Advice On Pain After Root Canal and Other Possible Complications

So, you’ve just had root canal and the tooth is still causing pain?! What’s going on???

In the first few days after root canal treatment (also termed RCT or endodontics), it is quite normal to experience some pain. Any pain should be mild, and the tooth may be tender to touch or bite down on. Likewise the gum around the tooth may feel tender, all as a result of the procedure itself or from the local anesthetic that was used.

This is a normal response, and although an annoyance it can be managed by taking painkillers and avoiding the area when eating. You should find things settling down within a few days.

Your dentist will advise you on what analgesic is best for you; typically ibuprofen and aspirin are advised to for pain management during recovery here (but as always only take any medication if you know it is safe for you to do so). See more in our article on toothache remedies.

If the symptoms do not begin to ease after a few days, or you get severe pain, you should contact your dentist. Symptoms that do not settle after a few weeks may be a sign of root canal complications

"A woman holding her cheek in pain after root canal"

Pain after root canal… Is it common and should you be worried?


Pain After Root Canal: A Sign of Complications?

RCT is usually very successful, in that the outcome is a retained, functional tooth and a pain-free mouth.

However as with any medical treatment, complications can occur with RCT. If symptoms fail to settle down after the procedure, this could indicate a complication with the treatment.

Root canal complications could include:

  • Post root canal pain and/or swelling. This may last a few days or may not resolve. If the throbbing pain does not eventually resolve, this may indicate a failure of the procedure…
  • Failed root canal. This is unfortunately a possibility with any tooth, but is much more likely with difficult teeth and your dentist may warn you of such possibilities before treatment. Potential difficulties will include tight, curved nerve canals and teeth that are difficult to access with the necessary instruments (eg as they are far back into the mouth or the patient has limited opening).
  • Fracture – Teeth are inherently weak after this work has been completed, due to the original damage (usually decay) and also the access cavity that is created to begin this treatment. As they are weak, they are more likely to crack. Depending on the extent of the crack, it may be one that is easily dealt with or one that can necessitate an extraction. (Prevention of such cracks is a main reason why root treated teeth are often crowned.)
  • Failure of and/or pain after root canal can also occur if the dentist is unable to find and clean out all the canals inside your tooth. Likewise, if those that are found aren’t filled adequately, a failed root canal can be the result. Sometimes endodontics are so complicated that, despite all the expertise and modern equipment the dentist or endodontist has, the treatment performed will ultimately not be enough to settle the tooth.
  • The dentist uses files to clean out the insides of the tooth, ie the pulp. These files need to be very small and sometimes they can break. Again, this is more likely with tighter root canals. A broken file may not adversely affect the tooth, but sometimes it can unfortunately result in a failed root canal.

So if the tooth does not settle and you are still in pain, what can be done?


Failed Root Canal Management Optionsdentist-mirror-probe

A root canal is said to have failed if the tooth does not settle (i.e. is still painful or causing other problems- e.g. symptoms of infection such as swelling). This can be for one of any of the complications outlines above.

If an RCT has failed, the options will include:

  • Root canal re-treatment.  This is often the first option and involves removing the previous endodontic filling and repeating the process. This is often best carried out by a specialist endodontist.
  • Apicoectomy. The tip of the root (where the problem lies) is accessed through a small incision in the gum and then cleaned from there. This surgical approach allows for better access to the tooth tip, to help ensure thorough cleaning of the area. Read more on this in our guide here.
  • Extraction. Sometimes, despite the best efforts of all concerned, this is the only option to relieve symptoms from an infected tooth. Once the tooth is removed, one may consider a replacement option such as a bridge or implant.



Tooth pain after root canal treatment is a common occurrence, but is usually minor and goes away within a week. Your dentist will advise you on pain relief, and read our article on relief of toothache for more advice, if needed.

If any pain lasts beyond this, it may be a sign that you need further treatment and you should contact your dentist.


Return to our main page on root canal treatment here.


  1. Had a root canal four days ago and have severe pain, fever, numbness and difficulty to swallow. Dentist iffice closed over weekend. Went to ER
    . Had cat scan of head. Showed infection. Given morphine shot and antibiotics. Temporary relief. Numbness is still there and still in pain . More difficulty to swallow. What could it be and can I gargle in warm salt water?

  2. Did anyone experience dry mouth/tongue after root canal?

  3. Root canals are a headache sometimes, especially if they are done wrong. A really common pain to feel is sensitivity. A lot of patients complain about sensitivity around that tooth and are irritated. Sometimes sensitivity toothpaste can help, but for the most part it can go away or it will be something you will have to get used to. Infection is also another common side effect. But, for the most part, if you have a great dentist, you should not have much pain/discomfort at all.

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