A dental crown is a type of dental restoration that covers the entire visible portion of a tooth. It is used to restore a tooth that has been damaged or to improve its appearance. Dental crowns are typically made of porcelain, ceramic, or metal, and are custom-made to fit the individual tooth. The procedure for placing a dental crown typically involves two visits to the dentist. During the first visit, the dentist will prepare the tooth by removing any damaged or decayed tissue and shaping the remaining tooth structure. An impression of the prepared tooth will be taken and sent to a dental laboratory, where the crown will be made. At the second visit, the dentist will check the fit and appearance of the crown, and then cement it in place. The results of the procedure are typically long-lasting.