Why do I need crowns?

A tooth crown is a protective covering used when decay and old amalgam (silver) fillings have damaged your tooth.

The previous removal of decay throughout the length of the tooth has greatly weakened it structurally.  Then the placement of a large amalgam (silver) filling has further weakened the remaining tooth.  This happens because amalgam fillings are not bonded to the tooth and the metal expands and contracts with changes in temperature.

Biting on amalgam fillings causes wedging or splitting forces on the remaining tooth.  The usual consequence is tooth fracture, which leads to an even larger filling, root canal treatment or tooth loss.

The solution is to remove the amalgam (and any fractures or decay) and bond to a stable material (composite) to support the remaining tooth and protect the nerve.

The key is to then provide strength and protection to the remaining tooth.  This is achieved by covering the outer surfaces with a crown to change the splitting forces to grasping forces.  This restores structural integrity and ensures the long term survival of the tooth.