Zirconia Dental Implants Crowns , Complete Dental Implants FDA
Abutment Material - Zirconia Physical properties
ZrO 2 adopts a monoclinic crystal structure at roomtemperature and
transitions to tetrgonal and cubic structures at higher
The volume expansion caused by the cubic to tetragonal to
monoclinic transformation induces large stresses, and these
cause ZrO 2 to crack upon cooling from high temperatures. When the
ziconia is blended with some other oxides such as yttrium oxide (Y
2 O 3 , yttria), the tetrago-
nal and/or cubic phases are stabilized.
Even though different brands of zirconia can be chemically similar
they are not necessarily the same.
Different brandsof zirconia ceramic are chemically similar, but
once processed it can exhibit different mechanical and optical
When working with zirconia there are differences in machinability
(e.g. wet millingand dry milling) and in sintering (e.g. sintering
temperature for Vita™ YZ-Cube is 1530°C; for Lava™frameworks is
1500°C; for Cercon™ is 1350°C).
What is different? In principle, there is pre-sintered zirconia and
HIP zirconia available on the market.
The pre-sintered zirconia is milled and the material still has a
soft, chalk-like consistency.
For full density, it is sintered again after milling.HIP material
is milled in the fully sintered state.
Note that the processing parameters for pre-sintered zirconia
affect its performance