While most teeth that have had a root canal and get proper care will last as long as other natural teeth, some teeth that have received endodontic treatment experience failure to heal or continuing pain months or years after treatment. That may require another endodontic procedure called retreatment.
Reasons for improper healing may be:
- Complicated canals undetected during the first treatment
- Narrow or curved canals not treated during the first treatment
- A crown or other restoration not placed at the right time after the first treatment
- Contamination from saliva inside the mouth not prevented by the restoration or crown
- New decay exposing the root canal filling material to bacteria, causing a new infection in the tooth
- A cracked or broken crown, or a loose filling, exposing the tooth to new infection