“Peri” means around and “odontal” means referring to the tooth. Periodontal disease refers to an infection of the structures surrounding your teeth. These include gums, the cementum that covers the root, the periodontal ligament, and the alveolar bone. In the early stages of periodontal disease, the gums are affected first. They may become puffy, sore, and bleed when brushing teeth. In more severe forms of periodontal disease, all other surrounding structures become infected as well. It is very important to understand the causes of periodontal disease, the early signs and symptoms, and how to prevent the disease from occurring in the first place.