Can canker sores be prevented?

Although there is no cure for canker sores and they often recur, you may be able to reduce their frequency by:

  • Avoiding foods that irritate your mouth, including acidic, hot or spicy foods
  • Avoiding irritation from gum chewing
  • Brushing with a soft-bristled brush after meals and flossing daily. This will keep your mouth free of foods that might trigger a sore.
  • Avoiding oral hygiene products containing sodium lauryl sulfate

You should call your doctor or dentist if you have:

  • Unusually large sores
  • Sores that are spreading
  • Sores that last 3 weeks or longer
  • Intolerable pain despite avoiding trigger foods and taking over-the-counter pain medication
  • Difficulty drinking enough fluids
  • A high fever with the appearance of the canker sore(s)

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