Enamel microhardness and fluoride uptake underneath fermenting and non‐fermenting artificial plaque

The effect of fluoride and magnesium on bovine enamel through a fermenting Streptococcus mutans layer was investigated. The enamel slabs with the microbial layer were incubated for 18 h at 37 °C. The addition of fluoride at a concentration of 25 ppm reduced the pH drop in the fermenting ‘plaque’ and also in part the calcium and phosphorus liberated from the enamel. The addition of magnesium at a concentration of 40 ppm alone had no effect on the pH decrease but increased slightly the enamel phosphorus liberation. Adding fluoride and magnesium simultaneously tended to lessen the effect of fluoride on enamel dissolution. Enamel softening was markedly prevented by the addition of fluoride alone and very slightly by the addition of magnesium. The fluoride content both in the surface and the subsurface layer of the enamel was much increased in the presence of added fluoride, especially underneath the fermenting plaque. Adding magnesium to the fermenting plaque decreased the magnesium content of the enamel surface, especially when fluoride was present.

Section: Dissolution O F Enamel Minerals By the Streptococcal Layer Asupporting

confidence: 65%

Effect of Magnesium and Fluoride on the Fermentative Dissolution of Enamel by a Streptococcal Layer as Measured by Microhardness Tester and a Proton Probe Microanalysis

Luoma¹,

Luoma²,

Räisänen³

et al. 1983

“…This did not prevent fluoride up take from the varnish. Plaque is suggested to promote fluoride uptake by enamel [Bruun and Stoltze, 1976;Charlton et al, 1974;Turtola, 1977;Weathered et al, 1972]. There is also evidence that the effect of fluoride is pronounced in the presence of fermenting plaque, i.e.…”

Section: Discussionmentioning

confidence: 99%

Effect of Dental Plaque on Fluoride Uptake by Enamel from a Sodium Fluoride Varnish in vivo

Seppä¹

1983

“…Similar re sults have been published by several authors [Purdell-Lewis, 1977;Davidson et cil., 1974;Turtola, 1977].…”

Section: Resultsmentioning

confidence: 99%

Microhardness Indentations on Artificial White Spot Lesions

Arends¹,

Schuthof²,

Jongebloed³

1979

In this study, Knoop hardness experiments on artificial carious enamel (pH 5.0, 4.5 and 4.0) are presented with the load perpendicular to the subsurface lesion. The results show that for human and bovine enamel the indentation length is proportional to the square root of the load. The proportionality constant is numerically estimated for all pH values for human and bovine enamel. The indentation measurements reflect the decalcification despite the presence of surface layer covering the lesion.