Why Do I Have a Toothache Coming Back Years After A Root Canal Treatment?

Toothache coming back years after root canal treatment

A toothache by itself is bad enough, but when there’s a toothache in a tooth that has been previously treated by your dentist, you wonder what is going on. One such case is of a tooth on which you have had root canal treatment done. It can start to hurt after many pain-free years, making you wonder what is wrong. There are many different reasons for why this happens. You should carefully assess the situation to see where the problem lies and proceed accordingly.

What is root canal treatment?

Root canal treatment, also known as endodontics, is the treatment of the innermost contents of the tooth. The innermost part of the tooth is the pulp, which is living tissue made up of blood vessels, nerves and other dental cells. When tooth decay reaches the pulp, the bacteria causing the tooth decay invade the pulp, which gets infected by bacteria. If the dental tissues surrounding the diseased pulp are still in good shape, the dentist carries out a root canal treatment. This involves opening up the tooth, removing all the pulp, treating the inside of the roots of the tooth with different chemicals, then filling it with an inert material and placing a crown on the tooth. This treatment ensures that the part of the tooth affected by bacteria is removed while preserving the healthy tooth tissue. The placement of the crown ensures that the tooth is given the structural strength and support that it needs, now that its living component has been removed.

How can a root canal treated tooth develop a toothache?

There are various ways a root canal treated tooth can start to hurt years after the endodontic procedure was completed. The problem may lie in the tooth itself or in the nearby teeth. Usually the problem is a recurring infection. It may also be a new infection. The problems which can cause a root canal treated tooth to hurt are:

  • The root canal treatment was incomplete and left living tissue behind: If there was some pulp left behind during the original root canal treatment, it could have gotten infected by a new bacterial invasion. The causes for pulp being left behind are manifold. It can be due to the root canals being complicated in shape, so that they all could not be reached by dental instruments during the root canal procedure. It could be due to the presence of accessory canals, which are extra branches in the root canal structure which may be missed during the root canal procedure.
  • The root canal treated tooth is cracked: As the living tissue of the tooth is removed during root canal treatment, the remaining tooth is dry and brittle. It may be that the tooth gets cracked due to a fall or other physical force years after the endodontic procedure was completed. This is more likely if the root canal treated tooth was not covered with a crown after the endodontic treatment, but can happen even with a crown present.
  • Leakage due to improper or breached seal: When the root canal procedure is carried out, part of a successful root canal treatment is making a seal between the root canal filling material and the remaining tissues of the tooth, so that there is no further bacterial invasion. If this seal is not properly achieved, it can leave room for a future bacterial invasion. If the seal is destroyed by tooth decay of the surrounding tissues, it can create a pathway for the bacteria to travel along and invade the tooth again, causing infection and pain.
  • Abscess or infection in a nearby tooth: If there is an infection or abscess in a nearby tooth, it can feel like the pain is coming from the root canal treated tooth. In some cases, the root infection may spread to include the tissues surrounding the root canal treated tooth and thereby involve the root canal treated tooth. In this way, even though the root canal treated tooth no longer contains dental pulp, the nearby teeth may harbor infection that sets off the decay process in the root canal treated tooth.
  • The crown covering the tooth is too high for your bite: If the crown on your root canal treated tooth gets loosened, it can start to interfere with your bite when you chew. In this way, it causes extra pressure on the tissues surrounding the tooth when you bite down. This causes pain to be felt in that tooth, which can develop into a toothache.

What to do for a root canal treated tooth that hurts years afterwards?

When you get a toothache in a root canal treated tooth, you should immediately make an appointment to see your dentist, who may refer you to an endodontic specialist. The solutions for your problem may go in one of three directions:

  • Re-endodontic treatment: The tooth may need to have the endodontic procedure repeated.
  • Treatment of the root tip: Alternatively, if the problem is at the tip of the root of the tooth, the root tip may be treated surgically without involving the rest of the tooth. This is done through a surgical procedure in which a flap of the gums is raised and bone is removed to access the root tip, the problem at the root tip is removed and the area is filled in and the overlying tissues replaced and allowed to heal. In this way, the tooth above the root tip does not need to be involved.
  • Tooth extraction: If the tooth is cracked or decayed beyond saving, it may have to be removed, in which case the tooth may be replaced by a bridge or by a dental implant.

In the time between now and your dental appointment, you may manage your toothache by taking painkillers, making sure your mouth is clean by carrying out proper brushing and flossing, using a mouthwash or warm salt water, and avoiding chewing hard foods with the tooth that hurts.