Effects of daily rinses using sodium fluoride and organic fluorides on rat caries.

The organic fluorides, alexidine dihydrofluoride and amine fluoride, provided greater protection against caries than sodium fluoride when used as a daily mouthrinse in rats. Alexidine dihydrochloride also provided significant caries restriction.

Collaborative evaluation of a rat caries model in six laboratories.

When highly controlled parallel rat caries studies were run simultaneously in six laboratories, a similar pattern of caries developed in every laboratory with a range in mean values such that the results of no investigator were significantly different from those of at least two others. These results indicate that the major factors influencing development of rat caries have been recognized and can be controlled within reasonable limits.

A method to assess cariogenic potential of foodstuffs.

By feeding rats their essential nutrition through gastric intubation and test foods on a programmed feeder it is possible to determine the cariogenicity of many foods in animals. Because the test food is the only substance that contacts teeth, all carious lesions that develop can be ascribed solely to the ingestion of the test food. Caries scores can be expressed as ratios of those occurring when animals are fed pure sucrose, thereby comparisons can be made from one experiment to another. The number of carious lesions that develop is directly related to the frequency of ingestion of sucrose. In addition, frequency of ingestion of sucrose has a significant effect on the establishment of S mutans in the mouths of animals. We believe that the approach used here can establish differences in the cariogenic potential of foods in a simple, unequivocal, and reproducible manner.

Inhibition of experimental dental caries using an intraoral fluoride-releasing device.

An intraoral fluoride releasing device designed to provide continual topical fluoride therapy for the prevention of dental caries was found to be effective in inhibiting caries in the rat model. Animals fitted with an intraoral device that released approximately 0.15 mg of fluoride per day developed 63% fewer carious enamel areas than animals receiving no treatment. Fluoridated drinking water (10 ppm) produced a 25% reduction in carious enamel areas. The fluoride-releasing device was more effective than ad libitum fluoridated drinking water in inhibiting caries on the approximal and sulcal surfaces. These results agree with the hypothesis that the continual presence of fluoride in oral fluids enhances the cariostatic effect of fluoride and, when combined with the results of earlier primate and human trials of the intraoral fluoride-releasing device, suggest that this fluoride delivery system can be developed into an effective anticaries agent.

Effect of topical application of stannous fluoride, stannous chloride and stannous tartrate on rat caries.

Topical application of 10 mM aqueous solutions of stannous fluoride inhibited caries in rats to a higher degree than 20 mM sodium fluoride, although the difference was not statistically significant. Furthermore, stannous fluoride reduced the number of Strep. mutans in plaque significantly; stannous ions have an antibacterial effect. Stannous chloride and stannous tartrate did not reduce caries in the rats, probably because of the low concentrations of available stannous ions in these solutions at low pH. The high concentration of stannous ions in solutions of stannous fluoride is probably partly due to the reduced hydroxide formation resulting from the buffering effect of HF formed at low pH in this solution.