Titanium and its alloys are being used as biomaterials in many orthopedic and bioimplant applications. Titanium is usually coated with hydroxyapatite (HAP) in order to enhance osteointegration. The hydroxyapatite coating process affects the bond strength which in turn determines the durability of the Ti implants and the adherence of the bone cells to the substrate. The coating bond strength should exceed the bone strength in order to obtain a better implant lifetime.

 EMD Technologies, LLC has developed a technology to coat hydroxyl apatite onto Ti and Ti-alloy surfaces based on a patented procedure . Using this process interfacial bond strength in excess of 40 MPa can be achieved between nanocrystalline hydroxyl apatite and the Ti base substrate.

Nanocrystalline hydroxyapatite deposited onto nanotubular TiO₂ layer of the Ti-base substrate.