Hello and Welcome to ‘Ask A Doctor’ service. I have gone through your query and can understand your concerns. As per your complain a painful ulcer over the gum in the area where a tooth was extracted few years ago seems to be most probably due to deep gum infection, any retained root piece, foreign body impaction etc. I would suggest you to first of all discuss with your dentist what is the exact cause for the lump and pain and get the cause removed as if there is any foreign body impaction or retained root piece then removal of the same can only provide permanent relief and not only taking medication. As of now along with antibiotics and Lidocaine application, you also need to take painkillers like Ibuprofen if there is moderate pain and for severe pain Tramadol or Ketorolac can be taken. Triple antibiotic ointment is for external use and should not be applied inside mouth or swallowed. .Hope this information helps. Let me know if I can assist you further. Thanks and regards, Dr. Honey Nandwani Arora