Root canal re-treatment is needed when a tooth that has undergone a previous root canal treatment has become infected again. Generally, root canal re-treatments are difficult to carry out. This is especially true when previous root canal treatments have resulted in blocking of canals, ledging of canals or perforation of the tooth.
Broken instruments within the root canal system have also become more frequent nowadays (shown in pictures above). Retrieval of broken instruments is very tricky and time-consuming. It requires endodontists with a sub-specialty in the retrieval of fractured instruments to carry out the procedure.
Many previously root canal-treated teeth may have post(s) within them, which can be difficult to remove. During re-treatment of the tooth, the use of an operating microscope will allow the canals within the tooth to be better visualised and to detect potential cracks.
If conventional re-treatment is not possible, a surgical approach may be needed.
Your endodontists can advise you on the advantages and disadvantages of each approach as well as the restorability of the tooth. If the prognosis of re-treatment is not favourable, extraction may be advocated.