Mechanical Properties of Hydroxyapatite in Bone at the Interface with Implants

We intend to obtain information about crystal growth and orientation close to the bone-implant interface using a non-destructive method. We will compare the results at the interface of cortical bone for hydroxyapatite Ca10(PO4)6(OH)2 (HAp) coated and uncoated titanium alloy. At the interface with an implant, bone tends to change its properties, affecting the acceptance of the implant. The preferred orientation of HAp crystallites at the interface bone-implant has been measured with the neutron 2-axis diffractometer D20 at the Institut Max von Laue-Paul Langevin. The implant has two faces, one uncoated and one coated with plasma-sprayed HAp (80mum). We probed the samples with a spatial resolution of 0.5 mm starting at the interface in order to inspect the distributions of the HAp crystallite distribution after implantation.