Diagnosing and treating periodontal disease, oral pathology, cosmetic periodontal procedures and dental implant. Periodontal disease and decay are caused by bacterial plaque, which is the primary cause of gum disease in susceptible individuals. Plaque is a colorless film that sticks to your teeth at the gumline. Plaque constantly forms on your teeth, and if it is not removed, it will harden into a rough, porous substance known as calculus (or tartar).