What this sounds like is a draining abscess, which is an infection associated with either the root of the tooth or the gum tissue around the tooth…or both. Bacteria accumulate in the root due to decay, or a dying tooth, or in the gum due to a deep pocket that has collected debris, creating pus. If left there, the bone and tissue break down creating a tunnel in the gum, called a draining fistula. Because the area drains into the mouth and no pressure forms, there will typically be no pain. You may get a foul taste in your mouth and only sporadic pain.