Fill in Gaps or Chips

Bonding can easily repair these minor defects, which darken a smile by revealing the interior of the mouth. A tooth that's not in alignment can have a similar effect. A process known as limited tooth movement, in which a retainer repositions the tooth in about eight to 16 weeks, can also fill in a gap.

Whiten Your Fillings

Conventional metal amalgam fillings tend to leach into tooth structure over time, leaving a gray cast. Replacing amalgam fillings with white composite fillings can brighten your smile, says Jeff Golub-Evans, D.D.S., of New York City's Dental Duplex. "The newest materials are very dense and resistant to wear.