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All The Reasons Why You've Pain After a Root Canal

Updated: May 3, 2023

It has been a day since you completed the root canal but why does it feel kind of painful? Is it normal or is something possibly wrong? How would you know if you need to do something about it?

fractured root canal tooth
fractured root canal tooth

Table of Contents:

Should you feel any pain after a root canal?

After a root canal, very mild pain along with soreness and tenderness around the tooth is completely normal for the first few days. The reason for the mild symptoms has to do with the fact that the procedure involves your dentist severing the nerve from your tooth. That is basically what a root canal is, removing the tooth nerve.

It could be considered abnormal if you didn't feel any symptoms at all after the treatment. Imagine an alternative scenario where your doctor severs the nerve from your hand, wouldn't you feel some type of inflammation or irritation for the next few days? That is precisely the same situation with your tooth after a root canal. Some inflammation and irritation from the tooth is nothing out of the ordinary.

How long should you expect to have pain after a root canal?

Even though it is normal to have mild sensitivity, pain, and symptoms after the treatment, it shouldn't last for over extended period of time. The pain should last at most 1-2 weeks but if it persists for a longer duration than that, you may want to check back in with your dentist. There could be something out of the ordinary that is affecting your tooth and that may need to be addressed.

Types of pain after a root canal - Causes & Treatment

There are a couple of common types of pain or symptoms that may persist after endodontic treatment once the nerve has been removed from the tooth. Some of these causes may require further treatment or additional exploratory procedures but it all depends on what is the specific cause. If any of these symptoms do not resolve on their own within 1-2 weeks, you should definitely seek help from a dental professional.

Here are some common symptoms that may persist after a root canal:

Sensitivity to hot or cold

A tooth should not be feeling sensitivity to any temperatures at all after a root canal and that includes hot or cold. The reason is because the tooth requires the nerve to be present for it to be able to sense any changes in temperature. If the nerve of the tooth was completely removed, this symptom should be physically impossible.

Causes: If you are feeling this symptom, there is a chance that the nerve may not have been completely removed. There are also rare situations where your tooth could have additional nerves that were not anticipated during the procedure. If that is the case, you may need a 3D cone beam CT scan to see where these extra nerves are.

Here is a picture of a root canals on two different molars. Each of them has 3 nerves and you can visualize it by the 3 white lines in each tooth. The white lines are the filling material for the root canal. Most molars only have 3 nerves.

Here is a dental x-ray of a root canal on a molar with FIVE nerves. As you can see, there are 5 white lines in the tooth denoting 5 nerves. This is a very rare situation because most molars don't have 5 nerves!

If your tooth has 5 nerves and only 3 were cleaned out and filled, that could be the reason why you're still feeling pain to hot or cold.

Treatment: You would need to return to your root canal specialist and have them look for additional nerves and if they do, they can hopefully remove them. There would most likely be an additional fee because most root canal specialists charge you per nerve. These are out of the ordinary situations.

Throbbing pain

A root canal treated tooth should not have a throbbing sensation at all because the nerve should've been removed. If you're having throbbing pain, it may indicate that the infection within the tooth may not have completed cleared out.

Cause: There may still be an infection inside the tooth that needs to be cleaned out. The abscess may have been missed or, the tooth may simply need more medicine placed within the canals.

Treatment: For cases where the infection is very severe, your dentist may not be able to complete the root canal in one visit. They may need to clean out the tooth and place an antibiotic medication inside of the canal and have you return in a few weeks. That medication can help sterilize the inside of the tooth and kill all of the bacteria. For very severe situations, you may need a couple of rounds of medication placed inside the canals before your dentist can finally finish the procedure and fill it.

Pain when biting

This symptom only bothers you whenever you are eating. You'll often feel pain when biting into all types of foods. It could be either very mild or feel very sharp. If you're not chewing, the tooth doesn't bother you.

Cause: Whenever you have pain when biting after a root canal, it could be either one of two things. One of them is very bad and the other one is not that bad.

  1. The crown that was placed after the root canal has an uneven bite. The bite is most likely high, which means that the dental crown was made a little bit too big. This situation is easily treatable and is not that bad.

  2. The tooth could be fractured. Pain from biting that feels extremely sharp could be very bad news because the tooth may be cracked. Depending on how big the crack is, the tooth may or may not be able to be saved anymore.


  • For a high bite, your dentist only needs to polish the crown down so that the bite evens out. After a few days the tooth should stop hurting and everything should feel normal again.root canal

  • For a fractured tooth, there is a good chance the tooth may need to be removed. If that is the case you will need to replace it with a dental implant. If the crack is very small, your dentist may be able to drill it out and then cover over it and protect it with a dental crown.

Once again, it all depends on how big the crack is. The size of the fracture will determine whether the tooth can still be saved or not.

Generalized root canal pain

The type of pain is used to describe root canal treated teeth where your dentist does not visually see anything wrong with the tooth. The root canal looks good and the bite looks even. Everything appears normal but you're still feeling symptoms of pain for whatever reason. Basically, your dentist is unable to pinpoint what is specifically causing you root canal pain.root canal

Causes: Even though your dentist may be unsure of what the cause is, here are some possible answers.

  • Tooth has an extra nerve.

  • Tooth is fractured.

Treatment: The only way to figure out what the cause is would be to send you to a specialist and get a 3D scan of the tooth. The specialist would be able to see on the 3D image what the problem could potentially be.

  • If it is an extra nerve, the root canal specialist will have to open the tooth back up and remove the additional nerve.

  • If the tooth is cracked, the entire tooth would need to be extracted. In this case, you may need to be referred to the oral surgeon for the tooth removal.


It is expected to have mild pain or tenderness after a root canal for the first few days. We would advise for you to be gentle while chewing on the affected side immediately after the treatment. Although if the root canal pain lasts for more than 1-2 weeks, it is an indication that something may be wrong and you most likely require additional treatment. If you're experiencing persistent pain, you should go back and have it evaluated by your dentist.

Author: Written by Dr David Chen, a long island city dentist.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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