An abscess is a collection of pus that forms in response to a bacterial infection. Dental abscesses are usually caused by bacteria that enter the tooth through a cavity or crack. The bacteria can then spread to the pulp of the tooth, which contains the nerves and blood vessels. If the pulp becomes infected, it can lead to an abscess.
There are several different types of dental abscesses, depending on their location. The most common type is a periapical abscess, which occurs at the tip of the tooth root. Other types of dental abscesses include periodontal abscesses, which occur in the gums, and buccal abscesses, which occur on the cheek.