Zirconium oxide bridges and crowns are now manufactured to perfection by various companies using CAD/CAM technology. The high quality of zirconia is characterized by very high strength, toughness, and wear resistance. This places even greater demands on the cutting process. 
Zirconia crowns or bridges. 
Due to the material properties, fine and very fine grits are more efficient at material removal. However, if the zirconia crown has a veneering ceramic, the requirements for the grit of the rotary instrument change. Frank Dental developed a unique diamond bur specifically for this purpose, which first uses a coarse grit to cut through the veneering ceramic and then a fine grit to remove the zirconia – without changing instruments.