Why Would My Tooth Hurt After a Root Canal?
By Mina Levi, DDS, 01/08/2015

At the San Francisco dental office of Mina Levi, DDS, we refer a number of patients to endodontists if there is nerve pain that requires a root canal. After a root canal, the root is gone; so many people think that there should be absolutely no pain after a root canal, which sometimes is not the case. In this article, Dentist San Francisco Mina Levi, DDS explains what a root canal is and why someone may have pain after a root canal is performed.

What is a root canal?
Inside of a tooth, under the white enamel part and under the next  hard layer called dentin, there is a soft tissue which is the pulp of the tooth. The pulp contains blood vessels, nerves and connective tissue. In a fully developed tooth, the tooth can survive without the pulp because the tooth continues to be nourished by the tissues surrounding it. When the pulp becomes infected or inflamed, caused by deep decay, repeated dental procedures, faulty crowns, crack in the tooth, etc, then endodontic treatment may be necessary to remove it. If the pulp infection is left untreated, it can cause pain or lead to an abscess. This pain is a sign that the dentist uses to decide if the tooth will need a root canal or not.

Root Canal San Francisco

A root canal removes the infected pulp and the inside of the tooth is cleaned out and disinfected, then filled and sealed with a rubbery material. After this, the tooth is restored with a crown or filling for protection. After the tooth is restored, the tooth continues to function like it did before.

What would cause pain after a root canal?

There are a number of possible causes of pain after the completion of a root canal. After a root canal is completed no living pulp tissue remains inside the tooth, but nerve endings remain in the ligaments that attach the tooth to the surrounding bone. These ligaments have nerve fiber associated with them that can feel pain.

Another cause could be inflammation of the periapical tissues post root canal. This inflammation may be due to extruded sealer or “over instrumentation” during the endodontic procedure. Sometimes the root canal files go past the apical terminus and can either inject some debris periapically or just damage the ligaments. This inflammation usually resolves by itself given enough time.

Another source of post root canal discomfort is a high bite and this can easily be corrected by a dentist. If a patient bites down, with no food in their mouth and their root canalled tooth hurts, then the bite should be adjusted.

Other possible causes of pain are a persistent infection or a root fracture. If a root canal is completed, but an infection still is present around the periapical area then a retreatment may be indicated especially if significant time has gone by without a resolution of the infection.


If you have tooth pain or think you require a root canal, or if you are having post-root canal pain, visit Dentist San Francisco Mina Levi, DDS on the web at www.minalevidds.com or give us a call at (415) 513-5066.