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Canker Sore After Tooth Extraction

Updated: Dec 19, 2023

You haven't had a canker sore (aphthous ulcer) in awhile but the day after your tooth extraction, it seems to have reappeared. Is that a coincidence or could the ulcer and mouth sore have been caused by your dentist?

Canker sore on lip
Canker sore on lip

Can you get a canker sore after an extraction?

It is possible to get a canker sore after having a tooth extraction from the immense stress of undergoing the procedure. That's right, it is purely stress induced which means that the cause is of psychological origins.

Potential canker sore locations:

  • Gums (gingiva)

  • Cheeks

  • Lips

  • Tongue

In case you were in disbelief, there have been plenty of studies to back up the claim of stressing causing your canker sore.

  • A study which compared those who frequently had recurrent aphthous ulcers (canker sores) reported significantly higher levels of psychological stress vs the control.

  • Another study found that stress had a variety of effects on our oral health which included canker sores, dry mouth, gum disease, teeth grinding, etc.

So it wasn't caused by the tooth removal?

If you were looking to blame your dentist as the scapegoat for giving you a canker sore, you'd be stretching it. As proven above, the reason you got one was purely due to stress and not from the tooth removal procedure. The act of taking out the tooth cannot directly give you a sore in your mouth.

Extracted teeth
Extracted teeth

However we do have to say that if your dentist was terrifyingly scary, perhaps they may have been a contributor to your stress levels. Perhaps you can still blame them? Why couldn't they have been less scary or make the treatment less anxiety inducing?

Canker sore after wisdom tooth extraction

Just so that there is no ambiguity, you can also get a canker sore after a wisdom tooth extraction. In fact, you're more likely to develop this irritating aphthous ulcer after removing your third molar.

upper wisdom tooth extraction
upper wisdom tooth extraction

Wisdom teeth are often impacted in the bone and the gums so the procedure is more complicated and even more stressful. The combination of those two factors will increase your risk of getting a canker sore after the extraction.

Possibly a coincidence

If you get canker sores every once in awhile, it could also have been a coincidence. Maybe it just happened to have come at an inopportune time that coincided with your dental visit.

In case you weren't aware, the exact causes of canker sores have yet to be determined. Researchers are still unsure about what causes them. As of the moment its mostly theories.

Possible causes of aphthous ulcers:

  • Citrus fruits

  • Melons

  • Tomatoes

  • Vinegar

  • Wine

  • Chocolate

  • Nuts (walnuts)

It is typically recommended to avoid the above foods if you get the condition often. It may still be individualistic so you should pay attention to what happens whenever you eat certain types of foods. If you find one that seems to trigger it you should definitely avoid it.

Although did you know that a certain ingredient in your ingredient could be a contributing factor?

Canker sore inducing toothpaste ingredient

Surprise, surprise but it has been shown that sodium lauryl sulfate (SLS), a synthetic detergent commonly used in toothpastes may increase the incidence of canker sores.

canker sore on lower lip

The study had the test subjects use a toothpaste containing 1.2% SLS for three months. Then they were instructed to use a toothpaste sans sodium lauryl sulfate for another three months.

The results showed a statistically significant decrease in aphthous ulcers from 14.3 down to 5.1 ulcers after switching toothpastes. That implies that SLS in toothpastes seem to induce or trigger more canker sores.

Why does toothpaste even have SLS?

If you suffer from frequent mouth ulcers, you may think that SLS is the spawn of satan and question its existence in toothpaste... However sodium lauryl sulfate in toothpaste does serve a purpose because it helps the product lather which gives it a foamy and bubbly texture.

The lathering aspect of it helps it clean the surfaces of your teeth and makes them feel clean. The reason it is present in dentifrice is the same as why it is in shampoo and other soaps.

Of course, there are plenty of toothpastes on the market which do not contain SLS. If you get frequent canker sores you may want to look into switching to one without it.

How to heal a canker sore

Here are some home remedies which you can try to help speed up the recovery:

  • Salt water rinse. The most gentle mouth rinse to use is salt water since it is non-acidic. Alcoholic based ones may burn and worsen the pain.

  • Baking soda rinse. Yes mixing a teaspoon of baking soda into water and using it as a rinse can also help. It's a home remedy that has been used for a long time.

  • Apply milk of magnesia. Dabbing it onto the sore may help alleviate some of the pain.

  • Avoid acidic or spicy foods. These often trigger the sores to appear and certainly don't help in alleviating pain. The acidity will make the sores burn and hurt.

  • Use ice cubes. You can either leave it in your mouth or hold it against your lips/cheeks.

  • Switch to a SLS-free toothpaste. Using a toothpaste without sodium lauryl sulfate will decrease the incidences of getting these aphthous ulcers.

Aside from all of the above, you simply need to give it time for it to heal. Canker sores will typically go away on its own after about 2 weeks.

Prevention Tips

Preventing the occurrence of mouth ulcers may be difficult because those who suffer from it tend to live with it throughout their life. However it does seem that if you're able to avoid certain triggers you can drastically decrease the incidences of it.

Tips to prevent aphthous ulcers:

  • Avoid triggers. If you know what triggers it, you should do your best to avoid them.

  • SLS-free toothpaste. Certainly doesn't hurt to use a toothpaste without it. In fact you should switch your shampoo and other soaps around the house as well.

  • Decrease your stress. It may be induced by stressed so try your best to stay calm during your procedure.

Another tip would be to brush and floss twice a day. If you keep your teeth healthy, you wouldn't need any extractions. That would certainly solve the problem of getting canker sores after a tooth extraction!


Getting a canker sore is certainly a possible complication after an extraction. Although the cause of it isn't from the procedure itself but rather it is stress induced. You were probably extremely anxious and stressed out over having a tooth removed. That most likely triggered the occurrence of your mouth sore.

Please try not to blame your dentist for it! The good news is that like always, the sore should go away after about two weeks. Last but not least, it is good practice to follow the general aftercare tips for an extraction.



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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