By: Christopher Mazzola, DDS
This topic originally appeared on PankeyGram.Org. Dr. Mazzola granted permission for igniteDDS to share with our readers.
The purpose of looking at recent research data is to see how we can improve our clinical outcomes. Different scholarly journals inform us of ways to decrease risk and hopefully increase the longevity of the services that we’re providing to our patients.
In this article, I’ll summarize what I’ve learned from recent research literature about the various types of zirconia we receive from our dental laboratories and properties of zirconia that influence the quality and longevity of the dentistry we do.
I found these facts fascinating from the perspective of wanting to know how to use zirconia optimally.
Composition: Choosing Between Strength and Esthetic Properties
There are three primary compositions of zirconia on the market: 3y, 4y, and 5y.
The Y in the composition descriptor refers to Yitria or Yttrium Oxide (Y2O3). The more Yitria the zirconia restoration contains, the more translucent the dental crown will be.
Adversely, the more Yitria the zirconia crown contains, the less flexural strength the crown has. The 3y zirconia restorations can handle adjustments better than 4y and 5y in terms of both strength and optical properties.
Color: Meeting Patients’ Expectations
The marketplace offers zirconia that is prestained and zirconia that is not prestained. In the case of prestained zirconia blocks, we have about a tenth of a millimeter in reduction capability before we notice a color change.
Knowing this is important when we need to adjust a zirconia restoration, so we can manage adjustments to deliver the shade of restoration our patient expects.
Zirconia Wear on Other Restorative Materials
If zirconia is rubbing against other zirconia restorations, there is less wear than if zirconia is rubbing against lithium disilicate ones and softer ceramics or composites. When you’re setting up an occlusion or you are looking at a hybrid denture versus a normal denture, you must take this into account.
If a patient has an upper fixed-hybrid denture, zirconia is going to wear those denture teeth relatively fast. Knowing this, we can best prepare our patient for the wear that is likely to occur.
Zirconia Removal Burs Vs. Restorative Diamond Burs
In an in vitro study, the burs that are marketed specifically for adjusting zirconia restorations did not perform better on 3y, 4y, or 5y zirconia, and they did not generate less heat.
Note About Polishing Zirconia
When we are polishing high-strength ceramics like zirconia restorations and lithium disilicate blocks, we must be careful not to push too hard, and we must use a continuous cooling spray of water. Otherwise, we risk nerve damage duethe to thermal irritation.
Also, if we generate too much heat, we will overheat the glue that bonds the fine diamond particles on the bur and are likely to render the bur useless.
Key Takeaways
These were some important facts about zirconia restorations I thought dentists should be aware of when choosing between different restorative materials. If you’re looking for more advanced educational courses on functional and aesthetic mouth rehabilitation with direct and indirect restorations, consider checking out the courses offered by The Pankey Institute. Transform your clinical expertise and learn valuable tips and tricks for your practice from experienced clinicians and their faculty members.
