A ceramic dental crown is a crown that is made entirely out of a ceramic material such as porcelain. Porcelain is a type of ceramic that contains a type of clay called kaolin. It is white and very hard, making it a good choice for use in a crown. The difference between an all-ceramic (porcelain) crown and a porcelain-fused-to-metal (PFM) crown is that in the case of a PFM crown, the part of the crown that actually goes over your tooth is made of metal. The porcelain layer is attached to the metal and makes the crown look like a regular tooth.