Root canal treatment (also referred to as endodontic therapy) is made necessary when a cavity reaches all the way to the nerve of the tooth or trauma has occured to the tooth that has caused pulp/nerve to die. Once this occurs, the pulp becomes infected and extends through the root tip. The infection begins to affect the surrounding bone (this is an abscess). By the time the pulp is infected it must be treated, and cannot heal on its own. If left alone, it can weaken the entire immune system. Symptoms that indicate the pulp has become infected may include prolonged sensitivity to hot/cold or sweets, constant pain, swelling, pain to biting or pressure, and a bad taste in the mouth. However, there are cases where no symptoms are apparent and the only way to tell is through radiographs and nerve vitality testing.
A root canal is a procedure that cleans out the infected tooth nerve tissue, and disinfect the canals of the tooth. Once the infection is resolved, the canal(s) are filled in to prevent any further infection. A core build-up and crown is strongly recommended for restoring a tooth that has had root canal therapy.