Marginal periodontal abscess occurs as a round swelling of approximately 1-2 mm or more in diameter. The teeth near the abcess usually do not have cavities.

The consistency of the abscess is soft, but the mucous membrane is a glassy, intense, deep red color and may present an opening which reveals a yellow-white color.

Tests on neighboring teeth do not reveal problems with their vitality.

Diagnosis is based on symptoms, tests and imaging tests, but also on identifying the resorption of the bone supporting the tooth.