Made to look like your own tooth, a crown is a dental restoration used to rebuild decayed or broken teeth that are not candidates for fillings. Also known as caps, crowns encase the entire visible surface of the teeth that have been reshaped (prepared) by the dentist. The crown is held onto the tooth by strong permanent cement. A crown can protect a fractured tooth and preserve the functionality of a damaged tooth by restoring its shape and strength. A crown may also be used simply to improve the cosmetic appearance of a tooth.