Dental bonding is a procedure in which a durable tooth-colored resin material is applied and hardened with a special light, which ultimately "bonds" the material to the tooth to restore or improve person's smile. Bonding is among the easiest and least expensive cosmetic dental procedure. The composite resin used in bonding can be shaped and polished to closely match the surrounding teeth. Most often, bonding is used for cosmetic purposes to improve the appearance of a discolored or chipped tooth. It also can be used to close spaces between teeth, to make teeth look longer or to change the shape or color of teeth. Sometimes bonding is used as a cosmetic alternative to fillings, or to protect a portion of the tooth's root that has been exposed because of gum recession.