It is rare, but sometimes dental procedures including root canals can fail and require some revision. Typically, failure is caused by bacteria and retreating the root canal can eliminate the bacteria and allow the tooth to heal. It is important to have a full consultation with your endodontist to review your treatment options. With the appropriate retreatment, your teeth can last as long as natural teeth. After Endodontic Retreatment it is important to return to your general dentist for your final filling or crown to seal out the bacteria.