A crown, also commonly known as a cap, is a covering that encases your entire tooth surface, restoring it to its original shape and size.
A crown protects and strengthens a tooth structure which cannot be restored with fillings or other types of restorations. There are several types of crowns, with porcelain, a tooth-colored crown, being the most popular as it resembles your natural teeth. They're highly durable and will last many years. However, like most dental restorations, they may at some point in the future need to be replaced.