Dental crowns, or "caps" have come a long way since your grandparents' day, and are a finely crafted to each patient's needs and aesthetics.
A crown is needed when a tooth and its structure are severely compromised by either decay or fracture and need to be covered for longevity and strength.
Crowns are also used to protect weakened, misshapen or discolored teeth to restore the tooth to its natural state. Crowns are also commonly placed after root canals are performed in order to preserve tooth integrity and strength.
Your dentist can advise you as to the best crown material for your individual case. The most common materials are full porcelain or porcelain fused to metal, although full gold and other materials are used according to patient's individual needs.