Scanning electron microscope and electron microprobe study of reactions of stannous fluoride and stannous chloride with dental enamel

Abstract

Ellingsen JE: Scanning electron microseope and electron microprobe study of reactions of stannous fluoride and stannous chloride with denial enamel. Scand J Dent Res 1986; 94: 299-305.Abstract -Stannous fluoride but not stannous chloride has shown a caries inhibiting effect in animal studies. The eJOfecJ of aqtieous solutions of stannous fluoride and stannous chloride on dental enamel surfaces was investigated by scanning electron microscope and analytical electron microprobe. Some large globules and a condnuous layer of small globules were observed after stannous fluoride treatment. The large globules were soluble in both water and alkali, whereas tbe small ones were only soluble in alkali. Both fluoride and tin were found to be present on the enamel surfaces by the electron microprobe after stannous fltioride treatment. The fluoride could not be detected after immersion in distilled water whereas alkali treatment removed the tin. The large fluoride-containing globules may consist of calcium fluoride as this substance is known to be slightly soluble in water and soluble in alkali. Stannous chloride treatment gave a layer of small tin-containing globules with properties similar to the layer formed on enamel treated with stannous fluoride. It is therefore suggested that the dn-eontaining layer is not associated with caries protection whereas calcium fluoride-like deposidon on the enamel probably is a factor in the caries inhibition caused by stannous fltioride.Stannous fluoride has been successfully used one possible aspect of die caries inhibition,, in caries prevention for a long time (1-5). and evidence for the presence of SnaFsPOj The mechanism of the caries inhibiting effect crystals on the enamel surface has been preof this compound is not completely undersented in several publications (6-9). It is stood. Reaction products between stannous knovifn that stannous fluoride, but not stanfluoride and enamel have been discussed as nous chloride, inhibits caries in rats (10, 11).

Effect of Fluoride Compounds on Enamel Erosion in vitro: A Comparison of Amine, Sodium and Stannous Fluoride

“…The reaction products of SnF 2 and enamel are not fully determined, but X-ray analysis showed that the aqueous reaction of SnF 2 and hydroxyapatite could result in the precipitation of Sn 2 OHPO 4 , Sn 3 F 3 PO 4 , Ca(SnF 3 ) 2 or CaF 2 salts [Babcock et al, 1978]. It has further been demonstrated that not only SnF 2 but also SnCl 2 is capable of depositing appreciable amounts of tin on enamel which were relatively stable in distilled water for days [Ellingsen, 1985].…”

Alternatives to Fluoride in the Prevention and Treatment of Dental Erosion

“…An early experiment [38] investigated the effects of Sn (as SnCl 2 ), on etched enamel. A 0.2% SnCl 2 solution was applied for 6 × 2 min and washed in between with running distilled water for 30 s after each treatment.…”

A qualitative and quantitative investigation into the effect of fluoride formulations on enamel erosion and erosion–abrasion in vitro

“…3 Stannous fluoride (SnF 2 ) solutions can form a surface glaze or coating when applied to enamel, which could have resulted in reduced enamel loss in various erosion only models. [4][5][6] Despite high concentrations of an aqueous NaF solution being shown to reduce erosion-attrition in vitro, 7 there are relatively few studies into the ability of NaF or SnF 2 aqueous fluoride solutions to withstand a combined erosive-abrasive challenge. Fluoride induced surface effects may remain on enamel for up to 12 weeks in vivo 8 and in vitro studies of NaF containing oral care products have been shown to offer protection from erosive drinks.…”