Zahradnik R T, Propas D, Moreno E C
J Dent Res. 1978 Sep-Oct;57(9-10):940-6. doi: 10.1177/00220345780570092501.
Applications of APF and NaF solutions to extracted human teeth reduced the extent of enamel subsurface demineralization induced by colonization of S. mutans but were ineffective against demineralization by acid lactate buffers. It is concluded that the CaF2 formed on the tooth surface during the treatment is responsible for the protection observed.