[Caries protective effect of a NaF containing toothpaste with and without calcium carbonate polishing agent]

A caries preventive effect depending on the free fluoride concentration was registrated on rats using dentifrices with NaF or MFP (alone or in combination) despite the presence of CaCO3 as abrasive material because the composition of these dentifrices was changed. The free fluoride concentration of dentifrices had induced the accumulation of fluoride into enamel. The ionized fluoride content of NaF-dentifrices was unchanged for 3 years. MFP was hydrolized and had continuously released fluoride ions. The caries preventive effect which was increased by HCO3- was reproducible in correspondence with the fluoride concentration after the storage for two years.