A crown, also known as a “cap”, can improve the appearance and function of your tooth by restoring its normal shape and size, and making it stronger. A crown can cover and support a tooth with a large filling when there isn't enough tooth left. It can also be used to protect a weak tooth from breaking or restore one that is already broken down. A crown is a good way to cover teeth that are discoloured or badly shaped, too. Most crowns, like veneers, are made entirely of porcelain and look very natural leaving no black line at the gum margin as seen with some traditional crowns.