Zirconia Crowns; the Future of Restorative Dentistry
A few years back, when you visited your dentist for getting a crown for your teeth, you would usually be presented with two options. You would have to choose between a gold based crown or a porcelain fused to metal (PFM) crown. Although the use of fixed prostheses prepared from gold based alloys has been reduced markedly over a few years, all ceramic and PFM crowns continued to be the most commonly used crown and bridge material. However, it was not until only a few years back when zirconia based crowns and bridges were introduced into the dental industry and were praised for their excellent strength and esthetics. Now, most dental practices are switching from the conventional PFM and all-ceramic crowns towards the use of zirconia for fabricating fixed dental prostheses.
What is Zirconia?
Well, this is interesting! Zirconia, or zirconium dioxide is a metal oxide that is actually a type of a dental ceramic; however, it possesses properties that are markedly different from the conventional ceramics that were being used previously. Not only zirconia crowns and bridges possess excellent esthetics, but they are also virtually indestructible!
The Benefits of Zirconia over other Crown Fabrication Materials
Let’s see why zirconia is increasingly becoming the preferred crown and bridge material among the dentists and the patients alike:
- Exceptional Strength – the excellent strength possessed by the zirconia crowns is alone itself sufficient for advocating their usage for crown and bridge fabrication. No matter what you do or eat with your zirconia crowns, they will not break or fracture!
- Superb Esthetics – nothing matches the esthetics provided by zirconia. Zirconia acts as the perfect core material for dental crowns and bridges, over which suitable glazing and staining can be performed to produce naturally looking and highly esthetic prostheses.
- Durability – zirconia is even more durable than the conventionally used PFM ceramics. Once you get your teeth reinforced with zirconia crowns, you don’t have to worry about their durability any more.
- Machinable Prostheses – dental manufacturers are nowadays producing zirconia crowns and bridges by using a CAD CAM assisted milling machine or 3D printing. These techniques not only produce crowns with excellent fit, but the prostheses are also very esthetics as each layer of the crown can be easily customized to match with the patient’s natural dentition.
- Safety and Biocompatibility – despite the excellent biocompatibility of gold based crowns and bridges, some patient’s still have to face some allergic reactions with them. Similarly, quite a few dental patients are also allergic to the alloys used for the fabrication of PFM crowns. On the other hand, zirconia possesses excellent biocompatibility and the crowns and bridges prepared from zirconia are extremely safe for clinical use inside the oral cavity.
Despite the many benefits of zirconia crowns and bridges, zirconia also possesses some drawbacks:
- Extreme Hardness – zirconia is extremely hard, even more so than the natural tooth enamel. As a result, it can abrade the enamel of the opposing tooth. Also, sometimes, difficulty is encountered during their milling and 3D printing.
- Not Suitable for Veneers – since zirconia is quite radiopaque, it cannot be used for preparation of veneers.
In regards to extreme hardness, isn’t there proof out there that smooth zirconia is the least abrasive material to the opposing dentition? If not the least, there’s studies that show its far less abrasive than PFM.