Among them are: Gold and other metal Porcelain (ceramic ... while they were more evenly split between all-zirconia crowns, PFM, and the lithium disilicate for posterior (back position) crowns.

In dentistry, there are different categories of crowns, including all-metal, all-porcelain, porcelain-fused-to metal (PFM), zirconia, and ceramic. Gold crowns are a type of metal crowns.