As occasionally happens with any dental or medical procedure, a tooth may not heal as expected after initial treatment for a variety of reasons:

Narrow or curved canals were not treated during the initial procedure.
Complicated canal anatomy went undetected in the first procedure.
The placement of the crown or other restoration was delayed following the endodontic treatment.
The restoration did not prevent salivary contamination to the inside of the tooth.

In other cases, a new problem can jeopardize a tooth that was successfully treated. For example:

New decay can expose the root canal filling material to bacteria, causing a new infection in the tooth.
A loose, cracked or broken crown or filling can expose the tooth to new infection.
A tooth sustains a fracture.

A retreatment is a procedure to remove the existing root canal filling material, re-soak, disinfect and refill the canals to try to save the tooth from extraction. Retreatment could be non-surgical/ surgical depending upon the complexity of the case.

What Is Non-Surgical Root Canal Treatment (NSRCT)?

Non-surgical root canal treatment is a procedure directed towards saving an endodontically failing tooth. At times, the patient's existing artificial crown must be removed. In other instances, access through the crown may be possible. The access opening is created in order to give the dentist non-surgical access into the root canal space through the biting surface of the tooth. Once this has been accomplished, a non-surgical retreatment procedure oftentimes requires:

Locating and treating previously missed canals.
Removing old filling materials from the root canal space.
Removing posts and broken instruments.
Enhancing existing root canal treatment.
Negotiating blocked canals and bypassing canal ledges.
Repairing mechanical and pathological perforations in the root.

Once these objectives have been accomplished, the root canal system is re-cleaned, re-shaped, disinfected, and three-dimensionally sealed. A protective restoration can then be placed and the tooth restored to a state of health and function.

What Is Surgical Root Canal Treatment (SRCT)?

Surgical root canal treatment is a procedural effort in which it is necessary to elevate a small flap of tissue adjacent to the involved tooth in order to gain access to and treat root canal disease. Surgical root canal treatments are usually minor, in-office procedures performed under local anaesthesia. Once the pathological area is exposed, the doctor performs a "curettage" to remove the diseased tissue from around the root. This is usually followed by an "apicoectomy," a procedure in which the diseased portion of the root is removed. A small filling is then usually placed to seal the remaining portion of the root. Surgical root canal treatment will oftentimes result in a good long-term prognosis for the tooth if the cause of pathology can be effectively eliminated.

Unfortunately, on occasion, retreatment efforts may not be possible or cost-effective and extraction may be the only alternative. However, saving a tooth that has been previously treated endodontically and is failing is usually possible, can be very predictable, and is typically the most conservative option for the patient.

Endodontists use advanced technologies like digital imaging and operating microscopes to perform surgeries quickly, comfortably and successfully.