In vivo characterization of the interface between cortical bone and biphasic calcium phosphate by the PIXE method

The aim of this study is to evaluate the resorption of a calcium phosphate ceramic composed of 75% hydroxyapatite and 25% beta-tricalcium phosphate (H TCP) used as a biomaterial, The animal implantation has been made in the co rtical femur of sheep. Delays of 2, 4, 8, 12, 16, 20, 28, 36 and 48 weeks b etween graft and analysis were used. The samples were a section of cortical bone containing the implant, The mechanism of bioceramic degradation was s tudied by the particle-induced x-ray emission (PIXE) method, The bone/impla nt interface was analysed and Ca, P, Zn, Fe and Sr were measured for the ni ne delay periods. We found a discontinuity of elemental concentration at th e interface. Thus, we observed evolution of the concentration of each eleme nt in HTCP according to time after implantation. Then we determined the kin etics of resorption. Copyright (C) 1999 John Wiley & Sons, Ltd.