Oral hygiene and dexa per os spray with solution furacilin 0.02% mouthwash. iv sol.vitamin C 5% 4.0+sol.NaCl 0.9% 10.0+vitamin B6 5% 1.0
If recurrent & painful that means benign ulcer (aphthous ulcer) : local spray or systemic analgesia is beneficial with avoiding of salty foods but if painless and progressive consult GIT specialist