DEVELOPMENT AND MINERALIZATION OF THE MOL AR GERMS IN SHEEP - THE EFFECT OF FLUORINE

Molar gems have been sampled from 3 control groups of 7 sheep slauthte red at 5, 9 and 13 months of age to observe their development with tim e. Similar samples have also been taken from 7 sheep slaughtered at 9 months after receiving 3.5 mg fluorine/kg/d during the last 4 months o f life. A third group of 7 sheeps was sampled after being slaughtered at 13 months of age after receiving 3.5 mg fluorine/kg/d during months 5 to 9 of life. The steps in the development of sheep molar buds are the same as those for humans. The 4 cusps making up the 1st or the 2nd molar are organized around 2 infundibulums. The crown elongates progr essively. The root only starts to form 3 to 4 months after eruption. F luorine does not provoke an observable modification of the morphology of the bud before mineralization using photon microscopy. However, the immature enamel shows interior zones where tissue formation seems to be disrupted.