Validation of the intraoral delta Ip system and use of the system to test the efficacy of Mentadent dentifrice.

Ongoing efforts within the oral care industry to improve dentifrices by the addition of anti-tartar compounds, bicarbonate and other agents, have necessitated the continuing evaluation of new products in order to assure their anti-caries effectiveness. However, clinical evaluation of new products is time consuming, prohibitively expensive and ethically questionable. Recently, a number of intraoral models have been developed that appear to be well-suited to evaluate new products. In the present study, an intraoral system was used that monitors short-term demineralization of surface enamel. Subjects wore appliances that contained Streptococcus mutans-coated blocks of bovine enamel and rinsed first with 15 ml of a 20% slurry of dentifrice and, after 30 minutes, with a 10% sucrose solution. Iodide penetrability (Ip) was determined before and after each intraoral exposure, and the difference, or delta Ip, was taken as the measure of demineralization. The model system responded linearly to increasing concentrations of fluoride in a series of standard dentifrice preparations. Mentadent, a fluoride toothpaste with baking soda and peroxide, was shown to reduce enamel demineralization and to provide protection comparable to a clinically tested dentifrice (Crest Regular). These results established the validity of the delta Ip method, and demonstrated the efficacy of Mentadent according to the criteria established at the ADA Consensus Conference on Intraoral Models in 1990.