What can i do to get rid of a mouth ulcer?

See your dentist: There are many various reasons which could cause a mouth ulcer (e.g. canker sore, pemphigus, etc.). I can appreciate your concerned about your dental health, but finding a proper diagnosis and treatment may be the answer to your problem. Rec.: see your dentist for examination and treatment if needed.

Have patience: Mouth ulcers generally heal in seven to ten days. I would not recommend putting anything on it as that can burn and cause additional healing time.

Be patient: They will resolve on their own.

Tincture of time: If truly an ulcer, will be gone in 7-10 days. If not, see Dentist or Oral Surgeon.