Abstract: A method for preparing a material for medical or veterinary use by uniformly mixing a thermoplastic polymer, preferably polyether etherketone (PEEK), at least with tricalcium phosphate (Ca.sub.3 (PO.sub.4).sub.2), and injection or extrusion moulding the resulting mixture under conditions suitable for converting the tricalcium phosphate into calcium hydroxyapatite. tite. The basic mixture preferably comprises a biocompatible metal oxide such as titanium dioxide (TiO.sub.2). The resulting material is useful for making endosseous implants or bone prostheses.