Surgical therapy on the gums treats infection that is too advanced and pockets that are too deep to reach by scaling and root planing alone. Your periodontist opens your gums to clean the pockets. He or she then repositions your gums so that they will be easier to keep clean during home care and follow-up appointments. To achieve this goal, the gumline often must be lowered, which exposes more tooth. Your periodontist gently separates the gum from the tooth, creating a "flap" and access to the infected pocket. This allows him or her to remove deep deposits of plaque and calculus. It also reduces the size of the pocket and the area where bacteria can grow. Little or no gum tissue is removed. Bone (Osseous) Surgery This procedure used to smooth shallow craters in the bone due to mild or moderate bone loss. After gaining access to the damaged bone with flap surgery, your periodontist reshapes the bone around the tooth to decrease the craters. This makes it harder for bacteria to accumulate and grow.