Chemical and Physical Properties of Altered and Sound Enamel

3. Fluoride and Sodium Content

¹ Eastman Dental Dispensary, Rochester, New York, and University of Minnesota, Minneapolis, Minnesota

Stained, white-spot, and brown-spot enamel from the teeth of persons raised in a low-fluoride area was found to be markedly higher in fluoride and lower in sodium than counterpart normal enamel from the same teeth. Both altered and normal enamel tended to be slightly higher in fluoride in older teeth than in younger teeth. However, the fluoride content of normal enamel was the same for outer and bulk enamel. Though the actual fluoride content was not directly related to the decreased dissolution of altered enamel, it was directly related to the degree of discoloration. Although fluoride increased in porous altered areas of enamel, it was postulated that it was concentrated, for the most part, in the outermost portion of the lesion.