“How do you know if root canal failed?”

Follow-up exam with your endodontist at about 6 months to a year. If he/she sees no healing or breakdown, or if you develop pain or swelling or pus draining through the gums, then it may have failed. Best to have it evaluated by your endodontist.

Sometimes you have symptoms like swelling, difficulty chewing, etc. Sometimes root canals fail without any symptoms and your regular dentist will find out during routine 6-month exams.

Root canals, when done properly, generally have a success rate between 85-95%. Failure is rare, but does happen from time to time. If a root canal does not relieve the symptoms within a few weeks to months after the procedure, then it could be considered a failure. Many times, an X-ray will be required to evaluate changes in the bone. These changes may take months or even years to occur, but are an important indicator for success or failure of root canal treated teeth. Either way, the success or failure of a root canal is best determined through consultation and examination with a root canal specialist called an endodontist.

Your root canal may have failed if you continue to have pain or swelling on the tooth, or it may be evident on an xray. You should return to your dentist for a check up 6 months after the procedure, and they would be able to check to see if it is failing.