Sintering 1530°C - 1580°C (see Sintering Cycle)
It is used to realize single crowns, bridges and “full contour” elements.
Dental technicians appreciate Zirconia because it is easy to work with (CAD-CAM technology) and achieves an excellent aesthetic result. This characteristic feeds a growing interest in a more translucent material.
REMARKS ON TRANSLUCENCY
Zirconia translucency depends on raw material and on sintering parameters.
- Higher percentage of Aluminium Oxide in Zirconium Oxide powder means lower translucency
A poly-crystalline product is less translucent than a mono-crystalline one. Due to that Zirconia becomes more translucent by removing Alumina crystals.
- Sintering parameters directly influence the level of Zirconia translucency
Micrographs carried out on Zirconia specimens with different sintering temperatures and permanence time at such temperatures, show that bigger crystals, resulting from higher sintering temperatures or longer permanence, give a greater translucency to the material.
At the same time, the grain size influences in a negative way the values of mechanical, hydrothermal and aging resistance of Zirconia.
- Raw material is essential to achieve translucency and to avoid the decline of technical characteristics
Hydrothermal and aging resistance, in particular, may have a severe decline if low quality raw materials are used. In this case it is possible to work Zirconia the same respecting translucency requirements requested by dental technicians, but the final framework during the years may show problems due to the use of a unsuitable material.
ZYTTRIA® material produced by CONCEPT achieves a great result: Zyttria® Z402 EXTRA-TRASLUCENT has a very low content of Alumina (<0,1%) and a sintering temperature between 1500°C and 1530°C, crystals are big enough but with values that are not greater than 300nm.
All these characteristics guarantee a high translucency, but at the same time, suitable hydrothermal characteristics and restance to aging.
The challenge continues: ZYTTRIA® Z402 EXTRA-TRASLUCENT PLUS
Thanks to its technical know how CONCEPT has developed ZYTTRIA® Z402 EXTRA-TRASLUCENT PLUS that unites high translucency and a very high level of technical performance which is a feature of Zirconia.