About dental crowns:
What is the difference between a crown and a bridge?
A crown, also know as a cap, is for an individual tooth. When a tooth is damaged to the point that a filling is inadequate to restore it, we can place a cap over the tooth, restoring it's size shape, and appearance , looking just like a natural tooth. In order to put the cap on the tooth, it has to first have any decay completely removed, and it's internal integrity restored. (If the decay has gotten down close to the tooth's nerve, it may call for a root canal and a post in order to keep the tooth from becoming hypersensitive). The dentist will shape the remaining tooth into an abutment, that is small enough to fit inside the cap, which is the same size as the original tooth.
A dental bridge is used to replace one or more teeth. To make a bridge, the teeth on either side of the missing teeth are ground down into abutments, and instead of an individual crown being placed on the abutments, a multiple unit crown/bridge is placed on the abutments. For example, if a patient has lost one of their front teeth, we could make the two adjacent teeth into abutments, capping them off with a three unit bridge. The missing tooth would be replaced with a "pontic", or suspended crown, held in place by the two "abutment" crowns. The result would be a restored smile, looking like three individual teeth, but in reality, is a three unit bridge of three crowns that are welded together. (Three are certain rules that a dentist must follow, and taking into consideration the condition of the roots of the abutment teeth, that will determine the length that a bridge can be).
Using modern technology, we can make high quality crowns, to replace teeth, from lightweight metal alloys, and ceramic composites.
At Dental Art we use several types of materials for crowns and bridges:
1. The basic crowns are standard porcelain fused to metal, The core of the crown is a metal cap, and then porcelain is fused over the metal to give a nice tooth appearance and shape. They are made with both standard margins, and porcelain margins, and cost from $240 to $265 each.
2. E.Max, all porcelain, metal free crowns and veneers. This is a durable material, suitable for either veneers, or full crowns on the front teeth. It has a very good luminescence, and is great for cosmetic dentistry. We don't recommend this type of crown for molars.
3. Zirconium/porcelain crowns. Other similar materials are Lava, and Cerec. The core of the crown is a very hard white ceramic material. A 3-D laser scan is made of the abutment tooth, and a computer cad/cam programs drives a lathe that cuts the zirconium material to fit exactly, creating a near perfect seal of the crown when it is cemented into place. These are our best crowns, both for durability as well as aesthetics. They cost $435 per crown unit.
4. We can also make gold crowns and porcelain fused to gold. However, due to the exaggerated price of gold, which changes from week to week, they cost the most. Prices will have to be quoted at time of inquiry, as the price of gold keeps changing.
The Advantage of Zirconium crowns over PFM crowns.
A standard pfm crown is made by first hand crafting a metal cap to fit over the abutment tooth, and then overlaying it with porcelain to give it the shape and appearance of a tooth. This has been the standard crown for decades, and they have served very well. The drawbacks are the imperfections in the fit of the cap over the tooth. The cap is hand crafted, and therefore cannot have a perfect surface to surface contact between cap and tooth. When the tooth is cemented on, the cement fills up any imperfections. However, with the passage of time, the cement can start to dissolve, and filtration will start up under the crown. Eventually a cavity will begin to form underneath the crown, compromising it.
With a zirconium crown there is a big difference because the cap is made by the aid of a computer. Zirconium is an extremely hard white ceramic material that comes in blocks. The zirconium is what is used to make the cap, upon which the porcelain is fused to to give the crown it's shape and appearance as a tooth. To make the cap, a 3-dimensional laser scan is first made of the mould of the tooth. The information is fed into a computer with a cad/cam program that runs a diamond lathe. In short, when the cap is made, it will fit with computerized precision over the abutment tooth. Therefore, the surface to surface contact is nearly perfect, creating a much better seal. Basically, a zirconium crown will seal much better, and therefore the crown will last much longer.
One more benefit to the zirconium is that because it has no dark metal inside the crown, rather a white ceramic material, it gives a superior luminescence to the crown. In other words, the crowns look more realistic, and beautiful.