It's not an exaggeration to say the modern root canal treatment has saved millions of teeth over the last century. Without this procedure, there's not a lot we can do to stop advanced tooth decay from infecting and destroying a tooth.

What's more, a root canal treatment could extend the life of a tooth for decades. Notice we said could—although most root canals do have satisfactory outcomes, there's still a chance a tooth may become re-infected. Here are 3 possible causes for an unsuccessful root canal treatment, and what you can do to lessen their impact.

The severity of the infection. Tooth decay usually begins at the enamel layer, softened by the acid produced by bacteria. Untreated, the infection can then spread through the next tooth layer of dentin until finally infecting the innermost pulp. From there the infection can move through the root canals to the bone, dramatically increasing the danger to the tooth. Root canal treatments have a higher chance of success the earlier they're performed in the disease progression, so see your dentist at the first sign of pain or other tooth abnormality.

The root canal network. An effective root canal procedure eliminates all dead or diseased tissue in both the pulp chamber and the root canals (these are then filled to prevent future infection). But this may prove difficult with teeth that have intricate root canal networks because of a higher risk of overlooking some of the canals. It may be best in such cases for an endodontist, a specialist in treating interior tooth issues, to perform the procedure using their advanced techniques and microscopic equipment.

The age of the tooth. Root canal treatment can weaken a tooth's structural integrity, especially with older teeth. This can make them more susceptible to fracture and a higher chance of infection. We can avoid this outcome by placing crowns on root-canaled teeth: The crown provides structural strength to the tooth and can add further protection against infection. Older teeth may also benefit from the placement of a small support post within it to further add stability before applying the crown.

If you would like more information on root canal treatment, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Root Canal Treatment: How Long Will It last?”

As the host of America's Funniest Home Videos on ABC TV, Alfonso Ribeiro has witnessed plenty of unintentional physical comedy…or, as he puts it in an interview with Dear Doctor–Dentistry & Oral Health magazine, "When people do stuff and you're like, 'Dude, you just hurt yourself for no reason!'" So when he had his own dental dilemma, Alfonso was determined not to let it turn onto an "epic fail."

The television personality was in his thirties when a painful tooth infection flared up. Instead of ignoring the problem, he took care of it by visiting his dentist, who recommended a root canal procedure. "It's not like you wake up and go, 'Yay, I'm going to have my root canal today!'" he joked. "But once it's done, you couldn't be happier because the pain is gone and you're just smiling because you're no longer in pain!"

Alfonso's experience echoes that of many other people. The root canal procedure is designed to save an infected tooth that otherwise would probably be lost. The infection may start when harmful bacteria from the mouth create a small hole (called a cavity) in the tooth's surface. If left untreated, the decay bacteria continue to eat away at the tooth's structure. Eventually, they can reach the soft pulp tissue, which extends through branching spaces deep inside the tooth called root canals.

Once infection gets a foothold there, it's time for root canal treatment! In this procedure, the area is first numbed; next, a small hole is made in the tooth to give access to the pulp, which contains nerves and blood vessels. The diseased tissue is then carefully removed with tiny instruments, and the canals are disinfected to prevent bacteria from spreading. Finally, the tooth is sealed up to prevent re-infection. Following treatment, a crown (cap) is usually required to restore the tooth's full function and appearance.

Root canal treatment sometimes gets a bad rap from people who are unfamiliar with it, or have come across misinformation on the internet. The truth is, a root canal doesn't cause pain: It relieves pain! The alternatives—having the tooth pulled or leaving the infection untreated—are often much worse.

Having a tooth extracted and replaced can be costly and time consuming…yet a missing tooth that isn't replaced can cause problems for your oral health, nutrition and self-esteem. And an untreated infection doesn't just go away on its own—it continues to smolder in your body, potentially causing serious problems. So if you need a root canal, don't delay!

If you would like additional information on root canal treatment, please contact us or schedule a consultation. You can learn more by reading the Dear Doctor magazine articles “A Step-By-Step Guide to Root Canal Treatment” and “Root Canal Treatment: What You Need to Know.”

Every year U.S. dentists perform around 25 million root canal treatments and save countless teeth from the ravages of decay. But if you search "root canal" on the Internet, you might encounter an unsettling charge against this tooth-saving treatment—that it causes cancer.

Root canal treatments are routinely used when tooth decay has infected the pulp, the innermost layer of a tooth. During the procedure, we access the pulp and remove all the infected tissue. We then fill the empty pulp and root canals, seal the access hole and later crown the tooth to prevent further infection. Without this intervention, the decay can continue to advance toward the roots and supporting bone, putting the tooth in imminent danger of loss.

So, is there any credibility to this claim that root canal treatments cause cancer? In a word, no: there's no evidence of any connection between root canal treatments and cancer—or any other disease for that matter. On the contrary: root canals stop disease.

As with other types of urban legends and internet hype, the root canal-cancer connection may have arisen from another discredited idea from the early 20th Century. A dentist named Weston Price promoted the notion that leaving a "dead" organ in the body led to health problems. From his perspective, a root canaled tooth with its removed pulp tissue fit this criterion.

In the mid-1950s, dentistry thoroughly examined Dr. Weston's theory pertaining to treatments like root canals. The Journal of the American Dental Association devoted an entire issue to it and found after rigorous scientific inquiry that the theory had no validity in this regard. Another study in 2013 confirmed those findings. In fact, the later study instead found that patients who underwent a root canal treatment had a 45 percent reduction in oral cancer risk.

Given the freewheeling nature of the Internet, it's best to speak with a dental professional about your oral health before trusting a post or article you've found online. Not only are they more informed than an unverified online source, they would certainly not knowingly subject you to a procedure to save a tooth at the expense of your health.

If you would like more information on root canal treatment, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Root Canal Safety.”