they are several reasons consult a dentist all are not the same ulcer it may sumthing else once visit a dentist he check and clear ur problem

there are so many causes of mouth ulcers like- -Stress or tissue injury is thought to be the cause of simple mouth ulcers. -Certain foods, including citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes and strawberries), can trigger a mouth ulcer. -Sometimes a sharp tooth surface also trigger mouth ulcers. -Some cases of complex mouth ulcers are caused by an underlying health condition, such as an impaired immune system; nutritional problems, such as vitamin B-12, zinc, folic acid, or iron deficiency and gastrointestinal tract disease, such as Coeliac disease and Crohn's disease. -When you first quit smoking, you may develop more mouth ulcers than normal, but this is temporary. Usually ulcer heals by itself only within 1 week. You can take 'Becosule capsule' once in a day for 1 week for faster recovery. Temporarily you can apply mucopain gel over ulcer for relief..

Hi,  mouth ulcer could be stress factor,  habits,  B6 deficiency.  Kindly do the deficiency test and Vist to nearest dentist.  Don't ignore the condition.