Detection, treatment and, prevention of periodontal diseases, from the American Dental Association.

The American Academy of Periodontology's description of periodontal (gum) diseases, including gingivitis and periodontitis.

Symptoms, causes, treatment, and prevention.

Illustrations, causes, prevention, and treatment, from the National Library of Medicine.

The National Institute of Dental and Craniofacial Research describes gum disease and presents an overview of risks and treatments.

Overview, symptom and treatment information from Oregon Health and Sciences University.