In recent years, bonding has proven to be a highly effective treatment for closing spaces between the teeth. Composite resin, a plastic material, is applied to the teeth to make them wider in areas where gaps exist. Bonding can also be used to close a space temporarily, until crowns are made, for example. On the other hand, if you are having your spaces closed through orthodontics, even if some of your teeth are too dark, bonding can be used to lighten them while the spaces are being closed.