Root Canal Infections & Other Complications

A woman massages her mouth, which hurts due to root canal infection.

With modern technology and the right expertise, root canals are as convenient and comfortable a dental procedure as a common filling. Although endodontic treatments are completely successful the majority of the times, patients should be aware of potential complications, like infection, that can arise after a root canal. As such, it is important for you to understand why an infection can occur after a root canal and what symptoms indicate you should contact your dental care provider for a follow-up.

What Is a Root Canal?

When the interior of your tooth decays to the extent that it affects the dental pulp, which is made of nerves and blood vessels, significant pain or discomfort can occur. Trauma to the tooth can initiate or accelerate this internal deterioration. In these instances, where the interior of the tooth is compromised, a root canal may become necessary. During this procedure, the dentist or endodontist removes the pulp, cleans and fills the inside of the tooth, and seals it with a crown.

Patients should almost never experience serious pain after a root canal procedure. Beyond some tenderness in the jaw (due to your mouth remaining open for the duration of the treatment) or minor soreness, there should be no feeling in the tooth, given that its nerves have been removed.

Infections After a Root Canal

Although it is rare, it is possible for an infection to develop after a root canal. They can appear as soon as about one week after the root canal, but it is possible for issues to arise even a decade later. They develop for a number of reasons:

  • An undetected crack in the tooth’s root has gone unresolved.
  • The tooth houses an abnormal number of canals and at least one went untreated.
  • The restoration which covers the root canal was ineffective, which allowed bacteria to reenter and reignite an infection.
  • The sealing meant to keep the restoration together degraded over time, which has allowed bacteria to recontaminate the inside of the tooth.

Symptoms of Root Canal Complications

Many of the potential signs of a failed or failing root canal overlap considerably with the same symptoms that revealed the need for a root canal in the first place. These can include tenderness, sensitivity to touch, swelling, persistent boils, bad taste/odor from the area, and general pain. The symptoms can be constant or intermittent, potentially going away for extended periods of time before returning. The severity of symptom may also waver. In fact, not every problem tooth will display detectable symptoms. It is not uncommon for a patient to feel as though the tooth is totally fine, only to have an x-ray exam reveal a problem. This is why preventive medicine, including regular dental visits, is so important for long-term oral health.

On the flip side, experiencing these common symptoms in no way guarantees endodontic failure. It is possible that they are in not related to the root canal procedure at all. For example, some patients experience “referred pain.” This is when an issue elsewhere along the length of a nerve in your mouth happens to create an uncomfortable sensation that feels like it is from your root canalled tooth, even though it is not. Another potential culprit is “phantom pain,” which is similar to the phantom limb pain amputees sometimes report.

Treating Root Canal Infections

In most instances, if the root canal has been fully successful, it will be totally asymptomatic. So, if your tooth canal experiences any of these symptoms after the typical period of healing has passed, you would likely benefit from a professional evaluation by your dentist or endodontist. As a general rule, patients should schedule their appointments sooner rather than later. Endodontic issues can be unpredictable, so there is the potential that flare-up could occur, shifting your situation from one of minor discomfort into acute, severe pain and/or swelling at any moment. However unlikely such a problem might be, there is simply no reason to delay seeking attention.