Endodontic Retreatment

Why would a tooth need another root canal?

Occasionally a tooth that has already been treated with a root canal will fail to heal.  There may be many reasons: the tooth may have had narrow or curved canals which could not be cleaned out at the first treatment,  new decay can expose the root canal to bacteria causing a new infection.  Sometimes a loose, cracked, broken crown (or filling) can expose the tooth to new infection.