Burning a canker sore
Do not burn a canker sore: heat or chemicals can damage the surrounding oral lining and delay healing, while gentle protection and pain control address.
The short answer
Do not burn a canker sore: heat or chemicals can damage the surrounding oral lining and delay healing, while gentle protection and pain control address the symptom.
What is a canker sore inside the mouth?
A canker sore, or aphthous ulcer, is a shallow break in the non-keratinized lining of the mouth, commonly on the inner lip, cheek, tongue edge, or soft palate. It is not the same as a fever blister on the outer lip.
How can you protect a canker sore while it heals?
Avoid spicy, acidic, salty, or rough foods, use a soft toothbrush, and rinse with plain water or a mild salt-water rinse. A dentist or doctor may recommend a protective gel or a topical corticosteroid after checking the ulcer.
When does a canker sore need dental examination?
Arrange an examination if an ulcer lasts beyond two weeks, repeatedly returns, is unusually large or numerous, or is accompanied by fever, weight loss, difficulty eating, or a firm area around it.
How long has your canker sore been present?
How long has the ulcer been present? Could a sharp tooth or appliance be rubbing it? Would a prescription mouth treatment help? Does its appearance require further testing?
Frequently asked questions
How long has the ulcer been present?
Could a sharp tooth or appliance be rubbing it.
Can this be treated at home?
Avoid spicy, acidic, salty, or rough foods, use a soft toothbrush, and rinse with plain water or a mild salt-water rinse.
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Who wrote this page
This library is published by Dental Nation, a licensed dental group practising in the United Arab Emirates. Pages are written and overseen by the same clinical team that treats patients in our clinics, and are held to a fixed editorial standard for safety and accuracy.
This page is patient education, not medical advice, and cannot replace an examination. Anything urgent — facial swelling, trauma, uncontrolled bleeding or severe pain — needs a dentist or emergency care now.