The Ugly Truth About Canker Sores


What are Canker Sores?

Many people have canker sores on occasion, but most don’t really know what causes them. Canker sores, otherwise known as mouth ulcers, are normally small lesions that develop in your mouth or at the base of your gums. They can be uncomfortable and can cause challenges with eating, drinking, and talking, are not contagious, and usually go away within a week.

Canker sores result from bacteria, viruses, or fungi, which inflame the lining of the mouth, causing swelling, redness, and ulcer formation. The most common locations for canker sores include the inside of the mouth, on the tongue or lips.

What causes canker sources?

There is no exact cause behind canker sores, however, a few causes have been identified.

  • Minor injury from dental work, hard brushing, sports injury, or accidental bite
  • Dental care products that contain sodium lauryl sulfate
  • Sensitivities to acidic food, such as strawberries, pineapple, or even chocolate or coffee
  • Vitamin deficiency—lack of essential vitamins like B-12, zinc, folate and iron
  • Allergic response to bacteria in the mouth
  • Stress
  • Bacterial, viral, or fungal infections,
  • Hormonal influxes during menstruation

Types of Canker Sores

It’s a good idea to take a look at the canker sore and decipher what kind of sore it is. Canker sores have three different types:

  • Minor: minor canker sores are small and oval shaped, will not result in scarring, and will heal within 1-2 weeks
  • Major: these canker sores are larger and deeper than minor sores. This type has irregular edges and can take up to 6 weeks to heal
  • Herpetiform: this type of sore is not common. Most often, these sores are located in the posterior mouth, will have irregular edges, and may come with more than one sore. This will heal within two weeks, most likely without scarring.

When do I see a dentist?

If you develop any of the following, please call our office at 239-936-0597 to set up an appointment right away:

  • Large canker sores in your mouth
  • New canker sores before the old one heals
  • A canker sore lasting more than 3 weeks
  • Severe issues eating and drinking
  • Sores that don’t hurt
  • Mouth sores that extend to your lips

How can I treat a Canker Sore Myself?

If you don’t have any of the serious conditions or symptoms above, there are a few things you can do to help your mouth heal quicker.

  • Use a topical paste or gel, such as Orajel Ultra Canker Sore gel
  • Placing damp tea bags on your mouth or sore
  • Take nutritional supplements, such as chamomile tea, Echinacea or licorice
  • Using a rinse of saltwater and baking soda
  • Apply ice to canker sore
  • Placing milk of magnesia on the sore
  • Avoid foods that could irritate your mouth, such as citrus (oranges, pineapple) and spicy foods. Try eating whole grain foods and eliminating acidic fruits and vegetables until it clears up

At Shane McDowell, we care about you and your family’s dental health! If you are suffering from long-term, painful canker sores or have any of the severe symptoms listed above, contact our office or email us at to schedule an appointment.


Mouth sores and treatment options

shutterstock_111235958Dental health is not always about just our teeth. A mouth sore can be painful, uncomfortable, and unattractive. Mouth sores can appear inside the mouth on the gums, tongue, lips, cheeks or the roof of your mouth. Also, cold sores can appear outside of the mouth, like on or near lips, underneath your nose or on the chin.

There are a number of possible causes for mouth sores, including:

  • Irritations, such as dentures or wires from braces rubbing up against the inside of the mouth
  • Mouth sensitivity to ingredients in toothpaste and other oral care products
  • Medication reactions
  • Skin, oral or systemic diseases
  • Bacterial, viral or fungal infections
  • Oral cancer

The most common type of mouth sores are canker sores, cold sores, leukoplakia, and thrush. We’ve briefly described each with related treatment options below:

  • Canker sores:  Appear inside of the mouth and usually consist of small ulcers that have a white, yellow or grey center and a flat red border. While many canker sores are painful, they usually go away on their own within seven to 10 days. The cause for canker sores has widely been speculated on. According to the American Dental Association, canker sores may be caused by fatigue, emotional stress, and certain foods.
  • Cold sores:   Appear around or on the lips and look like fluid-filled blisters. Cold sores are caused by herpes virus Type 1 and Type 2 and are contagious. These can be painful and unattractive. There are over-the-counter topical agents that can be used to counteract the effects of cold sores.
  • Leukoplakia:  Usually developing inside the mouth as a white or grey colored patch, leukoplakia is caused by excess cell growth of the lining of the mouth. Oftentimes, leukoplakia has been linked with cigarette smoking and chewing tobacco. It is also associated with cheek biting, irregular sized dental restorations and broken teeth. While leukoplakia is usually harmless, removing the cause of irritation is the best treatment option. This may involve visiting our dentistry to ensure that your dental appliances are repaired properly or so that we may best assess the cause.
  • Thrush:  Thrush is also known as candidiasis. This is actually a fungal infection that produces creamy white and red patches on the surfaces of a person’s mouth. Oral fungal infections occur when the yeast, Candida albicans, reproduces in higher than normal numbers. Thrush frequently occurs in those who are debilitated by disease, like diabetes and AIDS. Treatment for thrush consists of controlling the conditions that caused the outbreak. Since thrush is also in common with people who wear dentures, one way to treat it would be to clean the dentures properly to remove the Candida and therefor prevent more denture-induced problems.

In all cases of mouth sores, good oral hygiene is critical. Scheduling regular dental checkups at our dentistry in Fort Myers and making an appointment if your mouth sores persist for more than two weeks will help determine the cause.

We care about your daily oral health routine and look forward to continuing to serve you! For more information or to schedule an appointment with us, please visit our website at or call (239) 936-0597.