Can I Trust Zirconia Based Restorations?

Short answer... YES! Yes you can trust zirconia based restorations! But lets dig a little deeper into the discussion.

The restorative dental industry is as fast paced as it has ever been; a major shift in the industry is taking place right beneath our feet! Advancements in technology are guiding our industry into uncharted waters; digital impressions, cad/cam, and the topic of the day... new materials like zirconia.  If you want to stay in business and relevent in our industry, you have to adopt these processes and materials.  Sometimes that means navigating these uncharted waters without a compass.

Sure we attend seminars and "hands-on" courses, but there is no greater learning experience than doing, and we did!  We had a fair amount of success in the early days of zirconia, and we were lucky to be working with Dentists that were willing to push the envelope with us, but we also had failures.  As you probably know from experience, the zirconia never failed, it was the overlaying porcelain that would fracture and fail in high stress areas. This was a result from two things; the bond between the zirconia substructure and porcelain, and the design of the zirconia substructure.

What do they say about failures? Learn from them and turn them into successes.  So we learned, and we tweaked the process, and we are proud to tell you that we have a success rate that is near incalcuable at over 99.9%

So if you have been burned by zirconia based restorations and fracturing porcelain; fear no more!

How do we do it? What do we do different? It is simple really, we follow these 2 simple rules

Rule #1 - We use only trusted brand name zirconia, Vita InCeram YZ to be exact.
There is a lot of zirconia being sold out there, and you need to protect yourself and your patients. Differences among zirconia can be the level of zirconia purity, grain size, the processing of the zirconia into millable blocks or discs, and trace elements. These differences can result in clinical variances such as marginal fit, translucency of the zirconia, strength, and long-term viability. So in conclussion, know which brand of zirconia your lab is using.

Rule #2 - We support the high-stress areas of porcelain overlay with zirconia.
In order to prevent the fracture of porcelain we utilize reverse engineering to determine optimal zirconia substructure design.  Utilizing our state of the art Sirona InLab design software and milling unit we design the final restoration first (Picture 1 & 2); and then reduce that 1.2mm all the way around for proper porcelain support, paying close attention to cusp tips and marginal ridges (picture 3).  In the early days of zirconia (and even now sometimes), not much attention was paid to the support of the porcelain. When you outsourced your zirconia frameworks, you would recieve what we called a "thimble," a zirconia framework .5 mm all over (picture 4).  When you have a "thimble" type framework, you can end up leaving over 2mm of porcelain "hanging" in high stress areas.  A disaster just waiting to happen!
 
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Dr. Russel Giordano, a material science expert, has written and presented on the topic of zirconia based restorations.  Here is a link to one of his recent articles concerning the background of the material and clinical success.  Dr. Russel Giordano Article

Thanks for reading!