Zirconia and porcelain crowns are commonly requested over other metal alternatives because of their strength and natural appearance. Once milled zirconia restorations were introduced, patients often request zirconia rather than porcelain-fused-to-metal (PFM) restorations. Dentists may prefer to exclusively use an all-ceramic or zirconia restoration when they are restoring a single tooth. Dentists are starting to use zirconia crowns more often than traditional PFM or all-ceramic options because the material is incredibly durable and attractive in its appearance. Zirconia is very strong and is able to endure the daily forces of chewing without being easily damaged.
Zirconia is a metal oxide which is derived from zirconium. This is a metal found in the titanium family and is available throughout the world. Many common household items including dinnerware, pipes, and electrical fixtures are actually made using zirconia. Zirconia is naturally strong and durable, making it an excellent material to be used for dental crowns. Zirconia crowns are an excellent solution for patients needing a posterior crown as these restorations must be strong enough to chew food and bite down.
Porcelain-fused-to-metal Restoration
As suggested by the name, porcelain-fused-to-metal (PFM) crowns use a combination of porcelain and metal materials. A porcelain overlay is used to closely match the color of the natural teeth, however, the darker metal color below can be visible near the gums. This is especially common when patients have receding gums. When patients are looking for a restoration which is durable with a natural appearance, the dentist often recommends a PFM restoration.
Some of the key benefits associated with using a zirconia crown rather than a PFM restoration are summarized below.
Strength
Zirconia is an incredibly strong and durable dental crown material. It is estimated to be three times stronger than porcelain or PFM restoration alternatives. Zirconia is able to withstand wear and tear without chipping like a porcelain restoration. This incredible strength allows zirconia to withstand the strong forces associated with chewing and grinding. Monolithic zirconia is a single, solid block of zirconia. This type of crown is virtually indestructible and can endure harsh environments and forces.
Natural Appearance
Unlike porcelain-fused-to-metal (PFM) crowns, zirconia crowns do not contain a metal lining at the gingival margin. This metal lining can be visible near the gums and noticeable when the patient smiles. Zirconia crowns are able to completely avoid the use of a metal lining. In addition, a zirconia crown can be easily manipulated and adjusted to match the patient’s natural teeth.
Durable and Reliable
Zirconia is incredibly durable. It is more durable than the ceramics conventionally used for PFM crowns. Solid zirconia contains more stabilizers than PFM ceramics, this makes the crown more durable and able to withstand the strong forces of chewing and grinding food. When zirconia restorations are properly maintained, they can last for a lifetime.
Customized
Because of factors such as the chemical composition and processing requirements, zirconia can be manufactured to accommodate the unique needs of the patient. Because the restoration is so easily customized, the margin for error is reduced and the dentist can achieve an excellent fit.
Safety
Zirconia is highly biocompatible, meaning patients are not likely to have an allergic reaction. Reactions are relatively common from the alloys used in a PFM restoration. Zirconia crowns and bridges are incredibly safe and most patients are not at risk for having a reaction.