top of page

Do Root Canals Hurt? - The Truth

Updated: May 3, 2023

All your friends tell you that root canals hurt like hell but every dentist tells you otherwise. So who is lying and who is telling the truth. Do they actually hurt or is it just a made up story?

Our long island city dentist will tell you the whole truth and nothing but the truth.

Table of Contents:

Do root canals hurt?

Root canals normally do not hurt but there are certain situations where they can become extremely painful. A general guideline to follow for determining when they will hurt is whether or not you're already in pain before starting the procedure.

  • If you're not in pain going into the appointment, it most likely won't hurt.

  • If you're already in pain prior to going into the appointment, there is a good chance it can hurt.

Therefore, the amount of pain to be expected from a root canal would all depend on the condition of your tooth and why it needs the procedure.

What is a root canal?

This procedure involves removing the nerve from within the canal of the tooth. The tooth will remain in the mouth but the nerve will be leaving the tooth. The success of the treatment depends on how thoroughly the pulp is cleaned out from the canal.

Tooth Anatomy

The picture is to show you where the pulp and nerve of the tooth is, just to give you an idea of what the procedure entails.

Why would you need one?

There are a couple of reasons as to why you would ever need a root canal but they all revolve around the nerve being unhealthy.

  • Infected nerve. If the nerve gets irritated or inflamed, the tooth could potentially die thus necessitating the procedure.

  • Tooth decay that has reached the nerve. If you have a large cavity and it has grown all the way to the pulp, it can cause the tooth to die.

  • Tooth abscess. If you have an abscess on the tooth, the nerve most likely has died to bacteria.

All of these situations cause the nerve to either be unhealthy or the tooth to die. Treatment for an unhealthy nerve is to remove it.

When root canals hurt

Root canals can hurt if you're already in pain before even starting the procedure. The reason is because the nerve is so irritated and inflamed that it has trouble getting numb. In fact, there are times where it can be so infected that it doesn't get numb at all. In these cases, you may only be partially numb or worse yet, not numb at all despite receiving multiple doses of novocaine. This means that you will feel everything that your dentist is doing to your tooth.

Therefore, all those horror stories that you've heard about how painful a root canal was, were all associated with a severely infected nerve that just won't get properly numbed. If you were able to get adequately numb, the procedure shouldn't hurt at all.

Situations where tooth won't numb for a root canal

Here are some situations where you may experience pain from a root canal because the tooth won't get anesthetized or can only be partially numb. Basically the novocaine doesn't work or won't work as intended.

Hot tooth

A "hot tooth" is a term used to describe a tooth that has been diagnosed with irreversible pulpitis that is accompanied by moderate to severe pain. This condition has a couple of very distinctive symptoms that are easily identifiable.

Individuals with this condition usually have a very difficult time getting numb. They often require extra doses of anesthesia and even then, they may not get fully numb during the entire treatment.

Tooth abscess

If your tooth has an abscess, it means that it has a pretty big infection. Sometimes the infection can be so big that it makes it difficult for the anesthesia to numb the tooth.

An analogy would be trying to board a fully packed train. It is difficult to get on the train when it is completely full isn't it? The same thing happens for trying to numb a severely infected tooth. It is difficult for the anesthesia to reach the nerve when the tooth is filled with infected tissue.

Here is a picture of what a tooth abscess looks like.

pimple on the gums
pimple on the gums

Sometimes the infection can get so big that it forms a pimple by the side of the tooth on the gums. The pimple can eventually pop and you'll find white pus oozing out of it. That white pus is the infection from inside the tooth making its way out into your mouth.

Although interestingly enough, once the pimple pops and the abscess has a way of coming out, you should stop feeling pain. But prior to the infection having a way out, you will experience a lot of pain.

Abscess with facial swelling

A dental abscess can progress further and cause your face to swell up. The swelling can make your face look slightly larger or even as big as a golf ball. In extreme situations, the swelling can make one side of your face look like you've gained 20 pounds.

facial swelling
facial swelling

The swelled up parts of your face are completely filled with infection. This makes it extremely difficult to be fully anesthetized for the procedure. In fact, due to the amount of infection you can't even perform a root canal immediately. You would actually need to drain the infection first and then wait a few days for the swelling to come down before you can even attempt the root canal treatment.

When root canals don't hurt

With the exception of the scenarios above, root canals normally don't hurt at all. The reason for the absence of pain is all due to the fact that you should be fully numb for the procedure. The purpose of the local anesthetic is to make sure that you don't feel any pain. When your tooth is not severely inflamed nor infected, there is no reason why the anesthesia won't work as intended.

This is why it is important to go for your dental check ups every 6 months because your dentist can catch problems and infections before they start hurting you. If you get the root canal done before it starts hurting, you will most likely experience zero pain during the procedure.

On the other hand, if you ignore your dentist's advice to do the procedure and wait for it to start hurting... you should expect the treatment to not go as smoothly. There will be a high possibility of the root canal hurting.

How your dentist gets you numb and comfortable for the procedure

Typically for the procedure, 1-2 doses of local anesthesia should be more than adequate to get you fully numb. You should be very comfortable and not feel any pain at all. This is how your dentist does it.

  1. Apply some numbing gel.

  2. Wait 2 minutes for the gel to work.

  3. Give the dental numbing shot with Lidocaine or Novocaine.

  4. Wait 3-5 minutes for the anesthesia to start working.

  5. Start the root canal.

For patients who are extra nervous and anxious, we can also give some anti-anxiety medication, laughing gas, or IV sedation.

  • Anti-anxiety medication. The most commonly used would be Valium. When taken, it will make you relax because it breaks your anxiety.

  • Laughing gas. Otherwise known as nitrous oxide, once patients start inhaling it they start to loosen up a lot. They'll be so comfortable that they'll even sporadically start giggling and laughing.

  • IV sedation. This is reserved for those patients who need more than just medication or laughing gas. This type of sedation will completely put you to sleep. By the time you wake up the procedure will be over. The only downside is that you do require a chaperone to come with you and escort you home afterwards.

Being relaxed and not anxious is extremely beneficial to ensure that root canals don't hurt. Studies have shown that anxious patients have an increased perception of pain.

Perhaps the procedure doesn't even hurt you at all but the fact that you're super anxious might make you think it is painful. We suppose that is the fourth way that a root canal can hurt you.

The Verdict

Routine root canals should not hurt you at all but there are exceptions. The only times it can hurt is if you go into the appointment already in pain. Due to the severe inflammation and infection, you may not be able to get fully numb and that is the source of all the pain for a root canal procedure. Therefore as long as you take care of all problems before they start hurting you, no root canal in the world should hurt you!

Author: This article was written by Dr David Chen, a general dentist in long island city.



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!

Association Memberships:

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!

bottom of page