The porcelain that is used in porcelain crowns is called feldspathic porcelain. It is a very beautiful material to work with, and it used to be the only ceramic material used in dentistry. However, advances in bonding technology have made it possible to use other ceramics. Zirconia crowns and bridges are made with a ceramic that has so much tensile strength that it is called ceramic steel. They can be made to look as beautiful and natural as real teeth. e.max crowns are made by a different process to produce the same beautiful results. We’ll explore the differences here.
Zirconia Crowns and Bridges
Zirconia ceramic is so strong that it has applications in the aerospace and other high-tech industries. There is no need for a metal framework, and because of this, crowns made with zirconia don’t need to be opaque, and they will never show the dark gumline as porcelain-fused-to-metal crowns do. In the photo to the left you can see how light is transmitted through the material, allowing color to be drawn from the underlying tooth structure.
Feldspathic crowns are created by stacking and firing multiple layers of porcelain, and zirconia crowns are milled from a single block of ceramic. Zirconia is also highly biocompatible, meaning that it virtually eliminates the risk of allergic reactions. Hip replacements use very similar materials. Because it can be milled so thin, the border where it meets the tooth has an extremely precise fit. In addition, zirconia crowns are strong enough to support bridges. Here is a before and after photo set showing a restoration using zirconia crowns.
e.max is a name for a crown creation process that combines zirconia ceramic as the foundation with a feldspathic porcelain veneer. The zirconia crown is prepared as it would be, but the front part is ground down and overlaid with feldspathic porcelain. The process has a very beautiful outcome, and this kind of crown is popular among many dentists. The beauty of the porcelain combined with the strength of the zirconia foundation make this a great alternative to all-porcelain or even zirconia crowns.
Extra Training and Experience Required
Not all dentists will recommend an all-porcelain or ceramic crown for front teeth. The reason is quite simple. They require skills that are normally outside the scope of what is taught in dental school. Color manipulation is a precise art, taking into account how the underlying tooth structure shows through to influence the color choices of successive layers. The bonding technology is also very sophisticated, and if this is not properly completed, it could lead to problems.
If you’d like to find out more about crowns and bridges, click here to read our porcelain crowns page. And if you’re ready for a full exam or complimentary consultation, call our office or fill out our request an appointment form online.