Periodontitis is a chronic inflammatory disease that affects the tissue surrounding and supporting the teeth called the periodontium. Approximately half of American adults over the age of 30 have periodontitis.
Periodontitis occurs when excessive amounts of plaque, a sticky film composed mainly of bacteria, form on the teeth. Porphyromonas gingivalis, a type of bacteria, is thought to be a main contributor to the development of periodontitis. The ability for P. gingivalis to adhere to the tissues inside the mouth plays a role in the severity of periodontitis.