If you have ever had a canker sore, you know how painful they can be. In fact, canker sores can be so excruciating that part of their medical name, oral aphthous ulcers, comes from the Greek word “aphthi” which means “to set on fire” or “to inflame” (1). Unfortunately, one in five people deals with these painful mouth ulcers.
Although more common than dental caries (cavities) or periodontal disease, canker sores are still somewhat of a mystery. They have been observed in otherwise healthy people for thousands of years, but scientists are still trying to understand all the various factors that cause them to appear in one person but not another. Fortunately, we have discovered some ways to minimize the risk of getting a canker sore and how to shorten their duration and lessen the pain when they do appear.
You may notice a burning or tingling sensation somewhere inside your mouth, up to a day before the canker sore appears. Next, a small red bump appears in the soft tissue of the inside of your mouth. The bump bursts open, forming a shallow white, yellow, or grey ulcer surrounded by a red ring. Most are only a few millimeters in diameter but can be up to a half-inch across. Although relatively small, they are often incredibly painful and can make it difficult to eat, drink, and even speak. Fortunately, they do not stick around long and usually go away on their own within one or two weeks.
You will probably not have any other signs or symptoms. If you do develop a fever or swollen lymph nodes or feel sluggish, this may be a sign of an underlying infection and you should consult your doctor. Additionally, contact your dentist or doctor if the canker sores are spreading, larger than usual, lasting more than three weeks, or if the sores are painful enough that you are having trouble staying hydrated or cause severe pain even after taking over-the-counter pain medication. Let your dentist know if a sharp tooth surface or dental work causes recurring sores.
Canker sores only develop inside the mouth. If your sores form outside of your mouth or lips, they are probably cold sores, which are caused by a virus and are highly contagious. Unlike cold sores, canker sores are not caused by a contagious virus.
Scientists are still trying to discover if there are any root causes of canker sores, but we do know that there are many factors that can contribute to their formation. Nutritional deficiencies, autoimmune disorders, infections, genetics, hormones, smoking, stress, and some medications can cause canker sores to develop. Trauma to the soft tissues of your mouth, even from something minor like accidentally biting your cheek, brushing your teeth too hard, or rubbing against dental appliances can cause canker sores to form (1). Some foods, including citrus foods, coffee, tomatoes, strawberries, spicy foods, soda, gum, and sugary candies may also trigger canker sores. An allergic reaction to certain foods, such as tree nuts, milk, or soy is a common reason that people get canker sores.
Canker sores tend to run in families. This may be partly due to genetics, but it may also have something to do with the bacteria that live in your mouth. Although canker sores are not considered contagious, recent research has found that people who experience recurring canker sores have a different makeup of oral bacteria than people who do not get them (2). It has also been discovered that people who live together have a similar composition of oral bacteria (3). So, although canker sores are not contagious in the traditional sense, it is better to avoid sharing germs with someone who regularly gets canker sores, to avoid transferring their bacterial strains into your mouth.
Sodium lauryl sulfate (SLS) has been blamed for canker sores. A recent study found that using products free of SLS did not reduce the number of canker sores in a person, but did positively affect the healing process, by shortening the length of time the sores existed and reducing pain levels (4).
The first step is prevention. Discover what triggers your canker sores and avoid those triggers. Everyone is different and what causes canker sores in someone else may not cause you to develop them, so this may take some investigation. Keeping a food diary may help you notice if certain foods irritate your mouth. Your doctor can help you determine if a nutritional deficiency is a contributing factor and will prescribe a supplement if necessary. One small study found that taking a vitamin B12 supplement not only decreased the number of times that a person developed canker sores, but also decreased the pain while a canker sore was present (5).
Keep your mouth healthy with good oral hygiene. Floss once a day and gently brush twice a day with a soft toothbrush. While you have a canker sore, use a toothpaste that is SLS free, and try not to brush the sore.
If you notice that your braces are rubbing against the inside of your mouth and are triggering canker sores, be sure to use plenty of wax to protect your mouth. If any foods are causing them to form more often, especially sugary or acidic foods, avoid those foods while you are wearing braces.
Let your dentist know if any sharp areas on your teeth are causing canker sores, so the sharp part can be smoothed. Dentures, dental work, and dental appliances can also be adjusted if they keep causing canker sores to form.
If you do develop a canker sore, there are steps you can take to lessen the pain and duration. Obviously, avoid the foods that trigger canker sores for you, or any foods or drinks that cause them to feel more irritated and painful.
You can use a salt-water rinse or take a vitamin B-12 supplement to promote healing or suck on ice chips to soothe and numb the area. It is fine to take ibuprofen or acetaminophen for the discomfort but avoid aspirin as it is a trigger for some people. Topical pain medications or canker sore patches may help relieve pain.
If the canker sore is severe, not healing after two weeks, or painful enough that you cannot eat or drink, please see your dentist or doctor for an evaluation of the sore. They can prescribe an anti-inflammatory medication or mouthwash or an antibiotic rinse if necessary. However, these options are not appropriate for all individuals.
Canker sores are a common, painful problem. Please let us know if you get them regularly or have one that is extremely painful or lasting longer than usual. We are here to help you discover how to reduce your risk of developing canker sores and minimize the pain if one does form. Please do not hesitate to contact us if you have any questions or concerns.
At Jungle Roots Children’s Dentistry & Orthodontics, we strive to provide the highest comprehensive pediatric and orthodontic dental care in a unique, fun-filled environment staffed by a team of caring, energetic professionals. We believe the establishment of a “dental home” at an early age is the key to a lifetime of positive visits to the dentist.