Porcelain crowns are used in several procedures. A porcelain crown can be used to fill a gap in your smile. A dental crown, also known as a tooth cap, can cover a cavity too big for a filling. This protects your tooth from receiving more damage. Tooth caps can also be used to cover cracked or worn-down teeth to fortify them from further wear. Tooth caps are also used during dental implant procedures to restore your smile.