Effect of Iontophoresis on Fluoride Uptake and Retention in Enamel

Abstract

The purpose of this study was to examine the effect of fluoride iontophoresis on fluoride uptake and retention on the bovine enamel surface.
Bovine enamel was treated with fluoride iontophoresis at 50, 100 and 200μA for two or four minutes. Enamel treated with fluoride alone without iontophoresis was used as a control. The treatment regiments were one time only, or once a day for three consecutive days. The treated enamel was soaked in artificial saliva for 30 minutes, 24 hours and 1 week, and in 1M KOH solution for 24 hours.
The results were as follows :
1. Iontophoresis significantly increased fluoride uptake in the surface enamel compared with the control.
2. Fluoride uptake increased significantly with an increase in electric current.
3. Iontophoresis significantly increased fluoride retention compared with the control.
4. There was no difference in fluoride uptake between the two- and four-minute treatments with iontophoresis. The two-minute treatment with iontophoresis showed significantly higher fluoride uptake than the four-minute treatment of the control.
5. The treatment with or without iontophoresis showed a greater increase in fluoride uptake and retention in the enamel treated once a day for three consecutive days than for treatment only once. The rate of increase in fluoride uptake and retention were greater with iontophoresis than with the control.
The results of this study suggest that iontophoresis enhances the activity of fluoride with respect to fluoride uptake and retention in the enamel surface.