Crowns are dental restorations otherwise known as "caps" which are coverings that fit over teeth. Some of the indications for a crown are:

A previously filled tooth where there now exists more filling than tooth. The existing tooth structure becomes weakened and can no longer support the filling. Cracked Tooth Syndrome (CTS) - A tooth may exhibit pain with pressure, and this can be a sign of an internal fracture, usually due to a previously placed amalgam filling that expands and contracts with temperature changes. The only way to prevent the tooth from flexing is to place a crown to hold the cusps together. Root canal - After root canal, teeth tend to become brittle and are more apt to fracture. These teeth need to be protected by a crown. Bridges - When missing teeth are replaced with a bridge, the adjacent teeth require crowns in order to support the replacement teeth.

Crowns strengthen and protect the remaining tooth structure and can improve the appearance of your teeth. Crowns can be made from different materials which include the full porcelain crown, laboratory-fabricated composite crown the porcelain fused-to-metal crown and the all-metal crown (gold or precious metal). You and our doctors will decide which type is appropriate, depending upon the strength requirements and esthetic concerns of the tooth involved. Fitting a crown requires at least two appointments. During your first visit, the tooth is prepared for the crown, an impression or mold is made of the tooth, and a temporary crown is placed over the prepared tooth. At the subsequent visit, the temporary crown is removed and the final crown is fitted and adjusted and cemented into place. 
First Appointment: The first visit begins by giving you a local anesthetic. Depending upon the type of local anesthetic used, you can expect to be numb for one to four hours. If your anesthesia should last longer, do not be concerned. Not everyone reacts to medication in the same manner. Once you are numb, we will prepare your tooth in a very specific way in order to maximize the retention and esthetics of your new porcelain to metal crown. After the tooth is fully prepared, we proceed with the impression stage. At times, we use a thin piece of retraction cord that is placed around your tooth in order to get the impression material under the gum where the crown ends. Once the impression stage is completed , we will place a temporary (transitional ) crown on your tooth. These plastic (acrylic) restorations are placed on teeth to protect them and the gum tissues between dental visits.
The temporary cementing medium used is designed to allow the easy removal of the temporary at your next scheduled visit.  Second Appointment: At that time, the temporary crown is removed and any temporary cement is cleaned from the prepared tooth. We will fit the final crown, check for accuracy, adjust for any bite discrepancies and evaluate the esthetics. If all of these factors are acceptable, the crown is cemented to your tooth. It is not unusual for the new crown to be mildly sensitive to cold temperatures for a few weeks. However, if the sensitivity is severe, does not subside, or if the bite feels uncomfortable, contact us. Further adjustments to the crown may be necessary. We hope that this brief instruction sheet will answer most of your questions regarding crowns. Following these simple guidelines will help provide you with the finest in dental care. If you have any questions regarding this or any other procedure, please contact us.