What finding definitively indicates an acute periodontal abscess?

An acute periodontal abscess is characterized by specific clinical findings that suggest a localized infection in the periodontal tissues. While the lack of spontaneous drainage can indicate certain conditions, it does not definitively identify an acute periodontal abscess.

The presence of a fistulous tract is particularly significant. When there is swelling localized to the apex of a tooth along with a fistulous tract, it strongly suggests the existence of an acute periodontal abscess. This presentation is indicative of the body's attempt to drain the infection and is a hallmark of abscess formation.

Sensitivity to percussion can be associated with different dental issues, including pulpitis or periapical problems, but it is not unique to periodontal abscesses. A non-vital pulp reflects a situation that may be related to pulp necrosis rather than periodontal pathology.

In summary, the definitive indicator of an acute periodontal abscess is the presence of localized swelling at the apex coupled with a fistulous tract, which directs attention to the periodontal tissues involved in the infection process.