Rinse with warm salt water several times a day
Use a baking soda rinse
Apply over-the-counter canker sore gel or paste
Use a mouth rinse made for mouth ulcers
Avoid spicy, acidic, salty, and rough foods
Avoid alcohol-based mouthwash
Brush gently with a soft-bristled toothbrush
Suck on ice chips or cold foods to reduce pain
Take over-the-counter pain relief if needed
Use a protective oral patch or barrier product
Stay hydrated
Avoid biting the sore or irritating it with braces or dental appliances
See a dentist or doctor if it lasts more than 2 weeks, is very large, or keeps coming back