A dental abscess is when pus forms in the teeth or gums as a result of a bacterial infection. Bacteria are found in plaque (a byproduct of food, saliva and bacteria in the mouth), which damages the teeth and gums. The bacteria can eventually infect and spread within the soft tissues inside a tooth or gums, forming an abscess.
Without dental treatment, a dental abscess will continue to get worse, and may eventually lead to the destruction of the surrounding bone. Your GP will be able to prescribe treatment that is appropriate for your symptoms, but the only long-term solution for a dental abscess may involve treatment from your dentist.