When deep pockets between teeth and gums (6 millimeters or deeper) are present, it is difficult for a dentist to thoroughly remove the plaque and tartar. Flap surgery is a procedure where the gum flap is lifted away from the tooth. Diseased tissue and sometimes bone is removed. The rough surfaces of the tooth are then smoothed by root planing. The area is medicated and the gum flap is replaced and sutured allowing the bone and gum tissue to heal. One of the goals of flap surgery is to reduce the depth of the periodontal pockets to make them easier to keep clean.