As of 2017 Zirconia can be milled, and cannot be pressed, also the Zirconia crowns are usually cemented and cannot be bonded, if the retention of the prepared tooth is compromised, the dentist cannot bond, and only cement, meaning the crown can come off. This is one negative feature in regard to Zirconia for either partial coverage restorations or full coverage restorations such as Zirconia or Lava crowns, on the plus side, they are extremely strong and fracture-resistant if they are made monolithic.
The cons of Zirconia or Lava crowns is the fact that the dentist will be having a hard time adjusting them and polishing them in the mouth. The expert dentist must have a great master ceramist to give the final crown perfect in regard to color and the patient’s bite. Zirconia crowns can cause wear of opposing teeth if they are not polished properly.