In rare cases a treated tooth doesn’t heal properly or develops complications. Retreatment removes the old crown and filling material, cleans the canals, then refills and re-crowns the tooth, much like the original procedure. Its success rate is around 75%.
For most people, retreatment is better than extraction. A tooth with good bone support, a solid surface and healthy gums has a good chance of being saved, and keeping it usually costs far less than implants or bridgework, which also need maintenance and feel less natural than a real tooth. Retreatment is fairly simple and usually takes one to three visits.
Why a root canal can fail
- A cracked crown leaking filling material
- Curved or narrow canals missed the first time
- A delay in placing the final restoration
- New decay
- A new fracture
- Saliva getting under the restoration
- Complex canals that weren’t detected
What retreatment involves
- You’re numbed (or another type of anesthesia is used) and the tooth is isolated with a rubber dam.
- Any crown and post are removed to reach the inside of the tooth.
- Old filling material is vibrated loose with an ultrasonic instrument, and the canals are cleaned and reshaped. X-rays confirm they’re clean. Complex cases may get a medicated packing and finish at the next visit.
- The canals are sealed with gutta-percha, and a temporary crown or filling is placed.
- Later, your color-matched permanent crown is placed.