In most cases the choice will be between a Porcelain Crown and a Zirconium Crown.
Zirconium Crowns have several advantages of standard Porcelain crowns:
Strength and Longevity:
Zirconium is virtually indestructible whereas Porcelain crowns are prone to chipping. Crowns have a lifetime of around 10 years. Zirconium should last a lifetime.
Have you ever seen people with a large unsightly black line above their gums? Up until recently most crowns are Porcelain which is Fused to a Metal base. Over time, the metal begins to show more and more and the restoration can look opaque and monochromatic, with the tell tale dark grey line at the crown join.
The Zirconium Crowns not only look more translucent, but are much stronger than the Porcelain fused to the Metal posts. The Zirconium crowns are milled from a single block of crystal and can be up to five times stronger than a porcelain / metal fuse.
Less tooth Removal:
In cases where their is not much room for porcelain build up - for example if an tooth abutment is already quite bulky, a Zirconium Crown can be used because if provides more strength in less volume than a porcelain crown.