A root canal is a dental procedure that removes infected or damaged tissue from inside a tooth, then seals the space to prevent further infection. The term “root canal” actually refers to the natural hollow channels running through the roots of your teeth, but it’s commonly used as shorthand for root canal treatment (also called endodontic therapy). The goal is straightforward: save a tooth that would otherwise need to be pulled.
The Space Inside Your Tooth
Every tooth has a soft core of tissue called the pulp, tucked inside a hollow space that runs from the visible crown down through the roots. This pulp contains blood vessels, nerves, and connective tissue. It’s what kept the tooth alive and growing when it first developed.
The pulp serves several roles. It nourishes the tooth from the inside, provides sensation (which is why you feel temperature and pressure), and helps fight off bacteria. But once a tooth is fully mature, it can survive without the pulp because the surrounding bone and gum tissue continue to supply it with blood. That’s what makes root canal treatment possible: the pulp can be removed without losing the tooth itself.
Signs You Might Need One
Infection or inflammation in the pulp can develop from deep decay, a cracked tooth, repeated dental work, or trauma. Sometimes there are no obvious symptoms at first. When signs do appear, they can include:
- Lingering pain after eating or drinking something hot or cold
- Sharp pain when chewing or pressing on the tooth
- Swollen or tender gums near the affected tooth
- A small pimple on the gums that may ooze pus
- Darkening of the tooth, which signals the pulp is dying
- A loose tooth, caused by infection weakening the surrounding bone
- Swelling in the jaw or face
Pain that spreads from a single tooth into your jaw, face, or neighboring teeth is a strong signal that infection has progressed. Your dentist will use X-rays and other tests to confirm whether the pulp is infected or irreversibly damaged before recommending treatment.
What Happens During the Procedure
The process typically takes one or two appointments. Your dentist or endodontist (a specialist in treating the inside of teeth) numbs the area, then places a small rubber sheet around the tooth to keep it dry and free of saliva during the work.
A small opening is made in the crown of the tooth to access the pulp chamber. Using tiny, flexible instruments, the dentist removes the infected pulp tissue, then carefully shapes and cleans the canal walls to eliminate bacteria. The canals are flushed with an antimicrobial solution throughout the process.
Once the canals are clean and dry, they’re filled with a rubber-like material and sealed with a special adhesive cement. After the procedure, most teeth need a crown or other restoration to protect the now-hollowed structure from fracturing under the force of chewing. This final restoration is critical to long-term success.
Recovery and What to Expect Afterward
As the numbing wears off, you can expect some tenderness around the tooth for a few days. Mild jaw soreness is also common from holding your mouth open during the procedure. For most people, over-the-counter pain relievers are enough to manage the discomfort. In some cases, your provider may prescribe something stronger.
You can usually return to normal activities the same day or the next. Avoid chewing on the treated tooth until the permanent crown is placed, since the tooth is more fragile during this interim period. Most of the soreness resolves within a week.
How Long Root Canals Last
Root canal treatment has strong long-term durability. A large retrospective study tracking patients for up to 37 years found a 97% success rate at 5 years and 93% at 10 years. Even at the 20-year mark, 85% of treated teeth were still successful, and that figure held at 81% out to 30 and 37 years. These numbers reflect teeth that remained healthy and functional, not just teeth that were still in the mouth.
When root canals do fail, the most common reasons are missed canals (especially in molars, which can have more canals than roots), bacteria that persist deep inside the canal system, and leakage through the top of the tooth if the final restoration is delayed or inadequate. One study of over 1,100 failing root canal teeth found that missed canals accounted for 42% of the failures. Molar teeth are particularly tricky because a second canal in one of the roots is easy to overlook.
Root Canal vs. Extraction and Implant
The main alternative to a root canal is pulling the tooth and replacing it, usually with a dental implant. Both options have high success rates, but they differ in meaningful ways.
Research comparing the two approaches found similar failure rates of roughly 6% for each. However, implants carried a complication rate of 18%, compared to just 4% for root canal treatment. Implants also took longer to become fully functional and required more follow-up interventions. The most common implant complication was infection of the tissue around the implant, while the most common root canal complication was persistent infection at the tip of the root.
The two-year survival rates were statistically similar: about 94% for root canals and 92% for implants. The choice between them depends on the condition of the tooth, your overall health, and cost. A root canal on an incisor (front tooth) typically runs $500 to $1,000, while a molar root canal costs $800 to $1,500. Dental implants generally cost more than root canal treatment, especially once the extraction, implant post, and crown are factored together. When the tooth can be saved, root canal treatment is usually the simpler, less expensive, and lower-risk option.
Safety and the “Focal Infection” Claim
You may have come across online claims that root canals cause cancer, heart disease, or other systemic illnesses. These claims trace back to a theory from the early 1900s that has been thoroughly debunked. The American Association of Endodontists is clear on this: there is no valid scientific evidence linking root canal treatment to any health problems. One study actually found that patients who had multiple root canals had a 45% reduced risk of certain head and neck cancers compared to those who didn’t. Root canal treatment is a well-established, predictable procedure backed by decades of clinical evidence.