Frequently Asked Questions
New York University Mouth Motion Fatigue Study

Is the durability study an Ivoclar Vivadent study?
The NYU ceramic durability study was performed as part of a larger group of studies looking at many different ceramic systems. The initial goal was to determine best practices for working with veneered zirconia. Lithium disilicate was later added to the study because it had demonstrated significant clinical success.

Does the zirconia substructure fail in this study?
Due to the high strength of zirconia, the substructure remains intact. The veneering ceramic failure however has been shown to be quite substantial. The study reflects the challenges which have been observed clinically with veneered zirconia restorations.

Was only IPS e.max ZirCAD evaluated in the study?
The first study evaluated Lava™/Lava™ Ceram and Cercon®/Vita® Veneer (Dent Mater. 2009
Sep;25(9):1122-7. The second study repeated the same test protocol with IPS e.max ZirCAD / IPS e.max Ceram and monolithic anatomical crowns of IPS e.max CAD. The test results for all zirconia based crowns were similar.

Were the zirconia restorations in this study created using proper support?
Specimen restorations were fabricated by authorized centers for each of the materials tested. The zirconia substructures shown in the study used different support methods. Although, anatomical support of the substructure improves the durability of the veneering ceramic, it does not eliminate the chipping phenomenon.

Are there differences in quality of zirconia?
As a manufacturer of a zirconia restorative product, we believe that there are significant quality differences between various brands of zirconia. However, the substructure of a zirconia restoration is rarely at fault when a failure occurs. The issue is the dissimilar characteristics between zirconia and the layering ceramic. A failure of the layering ceramic is a failure of the restoration.

Does lithium disilicate’s strength diminish in a wet environment?
The NYU methodology was conducted in a simulated wet environment and lithium disilicate still performed far above the other all-ceramic materials tested and supports the excellent results of our clinical trials.

IPS e.max and IPS Empress are registered trademarks of Ivoclar Vivadent, Inc.
Lava, Cercon and Vita are not registered trademarks of Ivoclar Vivadent, Inc.