Effects of a high-bicarbonate dentifrice on intraoral demineralization.

Dentifrices available on the market today contain sodium bicarbonate in a wide range of concentrations. Anticaries efficacy has been demonstrated for these dentifrices in a variety of tests. New insights were gained in the present study in which the effect of a high-bicarbonate dentifrice on the sucrose-induced demineralization of tooth enamel in situ was examined. With the intraoral Delta Ip system it is possible to follow the minute changes in tooth enamel that essentially model the daily episodes of demineralization accompanying the ingestion of various foods. The results revealed a pronounced effect on the pH of the test plaque and a considerable reduction in mineral loss from the enamel. The effect persisted from more than 1 hour and, during that time, appeared to predominate over the effect of fluoride. These findings suggest that bicarbonate may provide additional protection against the loss of tooth enamel. Such effects may be significant for the design of new high-bicarbonate products.