Surface modification of biomaterial by laser irradiation method

Alumina ceramic (Al/sub 2/O/sub 3/) has been used for a hard tissue substitution material, such as for artificial joints and tooth roots, because of its high wear-resistance, high hardness and chemical stability. Al/sub 2/O/sub 3/ is, however, a bioinert material and requires mechanical fabrication by a screw cutter to be embedded in a human body. On the other hand, it is well known that calcium phosphate ceramics are bioactive materials. Since hydroxyapatite ceramics [HAp: Ca/sub 10/(PO/sub 4/)/sub 6/(OH)/sub 3/], especially, consist of an inorganic component in bone and have high biocompatibility, they are used as a bony filler. HAp is, however, inferior in mechanical strength. In the medical field, development of a material with both advantages mentioned above is desired. In this study, a simple method using a discharge-pumped KrF excimer laser is presented for formation of a KAp layer on A1/sub 2/O/sub 3/. The bio-compatibility of the sample formed by this method is confirmed with a simulated body fluid (SBF) containing an apatite-wollastonite glass (A-W glass) and the growing mechanism of the KAp layer is discussed.