Moline Porcelain Crowns
A crown is needed on a tooth that is badly broken down by decay, has a large old filling that may be failing, or has suffered trauma. A crown covers the entire tooth down to the gumline, with the purpose of avoiding further damage to it and allowing you to fully use the tooth.
Years ago, it used to be that when a dentist wanted to use porcelain in a crown, it had to have a metal foundation in order to be strong enough to hold up well. However, there are now high-strength ceramics that can be used for crowns. Crowns on back teeth can be made entirely out of these newer ceramics. Crowns on front teeth can be made with a high-strength ceramic core veneered with more aesthetic porcelain.
What is a Porcelain Crown?
Porcelain is a specific type of ceramic that can be manufactured to nearly perfectly replicate the appearance of a natural tooth. Besides being highly aesthetic, it is harder than tooth enamel and more resistant to staining. Today, there are other ceramics that have been developed that are much stronger than porcelain. Since they have similarities to porcelain and are often used together with porcelain, we’ll lump them together here.
Zirconia is one of these new ceramics that has the nickname “ceramic steel.” It has a property of flexural strength. Under stress, it will bend a little rather than break, a property in metals that makes them function so well in high-stress situations. One disadvantage of zirconia is that it comes to the laboratory in little blocks that have to be computer milled to the shape needed for the crown. Porcelain, by contrast, is baked in layers, giving the ceramist full control over the aesthetics and allowing layering of different colors to mimic the color gradients seen in natural teeth. But, a new type of zirconia called Katana comes in blocks that have a layering of colors and has a higher level of translucence, making it more aesthetic.
CEREC crowns are made of another new high-strength ceramic called lithium disilicate. They are manufactured right in the dental office with CAD/CAM technology (computer-aided design, computer-aided manufacture), which means that you can have the crown done in one appointment. Again, the crown is milled out of a block of material, which limits the aesthetics, making it so we generally don’t use it for front teeth.
The e.max crowns are made with a core of lithium disilicate with porcelain layered over the top. As such, they are highly aesthetic. On a front tooth, they can be matched so perfectly to the rest of your teeth that it is difficult to tell the crown from the natural tooth, even at very close range. Dr. Goebel prefers this type of crown for front teeth in almost all cases.
Here is a set of photographs of a mouth restored with porcelain crowns. You can see how natural they look:
Many dentists are still using the older technology of having porcelain bonded to a metal foundation. There are two aesthetic problems with this technology. One is that, with a metal foundation, it is impossible to make the crown translucent the way natural teeth are. A layer of opaquer has to be baked over the metal, and then the translucent porcelain over that. The other problem is that the metal will show through a little at the margin of the crown. Dentists try to place this margin below the gumline where it won’t be seen, but often, over the years, the gums will recede a little, exposing that dark line.
Do you think you need a porcelain crown? Dr. Goebel will be happy to meet with you for a consultation. Just call our office or visit our request an appointment page.