Bonding is a cosmetic procedure that can improve the appearance of teeth that are chipped, broken, cracked, stained or have spaces between them. With bonding, tooth-colored materials are attached, or bonded, to a tooth surface. The process can improve unsightly stains from coffee, tea, tobacco or certain childhood medications; front-tooth spaces; and accident-induced cracks or chips. Bonding is also to protect exposed tooth roots that result form gum recession and to fill small cavities. Bonding usually lasts from three to five years.