If you need a crown that requires minimal clearance or a crown to stand up to a severe bruxer, then a solid zirconia restoration is a viable alternative for posterior crowns and bridges. Designed and milled using CAD/CAM technology, solid zirconia restorations are sintered for over six hours at 1,500°C.
Solid zirconia does not have the same level of esthetics as the layered version, but what is lacks in esthetics, it makes up in sheer strength. Fabricated out of 100% monolithic medical-grade zirconia, it is virtually unbreakable. Even patients with the most severe form of bruxism will not have fracturing issues.
Layered zirconia restorations provide higher esthetics and the flexibility you need for all posterior and anterior cases. The zirconia substructure typically has a flexural strength of 1200 MPa, comparing favorably to traditional porcelain fused to metal crowns. Additionally, extensive laboratory testing has shown the fracture toughness and flexural strength of zirconia are significantly higher than that of alumina or any other all-ceramic materials.
With layered zirconia there is no metal to show through and no unsightly black lines at the gingival margins. Layered zirconia crowns and bridges are cemented conventionally with resin ionomers cement and demonstrate outstanding biocompatibility in the mouth. They can easily be adjusted chair-side with a green stone or a diamond bur.