Biomedical Engineering Reference
In-Depth Information
5.5
Postscript
A reliable
in situ
oxidation technique of zirconium united the advantages of ceram-
ics and metals, short circuiting their disadvantages and circumventing the prob-
lem of coating adhesion to the substrate. Meanwhile, OxZr, marketed under the
trade name OXINIUM
TM
, with an oxide thickness of 5 m, got its share in joint
arthroplasty and is a true technological leap.
Two other leaps in science and technology were briefly reviewed:
glassy metals
and
quasicrystals
. The aim was to open a window on ongoing research on materials
hardly present on the biomaterials forum. Coined by two and a half millennium of
thinking in terms of Euclidean order, we hardly realize how deeply it determined
our vision on structure and physics of matter. All metals discussed thus far were
crystalline and the introduction of these new items should stimulate to look behind
the present horizon.
Polymer chemists and biologists were already longtime familiar with less ordered
or chaotic systems. Silicate glasses are common goods since more than two millen-
nia but glassy metals were not. What do they keep in store for the biomaterialist?
Five-fold rotational symmetry was only common in flowers but unseen or seen
as impossible in crystalline matter. But they do exist, can be mass-produced and
combine a number of peculiar properties that may one day be exploited by the
biomaterialist.
