Morphology of Enamel Surfaces Treated with Topical Fluoride Agents: SEM Considerations

Abstract

Three topical fluoride agents deposited surface coatings of different morphology and thickness on intact human enamel surfaces. The agents studied were an acidic silane fluoride lacquer, a neutral NaF lacquer, and an APF gel. Each agent reacted with the enamel surface differently, producing its own distinctive etching pattern. The smallest particles observed in the surface coatings were from 20 to 30 nm in diameter and appeared to have indistinct morphologies. They often agglomerated into spherical globules ranging from 1-3 micron in diameter.

The effect of resin infiltration <i>vs.</i> fluoride varnish in enhancing enamel surface conditions after interproximal reduction

“…The SEM images of enamel surfaces after IPR in this study also displayed a roughened enamel surface, which is in agreement with those previous reports. Although the application of fluoride varnish and resin infiltration could not completely fill up these grooves and furrows, the treated surfaces were relatively smoother than the controls, especially after the pH-cycling 26) . Fluoride varnish has been widely used as a cariespreventive intervention for more than three decades.…”

“…And a recent in situ study has found that fluoride varnish (5% NaF) could significantly remineralize the enamel and provide 50.1% surface hardness recovery 28) . Though the mechanical protection of varnish coating may be removed by toothbrushing or mastication in the oral cavity, it may also be expected that this loss will occur to a lesser extent in grooves and furrows in the approximal tooth surfaces 26) . Low fluoride concentrations can prevent enamel demineralization; high fluoride concentrations, such as these achieved with fluoride varnish (22,600 ppm fluoride) used in this study, can also inhibit bacterial metabolism and acid production through interference with the enzyme enolase 29) .…”

The Influence of Different Fluoride Compounds and Treatment Conditions on Dental Enamel: A Descriptive in vitro Study of the CaF₂ Precipitation and Microstructure

“…Consequently, it is assumed that the ability to form such fluoride deposits is a key factor in the cariostatic efficiency of fluoride dentifrice components [Øgaard, 1990;Øgaard et al, 1990;ten Cate, 1997;Featherstone, 1999]. However, most of the information about calcium fluoride precipitates has been gained from studies based on long-term fluoride treatments with relatively high fluoride concentrations, comparable to those used in treatments with gels and varnishes [Nelson et al, 1983;Cruz et al, 1992;Duschner et al, 1997]. Little is known about the role of these processes during the use of fluoride dentifrice with application times limited to few minutes.…”

Inhibition of Secondary Caries Lesion Progression Using Fluoride Varnish

“…In this study we decided to enhance the remineralization potential of the varnishes by not rinsing, like other authors [Seppä, 1988;Scholtanus et al, 1986]. If FV enhances the formation of a layer of soluble fluoride, mainly CaF 2 -like deposits on enamel [Nelson et al, 1983], this slowly dissolving material is an important source of fluoride for enhancement of remineralization and uptake in the outer enamel over a long time period.…”