摘要 |
A dental or orthopaedic implant comprises a metal or metal alloy whose surface has been converted at least over part of its area to an oxide film X, the oxide film comprising a calcium phosphate-containing material as a composite component over at least part of its area Y The metal or metal alloy preferably comprises a Group IIIA or IVA transition metal or alloy containing the same, and more preferably comprises titanium. The metal or metal alloy surface of the implant is preferably oxidised and/or the composite is preferably formed by Plasma Electrolytic Oxidation. The calcium phosphate-containing material preferably comprises an apatite, for example hydroxylapatite, or tricalcium phosphate. In a preferred PEO process, high frequency current pulses of a particular form, and within a particular frequency range, are used, combined with the generation of acoustic vibrations in 20 a sonic frequency range in the electrolyte, the frequency ranges of the current pulses and the acoustic vibrations overlapping. |