Biomimetic apatite coating on Mg-PSZ/Al2O3 composites. Effect of the immersion method

A bioactive zirconia/alumina composite for orthopedic applications has been developed. The composite was obtained by uniaxial pressing of powder mixtures. To bioactivate the composite a biomimetic method, consisting in the immersion of samples in SBF and 1.4 SBF, was used. The immersion procedure was performed by two different routes: (i) single immersion (21 days in SBF) and (ii) re-immersion method (7 days in SBF+14 days in 1.4 SBF). No change was observed on the surface of the samples immersed for 21 days in SBF. However, a dense and homogeneous bonelike apatite layer was formed on the ceramic composite by using the re-immersion method. The average value for the thickness of the apatite layer was 20 μm.