• Narrow or curved canals were not treated during the initial procedure.
• Complicated canal anatomy went undetected in the first procedure .
• A crown or other restoration was not placed soon enough after the procedure.
• The restoration did not prevent saliva from contaminating the inside of the tooth.
• New decay can expose the root canal filling material to bacteria, causing new infection.
• A loose, cracked or broken crown or filling can expose the tooth to new infection.

Procedure: 

1. The endodontist will reopen the tooth to gain access to the root canal filling material. In many cases, complex restorative materials such as a crown, post and core must be removed to permit access to the root canals.
2. After removing the canal filling, the canals are cleaned and examined for additional canals or unusual anatomy that requires treatment. After cleaning the canal(s), the endodontist will fill and seal the canal(s) and place a temporary filling in the tooth. You will need to return to your general dentist to have a new crown or other restoration placed on the tooth to protect and restore it.