A study of the effect of fluoride delivered from solution and dentifrices on enamel demineralization

An in vitro demineralization model has been developed and used to examine the effect of various fluoride treatments on early enamel demineralization. The effect of fluoride treatments on the calcium demineralization rate of enamel was studied by analyzing the amount of calcium which demineralized from teeth into solution when the teeth were exposed to weak acid solutions. Continuous (72 h total) exposure of enamel to very low levels of fluoride, 0.014 ppm, was observed to have a protective effect against demineralization, as was intermittent exposure to higher levels of fluoride delivered from solution and from dentifrices for shorter periods of time (40 min total). This work suggests that the residual salivary fluoride concentrations reported to be reached by water fluoridation (0.016 ppm) or brushing with a fluoride-containing dentifrice (0.014 ppm) give a level of fluoride in saliva which may give some protection to the dental enamel from demineralization.