Root canal procedure is the most painful among all dental procedures and an unsuccessful surgery means the operated tooth should be removed. But when properly performed nine out of every ten procedures are successful and the patient has no signs of infection or pain. While performing root canal procedure the dentists removes the tiny nerves and blood vessels within the root(s) by making a small hole in the tooth. The roots are then shaped and disinfected. Then they are filled with an inert material. An abscess is a condition where a failing root canal swells up.

Infected nerves and blood vessels can be a cause for failing of root canal. If the inert material does not seal off the roots properly then the tooth gets damaged due to perforation by bacteria. A root canal procedure can fail even after months or years after completion. A permanent filling or crown should be used to protect the tooth to avoid failing of the root canal procedure.

In many situations even after failing the root canal can be treated again. Here the old inert filling is removed and the roots are disinfected. Then they are filled again. In other cases the tip of the root is surgically removed and placing a filling over the root tip by a procedure called apicoectomy. The infected tooth has to be removed if all procedures fail.

The skill, experience and the way the dentist perform the treatment contribute a lot to the success of a root canal treatment. Some dentists also may even send their patients to an endodontist who are specialists in root canal procedure, if they don't the treatment comfortable enough. New innovating techniques are carried out keeping in mind the high success rate of root canal treatments.