A crown, or a cap, a covering fitted over a carved-down tooth, is usually used in cases where the tooth has decayed to the degree that it would take an extremely large filling to repair the tooth. Sometimes a crown is necessary when replacing a mercury-filled tooth, because the mercury filling weakened the tooth, and a fracture occurred. Since most crowns are made in a dental laboratory, an impression of the tooth will be taken, and a temporary crown must be made and placed on the tooth while the permanent crown is fabricated. If you need a crown and don’t want to have your amalgams removed, it is best to get a ceramic or composite crown.
Sometimes anterior (front) teeth have very large restorations that are visible. Even though these restorations were invisible when they were originally placed, they often discolor over time. These restorations can be replaced with porcelain crowns to create a beautiful smile. Using crowns allows the dentist to correct many things. Spaces can be closed, rotated teeth can be “straightened,” tooth length can be adjusted to create a harmonious smile “curve,” and exact tooth color can be chosen. Also, porcelain will not darken with time.