Rexidin M forte gel/Dologel CT, 5 times/day, In clean mouth use finger/fresh ear bud for applying the gel, keep applied on gum area for 3 mins, not to swallow the saliva, rinse mouth thoroughly after 3 minutes. Not to eat anything for next 20 minutes. C.Melcovit gold, once a day, after food.2 weeks.

You need to get an xray done for the last tooth The issue might be due to sharp cusp tip i.e.the teeth from upper/ occlusal surface is sharp Or the tooth might be carious

Hello , its traumatic ulcer and is caused due to co stant irritation of sharp cusp tips of ur upper last tooth . U need to  visit a dentist for coronoplasty or restoration  if it is carious . Bcos even if u apply any ointment it will not heal unless  the irritation is removed . Temprory releif with local apication of mucopain . 2 to 3 times a day . After doing all the procedures  if it still persists then u can consult me  personally   . I m an Oral Medicine and Radiologist   and then will guide for further investigations and treatment .

Don't worry.It looks like a ulcer there.Since the tooth is not clear I am assuming there is a caries on the corner of the mouth and the tooth is broken.I would suggest you to consult with a Dentist and get ot treated.The ulcer is due to the broken tooth. Till then you can apply Zytee ointment there