thanks for the query
normally mouth ulcers are caused due to
* vitamin deficiency
* stomach upset
*strong antibiotic medication
start taking a multi vitamin tablet ELDERVIT once a day for one month.
twice brushing with mild tooth brush and rinsing with a mouth wash.
apply MUCOPAIN on the ulcers.
get yourself checked by a physician for stomach related problem
take some holistic approach for stress free lifestyle.
do visit a dentist
if problem sustain.