Medical Applications of Calciumphosphate Bioceramics

We discuss various methods to produce bulk apatites, plasmasprayed coatings of apatite and other calciumphosphates onto metallic substrates, and composites of calciumphosphate powders with polylactic acid. In animal studies it has been shown that the interfaces of these bioceramics with bone is characterized by a bioactive behaviour, meaning that bone bonds to surfaces of implants covered with calciumphosphate. Clinically, it has been found that bulk ceramics are suitable for small, unloaded implants to replace or augment bone, while plasmaspraying of metallic implants results in both bioactive behaviour of the surface and sufficient mechanical strength of the bulk of the implant. Composites of calciumphosphate ceramics and polylactic acid are promising and need further investigations. Currently, Hydroxylapatite (HA) coatings as developed by our laboratories are used in Food and Drug Administration (FDA) approved hip joints.