An abscessed tooth is a painful infection at the root of a tooth or between the gum and a tooth
. It's most commonly caused by severe tooth
decay. Other causes of tooth
abscess are trauma to the tooth, such as when it is broken or chipped, and gingivitis or gum disease.
These problems can cause openings in the tooth enamel, which allows bacteria to infect the center of the tooth (called the pulp). The infection may also spread from the root of the tooth to the bones supporting the tooth.