Root Canal Retreatment


The objective of a root canal treatment is the removal of bacteria and decayed tissue from the pulp cavity. Unfortunately this is not always successful! Anatomical characteristics of the root canal system that are very difficult to treat with conventional technology can be one of the reasons for this. Besides very stubborn germs, repeat infection due to leaky fillings or the restoration can also be responsible for symptoms to flare up. But occasionally, even root canal treated teeth with no complaints (!) need to be retreated. This can occur with chronic bacterial infections in the root ends for example. Or when the root canal filling is radiologically insufficient in the case of a restoration with tooth replacement, meaning it’s too short or leaking for example.

The existing root canal filling must be removed in each one of these cases. By using new methods, the root canal system can be precisely cleaned and disinfected again. This process is described as Root Canal Retreatment.

By the way – most root canal retreatments can be performed without anaesthesia and are pain-free!

What exactly does this look like?

A root canal retreatment procedure is more or less the same as a conventional root canal treatment. First, potential tooth decay or old leaky fillings are removed. The dental crown is cleaned with much care from the inside, and the root canal orifices with the infected root canal filling are exposed. The existing root fillings are then removed with special instruments (see image 1 and 2). Often times additional, previously undiscovered root canals are found, which could also be the cause for discomfort. Rinsing the root canals is of special significance. A rinsing protocol developed specifically for root canal retreatment is used to eliminate the remaining bacteria.

Once the root canal system is cleaned and disinfected again, it can then be filled with a new root canal filling. As is the case with root canal treatment, this root canal filling is performed with a so-called three-dimensional thermoplastic obturation. All open cavities are sealed in this process. In ideal cases a decrease of potential root end inflammation signs can be seen in the months to follow (see image 3 and 4).

Case Study I

Upper, symptom-free incisor with a visible, “too-short” root filling, not reaching the root end and appearing very leaky. This tooth will get a new crown!

Old metallic root canal post removed during retreatment.

After root canal retreatment, i.e. disinfection, new root filling and modern root canal post made from fibre.

Case Study II

Upper canine with pressure-pain, with radiologically inconspicuous root filling, treated elsewhere 3 years ago. Inflammation in the root end, which can be seen in the X-ray as the black area at the end of the root.

After root canal retreatment, i.e. disinfection, new root filling and modern root canal post from fibre. This X-ray was taken 4 months after treatment; the inflammation in the root apex is visibly regressing.

The difficult cases…

Some cases present especially difficult circumstances for root canal retreatment. This can be caused by material fatigue of broken off root canal instruments for example. Removal of these instruments is often times possible, but it also takes a lot of time. In every case, the individual situation of your tooth is analysed by us and discussed with you before treatment. An honest assessment about the prognosis of your tooth will make it easy for you to decide whether to keep the tooth or not!

Upper molar with broken-off instrument in the anterior-external root.

Instrumentation and cleaning of the root canal is possible once the instrument fragment is removed.