The in vitro demineralization potential of a sodium fluoride, calcium and phosphate ion-containing dentifrice under various experimental conditions

While fluoride has had a dramatic effect in reducing the rate of caries, it has failed to provide complete protection against caries development, and tooth decay is still widely prevalent. The objective of this study was to d etermine the demineralization prevention potential of a remineralizing dent ifrice with fluoride (Enamelon(R)). and an assured supply of calcium and ph osphate ions on bovine enamel in a cyclic remin/demin regimen using various experimental conditions. A conventional fluoride toothpaste, Crest(R), and a placebo dentifrice were used as controls. One-hundred and forty-four gro und and polished 4 mm bovine enamel cores were prepared and assigned to var ious test treatments using six specimens per treatment group. They were sub jected to six cyclic treatments consisting of one-minute exposures at room temperature to the test product diluted 1:2 in water, remineralization for a specified time at 37 degrees C, and demineralization for a specified time at 37 degrees C. The enamel specimens were tested for microhardness initia lly, and after the first, third and sixth treatment, remineralization and d emineralization cycles using a Buehler Micro-hardness Tester with a 200 g l oad. Differences in micro-hardness between the test groups were analyzed fo r significance by performing multiple pair-a ise comparisons using Bonferro ni significance levels at the 95% confidence level. The results of this stu dy showed that Enamelon Toothpaste was generally more effective in preventi ng demineralization of enamel than the fluoride dentifrice at 0.5 and 1.5 h ours, and the non-fluoride control dentifrice at all time measurements. Pre vention of enamel demineralization by the dentifrices was affected by chang es in demineralization time and pH, but not by changes in remineralization time.