Introduction
A revision means that, in principle, the root canal treatment is performed again: The existing (old) root filling material is completely removed and after careful cleaning of the enlarged root canals a new root canal filling is inserted.
What is a revision?
If the dental nerve is diseased (in case of pulp necrosis, pulpitis or apical periodontitis), a root canal treatment is usually performed by the dentist to preserve the tooth. Despite very high success rates, due to the complex structure of the tooth’s interior, the inflammation at the root tip may not heal completely. Then it may be necessary to revise the root canal treatment.
Indication for a revision
Indications for the revision of root canal treatment are radiological or clinical signs of an existing or newly developed inflammation at the root tip of a root canal treated tooth. The inflammation is also called apical periodontitis and it leads to osteolysis (bone resorption) at the root tip. This change is visible on an X-ray.
After a completed root canal treatment, the inflammation should at best recede, and the x-rays taken during check-ups (about 6 months later) should show a significant decrease in osteolysis. A revision may also be necessary if pain reoccurs in teeth that have been treated with root canal treatment. Pressure pain is often felt in the gums and jawbone in the area of the tooth roots.
Also a bite pain can occur when the tooth is stressed. In addition, swelling of the gums or a fistula may occur. Another indication is an incomplete or insufficient root canal filling, especially if the covering filling is leaking.
How does a revision of the root canal treatment proceed?
After a preliminary check and detailed explanation to the patient, the existing root canal filling should be removed as completely as possible. This varies in difficulty depending on the root filling material and the success of the revision is not always guaranteed. Common filling materials such as Guttapercha® can usually be removed quite easily.
For this purpose, either the covering filling must be removed or a sufficiently large opening must be drilled into the crown. The root canals are then widened manually or mechanically with so-called endo arrows. They serve to completely remove the remaining inflammatory tissue in the tooth.
They also ensure thorough cleaning and widening of the canals. To be able to assess and clean the root canals well, the use of a microscope can be helpful. In addition to mechanical cleaning, chemical cleaning of the root canals should also take place.
Rinsing solutions such as sodium hypochloride, EDTA or chlorhexidine (CHX®) are used for this purpose. It is important to clean and disinfect the entire length of the root canal, as well as to search for possible secondary canals or further root canals. Depending on the condition of the tooth, the revision and the new root canal filling can be done in one session, i.e. at one appointment.
However, if the treatment is more complex, a medication (e.g. Calcipro®) is inserted into the tooth for the time being. Then the tooth is closed with a temporary filling (e.g. Cavit®). At a second appointment, the final root canal filling is then performed. After the treatment, an X-ray is taken for control purposes.
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