Well i can only add to all the good things what doctors below have said. See the gums getting swollen again and again may be an indicator of inadequate treatment. Cleaning with the help of machine that is ultrasonic scaler may sometimes be inadequate. You have to undergoe root planing and currettage if the problem jsnt subsiding. Please get xrays done to confirm weather the problem isnt in the bone and is just in the gums only. I hope u dont have a medical history of any medicines ur taking or ur on the family way. Also i would advice to do in between the teeth cleaning with floss or with a interdental brush.

The only permanent solution for your problem is good oral hygiene..but at first you have to visit  a dentist for deep scaling and root planning in multiple sittings followed by mouth wash,warm saline rinses and gum massage wid an oinment prescribed by a dentist.. And after that you should maintain your oral hygiene by yourself only.

Like u should brush everyday, take bath everyday,.. it is recommended to visit your dentist once every 6 months. Some people have more tendency for gum diseases  when compared to others, which may be due to poor oral hygiene habits, hereditary or other n number of factors. Usually professional  teeth cleaning  also called as oral prophylaxis is mandatory once every 6 months along with regular habits of brushing  twice daily  n flossing.