A crown may not be necessary after a root canal, but it is often recommended to protect the tooth and provide additional strength, according to WebMD. The crown covers the damaged tooth, helps to prevent the filling from falling out and assists in preventing the tooth from cracking. A permanent crown seals the tooth and helps to prevent infection and decay.
Colgate notes that in lieu of a crown, a permanent filling may be used to secure the filling inside the tooth once the pulp is removed during the root canal. Immediately following a root canal, the dentist may place a temporary filling over the tooth to allow time for a permanent crown to be created from a mold of the damaged tooth. Temporary fillings are not intended to last for an extended amount of time and must be replaced with a permanent filling or crown.
WebMD notes that the dentist may elect to use a temporary crown to cover the damaged tooth that is replaced later with a permanent crown. At some point, even permanent crowns may come loose or sustain damage over time. If the crown protecting a tooth that has undergone a root canal treatment becomes damaged, it may need to be repaired, replaced or secured with dental cement.