A crown is a covering used for a tooth that is chipped, discolored or has a large filling that needs support. Crowns may also be used to restore a weak tooth, or you may elect to have a crown for cosmetic reasons. Bridges are a series of crowns that enable a missing tooth to be replaced without the need for a removable device such as a partial denture. Both crowns and bridges produce a beautifully natural and durable result.