A root canal, or endodontic treatment, is a dental procedure to remove the pulp or nerve of a tooth that has become damaged due to decay or injury. Root canals alleviate pain or counteract an infection in the tooth, called an "abscess." After a root canal, the tooth that remains no longer has a nerve, and the dentist strengthens it by adding a crown on the tooth. Occasionally a root canal fails because something has happened during the treatment, but the failure may not be evident until later. After a failed root canal, treatment options include retreatment, endodontic surgery, or extraction of the tooth.
Dentists and endodontists recommend root canals when a patient comes in with symptoms of extreme pain during chewing, sensitivity to hot and cold foods after the food is no longer in the mouth, tenderness in the gums surrounding the tooth, tooth darkening, or a lasting or recurring pimple on the gum. The dentist or endodontist diagnoses the patient's need for a root canal by performing dental X-rays or an examination.
Endodontic treatment removes the nerve, or pulp, from the tooth. Some teeth only contain one nerve, while molars contain up to four or more. The root canal treats the infected tooth and relieves the pain and sensitivity. Most of the time, a tooth is saved from extraction (removal) and the infection is cured by a root canal. After a root canal, the dentist or endodontist seals the tooth to prevent further bacteria or decay from getting into the channels where the nerves were. Sometimes the dentist will treat the infection with antibiotic pills that the patient takes by mouth, or by filling the channel of the tooth. The sealing of the tooth takes place either during the same appointment or during a second appointment. After the tooth is sealed, the dentist or a cosmetic dentist strengthens the tooth with a crown.
Some patients experience pain during the root canal procedure. If a patient presents with a "hot tooth," with pain or infection, it is more difficult for him to get fully numb. In those cases, anesthesia delivered via mouth or IV helps the patient remain more comfortable during the procedure.
If infection is present prior to the root canal, it may take several trips to the dentist or endodontist to complete the procedure because the dentist determines the infection is completely gone prior to her final sealing of the tooth's canals.
Sometimes (in 5 percent to 15 percent of cases) a root canal fails because something has happened during treatment. Because every person is different, every tooth is different. A patient's tooth that, in another patient, only has one root, may have two roots in his case. For that reason, the dentist may fail to clear the unexpected root. If the tooth is not completely treated by the root canal will fracture or become infected and the root canal fails.
Fractures can be immediately visible or not seen for weeks or months. Decay gets into the fracture, and the tooth then breaks apart. When a tooth has broken apart, extraction commonly is the only treatment alternative. If the tooth is extracted, or removed, a cosmetic dentist evaluates the patient's options for its replacement, like a bridge or implant.
Infection as a result of a failed root canal requires treatment with antibiotics, pain relief, and often removal of the tooth. Without treatment, an infection spreads throughout the patient, causing fever and other complications of illness. In extreme cases, infection may spread to the heart or brain.
When a patient experiences a failed or complicated root canal, she is subjected to additional pain, inconvenience, and cost. According to WebMD, a root canal can cost $350 to $1,200. Patients without dental insurance pay all of that cost out-of-pocket, and additional visits add additional cost. A failed root canal requires the patient to seek follow-up treatment.
If removal of the tooth is required, the patient incurs the costs of extraction, anesthesia if needed, and cosmetic replacement of the tooth. These costs add up on top of the initial cost of the root canal that has failed.
Sometimes a special kind of surgery saves the tooth after a failed root canal, however, this only works in 50 percent to 75 percent of cases. An endodontist with special training and tools performs this surgery, called an apicoectomy.
A root canal as recommended by a dentist saves an infected or decayed tooth in the majority of cases. Patients may worry about the risks anyway. A tooth extraction is the alternative treatment to a root canal. Dentists recommend against tooth extraction in cases that they believe can be treated with root canal therapy because a patient's health suffers from excessive tooth loss. Cosmetic replacement of an extracted tooth is expensive and may weaken the surrounding teeth. Bone loss on the jawline is another complication of tooth extraction. Dentists conclude that the majority of patients benefit from root canal therapy instead of tooth extraction when possible.