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 bond coating of 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 apatite in the second layer is a bioactive agent that can
osteobond to tissue. 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.