Canker Sores


Karen Kelley RDH

Canker sores can be a nuisance and a pain to people who frequently get them. As a hygienist, it’s one of the things I often get asked about. Here’s some information about canker sores and some ideas for prevention and relief.


Most canker sores are round or oval with a white or yellow center and a red border. They form inside your mouth —on or under your tongue, inside your cheeks or lips, at the base of your gums, or on your soft palate. (Even though they look similar, they are not the same as a fever blisters which occur on or around the lips and are from the herpes virus.) Canker sores may begin with a tingling or burning sensation a day or two before the sores actually appear. There are several types of canker sores, including minor, major and herpetiform sores. Minor canker sores are the most common and what will be addressed in this article. They are usually small and heal without scarring in one to two weeks.

The precise cause of canker sores remains unclear, though researchers suspect that a combination of several factors contribute to outbreaks. Possible triggers for canker sores include: a minor injury to your mouth from dental work or other trauma, overzealous brushing, spicy or acidic foods, or an accidental cheek bite. Strangely enough, many toothpastes and mouth rinses contain sodium lauryl sulfate which for those who are prone to getting canker sores, can be an additional trigger. Another trigger can be from certain foods, particularly chocolate, coffee, strawberries, eggs, nuts, cheese and highly acidic foods, such as pineapple. Research also associates canker sores to a diet lacking in vitamin B-12, zinc, folate (folic acid) or iron and they have also found a link to emotional stress and hormonal shifts. Certain diseases may also cause canker sores to manifest more frequently. An interesting fact is that being female makes you more susceptible as well as having a family history of canker sores.

The following are some home remedies for the relief of canker sores from the Mayo Clinic website:

1. Rinse your mouth using salt water, (1 tsp of salt to 1 cup of warm water), baking soda (1 teaspoon of soda to 1/2 cup warm water), equal parts of hydrogen peroxide to water or a mixture of 1 tsp Benadryl to either 1 tsp Kaopectate or 1 tsp Maalox. Be sure to spit out the mixtures after rinsing.

2. Dab a small amount of milk of magnesia on your canker sore a few times a day with a cotton swab .

3. Cover canker sores with a paste made of baking soda plus a small amount of water — just enough to make a paste.

4. Apply ice to the canker sore. The slowly dissolving ice will make the sore feel better.

Over-the-counter products that contain the numbing agent benzocaine, such as Anbesol and Orajel can also be beneficial.

A prescription medication that some find helpful is Kenalog in Orabase. It’s a thick gel that is placed on the canker sore with a cotton swab every few hours. It helps to reduce the inflammation so that the sore feels better and is less puffy.

There are some things to avoid so that canker sores can be prevented. These include abrasive, acidic or spicy foods that can cause further irritation and pain. When brushing your teeth, brush gently using a soft brush and toothpaste that doesn’t contain sodium laurel sulfate (SLS). The following products are SLS free: Biotene, Sensodyne ProNamel and Rembrandt Canker Sore. Also, make sure your diet contains enough B-12, zinc, folate and iron.

Keep in mind that even though canker sores are painful, canker sores tend to heal well on their own. Consult your dentist when canker sores do not heal after 14 days, are accompanied by a fever, or appear to be infected.





Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s