The influence of saliva on the formation of calcium fluoride-like materialon human dental enamel

After a topical fluoride application two resulting features can be observed and measured: the formation of calcium fluoride and a decrease in caries i ncidence. For the formation of solid calcium fluoride the source of calcium may be either the enamel itself or remaining saliva or - in plaque - plaqu e fluid and calculus. The aim of the present study was to examine whether s aliva through its calcium content has any influence on the amount of calciu m fluoride formed by a topical fluoride treatment of enamel. The roots and the fissure systems of 64 freshly extracted intact third molars were covere d with nail varnish and allocated to eight groups of 8, Half of the groups were put in fresh paraffin-stimulated saliva for 5 min after which surplus of saliva was shaken off whilst the other groups remained in distilled wate r. The teeth were given a 2-min topical treatment with either distilled wat er (control), neutral 0.2% NaF, neutral 2% NaF or 2% NaF acidified with 0.1 mol/l H3PO4. After the topical treatment the teeth were rinsed in running tap water for 5 min, dried and revarnished before determination of calcium fluoride. It was found that the amount of calcium fluoride formed depended on the concentration of fluoride (the higher the fluoride concentration, th e higher was the amount of calcium fluoride), the acidity of the solution ( presumably due to the increase in available calcium through enamel dissolut ion) and the presence of saliva (presumably due to its calcium content and its mucinous nature). As there was always more calcium fluoride formed in t he presence of saliva, thorough drying of the teeth prior to topical treatm ents may be superfluous Copyright (C) 2001 S. Karger AG, Basel.