Prior to purchasing the practice, I was creating many zirconia crowns for the back teeth due to their strength. At the time I was having to send all of my cases to lab and often chose the zirconia route unless the tooth was in an esthetic area. When I purchased Dr. Davis's practice and the technology that came along with it, I was excited to be able to fabricate crowns in office. At the CEREC training center in Scottsdale I learned the ins and outs of every dental material in depth. While eMax is more esthetic and about twice as strong as tooth structure, zirconia is about four times as strong! Strong is not always better, as we are also concerned about breaking opposing teeth, but sometimes the clearance between the teeth and the opposing tooth is not enough to make an eMax crown. In addition, if the opposing tooth is also made of zirconia, we would want the same material to bite against each other.
The current mills did not have the capability to make zirconia crowns as they require a vacuum mill process and a different time of sintering oven. We would have to prepare the tooth, temporize the tooth and then send the digital case to a lab to be made. For about two weeks the patient would be in a temporary crown and then return to have the zirconia crown from the lab cemented. While this is how the majority of offices operate, I have come accustomed to being able to place my restorations the same day. I had a goal and worked it into my practice's operating plan to be able to purchase the zirconia mill and oven. After a year in practice we are so excited that this new technology is here!
I spend down time connecting with colleagues in the CEREC/same day crown world and they are impressed with the great fit and strength zirconia provides. It is also a more conservative tooth preparation as the crown only needs 0.7-1mm of tooth reduction on the biting surface compared to 1.5-2mm with eMax. If you would like to know more or have your next crown made in zirconia, please feel free to ask us! We typically will choose what we think is best based on the location in the mouth, opposing tooth situation and bite clearance, but welcome any input from our patients as well. As always, we look forward to serving you and continuing our mission to provide cutting edge dental care in our practice.