I MADE THAT: BruxZir Solid Zirconia

When Robin Carden and the team at Glidewell Laboratories began the BruxZir development process in 2007, they wanted to create a monolithic zirconia material with improved translucency and strength. Carden led the process, with a team of about 50 people contributing. Thanks to President/CEO Jim Glidewell’s commitment to R&D and investment in the machines necessary to make it happen, BruxZir® Solid Zirconia was released in 2009, and has been gaining in popularity ever since. Here’s the story behind this esthetic, strong solid zirconia material. 

Q: Where did the idea for BruxZir come from?

A: The idea first came up in 2005 when Jim Glidewell made a crown out of DENTSPLY’s Cercon®, but it was really opaque and bright - nowhere close to matching teeth. I was originally working as a consultant on Prismatik Clinical Zirconia™ when Jim called and asked me to be vice president of research and development. This opportunity is what ultimately led to the creation of BruxZir.

Having worked with advanced ceramics since the 1980s and zirconia on a variety of different applications, I was very familiar with these materials. When we started working on BruxZir, we knew we needed a high strength, high translucency material. One way I’ve learned to work with ceramics is to chemically and mechanically treat the powder. You want the powder to be as high in purity as possible.

We’re the only company in the world that uses powder that has no binder in it. Every other manufacturer uses binder to hold the particles together. After you fire the material, the binder remains and you get weaker strength and poor translucency. So we asked ourselves “How do we improve on this?” We get specially made high-purity powder with no binder in it. When the powder comes in we convert it into what we call a “zirconia milkshake.” We use a patent-pending colloidal process that starts by breaking down the raw zirconia powder mechanically and chemically to make this “milkshake.” We then pour that milkshake into discs and use pressure to condense it and vacuum to remove the water. This process leads to higher density that improves strength and translucency when compared to other monolithic zirconia materials.

Read this lab's story on the ROI it saw from using BruxZir...

In layman’s terms, if you ever walked in a desert or on dry lake bed and crunched clay square pieces, that’s similar to how the particles come together and filter out during the BruxZir processing. With this colloidal process we developed that has four patents pending, we’re able to actually achieve higher densities without the use of binders. This processing gives us high translucency in the warm spectrum. You can have good translucency in cool or white colors but we don’t want that. We want high translucency in the warm color range,500 to 800 nm-that’s the warm color of the mouth. As you put a BruxZir restoration in the mouth, it almost disappears. So that’s how we developed the material. It’s going very well-there are more than 200 authorized BruxZir labs worldwide now.

The real benefit of working at Glidewell Laboratories is that Jim Glidewell continually invests in R&D. We also have one of about every testing fixture that’s needed in advanced ceramics, which was key to developing BruxZir and the new BruxZir™ Shaded material. Our fixed department has switched over to using this new pre-shaded BruxZir material. It’s a real time saver because you don’t have to dip the restoration after machining. That’s going to save labs a lot of money. One of the problematic processes we see in labs is dipping, not to mention the time it takes. When you dip into a liquid, if you over or under dip, it comes out the wrong color. Someone has to watch these things. Very rarely does a restoration meet the appropriate dipping time. With BruxZir Shaded you have 100 percent color saturation and no drying time.

Q: What is the main benefit for dental professionals?

A: They seat faster without adjustments. Dentists also like it because the margins are very sharp and have an ideal emergence profile because BruxZir is a monolithic material. With a PFM, you have the metal, you have the opaque and porcelain, and you have the glaze, so you have four materials coming down to the margin area; this does not make for a sharp margin or an ideal emergence profile. Also, with BruxZir, if a patient crunches ice or drinks hot tea, the material moves all as one - a physical phenomenon called thermal expansion. But with PFMs, there are actually four materials that have to move: porcelain, metal, opaque and the glaze on top. So you have four materials moving, and they’re very weak materials. When you put in a PFM, a lot of patients come back because of chipping around the margin, which the dentist then has to fix, usually with composite. But you don’t have chipping or wear issues with BruxZir. It also wears equally with the opposing enamel. So I think from the lab standpoint, they get a lot of positive feedback from dentists who are looking to prescribe this material more and more.

The digital age allows zirconia to be a part of restorative dentistry. It never would have entered the dental market if CAD/CAM weren’t available to machine it. Because of BruxZir’s strength and esthetics and the consistency of digital CAD/CAM systems, you get the same dimensional control on the contours, margins, contacts and occlusion. Once you have a digital design file that can be machined, you get high accuracy. By producing BruxZir with our patent-pending colloidal system, we get super accurate dimensional repeatability.

Q: What features are you most proud of?

A: The ability to produce a consistent fitting, strong and esthetic material with minimal returns for chips and breakage. If you look at our block return rate for all of the blocks we produce, it’s not even measurable. It’s less than 1 percent. The material is consistent. So I’m most proud of the consistency of strength and translucency, and the feedback we get about the fit. Another thing that’s happening because of the material’s high translucency is that even though it was originally intended just for the posterior, dentists are now also using it for anterior cases. Especially to replace PFM anterior bridge cases that keep breaking. That’s exciting.