Endodontist Questions Root Canal Treatment

What are the signs of a failed root canal?

How can I identify that a root canal treatment has failed? Are there any symptoms to look out for?

9 Answers

Pain, swelling, drainage
Pain to bite/touch and swelling are the typical symptoms of infection arising from a failing root canal treatment (RCT). An conventional X-ray or 3D X-ray could show a "hole" in the bone at the tip of the root also. For chronic infections, there can be a "bubble" on the gum.
Failed root canal therapy may experience pain, swelling, tenderness biting, pressure sensitive on the gums, pus draining through the gums and breakdown
Signs of a failed root canal may include, but are not limited too, pain to chewing, sensitivity to temperature, pain and/or swelling in the gum or jawbone adjacent to the tooth in question.  Sometimes the tooth is asymptomatic, and the evidence for the failed root canal is visible only on an xray.  A definitive diagnosis of a failed root canal can only be determined by a qualified dentist or endodontist after a thorough clinical exam, intraoral testing, and a review of current xrays of the tooth in question. 

Typically tenderness to touch on a tooth that has had a root canal is an early sign of an issue. Also, the presence of a swelling or a white head pimple on your gum tissue may be a sign that a root canal treated tooth is not healthy.
Pain on biting, swelling, sensitivity to hot are some signs which can indicate that the root canal needs to be re-evaluated.
Pain to bite on the tooth, or a swelling/pimple in the area, is a good indication of something is wrong. A dentist should take x-rays of the tooth if any of those symptoms are present. Furthermore, a full mouth set of x-rays (FMX) should be taken periodically of all teeth to check for problems. There is some debate on how often. Often insurance dictates this; the common range for insurance companies allow an FMX every 2-5 years.
If a tooth is having any kind of symptoms after root canal treatment, it may be failing. But sometimes failing root canal does not have any symptoms. These kind of cases can only be identified when your dentist takes routine x rays.
After a thorough history, clinical, and radiographic exam, if an infection is confirmed around the apices of a tooth with a previous root canal, then it would appear that the root canal is failing. Other causes must be ruled out.

Hope this helps,

Raksha Mirchandani, DDS, MS