A Family Dental Practice Where We Treat Our Patients Like Family.

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A Family Dental Practice Where We Treat Our Patients Like Family.

High-quality care you can trust!

What You Should Know About Canker Sores

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Patients often ask me what to do for canker sores, those dreaded sores we sometimes get in our mouths for seemingly no apparent reason. They come, they last a few days to a few weeks or even months and then go away. They may come back at a different spot in the mouth or in the same spot a little later. But what are they? What is the cause of canker sores? Is there any treatment for them? Today we’ll be discussing canker sores, clinically known as aphthous ulcers.

What is a Canker Sore?


The clinical name for canker sore is aphthous ulcer. They are whitish sores with a red halo. There are 3 different types of aphthous ulcers: 1.) minor, 2.) major, and 3.) herpetiform. Minor aphthae are the most common and present as singular or multiple, being less than 1 cm in size. Major aphthae typically present as 1-2 lesions, are larger than 1 cm, and appear on the lip or back of the throat. Major aphthae are deeper in the tissue than minor lesions and are more likely to lead to scarring.

Herpetiform aphthae present as many very small lesions as possible, each only 1-2 mm in size. They’re called herpetiform because they closely resemble the morphology of the oral disease, herpes. The main differences between herpetiform aphthae and herpes include symptoms, location of the lesions and appearance of the lesions. Herpes lesions generally have a neurologic sensation at first such as numbness, tingling or a burning sensation, whereas herpetiform aphthae don’t have neurologic symptoms. Herpes virus generally appears on keratinized tissue, i.e. the hard palate, attached gingiva and vermillion border (border around the lips), whereas herpetiform aphthae appear on non-keratinized tissue, i.e. buccal mucosa, the floor of the mouth and sides of the tongue. Herpes lesions are generally more blister-like and herpetiform lesions are flatter. It is important to remember that herpes lesions are contagious while all forms of aphthous ulcers are not contagious.

What Causes These Sores?

The exact cause for aphthous ulcers is unknown, though clinicians have documented various trends including trauma, stress, allergy or vitamin deficiency. When canker sores are frequent or severe, they can be part of a systemic condition such as infection, anemia, diabetes, Crohn’s disease, celiac disease, Behcet’s disease or immune system disorders. Most commonly, trauma to the oral tissue can induce a canker sore. For example, if you accidentally bite your tongue, you may notice a canker sore develop the next day. Similarly, if you eat some chips and scratch your mucosa, a canker sore may form. These can be recurrent lesions if the patient repeatedly irritates that area in the mouth.

Remedies to Help With Canker Sores

As for treatment, unfortunately there is no treatment for canker sores. However, there are certain remedies to help alleviate the pain. There is a product that I have found to be very helpful for patients, called Propolis. It’s a natural secretion sourced from honeybees! Other remedies which can help include hydrogen peroxide rinses (for example, Colgate Peroxyl), saltwater rinses, baking soda slurry rinses, or placing topical benzocaine anesthetic (for example Orajel) on the sore. If your canker sore is severe, your dentist may prescribe a mouth rinse for you which may contain anesthetic, steroid, antibacterial and antifungal properties. Obviously if the apthous ulcers are indicative of an underlying condition, then that condition must be treated. For example, if the patient is vitamin B12 deficient, then that nutritional imbalance must be corrected with diet or supplements.

If you have any form of aphthous ulcer, it is important to avoid spicy, acidic, or very hot foods which can irritate the lesions. The following foods have been anecdotally found to lead to the presence of canker sores: chocolate, coffee, acidic fruits or vegetables and spicy foods.

If you are ever unsure of what to do about these pesky, annoying, and painful lesions, ask your dentist!