[The stability of fluoride concentrations at the enamel surface].

A new method for in vitro fluoridisation of dental enamel is presented where commercial fluoride tablets of available fluoride compounds are subjected to comparative tests (Sodium fluoride, magnesium fluoride, or trisodiumhexafluoroferrate). Special consideration was given to stability of fluoride concentration on the enamel surface. Considerable differences were observed in the level of fluoride content directly after the last administration of fluoride and also the amount of fluoride concentration in 24 hours. The highest initial fluoride concentration was achieved with NaF (pH 4.0) and Na3FeF6 in combination with NaF, CaF2 and MgF2 (pH 4.0) whereas the greatest stability was reached with NaF.