[The effect of Duraphat varnish on fluoride content of enamel in deciduous teeth]

The aim of this study was to analyse the fluoride distribution in deciduous teeth enamel after using Duraphat varnish,and to supply the evidence for preventing deciduous caries by using Duraphat varnish.

After coating Duraphat varnish, the alteration of fluoride distribution in the enamel was observed with electron probe micro-analysis. The result was compared with the control group and NaF solution group. The effect of dose and period of coating Duraphat varnish on fluoride distribution in enamel was evaluated by X-ray photo-electron spectrometer(XPS). The data was analyzed with SPSS17.0 software package.

The mean values of fluoride concentration in the control group, NaF group and Duraphat varnish group were(0.0406±0.0234)wt%,(0.1006±0.1040)wt% and (0.1844±0.1293)wt%,respectively.The concentration of fluoride in the Duraphat varnish group was significantly higher than that in the NaF group (P<0.01). In period-dependent test,the mean values of fluoride concentration at 10μm under the enamel surface of short period group and long period group were(0.2407±0.0034)wt%, (0.1434±0.0133)wt%; The concentration of fluoride in the short period group was significantly higher than that in the long period group(P<0.01). In dose-dependent test, the mean values of fluoride concentration at 10μm under the enamel surface in the low-dose group and high-dose group were(0.4417±0.0034)wt%,(0.4413±0.0044)wt%, the concentration of fluoride in the low-dose group and high-dose group had no significant difference(P>0.05).

It is an effective way to increase the concentration of fluoride in enamel by coating Duraphat varnish on the surface of deciduous teeth. Shorten the coating period could increase the concentration of fluoride in enamel effectively but the concentration of fluoride in enamel does not go up along with the coating dose increase.