A dental abscess is typically caused by a bacterial infection. The bacteria can enter the tooth when the dental pulp, the innermost part of the tooth that contains blood vessels and nerves, becomes inflamed or dies.

Here are some common causes of a dental abscess:

  1. Tooth decay: This occurs when bacteria in your mouth form acids that eat away at your tooth and its enamel. If this decay progresses, it can bore a hole into the tooth, allowing bacteria to infect the dental pulp.
  2. Gum disease (Periodontal disease): This is an infection of the tissues and bones that surround and support the teeth. It’s usually caused by poor oral hygiene habits that allow plaque—a sticky film of bacteria—to build up on the teeth and harden.
  3. Broken or chipped tooth: If a tooth is broken or chipped, bacteria can get into the pulp of the tooth, leading to infection and abscess.
  4. Dental procedures: Sometimes, dental work can inadvertently lead to an abscess if the tissue inside the tooth becomes inflamed or bacteria are introduced.
  5. Weakened immune system: People with weakened immune systems are more susceptible to infections, including dental abscesses.

If left untreated, the infection can spread from the root of your tooth to the bones supporting your tooth.