Why does my dead tooth need a root canal retreatment? - Tooronga Family Dentistry in Glen Iris

Teeth that have had a root canal treatment performed in them loose the ability to fight bacteria which try to infiltrate them, since the dental pulp or it’s remnants were removed. Most teeth with a root canal treatment were found to last in function more than 10 years as published in a long term study . With the right restoration and proper care, the teeth that have had a root canal treatment can last a lifetime. But sometimes, as seen on the right, a tooth that has been treated can become painful or diseased months or even years after treatment. In most cases the reason is that bacteria have managed to establish themselves inside the tooth and migrated down the canals to the tip of the root, where they create a new infection or abscess, as shown with the red circle in the image on the right. The common reasons that bacteria have managed to refill the tooth are:

The filling or crown that were placed on the tooth do not seal the cavity well leaving a door for the bacteria to reenter and establish themselves.
The filling or crown that we placed have become loose or come off and the root canal was exposed to the oral environment.
One or more canals have not been cleaned the first time.
The canals were not cleaned all the way.
The sealing material inside the canal did not fill all the canal volume.
Cracks in the roots that allow bacteria to proliferate.

If your tooth failed to heal or develops new problems, there is possibility to make a root canal treatment for a second time, called a retreatment, which may be able to save your tooth. The aim of retreating a tooth which has had a root canal treatment in the past is to try and disinfect it again. This way you can retain the tooth and prevent its removal.

In the retreatment, the previously placed sealant is removed and all the canals are cleaned and disinfected. The retreatment may be more complicated from the initial treatment, since many times there are hurdles to cleaning the canals like a post or a crown that have been cemented on top of the root canal filling. Once the pathogenic bacteria have been eradicated and the canals are clean, they can be resealed to avoid the bacteria from re-entering the canals and a new filling or crown can be placed, as seen on the right. The success rate of the retreatment is quite high and stands at 83%.

If you suffer from a tooth that was treated with a root canal treatment, please contact us to examine the reason.