What is root canal treatment?

Indications and Procedures

At the center of every tooth is soft pulp tissue. Among its main components are blood vessels that nourish teeth, sensory nerves, and supportive connective tissue. Tooth fractures or deep dental caries (cavities) irreparably damage this pulp. When this happens, root canal treatment is rendered. All dentists can carry out this procedure, but specialists who limit their practice to such efforts—endodontists—are the most skilled. The symptoms that often require root canal treatment are steady throbbing pain and sensitivity to pressure on or tapping of the tooth. Because pulp disease is associated with bacterial infection, gum abscesses may occur in extreme cases.

Root canal therapy is carried out when upon examination the pulp is found to be irreversibly damaged. A local anesthetic is administered by injection to desensitize the area. The tooth is then opened by drilling an access channel. Then, the pulp is removed from the center and from the tooth root portions—the root canals—that it also fills. Next, the pulp chamber and root canals are cleaned and reshaped by drilling and with specialized endodontic files. Lastly, the canals are filled with inert materials such as gutta-percha (a rubber-like substance), and a temporary filling is put in place. At a later time, when it is clear that the procedure has been successful, a permanent filling or an artificial crown is substituted.

Antibacterial medicine may be directly administered in the tooth itself during the procedure, and antibiotic medication may be prescribed for follow-up care.

Uses and Complications

Root canal therapy prolongs the life of teeth by creating a tooth that retains much of its strength over time. Without pulp, however, the blood supply and support of the tooth are reduced. Hence, teeth that have undergone root canal treatment are likely to become brittle and susceptible to fracture. Other possible risks associated with root canal treatments include recurrent abscess, nerve damage, pain, swelling, and infection; those risks are greater in patients with preexisting systemic conditions such as bleeding disorders, circulatory conditions, or immune system disorders, and those who smoke.

The success of root canal therapy is about 90 percent. Nevertheless, it can produce later complications, including fine, virtually undetectable canal fractures that may allow the entry of bacteria; imperfectly filled canals can have the same result. In such cases, repeated root canal therapy may be needed or the tooth may require extraction. These problems, although relatively uncommon, occur because of the nature of this delicate surgery. For example, it is not possible to view the surgical site directly. Rather, the site is approximated by x-ray pictures taken at each treatment stage.

Perspective and Prospects

Root canal treatment has improved markedly in recent years, and further advances are expected, such as better surgical tools and filling materials and an enhanced ability to evaluate the success of the procedure. In addition, efforts to preserve and/or regenerate damaged tooth pulp are ongoing.

Bibliography

A.D.A.M. Medical Encyclopedia. "Root Canal." MedlinePlus, February 22, 2012.

Connecticut Consumer Health Information Network. “Your Dental Health: A Guide for Patients and Families.” UConn Health Center, November 27, 2012.

Chwistek, Marcin, ed. "Root Canal Treatment." Health Library, March 15, 2013.

Klatell, Jack, Andrew Kaplan, and Gray Williams, Jr., eds. The Mount Sinai Medical Center Family Guide to Dental Health. New York: Macmillan, 1991.

Langlais, Robert P., and Craig S. Miller. Color Atlas of Common Oral Diseases. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2009.

"Myths about Root Canals and Root Canal Pain." American Association of Endodontists, 2013.

"Root Canals." American Association of Endodontists, 2013.

Smith, Rebecca W. The Columbia University School of Dental and Oral Surgery’s Guide to Family Dental Care. New York: W. W. Norton, 1997.

Taintor, Jerry F., and Mary Jane Taintor. The Complete Guide to Better Dental Care. New York: Checkmark Books, 1999.

Whitworth, John M. Rational Root Canal Treatment in Practice. Chicago: Quintessence, 2002.