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Fluoride and enamel solubility
Author(s) -
LARSEN M. JOOST,
THORSEN ANETTE
Publication year - 1974
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.1974.tb00401.x
Subject(s) - fluorapatite , fluoride , supersaturation , solubility , octacalcium phosphate , chemistry , enamel paint , phosphate , inorganic chemistry , brushite , nuclear chemistry , apatite , mineralogy , materials science , organic chemistry , composite material
— The present paper deals with the solubility of enamel and the influence of fluoride on the degree of saturation with respect to hydroxyapatite. Enamel surfaces were exposed to 8 ml buffer at various pH values. The buffers were analyzed at suitable intervals for calcium, phosphate, fluoride and pH and the ionic activity products for fluorapatite, hydroxyapatite, calcium fluoride, brushite and octacalcium phosphate were calculated. It was found that the buffers were supersaturated with respect to fluorapatite and remained unsaturated with respect to the other salts investigated. Under these conditions fluorapatite was formed while hydroxyapatite dissolved, the system thus tending toward equilibrium at which the liquid phase is saturated concurrently with respect to both apatites. It is suggested that at least a part of the solubility reducing effect of fluoride is due to fluoride rendering the liquid phase supersaturated with respect to fluorapatite. This results in formation of fluorapatite, rendering the liquid phase unsaturated with respect to hydroxyapatite.