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 determine the demineralization prevention potential of a remineralizing dentifrice with fluoride (Enamelon), and an assured supply of calcium and phosphate ions on bovine enamel in a cyclic remin/demin regimen using various experimental conditions. A conventional fluoride toothpaste, Crest, and a placebo dentifrice were used as controls. One-hundred and forty-four ground and polished 4 mm bovine enamel cores were prepared and assigned to various test treatments using six specimens per treatment group. They were subjected 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 micro-hardness initially, and after the first, third and sixth treatment, remineralization and demineralization cycles using a Buehler Micro-hardness Tester with a 200 g load. Differences in micro-hardness between the test groups were analyzed for significance by performing multiple pair-wise comparisons using Bonferroni significance levels at the 95% confidence level. The results of this study showed that Enamelon Toothpaste was generally more effective in preventing demineralization of enamel than the fluoride dentifrice at 0.5 and 1.5 hours, and the non-fluoride control dentifrice at all time measurements. Prevention of enamel demineralization by the dentifrices was affected by changes in demineralization time and pH, but not by changes in remineralization time.