A multi-layer coating is particularly useful for the coating of implants
such as orthopedic and dental implants, particularly metallic implants.
The first layer comprises a dense material insoluble and inert in body
fluids. The second layer comprises apatite and a binder. The first layer
protects the metallic implants from corrosion, apatite dissolution, and
interfacial reaction with apatite and the binder. The binder allows
adjustment of the thermal expansion coefficient between the coating and
the metallic substrate. This multi-layer coating has both high bond
strength to implants and excellent bioactivity with the surrounding body
tissue.