Gum disease (periodontal disease) is an infection of the tissues and bones that surround and support the teeth. It's caused by the growth of bacteria present in plaque, which is a clear, sticky substance that your mouth produces.
Periodontitis is a severe type of gum disease that can't be reversed. Gingivitis is a type that can be mild to severe, but it can be reversed.
Keeping your teeth and gums healthy can lower your risk of gum disease.