The effect of baseline lesion mineral loss on in situ remineralization

The effect of baseline lesion mineral loss on the remineralization of enamel lesions by a sodium fluoride dentifrice was studied in situ by means of an appliance carrying enamel sections. Artificial lesions of various sizes were created, by means of acidified gelatin, and were then mounted on the appliances of five volunteers. Each brushed twice daily for two min with a 1000 ppm F sodium fluoride dentifrice. Measurements of mineral content were made at baseline and at weekly intervals by microradiographic/microdensitometric techniques. Data from all five volunteers showed a linear increase in remineralization rate with increasing lesion size. Thus, in studies which compare the effects of different remineralizing formulations, care must be taken to ensure that initial lesion sizes are matched, or that the results are expressed as a percentage change in mineral content.