Crown lengthening is a procedure with multiple uses. Crown lengthening can be done to change a patient’s “gummy” smile into a more beautiful smile that shows more tooth than gums. Crown lengthening is also performed when decay reaches the bone level on a tooth that is to receive a crown or “cap”. The crown cannot be seated if the finish line of the crown rests on bone. In these cases, a small amount of bone is removed so that more of the tooth is exposed and a crown can be properly seated onto the tooth.