consult dentist asap

Visit a dentist for proper evaluation. it may be a viral infection also, dentist may recommend mild steroid based ointment or a mouth wash. take lot of vitamin supplements

There are many reasons for oral ulcers especially those which are multiple. A proper case evaluation will be required to determine the diagnosis. The right treatment can be suggested after the right diagnosis only. You can use anaesthetic ointments like dologel CT for temporary symptomatic relief till that duration. Any oral ulcer normally takes 7 to 10 days for healing. Regards.