Sometimes called a gum boil, a periodontal abscess is a pus-filled sac that may form between teeth and gums. It is caused by an infection, which may have come from food or other objects trapped beneath the gum line, or from uncontrolled periodontal disease. Because pressure builds up quickly inside them, abscesses are generally quite painful. Symptoms may include a throbbing toothache which comes on suddenly, tenderness and swelling of the gums or face, and sometimes fever. Occasionally, pus draining into the mouth through an opening in the sac relieves the pressure and pain, but may cause a strange taste.
If left untreated, abscesses can persist for months and cause serious health problems, including infections that spread to other parts of the body. That's why it is important to see a dentist right away if you experience symptoms. He or she will find the location of the abscess and treat it appropriately. Treatment usually involves draining the pus and fluid, thoroughly cleaning the affected area, and controlling the infection.