canker sores

Around 20% of the general population has suffered from a very frequent occurrence. Canker sores appear more frequently in adolescents and young adults, being extremely annoying for the patient.

What are canker sores?

These sores are one of the most common diseases of the mouth. They are small, round or oval ulcers of a white or yellow color and with a reddish outline. They generally affect the soft parts of the mouth,  gums, tongue, cheeks, and lips.

We realize that we have this type of sore when we drink acidic juice or something salty, causing great pain when we eat and speak.

Canker sores usually heal on their own and then reappear in the same place or another one after a time.


There are three principal classifications::

  • Mild or minor: They are the smaller ulcers that affect the majority of the population, healing in approximately a week without leaving a scar when healed.
  • Major or serious: These ulcers are larger than 1 centimeter in diameter, take about two weeks to heal, are very painful and leave a scar.
  • Herpetiform or severe: They are the least common canker sores in the population.  Very small groups form a larger ulcer, causing pain when eating and speaking. They heal in approximately less than a week.

What causes them?

The exact cause of canker sores has not been defined, but it is thought that several factors increase the probability of occurrence.

  • An allergic reaction
  • Stress
  • Injury from an orthodontic appliance 
  • Viral infection
  • Nutritional deficiencies
  • Lack of vitamin B-12, zinc, folic acid, or iron
  • Hormonal changes

Are they contagious?

Canker sores are not contagious. Even if you have an open sore, they are not communicable. If you have a sore in your mouth and you don’t know if it is a canker or cold sore, look at its location; cold sores usually appear outside the mouth, around the lips, chin or nostrils. Canker sores always appear within the mouth.


Canker sores initially start with tingling and burning in the mouth after which a red bump is formed that eventually becomes a white or yellowish open sore with a red border due to inflammation. A canker sore can measure less than 1 centimeter and appear as one or more lesions. The most noticeable symptom is pain when talking or eating.

When to go to the dentist for them?

If you are one of the people who suffer from thrush or experience outbreaks more than three times a month, you should seek professional help from a dentist to rule out the presence of food allergies or other systemic causes. Large, painful canker sores that keep you from eating or drinking require a dental visit or those that cause a fever or last more than two weeks. You may be prescribed a topical medication or a special mouthwash to help reduce the discomfort.

Can canker sores be prevented?

We cannot prevent canker sores since the cause is not well defined. What can be done is to reduce the discomfort in the mouth. We recommend brushing your teeth with a soft-bristle brush after every meal for a mouth free of foods that could cause a problem.


  • Most canker sores heal on their own in a few days to a couple of weeks. While you wait for them to go away, you can take pain relievers.
  • Avoid acidic and spicy foods, as they can cause more irritation and pain.
  • Brush your teeth and rinse your mouth with toothpastes that do not contain (sodium lauryl sulfate).
  • Use alcohol-free mouthwash.

Contact us

If you have any questions about this or other topics, you can contact us at Channel Island Family Dental as well as our Facebook page. We look forward to your visit and will make a timely diagnosis. Our dentists in Oxnard, Santa Paula, Ventura, Newbury Park, and Port Hueneme will be able to guide you towards the best treatment to take care of your health and return your best smile.

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