Hydroxyapatite implantation in titanium implant's surfaces

摘要

Titanium and some of its alloys are commonly accepted as materials for orthopedic implants such as artificial tooth roots mainly due to its superior mechanical strength. Bone formation around titanium implants can make a contribution to long-term stable fixation of the implants. Therefore, enhancement of osteoconductivity of the surface of the implants has been a key to improve the implant. We are attempting to improve the fixation of the titanium implants to bone by implanting hydroxyapatite (HAP) spots on the implant's surface. The spherical HAP ceramics were pressed against the surface of pure titanium substrate by a loading rate of 0.1 kN/min up to 1 kN at 850 deg C. By this method, most part, except near surface, of the spherical HAP ceramics was surrounded by deformed titanium, resulting in mechanical holding of the spherical HAP ceramics. The HAP spots on the titanium surface are expected to bond to bone much faster than titanium. Furthermore, cavities made by the implantation have sufficient volume to induce bone ingrowth that contributes long-time stability of the implants by microanchoring.