Zirconia - An esthetic alternative

Zirconia is a very hard ceramic that is used as a strong base material in some full ceramic restorations. The zirconia used in dentistry is zirconium oxide which has been stabilized with the addition of yttrium oxide. The full name of zirconia used in dentistry is yttria-stabilized zirconia or YTZP.

The zirconia substructure (core) is usually designed on a digital representation of the patient’s mouth, which is captured with a 3d digital scan of the patient, impression, or model. The core is then milled from a block of zirconia in a soft pre-sintered state. Once milled, the zirconia is sintered in a furnace where it shrinks by 20% and reaches its full strength of approximately 1100MPa.

The zirconia core structure can be layered with aesthetic feldspathic porcelain to create the final color and shape of the tooth. Because bond strength of layered porcelain fused to zirconia is not strong, "monolithic" zirconia crowns are often made entirely of the zirconia ceramic with no aesthetic porcelain layered on top. Zirconia is the hardest known ceramic in industry and the strongest material used in dentistry. Initially Monolithic zirconia crowns were dense in appearance with a high value and low in translucency and fluorescence. For aesthetic reasons, many dentists will not use monolithic crowns on anterior (front) teeth. But today with the introduction of newer zirconia block by Kuraray Noritake Dental Inc, world leaders in ceramic technology called the Katana ML which contains different colors in the same block with high degree of translucency, it is possible to make esthetic monolithic zirconia crowns.


Multi Layered, KATANA Zirconia (ML)


Translucency of 1.0mm Thickness


Translucency Parameter


Low Monoclinic Transformation

What is Monoclinic Transformation?

Underhydrothermal condition, tetragonal system of zirconia surface transforms to monoclinic and gets brittle. (See figure of Company A)

KATANA Zirconia, however, will have minimal monoclinic shift and maintain its strenght. (See figure of KATANA Zirconia)

3D printing

3d printing