A failed root canal procedure is one in which the dentist has failed to remove all the dead or diseased tissue from an infected tooth. Root canals are treatments for infections that affect the root or pulp of the tooth. Infections result in pain, dead tissue or even abscesses. In root canal treatment, also called endodontic treatment, the dentist cleans out the canal to remove the infected tissue. Root canal problems occur when the procedure has not fully removed the diseased tissue or when a route has been left open through which infection can return.
Getting a root canal usually eradicates the infection and saves the tooth. When a root canal procedure fails, however, it usually means that the dentist has missed an extra canal in the tooth. Some teeth are expected to have only one canal when, in some patients, those teeth actually have two. Another reason why a root canal procedure may be unsuccessful is that a tooth may have an intricate canal structure deep inside the pulp, which the dentist either misses or is unable to reach with his or her instruments.
A failed root canal can also be the result of an accident during the procedure, in which a dental instrument breaks and becomes stuck in the canal. Structural irregularities, such as curves, ledges or obstructions, can make it difficult for a dentist to completely eliminate the infected tissue. Another cause of root canal complications is when a crack develops in the root of a tooth and the canal cannot be sealed against subsequent re-infection.
One of the most obvious symptoms of a failed root canal are inflamed gums around the tooth, signifying continuing bacterial infection and decay. Other symptoms of a failed root canal include throbbing pain that gets worse, sensitivity that grows more acute, and the seepage of fluid from around the tooth. Sometimes, however, a failed root canal causes no discernible symptoms, which is why patients should seek follow-up examinations from their dentists, including x-rays.
When a patient notices symptoms of a failed root canal, he or she should seek treatment as soon as possible. One solution is for the dentist to remove the old filling material, perform a new root canal procedure and get a better seal. Another option is for an oral surgeon to perform root canal surgery, which usually involves apicoectomy, a procedure in which the surgeon cuts the tips off the roots of an infected tooth. Sometimes root amputation must be performed, where a root has to be completely removed.