When a tooth cracks, has an old large filling, is severely damaged by decay or has had root canal treatment, a crown (or cap) may be recommended to restore the tooth. Crowns are an excellent way to strengthen a tooth and protect the remaining tooth structure. Depending on their purpose, crowns can be made from a variety of different materials. Cosmetically, a crown made from porcelain is a highly aesthetic and very strong restoration that is able to both restore your tooth and enhance the appearance of your smile because, as with inlays and onlays, it is designed to look and feel like a natural tooth.