E. Jallot et al., Resorption kinetics of four hydroxyapatite-based ceramics by particle induced X-ray emission and neutron activation analysis, EPJ-APPL PH, 6(2), 1999, pp. 205-215
From the viewpoint of hard tissue response to implant materials, calcium ph
osphates are probably the most compatible materials presently known. During
the last few years, much attention has been paid to hydroxyapatite and bet
a-tricalcium phosphate as potential biomaterials for bone substitute. A goo
d implantation of biomaterials in the skeleton is to reach full integration
of non-living implant with living bone. The aim of this study is to compar
e the resorption kinetics of four kinds of calcium phosphate ceramics: hydr
oxyapatite (Ca-10(PO4)(6)(OH)(2)), hydroxyapatite doped with manganese or z
inc and a composite material of 75% hydroxyapatite and 25% beta-tricalcium
phosphate (Ca-3(PO4)(2)) Cylinders (5-6 mm in diameter) of these ceramics w
ere packed into holes made in the femur diaphysis of mature ovine. At 2, 4,
8, 12, 16, 20, 28, 36 and 48 weeks after the operation, bone/implant inter
face was embedded in polymethylmethacrylate. We used the PIXE method (parti
cle induced X-ray emission) to measure the distribution of mineral elements
(Ca, P, Sr, Zn, Mn and Fe) at the bone/implant interface. At 4, 8; 16, 28
and 48 weeks after implantation we studied a biopsy of the ceramics by neut
ron activation method. Then, we have a global measurement of mineral elemen
ts in the biomaterial. The results showed that the resorption kinetics of h
ydroxyapatite doped with zinc was faster than that of the three other bioce
ramics.