Right before COVID-19 broke out, I had a patient reach out to me asking me the question, “Doc, you said my implant is ready and I am concerned the coronavirus thing is going to be big… how fast can I get a tooth?” I felt his pain. He’s been waiting for months waiting on the implant to integrate and all of a sudden, a pandemic and possible office closure is on the horizon. How can I help this patient?
In a traditional dental practice workflow, the steps to fabricate a screw-retained crown would be the following:
Clinical Visit 1 – Make PVS impressions. After dismissing patient, impressions are boxed and sent to the lab. Total time 30min – 2 days.
Laboratory – Receive impression 2-4 days later, make stone models and send to design lab for abutment. 5-7 days later, abutment is received, fabricate Zirconia crown. Total time 14-20 days.
Clinical Visit 2 – Deliver restoration. Total time 1 day.
So let’s assume that things go fairly well delivering the crown, in an ideal world, we could be looking at between 14-22 days from the day we make the impression! So when looking at our patient’s request of getting him a screw-retained crown ASAP, this model falls short of meeting or exceeding the patient’s expectations.
So that’s the traditional workflow, but let’s contrast the above and see how we can expedite his case using in-office laboratory workflows!
Clinical Visit 1 – Make digital impressions with a NT Trading Scan Body and a 3Shape TRIOS Intraoral scanner. Export digital scans to laboratory design computer. Total time 30 min.
Laboratory – Import optical scans into 3Shape Dental Systems Laboratory Software. Align scan body using similar point-point alignment functions within the software. Using built-in functions within the software, shape the crown and adapt the virtual design fit next to each adjacent tooth.
Laboratory (continued) – Export the final designed crown from 3Shape and import into VHF milling (CAM) software. Mill the crown using Zirconia Disc (I used Katana STML shade C3). Remove finished milled crown, desprue, and sinter. Stain and glaze the crown and use Nextdent 5100 Model 2.0 Resin to assist in confirming contacts of finished crown. Cement Zirconia crown to ti-base.
Total laboratory time 9-10 hours (30 min to design, 1-2 hour to mill and desprue, 7 hours of sintering time, 1 hour to stain & glaze and cement to ti-base). Note most of this time is “passive” time, not 9-10 hours of working lol!
Clinical Visit 2 – Try-in crown, confirm fit, occlusion, and esthetics. Torque crown to recommended torque value. Seal occlusal screw access with composite resin. Total time 15 min.
By using in-office optical scanning, laboratory design software, milling machines in my office and a bit of learning about how to do this process, I was able to turn around a monolithic Zirconia screw-retained crown in just a few hours, not weeks.
For many dentists, this may be a bit of a challenge incorporating multiple systems, software, and different systems. For many dentists, I recommend using CEREC to do a similar workflow. Really, Michael Scherer thinks CEREC is good?!?! Absolutely, I have long been an advocate for CEREC as it’s a wonderful system that many clinicians can buy and right out of the box make it work… but frankly it just wasn’t right for me and my office. I like the material flexibility of having my own full laboratory setup. The combination of robust disc based milling systems combined with open intraoral optical scanners is key for me.
I am an advocate of dentists taking control of doing laboratory work! We are trained in dental school to do it, why not? I’m also a huge advocate of dental laboratory technicians! In fact, I have an in-house laboratory technician, Mr. Kris Feichtmeir CDT, who is amazing!!
The key here is the flexibility… being able to look my patient right in the eye when he says, “Doc, how fast can you get me a tooth.” and I can respond, “How about in a few hours?”. The smile on the patient’s face is immeasurable and exceeding expectations is an unbelievable feeling.
Interested in learning more about digital dentistry and step-by-step videos on how to do laboratory techniques? Check out the online course www.LearnDental3D.com