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Helpful Dental Tips: Canker Sores


Canker sores are small, shallow ulcers that appear in the mouth.  They are typically white or grey at the center and rimmed in red.  There are two types of canker sores:

simple canker sores– usually those ages 10-20 will get this type of sore; they will appear 3-4 times a year, lasting up to a week each time.

complex canker sores– these sores are less common and occur more often in those who have had canker sores before.

In the case of a simple canker sore, scientists and doctors are still not sure what causes them.  They can often appear in correlation to a stressful event or situation, or can develop as a result of damage being done to oral tissue.  This damage would entail something like a sharp tooth or rough edge on braces irritating the inside of the cheek and creating a canker sore.  Food can often times be a trigger for simple canker sores as well.  Fruits and vegetables that are high in acidity, such as citrus fruits, pineapple, figs, strawberries, or tomatoes, can cause irritation within the mouth and result in a sore developing.

Complex canker sores, on the other hand, can often be the result of a weak immune system.  However, more often than not, they are caused by vitamin deficiencies within the body such as an insufficient amount of vitamin B-12, zinc, folic acid, or iron.  It is important to note that canker sores are not cold sores.  Cold sores are a virus and must therefore be dealt with differently.

How to Prevent Canker Sores

            Canker sores can appear on the roof of the mouth, the interior of the cheek, on the gums, or even on the tongue.  If a canker sore is particularly large, it can cause the side effects of a fever or even swollen lymph nodes.  Typically a sore will not last more than a week and its painfulness will subside as the days go on.  You can help prevent canker sores by avoiding irritating foods such as citrus, overly spicy foods, acidic vegetables and even sour candies that are high in acidity.  Chewing gum can sometimes be an irritant as well.  Brushing and flossing after meals can help keep these irritations at bay.

If Sores Persist…

            Some home remedies to try include,

– rinsing your mouth with salt water

– swab the sore with diluted hydrogen peroxide to help kill bacteria

– try dabbing Milk of Magnesia on the sore to assist in reducing pain

– purchase some pain relieving gel, such as Orajel, to numb the area

– make sure to clean mouth after every meal to keep the sore is as clear of bacteria as possible.

If a canker sore simply will not go away after a week, contact your dentist.  They may prescribe an antimicrobial mouth rinse or, if it’s particularly bad, a corticosteroid ointment.




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506 East Hastings Rd.
Suite B
Spokane WA 99218

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