Reactions of Fluoride Ion with Powdered Enamel and Dentin

Abstract

A REPORT on reactions of the fluoride ion with synthetic hydroxyapatite was presented recently.1 It was shown that with relatively pure hydroxyapatite there is a gradual change in the type of reaction as the fluoride concentration increases. With a high ratio of liquid phase to solid (10 L. of solution to 2.5 Gm. of apatite), fluorapatite is formed at the lowest concentrations of F-and gradually, as the fluoride concentration increases beyond 100 ppm, more and more of the fluoride is converted to calcium fluoride. With a low ratio of liquid to solid (100 ml. of solution and 2.5 Gm. of apatite), the formation of fluorapatite is the chief reaction up to a concentration of 0.2 per cent fluoride; beyond this point, more and more calcium fluoride is formed.Several mechanisms for the reaction of fluoride with enamel, dentin, and bone have been suggested. Neuman, Neuman, Main, O'Leary, and Smith2 have shown that fluorapatite is formed below the solubility product of calcium fluoride. Falkenheim and Hodge,' and Volker, Hodge, Wilson, and Van Voorhis4 have shown that surface adsorption of fluoride takes place. The double decomposition of apatite with high levels of fluoride has been demonstrated by Gerould,5 Scott, Picard, and Wyckoff," and others. This paper presents the results of the extension of the work on synthetic hydroxyapatite to powdered enamel and dentin and an attempt to correlate these findings with those of other workers.

The Fluoridation of Nonstoichiometric Calcium Hydroxyapatite. An Infrared Study

“…In such phosphate loss from fluorided hydroxyapatites cases, mixed phases of calcium fluoride and at low fluoride concentrations has been reported hydroxyapatite are formed according to the (16). Furthermore, it follows from the Ca/P equation ratios that in the two starting materials, 40 and apatite (17), and hence these results together For personal use only.…”

“…method using nitrogen adsorption at 77 'K. (16)(17)(18). It is generally held that fluoride ions impregnating solution on the extent of fluoridation.…”

Observation of Fluorine Invasion Condition in White Spots of Human Enamel Treated with Fluoride

“…From reports of the literature, when fluorine was applied to the tooth, CaF 2 occurs at high doses and FAP forms at low or medium doses [1][2][3][4] .…”

“…Regarding with prevention of caries using fluoride, there are many basic researches such as formation of fluoroapatite (called as FAP in the text) 1,2) , calcium fluoride (called as CaF2 in the text) 3.4) or improvement of apatite crystals 5,6,7) . Most of these researches include in vitro use of synthetic apatite and its chemical reaction with fluoride solution.…”

Transition of Fluoride into Tooth Substance from Sustained Fluoride-Releasing Sealant - In vitro Evaluation -

“…Regarding with prevention of caries using fluoride, there are many basic researches such as formation of fluoroapatite (below FAP in the text) 1,2) , calcium fluoride (below CaF 2 in the text) 3.4) or improvement of crystal structure of apatite 5,6,7) . Most of these researches include in vitro use of synthetic apatite powder and its chemical reaction with fluoride solution.…”