Porcelain bonded Crowns
Most crowns are Porcelain bonded to precious metal. A precious metal base is made and then porcelain is applied in layers over it.
A small disadvantage is, that because of the metal cap underneath the ceramic, light will not shimmer through like it would on a natural tooth. This flaw can be adjusted with an individual layering oft he ceramic.
If the gingival line retreats the metal can show through. It can be prevented with the production of a special ceramic edge. The part oft he crown facing the lip is molded metal-free. This procedure however is very elaborate, since the marginal area needs to be prepared with an precise gradiation.