Cause of gum boil has to be ruled out .get xray of the area. Antibiotics along with analgesics has to be taken. You can consult through this for prescription of medication.

Hii.. If you have gum boil under the teeth you got filled, then there is possibility of spreading the cavity & infection into the roots. No need to worry. You should get the checkup done. Dentist will take the X ray & proceed with the treatment. I require pic of your oral cavity to proper diagnose & plan a treatment for you.