Porcelain crowns, sometimes referred to as “caps”, are tooth-shaped, tooth-colored restorations that are bonded onto existing tooth structure for one of the following purposes:
-To maintain a tooth that has lost a large portion of its natural structure due to fracture or excessive wear and tear
-Properly restoring a tooth that has a very large cavity
-Replacing a failing or unacceptable existing crown
-Prolonging the life of a tooth that has received root canal therapy
-To replace a large, weak filling
-For cosmetic improvement
Are there different types of crowns?
Yes, there are many different types of crowns. In the past, crowns were made entirely of metals like gold or silver. In later years, white porcelain crowns with metal sub-structures (also known as porcelain fused to metal crowns) were introduced. While more esthetic than their predecessors, these porcelain fused to metal crowns were still very challenging when it came to creating beautiful, natural-looking tooth restorations. These types of crowns are sometimes referred to as looking like “Chiclets” chewing gum due to their unnatural, opaque appearance.
Even though metal and porcelain fused to metal crowns are still very useful for certain purposes, the new standard in esthetic crown restorations is the all-porcelain or all-ceramic crown. All-porcelain/ceramic crowns do not contain any metal and offer numerous advantages to their metal-containing counterparts.
How are all-porcelain/ceramic crowns different from other crowns?
Natural teeth achieve their appearance due to having different layers of structure from the inner core to the outer shell, with each layer having different properties. The inner core of a natural tooth is made of dentin, a substance that is slightly yellow and somewhat opaque or solid in color. The outer shell of a natural tooth is composed of enamel, a harder and more translucent (meaning light passes through it more easily) structure. The normal layering of these different structures is what gives teeth their beautiful natural appearance.
This natural appearance is much more easily achievable with porcelain/ceramic crowns because these materials come in various shades of white. Porcelain/ceramic crowns can be layered with various shades, opacities, and translucencies of color to achieve picture perfect matches that look just like natural teeth. This type of layering is simply not possible with metal-containing crowns. See the pictures here for an illustration of these concepts.
Are all-porcelain/ceramic crowns appropriate for every situation?
While all-porcelain/ceramic offer major cosmetic advantages and can sometimes offer greater strength, they are not appropriate for every single situation in which a crown is needed. Ask your dentist what type of crown is most appropriate for your needs.