What Are Canker Sores? How Do You Treat Them?

What Are Canker Sores? How Do You Treat Them?

While they're not contagious, canker sores can be painful, and most over-the-counter medications don't help heal them.



A canker sore is a a painful ulcer that can appear on your gums, the inside of your lip, your tongue, or the roof of your mouth. Also called apthous ulcers, they typically form in the shape of an oval that is white in the middle and red around the edges.

They are not contagious or pre-cancerous, and are not caused by any specific bacteria or virus.

Canker sores are sometimes confused with cold sores, which appear as clusters of blisters on the outside of the lips and are contagious.

What causes canker sores?

While there is not one known cause, it is believed that multiple factors contribute, including genetics, stress, and certain foods and irritants.

If you find that you get canker sores very often, it may be time to check the ingredients of your toothpaste. SLS, also called Sodium Lauryl Sulfate, is a foaming agent present in most toothpastes. For people with sensitive skin or who are prone to ulcers, it can be an irritant. For such patients, I recommend switching to an SLS-free toothpaste such as Sensodyne Pronamel.

When should you see a dentist for a canker sore?

Most canker sores heal on their own within one or two weeks, and none of them cause cancer. If a sore persists longer than two weeks, you should check with your dentist to make sure it is not a different condition. If you have an especially painful or large ulcer, your dentist may also be able to prescribe you medication to help it heal faster.

How do you make a canker sore heal faster?

There are many over-the-counter medications for canker sores. However, most of them only treat the symptoms by numbing the pain.

Your dentist can prescribe medication called Debacterol which usually allows the ulcer to heal much faster. Only one topical application is needed, although it can be painful for several seconds.

For home care, it can be helpful to avoid anything that could irritate the ulcer further, such as citrus and other sour foods, and spicy foods.

Warm salt water rinses two or three times a day can be soothing as well.