A dental crown is a cover or “cap” that restores a compromised tooth to its original size, shape, and function.
Some reasons you might need a crown include:
- You have a cavity that is too large for a filling
- You have a tooth that is weakened (cracked or worn down)
- You need to protect a restored tooth after having a root canal treatment
- You want to hide a discolored tooth and improve the appearance of your smile
Dental crowns can be made from a variety of materials, including ceramics, metals, and composite resins. A ceramic that’s becoming popular is the high-tech zirconia. Extremely strong, it is sometimes called “ceramic steel.”
A bridge is a restoration used to replace a missing tooth. It consists of a false tooth suspended between two crowns. The problem with using pure porcelain for a bridge is that, while porcelain is strong, it won’t bend. Instead it fractures under stress. Zirconia, however, will flex, enabling it to be a very practical material for a bridge, even on back teeth that are under a lot of chewing stress.
There are two options for zirconia crowns. In very high-stress situations, such as a crown on a back tooth of a patient who grinds their teeth, they are made completely of zirconia, or “monolithic zirconia.” Zirconia is provided to the dental lab as blocks of material of varying shades, and the lab then mills the crown to precisely fit the patient’s tooth and the bite. The lab technician has only a limited amount of flexibility with the color. There is no ability to customize the coloring of the crown beyond selecting the block of a matching color. For that reason, it is probably not a good option for a front tooth.
Another option is “layered zirconia.” This technique uses a core of zirconia, and then porcelain is baked onto the surface. This gives the laboratory technician the latitude to duplicate all the subtle color variations of the patient’s natural tooth.
Pros & Cons of Zirconia Crowns
Because of their many benefits, zirconia crowns are growing in popularity. These benefits include:
- Strength. Crowns need to be made of a durable material in order to withstand biting and chewing forces. Zirconia is one of the strongest materials available for crowns–about five times stronger than porcelain.
- Longevity. Zirconia crowns are resistant to cracking and chipping, making them a long-lasting restoration choice.
- Safety. Zirconia is highly biocompatible, with reports of sensitivity reactions being rare. Zirconia restorations are a great choice for patients looking for a metal-free option.
- Less Prep. Zirconia crowns require less removal of natural tooth structure as compared to some other types of crowns.
The list of drawbacks for zirconia crowns is short, but still worth sharing:
- Hard To Match. Zirconia is not as translucent as porcelain or lithium disilicate (e.max) and therefore does not mimic the tooth’s natural appearance as well as these other materials. For this reason, zirconia is most ideal for restoring posterior teeth (molars), while other materials are better for highly esthetic situations such as anterior (front) teeth.
Is Zirconia Right for You?
Here at Contemporary & Esthetic Dentistry, zirconia crowns are just one of the metal-free dentistry options we offer our patients. Lithium disilicate–found at the core of e.max crowns–is another metal-free, high-strength ceramic used for restoring damaged teeth.
If you would like to learn more about zirconia crowns and other types of porcelain crowns, contact our office today to schedule a consultation with Dr. Farber. Or, if you prefer, you can request an appointment, and we’ll call you.