Evaluation of the anticaries benefit of fluoride toothpastes using an enamel insert model

The remineralization potential of fluoride toothpastes was studied using an in situ enamel insert model. Matched blocks of artificially demineralized human enamel were attached to partial dentures of 16 adult volunteers who brushed their teeth with either a toothpaste containing 1,500 ppm F or one containing 2,500 ppm F for a period of 6 weeks in a balanced, randomized crossover experiment. Computerized image analysis of microradiographs was used to measure the mineral density distribution in the enamel before and after in situ treatment. Both toothpastes demonstrated remineralization of artificial carious lesions. Significantly more remineralization was observed in enamel samples treated with the toothpaste containing 2,500 ppm F compared to that containing 1500 ppm F. This result is consistent with the outcome of a recent caries clinical trial testing the same toothpastes and finding enhanced anticaries efficacy from the higher fluoride level.