KINETICS OF THE DIFFUSION OF SOME ELEMENTS EVALUATED BY NEUTRON-ACTIVATION IN A CORAL IMPLANTED INVIVO

Some studies show that a coral implanted on bone tissue is gradually t ransformed to become a neoformed bone. In our work, we have, for the f irst time, determined quantitatively by NAA the transformation of a co ral used as a biomaterial implanted ''in vivo'' in some ovine jaw-bone s. Each month and during 9 months, biopsies were extracted. For neutro n production, the nuclear reaction Be-9(d, n)B-10 was used with 17.5 M eV energy deuterons- The neutrons had a mean energy of 7 McV and a flu x of 10(12) n CM-2 S-1. The radioactivation generated permitted concen tration measurements of Ca, P, Mg, Sr and F in each part of the biopsi es and a study of mineral transformations versus time in the coral imp lanted. Three months after implantation, Ca belonging to CaCO3 represe nted 11 % and Ca provided by the apatite formed represented 20% of the total mass. These quantitative evaluations clearly showed that five m onths after implantation, the coral had become a neo-formed bone.