Effect of fluoride addition on ionized calcium in salivary sediment and in saliva.

Fluoride was added in increments to pooled whole saliva. The ionized calcium concentration was determined in the saliva and the salivary sediment after centrifugation. The maxima of the ion product with respect to calcium fluoride were for salivary sediment and saliva found at 15 mmol/l and 25 mmol/l of fluoride, respectively. The study indicated that calcium fluoride may precipitate in the plaque matrix during and after topical application of fluoride.