Hi Mr. Mishra,
There are lot many reasons for recurrent oral ulcers.
most common is apthous and herpatic ulcers.
mainly they are stress
related. when you are under stress your immunity falls, and they reoccur very fast.
several aggravating fasts like spices, tobacco, sharp tooth, irritation by orthodontic brackets, wires, reaction with tooth paste etc can precipitate ulcers.
you need to be on healthy and nutritious diet. take diet supplements, use oral disinfectant like clohex, listerine
Dr. Vishal Jain, Vitaldent, faridabad