Aluminia and zirconia bioceramics in orthopaedic applications

Abstract

Interest in ceramics for biomedical applications has increased over the last thirty years. The ceramics that are used in implantation and clinical purposes include alumina, partially stabilised zirconia (PSZ) (both yittria [Y-TZP] and magnesia stabilised [Mg-PSZ]), bioglass®, glass-ceramics, calcium phosphates (hydroxyapatite and ß-tricalcium phosphate) and crystalline or glassy forms of carbon and its compounds. An improved understanding of currently used bioceramics in implants and in bone replacement materials could contribute significantly to the design of new generation prostheses. Overall, the benefits of advanced ceramic materials in biomedical applications have been universally accepted, specifically, in terms of their strength, biocompatibility and wear resistance. However, the amount of supporting data is not large and the continuous development of new methods is pertinent for better understanding of the microstructure-properties relationship and, in general, for obtaining new directives for their further improvement. This paper gives an overview and re-examines key-issues which concern both processing and applications of alumina and zirconia (PSZ and Y-TZP) ceramics as orthopaedic biomaterials.