Teeth are often restored using silver or porcelain fillings. However, when too much of a tooth's structure is removed to support a filling, a crown or "cap" may be needed. A crown may be needed to:

Restore a tooth when it is unable to support a large filling
Attach bridges
Protect a weak tooth from fracturing or restore fractured teeth
Cover badly shaped or discolored teeth
Cover dental implants

A crown essentially covers a tooth to restore it to its natural shape and size. This permanent covering fits over your original tooth to strengthen or improve the appearance of the tooth. Fitting a crown generally requires at least two visits to the dentist's office.

Click Here for More Information