Abstract
We have investigated the possibility of topical application of a fluoride (F)solution containing tannic acid (TA) for caries prevention in children. The purpose of this study was to clarify the effect of the concentration of TA in the F solution on F uptake in synthetic hydroxyapatite (HAp) and to elucidate the deposits formed on HAp treated with this solution. HAp was immersed in 2%NaF solutions containing 0.05-5% TA for 5 minutes,1 hour,1 day and 10days, and the amount of F in the HAp was determined. The deposits formed on the HAp were investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The following results were obtained.
1) The F uptake in the HAp was increased by increasing the concentration of TA in the F solution.
2) Under the SEM, the deposits formed on the HAp treated with the F solution containing TA were large and morphologically different from those found on the HAp treated with the F solution without TA. The size of the deposits became larger with increasing of the concentration of TA in the F solution.
3) By XRD examinations, CaF2 peaks were detected on the HAp treated with the F solution containig 5% TA for 1 day and 10 days and the specimens treated with the F solutions containing the lower percent TA or without TA for 10 days.
These results demonstrated TA accelerated the F uptake in HAp. However, since the deposits might be a mixture of CaF2 and the complex composed calcium and TA, we must investigate how these products would be retained in the mouth.
