In vitro fluoride uptake by enamel and dentin: A comparative study of two varnishes

The uptake of fluoride in enamel and dentin after application of an experimental fluoride varnish has been studied and compared with the uptake from a commercially available varnish (Duraphat). Each varnish was applied to 10 extracted human cuspid teeth. Successive etchings with perchloric acid were carried out separately in enamel and root dentin to obtain samples at three different depths. The concentrations of fluoride and calcium in the samples were determined, and the fluoride uptake was calculated. The experimental varnish gave a significantly greater fluoride uptake at all three sample depths in both enamel and dentin.