The effect of dose on maternal-foetal transfer of fluoride in rabbits.

Placental transfer of fluoride was investigated by fluoride determination in the bones and teeth of newborn rabbits whose mothers had been treated with fluoride during pregnancy. The mothers were given doses of 0, 0.10, 0.52 and 1.05 mmol fluoride per kg body weight as sodium fluoride, from the 16th day after conception to the end of pregnancy. All the doses produced a significant increase of fluoride level in the bones and teeth of newborn rabbits, indicating that the placenta was no barrier for the passage of fluoride.