We are approaching an important milestone here at Glidewell: On June 1, 2009, BruxZir® Solid Zirconia crowns and bridges were launched as an official product, and the first crown was prescribed by a doctor in Massachusetts.
Truth be told, he didn’t actually prescribe it. The doctor sent in an impression asking for a Procera (porcelain fused to alumina oxide) crown on tooth #15. The manufacturers of all bilayer crown materials (Procera included) have always had the same prep requirements: 1.5 mm is the minimum acceptable amount of occlusal reduction, and 2.0 mm is ideal. Most of us are probably familiar with how difficult it is to pull off that amount of reduction on an upper or lower second molar. On many lower second molars, if you reduced that much in the central groove, they would end up being subgingival!
So when our technicians saw that there wasn’t enough occlusal reduction for a Procera crown, they asked the dentist if they could change the crown to BruxZir Solid Zirconia, as the only other choice was cast gold, which the patient had refused at the chair, according to the dentist.
Many dentists who had been burned by an all-ceramic system (or two!) in the past were leery of trying this new monolithic zirconia material, and I can’t blame them. Even as BruxZir Solid Zirconia passed the one-year and two-year marks with good results from the CR® clinical study, many dentists told me, "Let me know when it gets to five years, and I will try one." As dentists, most of our clinical failures come in the first year or two of service. Making it to five years is an important clinical signpost, and not just because the insurance company pays for a new one then.
There is certainly nothing wrong with being prudent when it comes to selecting crown materials, and perhaps now that we are at five years, dentists will try one out on a staff member or an in-law, just to be safe.
The newest addition to the BruxZir family is the Full-Arch Implant Prosthesis, and it may do to the hybrid denture what the BruxZir crown has done to the PFM: Replace a bilayer restoration with a stronger monolithic restoration. Happy fifth birthday, BruxZir Solid Zirconia!