If the bump is periapical abscess, root canal treatment is indicated.
I KNOW EXACTLY WHAT YOU ARE TALKING ABOUT. I HAVE THE SAME EACT THING THAT COMES ABOVE 2 DIFFRENT TEETH. IT IS AN ABCESS. IT WILL MOST LIKELY COME TO A HEAD AND WILL POP AND THAT WILL RELEASE THE PRESSURE. MY ADVICE TO YOU IS TO HURRY UP WITH THE ROOT CANAL. I HAVE BEEN DEALING WITH THOSE THINGS FOR YEARS,ONLY B/C I AM TOO AFRAID OF THE DENTIST OFFICE.