The effect on dental enamel of varying concentrations of fluoridated milk with a cariogenic challenge in situ

Abstract

ObjectivesThis study investigated the effect of two concentrations of fluoride in milk, 2.5 and 5.0ppm, on the prevention of demineralisation with a cariogenic challenge compared with milk with 0ppm F. MethodsIn a controlled, randomised, cross-over, double-blind in situ study, 23 subjects wore a lower removable appliance with 2 enamel slabs for 21days during each study arm. Subjects used F-free toothpaste and the cariogenic challenge comprised of five 2min dippings per day in 12% sucrose. The slabs were dipped in 50ml of milk with 0ppm, 2.5ppm or 5.0ppm F twice daily for 5min. Subjects drank 100ml twice per day of the same milk. Slabs were analysed with Knoop microhardness to assess changes in mineralisation. ResultsResults showed that enamel was softened in all groups but the extent of enamel softness was reduced with an increasing concentration of F in milk, being highly significant for both F groups compared to the control (p<0.0001). 5.0ppm F group showed a trend towards less softening compared to the 2.5ppm F but was not statistically significant. ConclusionsIn our in situ model, 2.5 and 5.0ppm F in milk significantly protected enamel from demineralisation.