Plaque buildup irritates the gums, and they become inflamed ( gingivitis Gingivitis Gingivitis is a mild form of periodontal disease characterized by inflammation of the gums (gingivae). Gingivitis results most often from inadequate brushing and flossing but may result from... read more ). In time, the gums pull away from the tooth, creating a pocket that fills with more plaque.

Bacterial infection moves down to the root of the tooth and eventually destroys the bone supporting the tooth. Without this support, the tooth loosens and falls out or requires extraction because of a periodontal abscess.