Tooth Abscess



A tooth abscess is caused by bacteria. It begins when bacteria invade and infect the tissue around a tooth. This results in pus build-up. An abscess happens when the pus cannot drain.

Problems that allow bacteria to invade a tooth are:

  • Severe tooth decay
  • A break or crack in a tooth
  • Failed root canal treatment
  • Advanced periodontitis
  • Dental trauma

Risk Factors

Things that may raise the risk of this problem are:

  • A build up of tartar beneath the gum line
  • Poor dental hygiene



A person with an abscess may have:

  • Throbbing and pain in a tooth or gum area
  • Sudden tooth pain
  • Pain when biting
  • Pain from hot or cold
  • Redness, tenderness, or swelling of the gums
  • Fever
  • Bad breath or a foul taste in the mouth
  • An open, draining sore on the gums
  • A loose tooth


The dentist will ask about symptoms and health history. A dental exam will be done.

Images may be taken of the tooth and the bone around it. This can be done with x-rays.

A sample of the abscess fluid may be taken and tested.



The goal of treatment is to ease symptoms and treat the infection. Options are:


These procedures may be done to get rid of the infection:

  • Drainage—An incision is made in the abscess to allow pus to drain from it
  • Root canal—Pus and decayed tissue are removed from the inside of the tooth, then it is filled and sealed
  • Tooth removal—A tooth with severe decay or infection is removed. It can be replaced with a partial bridge, denture, or tooth implant


Medicine may be given to ease pain. Antibiotics will be given to treat the infection.


To lower the risk of this problem:

  • Use a soft-bristled toothbrush and brush with fluoride toothpaste after meals or at least twice per day.
  • Floss every day.
  • Get regular dental check-ups and teeth and gum cleanings every six months.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.