Due to the complexities of root canal treatment and that further decay or fractures may allow bacteria to gain access to the existing root filling, it is sometimes necessary to re-treat teeth that have already been root filled – re-root canal treatment.
The aim of this treatment is exactly the same as initial treatment but involves the added stage of removing the old root filling material first. As this is generally a type of rubber, there are several methods available for successfully removing it and gaining access to the full canal system to enable thorough cleaning and disinfection.
It is an intricate procedure and can, therefore, take place over 1 or 2 appointments each of which could be between 1 or 2 hours. The procedure itself is painless and performed under local anesthetic, although there can be a little discomfort for up to 48 hours afterward which can be controlled with painkillers if necessary.
The success rate for re-root canal treatment is a little less than for original treatments as between 65-75% although, with new dedicated equipment such as microscopes, this success rate is increasing.
Periapical surgery (apicectomy)
Occasionally, re-root canal treatment is not possible and so a surgical approach is then considered. This involves raising a surgical flap of gum tissue to enable access to the end of the tooth perpendicular to the root. The old infected lesion can then be removed along with the last few millimeters of the root (apex) and a new filling is placed to seal the root filling.
This procedure can be performed under local anesthetic but due to the surgical nature, sedation is often considered. Apart from some initial bruising and occasional swelling, this procedure is well tolerated by the body and healing is often quick and uneventful.
The success rate for apicectomies can vary depending on the studies quoted, but generally, an overall success rate of 75% could be considered a good average.