What are dental crowns?


A crown is a specific restoration that places a 'cap' on an existing natural tooth, or on top of a dental implant. They are often needed when a large area of decay has penetrated deep into the tooth and there is no longer sufficient tooth structure to support a simple filling. Crowns are typically bonded to a tooth with a dental cement, however, friction is the main source of retention on a dental crown.

Cosmetic dental crowns


While crowns are critical for maintaining as much natural tooth structure as possible, they can also offer significant strength and cosmetic advantages. In patients seeking a complete transformation of the cosmetic appearance of their teeth, crowns can be utilized to great effect. While veneers would be the typical course of action,  they unfortunately are not always an option due to circumstances like existing tooth decay or significant bruxism (teeth grinding or clenching, particularly at night). Crowns can therefore be used to provide a more reliable result while providing a significantly enhanced cosmetic appearance.

Dental crown procedure

 An example of a prepped tooth


Typically, an impression is first taken of the existing tooth to create a mold for a temporary crown you will receive that same day.   The problematic tooth structure is then removed using a drill to form what is called a preparation, or a 'prepped tooth'. In some cases, a 'buildup' is necessary when there is insufficient natural tooth structure remaining, which involves using a restorative material like composite to increase the size of the supporting surface for the crown. A second impression is then taken of the prepped tooth and surrounding area in order to fabricate the final crown in a laboratory based on your specific bite and the surrounding teeth. The temporary crown is then placed on the prepped tooth, with the final crown placed in a subsequent appointment after it has been fabricated in the lab. If you would like to read about same day, one day, or CEREC crowns, please click here.

Gold crowns

 An example of a gold crown


Gold crowns, which ironically are also considered the gold standard, are extremely durable, particularly due to gold's malleability. As a result, gold crowns are one of the best materials for a crown if the aesthetic appearance is not a high priority. They also can be quite expensive dependent upon the current pennyweight price of the gold itself, which fluctuates significantly. Traditionally, gold crowns are considered the most conservative approach and require the least amount of tooth structure removed, however, some current materials are arguably becoming comparable.

 

What are zirconia crowns?


Zirconium oxide ceramic, or zirconia crowns, are the hardest material a crown can be made of. In terms of full zirconia crowns, or crowns made entirely of zirconia, they offer a better cosmetic result than gold, however, they have very little translucency, which does not allow for a natural looking restoration due to their opaque nature. As such, it is best reserved for a posterior tooth, or a tooth in the back of the mouth. Porcelain fused to zirconia crowns, which have a porcelain layer fused to an underlying zirconia core are a more cosmetic middle ground, however, they lack the full strength of the all zirconia crown. Many so-called 'biologic' or 'holistic' dentists will refer to this as a 'metal free crown'. This is inaccurate as zirconium itself is a metal, similar to titanium in many regards, as is yitrium which is typically added to stabilize the compound. Zirconia crowns are very difficult to adjust or remove later due to the extreme hardness of the material. While zirconia crowns are structurally metal, they are completely white, or tooth colored in appearance, lacking any gray color.

What are e.max crowns?


Lithium discilicate crowns, or e.max crowns as they are commonly called, which are frequently claimed to be 'metal free' crowns as well, are actually a metal, with lithium being an alkaline metal on the periodic table. E.max crowns currently offer the most aesthetically pleasing result, however, they are also the weakest, leading them to be suitable only for front teeth where aesthetics are paramount. E.max crowns offer an unparalleled level of translucency, which is necessary in order to create a natural look to a restoration. There are some new iterations of full zirconia crowns that are coming close to the aesthetic appearance of e.max, however, e.max crowns still remain unrivaled in terms of cosmetic results. Like zirconia crowns, e.max crowns are white in appearance and do not have a typical metallic or gray look as is commonly associated with metal.

What are pFM crowns?

 An example of metal showing on a PFM dental crown


Porcelain fused to metal, or PFM crowns, are similar to porcelain fused to zirconia in terms of strength. The major difference between a PFM and a porcelain fused to zirconia crown is the that the underlying core in a PFM crown is a silver-colored metal alloy, which can often show through. As a result, a gray hue near the edge of the tooth where it meets the gum line can often be seen, and the entire crown has to be made far more opaque in order for the metal core not to show through. While PFM crowns lack the strength of a full zirconia, they are stronger than an e.max, however, due to the higher price of PFM compared to zirconia and less aesthetic results, PFMs are becoming less common. The major advantage of a PFM is the ease of which they can be cut if they ever need to be replaced.

how much do Dental crowns cost?

A crown can vary significantly in price dependent upon the type of crown, any necessary associated work to place the crown, the location of the crown, and your specific insurance coverage. Typically a crown will run anywhere between $500 and $2000, although some insurance plans will actually cover the entire cost of the procedure.