7 Reasons For Pain After A Root Canal

7 Reasons For Pain After A Root Canal

 Whitney DiFoggio MA, RDH
Written by Whitney DiFoggio MA, RDH
Medical Reviewed on Feb 10, 2023
byDr. Matthew Hannan DDS
🔬 Evidence Based
7 Reasons For Pain After A Root Canal

Worried about the pain after root canal treatment? If you’re experiencing mouth, ear, or jaw pain after root canal therapy, it might not necessarily be due to the endodontic procedure your dentist just completed. In fact, discomfort or throbbing pain after root canal therapy isn’t as common as you might think!

Pain After Root Canal Therapy  

One of the most common rumors people hear about dental offices is that they’ll experience horrible, throbbing pain after root canal therapy. Thanks to state-of-the-art equipment, that’s not usually true. Typically, people are in pain ahead of getting a root canal, because of the abscess in their mouth. The actual root canal is meant to relieve the source of their pain, helping you feel more comfortable overall. It might come as a surprise if you’re in severe discomfort after your dental procedure, considering your dentist was treating the infection and not poking around in there making things worse. When you are in pain, it could be due to something else.

Root Canal Recovery Period 

It’s not unheard of to experience some soreness or sensitivity after any dental procedure. The anesthetic can take a few hours to wear off before your mouth feels like itself again. Major restorations like root canals, crowns, or even large fillings could leave you feeling a bit more aware of that part of your mouth for a couple of days. But there’s not necessarily a “recovery” to plan for like you would with wisdom teeth removal.

Typically, the only reason you won’t go straight back to your usual diet after a root canal is that your dentist will place a temporary crown (“cap”) on that tooth. You need to be careful with it, so as not to pull it off with anything too sticky or hard. But aside from being careful with the way you eat, there aren’t any major changes you’ll need to make those first several days.

7 Reasons Why You May Have Pain After Root Canal Treatment

In the situation that you do experience some discomfort after a root canal, there’s usually a really good reason why. And by playing a bit of detective work, you can figure out the source of the discomfort (so that you can treat it accordingly.) Generally, any discomfort will be best managed with an over-the-counter pain reliever such as Motrin, a cool compress, and rinsing with some warm salt water. Rarely if ever would you need an actual prescription painkiller. Dental technology, techniques, and medications have come a long way!

All of that being said, here are the most common reasons why someone might be feeling some type of throbbing pain after root canal treatment:

1. Where the Local Anesthetic Was Injected

Hands down, the most common reason why people are sore after a root canal, or any dental work for that matter, is because of the injection that’s necessary to get them comfortable. Your dentist has to administer local anesthetic in that area of your mouth to numb the tooth up. But that also means getting an injection (or three) in your gum tissues at various parts of your mouth. If you remember having a sore arm after a vaccine, it’s easy to see how your mouth can hurt where local anesthetic is injected.

2. Holding Your Mouth Open for Too Long

One of the other common situations that can cause a sore mouth after root canal treatment is from holding your mouth open for a long time. Your jaw joint (TMJ) on either side of your mandible and just in front of your ear can get a little sore. Especially if you’re having to strain it by opening wider than normal for a hard-to-reach tooth. To lessen the strain on your joint, your dentist will use a bite block that you rest your teeth against. It essentially works like a prop holding a door open, except in this case it’s your mouth. The more you can relax your TMJ, the less sore your jaw is likely to be afterward.

3. Failed Root Canal 

From time to time, root canal treatment can fail. Perhaps there was some nerve tissue left behind or the canal wasn’t completely cleaned out. In some cases, there can even be secondary canals that your dentist cannot see. If the tooth continues to hurt, your dentist may need to send you to a root canal specialist (endodontist) to have the tooth re-treated. Retreatments are a bit more complicated than a standard root canal, so they need to be performed by an expert who has the right type of equipment on hand.

 4. Referred Pain

It’s completely normal to feel a toothache coming from an area that’s not actually where you think it’s coming from. You might have a cracked tooth or cavity that’s in a tooth elsewhere in your mouth. There may even be some residual swelling inside of your jaw. Since several teeth share major nerves, it can make your brain think a specific tooth hurts when it’s actually another one.

5. Sensitive Teeth and Gums

Some people tend to just have more sensitive teeth and gums. Especially when there’s an infection that’s healing, like an abscess or cyst. When one tooth is worked on for a longer procedure like a root canal, the tissues can also get a little irritated. Even the adjacent teeth may tend to feel sensitive for a while. Your dentist may recommend using a sensitivity toothpaste leading up to your appointment and for at least a couple of weeks afterward. But if there’s anything out of the normal, be sure to let your dentist know. 

6. The Dental Dam

Root canal treatment is extremely detailed and tiny little pieces of equipment are used. To keep your tooth completely isolated from the rest of your mouth, your dentist will need to use a “dental dam” that exposes your tooth while covering all of the other ones. Sometimes placing a dental dam can make the gums around your tooth a little sore. But the tradeoff is worth it because it keeps you safe and prevents you from accidentally swallowing anything.

7. Your New Crown is “Too High”  

After your root canal is complete, your dentist will put a crown over your tooth. The way the crown meets the tooth on the opposite arch needs to be perfect so that the pressure is distributed properly. If one area is a little too high—even if it’s just fractures of a millimeter—it can make your tooth hurt after a while. The good news is that your dentist can check it with special articulating paper and adjust it as needed. It’s not a permanent problem by any means.

Jaw Pain After Root Canal

Some of the most common soreness or “pain” people experience after endodontic services is related to their jaw (TMJ). Since some root canals take longer to perform than others—because of how many roots the tooth has, or if the root is hard to reach—your mouth might be open longer than someone else’s. All that time propped open wide can, for some people, make their jaws sore.

Fortunately, most dentists or endodontists will use a soft prop or pillow to rest your teeth on. That way your mouth stays open for the necessary time, but you’re not having to physically keep it open with your muscles, joints, or having pressure applied to your mouth to keep it open. 

Jaw pain after root canal therapy is temporary, but it can last for a few days. It’s the same with any joint in your body that’s sore or strained. Alternating cold and warm compresses on the jaw that hurts can help alleviate discomfort. An anti-inflammatory like Motrin/ibuprofen is also helpful.

Treating Pain After A Root Canal

Any time your mouth is sore after dental treatment, root canal or not, the best way to manage oral pain is with anti-inflammatory medication, warm salt water rinse, and a cool compress. For the first 24 hours, you can also incorporate a warm compress, alternating them 20 minutes on, and 20 minutes off. 

Generally speaking, some mild to moderate soreness can be expected with major dental work. Especially in the gums around the tooth or where injections were applied. But if you’re in serious pain to the point where there is shooting pain through your jaw or tooth, something isn’t right. If that’s the case, your dentist may need to perform additional treatment rather than just call something in.

The exception would be if you still had significant inflammation in your jaw because of the abscess. Any serious infection will likely be treated with antibiotics. Usually, if the abscess is severe, your dentist will have you take antibiotics leading up to the root canal so that the procedure can be as gentle and effective as possible. It can be difficult to numb your tooth if there is still significant inflammation. Assuming your symptoms improve, do not stop taking your antibiotic; make sure you take the full course of the medication as directed.

Prevent Complications 

With the right home care, you can easily avoid self-induced complications following root canal treatment. As with any dental procedure, your dentist is going to give you specific directions to follow once you get back home. Make sure you follow them, even if they seem silly. The last thing you want is a preventable complication, such as your temporary crown falling off or interactions with the medications that you’re taking.

For the time being, make sure you avoid chewing on the side of your mouth with the root canal. Once your dentist fixes a permanent crown over the tooth—usually two weeks later—you can go back to chewing on it normally.

Be sure you’re brushing and flossing around each of your teeth daily. Even though your tooth has had a root canal inside of it, the outer tooth surfaces can still succumb to dental plaque and develop cavities. Crowns cover most of the tooth up to the gumline, but there is still a small margin where bacteria can come into contact with your enamel. You have to keep it clean if you don’t want the crown or root canal to fail. In the meantime, be sure to visit your dentist every six months for checkups, so that they can screen for complications ASAP. 

When To Talk To A Dentist 

If you’re in so much pain that you can’t go to sleep the night of your root canal, you don’t have to tough it out. First, re-check your home care instructions to make sure there’s nothing you missed. Second, try the above-mentioned home care tips (medication, cool compress, warm saltwater). And finally, if none of that helps, reach out to your dentist’s office.

Most dentists will have some type of an on-call or messaging service where current patients can get a hold of them if necessary. You might have to leave a message depending on the time of day, but usually, someone is always monitoring it and will get back to you. Depending on what your symptoms are, they might call in some medication to get you through the night and then arrange to see you at their office the next day.

If for any reason you have severe facial swelling or bleeding—both of which are extremely rare—then head to your nearest emergency room. This is more of a disclaimer statement because you typically never see something like this after a root canal, but if it’s that bad, you need to be at a hospital.

Overcoming Pain After Root Canal

Sharp or throbbing pain after root canal treatment probably isn’t because of the actual endodontic restoration. Any pain after root canal therapy tends to tie back to issues like where the local anesthetic was injected, a really bad infection, or keeping your mouth open for a long time during the appointment.

Root canal therapy is meant to relieve pain and discomfort, not cause more of it. If you’re hurting or in more pain after a root canal, that isn’t normal. Always speak to your dentist, especially if you’re not able to eat, sleep, or go to work. But most importantly, make sure you’re following your home care instructions properly to limit the risk of any irritation once you return home.

 Whitney DiFoggio MA, RDH
Written by Whitney DiFoggio MA, RDH"Teeth Talk Girl," is a registered dental hygienist. She started her dental health journey on YouTube, educating the public through videos.
Dr. Matthew  Hannan DDS
Medical Reviewed byDr. Matthew Hannan DDSDr. Matthew Hannan is a board-certified dentist and graduate of UT Health San Antonio School of Dentistry.
Last updated onJune 24, 2023Here is our process

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