Fluoride Concentration in Teeth

After fluoride is ingested, it is distributed from the plasma to all tissues and organs of the body, and gradually becomes incorporated into the crystal lattice structure of teeth in the form of fluorapatite. In teeth, the fluoride concentration is very high on surface enamel, but falls steeply within the first 100 µm. Then fluoride concentration remains constant up to the enamel–dentin junction. Fluoride concentration once again increases inside the dentin, increasing deeper into the tooth, with fluoride steadily accumulating over a lifetime at the dentin-pulp interface. It should be noted that there is no homeostatic mechanism that maintains fluoride concentration in the body. Therefore, regular exposure is required to maintain fluoride concentration in enamel, saliva, and in biofilm on dental surfaces.1