Root Canal Retreatment Explained (video courtesy of the American Association of Endodontists)

With proper care, most teeth that have had endodontic (root canal) treatment can last as long as other natural teeth. However, in some cases, a tooth that has received endodontic treatment fails to heal as expected. A root canal re-treatment is required when a previous root canal doesn’t heal as expected due to re-infection or other complications.

Improper healing may be caused by:

  • Curved or narrow canals were not treated during the initial treatment.
  • Complicated canals went undetected during the initial treatment.
  • The crown or restoration was not placed within the appropriate amount of time following the procedure.
  • The crown or restoration did not prevent saliva from contaminating the inside of the tooth.

In some cases, new problems can influence a tooth that was successfully treated:

  • New decay can expose a root canal filling material, causing infection.
  • A cracked or loose filling or crown can expose the tooth to new infection.
  • Grinding (Bruxism) can alter a tooth’s presentation.

A retreatment is similar to an initial root canal but instead of removing the pulp tissue, Dr. Howard and Dr. Camba has to remove the old root canal filling material. The canals are cleaned and enlarged the same way.

Our office will often not initiate endodontic re-treatment until a CBCT ‘Cone Beam’ 3D scan is taken of your tooth. This 3D scan provides an unprecedented view of the oral cavity and helps us to better find out ‘why’ a re-treatment is warranted (i.e. was there a missed canal, a crack, unusual anatomy, etc). More information on the merits and value of a CBCT scan can be located in the CBCT portion of our website.

Once retreatment has been selected as a solution to your problem, Dr. Howard and Dr. Camba will follow many of the same steps as an initial endodontic treatment. Dr. Howard and Dr. Camba will achieve profound anesthesia, isolate the tooth using a nitrile rubber dame, and gain access to the root canal filling material. This restorative material will be removed to enable access to the root canal. The inner portion of the tooth will be thoroughly examined for missed canals, unusual anatomy and cracks using his operating microscope. Once cleaned, the canals will be filled with a medicine called Calcium Hydroxide. Ca(OH)2 is a highly alkaline material (pH = 13) that alters the environment of the bacterial that causes root canal failures. The medicine is often left inside the tooth for 2-4 weeks to allow adequate time for the medicine to percolate to all fins, ledges, walls, and extra anatomy within the treated tooth.

Oftentimes, one round of Calcium Hydroxide is adequate to get the intended therapeutic effect desired. If the tooth in question is still symptomatic, Dr. Howard and Dr. Camba has numerous alternatives still at his perusal for treatment. That being said, the vast majority of teeth are asymptomatic upon the return visit, allowing completion of your re-treatment session. The tooth is then re-accessed, rinsed, and filled like a standard root canal therapy tooth. The tooth will receive a temporary filling and the patient is to return to their general dentist within two weeks for final restoration.

Call Us Today!


Call us to quickly book an appointment that fits in with your schedule! We are open Monday-Friday.



"I have just returned from an appointment with Dr. Howard and my faith in the dental profession as a whole has been restored. I had to get a root canal done, and to my shock, it was a painless, relatively fast, and surprisingly pleasant experience"

- Annelyss M.

Navigation Menu