Formation of a combined bioceramics layer on titanium implants

Titanium and its alloys are currently the main materials for prosthetics, despite the fact that they, like other metals, have significant drawbacks: they cause metallosis, can provoke the formation of fibrous tissues and bone resorption in the contact zone, are toxic and, in some cases, allergenically dangerous. The noveday trend in implant technology is the prevention of direct contact of living tissues with the metal surface. For this reason, various types of protective coatings are used, usually on the base of ceramics or carbon. It is known that in the contact zone it is preferable to create a well-developed or even porous surface with osteoconductive and osseointegrative properties. This paper discusses the combined technology of modification of titanium. Implant surface treatment includes two main stages: 1) growing a porous protective layer of titanium dioxide deep into the material surface and 2) filling the pores formed on the surface of titanium dioxide with hydroxyapatite to ensure high osseointegrative properties. The formation of a layer of titanium dioxide is provided by micro arc oxidation processing with controllable density of pulsed current; then the pores are filled with crystalline hydroxyapatite by detonation spraying. The results of studying the structure and surface properties of the modified titanium samples are presented and discussed.