X-ray diffraction analysis of carious dentine treated with stannous fluoride

Chemistry of Topical Fluorides

“…The reaction products between a stan nous fluoride solution and dental enamel have been studied by Wei and Forbes [1968], , Krutchkoff et al [1972] and Nordquist et al [1975] in a series of investigations using X-ray diffrac tion, infrared internal reflection spectrosco py, scanning electron microscopy and elec tron microprobe. After brief treatment of dental enamel with an 8 or 10% stannous fluoride solution, a rapid penetration of tin and fluoride into the enamel is seen with an average penetration of 20 /<m and an occa sional linear penetration of 30-50 /im.…”

“…More recently, Wei and Forbes [1968b] found, by means of X-ray diffraction, a new crystalline material within the dentinal ma trix after carious dentine had been treated with a 10% solution of stannous fluoride for 24 h. The compound was later identi fied as the tin-fluoride-phosphate com pound Sn3F3PO., , In frared internal reflection spectroscopic studies of flattened enamel surfaces showed formation of Sn3F3P 0 4 in the surface of planed enamel blocks after 2 h exposure to 10% stannous fluoride but not after a 4-min exposure [Krutchkoff et al, 1972], A detailed description based on electron microprobe and scanning electron micros copic studies of the changes in surface en amel exposed to stannous fluoride for peri ods ranging from 30 sec to 1 week has been presented by and Wei [1974]. Their findings may be summarized as follows: No morphological changes were apparent after a 30-sec expo sure.…”

Hydrolytic Properties of Sn3PO4F3(Short Communication)

“…At this temperature it decom poses in a very complex way [Narda et al, 1984], It is evident from the results above that the Sn3P0 4F3 which is generated on the dental surface after topical applications of SnF2 [Wei and Forbes, 1968;Jordan et al, 1971;Krutchkoff et al, 1972] owes its pro tective capacity, at least partially, to its great hydrolytic stability. The stability of this phase is apparently increased at low pH values, and this would be another rea son to explain its protective action.…”

“…Samples of Sn3P04F3 have been nor mally obtained by reaction between SnF3 and synthetic hydroxyapatite [Wei and Forbes, 1968;Berndt, 1970] or from solid SnF2 and concentrated phosporic acid [Jordan et al, 1971]. We have now found that it is possible to prepare this phase by direct precipitation from aqueous solu tions, according to the following (typical) procedure [Narda et al, 1984]: 7.05 g of crystalline SnF2 are dissolved in 40 ml of warm water.…”

The Effect of Demineralization on SnF2-Treated White Spot Enamel Lesions

“…This observation is not, however, borne out in the deeper parts of the surface layer which show a significant degree of rehardening. Wei and Forbes [1968] established, us ing X-ray diffraction techniques, that the same crystalline compound, Sn3F3P 0 4, was formed when synthetic apatite was treated with SnF, solutions of differing concentra tions. More recently, these authors have confirmed this result using an electron mi croprobe.…”