Periodontics is concerned with the prevention, diagnosis, and treatment of periodontal disease, and in the placement of dental implants. It involves a wide range of treatments, such as scaling and root planing (in which the infected surface of the root is cleaned) or root surface debridement (in which damaged tissue is removed). Patients with severe gum problems are treated using a range of surgical procedures. In addition, periodontists are specially trained in the placement and maintenance of dental implants.