The most common material used is made of porcelain and called emax. This is the same material that my lab had been using on the crowns I sent them to make since 2007. Because I had good results with emax before, I was confident in the strength and aesthetic appearance of the crowns I would be making when I started making crowns in one day. Sometimes I also use a material called enamic. It has a porcelain core infused with resin that has some advantages in certain situations.
If you need a crown please give me a call at 503 665 9737 Harry D Chambers DDS