I got this comment from a visitor that I feel warrants its own post. He has corresponded with me before on this topic. He is an analytic chemist who seems to understand very well what he is talking about. He was commenting on an earlier post I made titled, “Am I allergic to these crowns?”

I have additional information that may explain people’s adverse reaction to zirconia. I had a bridge made from Origin Beyond Plus zirconia from B&D Dental Corporation several years ago. The dentist told me it was Bruxzir though. After about a year it began giving me the same reaction that I got from lithium ceramics – burning tongue and a nasty chalky taste to the material. I kept asking the dentist if he could replace it with a PFM but he said his lab didn’t do those. I finally broke it off with that dentist and asked for all my records. That’s when I found out the name of the zirconia and wrote an e-mail to B&D Dental Corporation documenting an adverse event. That is something the dentist could have done, but apparently it is not a requirement for dentists to report these things. The company got back to me quickly and told me that zirconia restorations are often glazed with lithium. The reps exact wording: “During fabrication, dental laboratories often apply a glazing porcelain in the final stage to give the crown a glossy finish. Depending on the manufacturer, some glazing porcelains may contain lithium compounds. This material is not part of our zirconia, but rather an optional surface layer applied during the lab’s finishing process.”

He want on to say that the zirconia does not have to be glazed. It can be polished. Most labs probably will not do that because according to him it is time consuming:

“After the zirconia crown is sintered at 1450°C, it can be left unglazed and instead finished with manual hand‑polishing. This produces a fully functional, smooth, and esthetic surface made of pure zirconia only, without adding any glazing porcelain or external minerals. Although hand‑polishing requires more time and effort from the technician, it is an excellent option for patients with material sensitivities.”

I have also written to other companies to see if they will let me know about lithium in the zirconia products. A representative at Kuraray let me know that there is some lithium in their Katana even though it is advertised as a pure zirconia product. I suggest everyone get the records and identceram certificates of everything dentist put in their restorations and then contact the labs to see if they can get more information. I do not know for certain that my bridge contains a lithium glaze because that lab is now closed. I could have it analyzed by LA-ICPMS if I can get someone to replace it. Or wait until it falls off. Another dentist told there was decay under it but she said she uses katana so I am looking for another dentist without luck. They’re reluctant ton take on a patient who reports allergies. They love to use lithium disilicates.

(From a visitor who is an analytic chemist named Dave)

(See Dr. Hall’s comment below.)