Abstract :
Tetragonally stabilized, polycrystalline zirconia
(TZP) is an interesting material for dental
applications due to the tooth-like appearance, biocompatibility
and, compared with other advanced
ceramics, high bending and tensile strength. At
present fully sintered TZP dental crowns or bridges
can only be made via CAD-CAM supported mechanical
milling processes, but the high costs and long
processing times are disadvantageous. In contrast to
this process a less expensive preparation is possible
via near net-shape electrophoretic shaping from
aqueous suspensions and consecutive sintering. As
the deposition rate for electrophoretic deposition
(EPD) is independent of particle size, bimodal
starting powders can be used for optimizing the
green density of the compact. Thus the shrinkage
during sintering can be minimized. Furthermore, the
pore structure can be controlled.
In this paper the preparation of dental crowns via
EPD is shown. With a combination of commercially
available micron-sized Ce-stabilized zirconia (Ce-
ZrO2) powder, nanosized zirconia powder (nano-
ZrO2), and a submicron alumina powder (Al2O3)
compacts with relative green densities up to 78%
could be achieved. These compacts could be completely
sintered at 1,600 C with a linear shrinkage of
less than 9%
