A tooth abscess occurs when pus collects in either the teeth or the gums, due to a bacterial infection. It can be caused by a variety of events such as tooth decay which isn't treated in time, unsuccessful root canal treatment or even broken teeth. Antibiotics slow down and prevent the spread of the infection and are generally prescribed when the infection is more severe and the patient cannot see a dentist in time. They are usually taken while waiting for treatment, alongside painkillers as the abscess can become extremely painful and the antibiotics take a couple of days to reduce the size of the swelling. Antibiotics are not prescribed over the counter because they are often overused and have resulted in antibiotics losing effectiveness in general as the bacteria build up increased immunity to them. In addition, antibiotics offer only a temporary solution to the problem and you still need to see a dentist, who will initially prescribe an antibiotic (usually amoxicillin, however penicillin is said to be equally effective) while you wait for further treatment and then treat it by either removing the tooth or draining the pus. You are better off seeing a doctor/dentist than trying to get your hand on antibiotics as you will be prescribed the right dosage, while also getting on the waiting list and therefore getting treatment sooner.
