exhibited the potential as an effective fluoride delivery device for general use in prevention of caries.

Highlights

3.5, and fluoride varnishes like Duraphat containing 5 wt% sodium fluoride or 2.26 wt% F− at pH 4.5 in an alcoholic suspension of natural resins[12]
For the fluoride strip group, the F 1s signal detected at exposure time of more than 2 hr (Fig. 2(B)) indicated that fluorination of LFHAP, took place
The fluorinated LFHAP present on the enamel specimen surface after experiments that gives a detectable F 1s signal by X-ray photoelectron spectroscopy (XPS) is termed FHAP

Summary

Introduction

3.5, and fluoride varnishes like Duraphat containing 5 wt% sodium fluoride or 2.26 wt% F− at pH 4.5 in an alcoholic suspension of natural resins[12] For effective treatments, both agents have to be applied at high concentrations in-office by professionals and their long-term use is inconvenient. Casein phosphopeptide-amorphous calcium phosphate complexes have been developed and have been added to chewing gum, mouth-rinse, sealants, and milk for enhanced remineralization of enamel[13,14] Their long-term efficacy in caries prevention needs to be further investigated. Slow-release devices of low level fluoride are regarded as a potential method to elevate fluoride concentration at the biofilm/saliva/dental interface and inhibit dental caries[15,16]. Using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), we examined the nature of the fluoride deposition at the enamel surface and investigated the potential caries preventive action of the fluoride strip application using an in vitro enamel demineralization assay

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