What are the Types of Dental Crowns?
There are so many different circumstances that might call for a dental crown, and there are different types of dental crowns that suit each of these circumstances. In addition to the types and usages of dental crowns, there are multiple different materials used to make dental crowns, and each meets different needs for different patients. While other types of dental crowns exist, the most commonly used materials are gold, porcelain, porcelain fused to metal, zirconia, and ceramic compounds like lithium disilicate, or EMAX.
The choice of material is based on the location and complexity of the restoration and the needs of the patient; clearly, choosing a gold crown to replace one of the upper front teeth would make a very specific aesthetic statement while being more durable than necessary, while a gold crown used in the back of the mouth would be largely invisible and as sturdy as needed. On the other hand, porcelain crowns might be a great option for the front teeth, matching the natural teeth impeccably in luster and hue, but might not be durable enough to recommend for restoring the second molars.
Gold crowns, actually made of gold and metal alloy, are strong and highly durable, making them an ideal option for the second molars, the back teeth that undergo the majority of force from the jaw while chewing and grinding food. Clearly, they’re visible, so they’re not recommended for people who want natural-looking restorations, and they can also adversely affect people with allergies to certain metals, though this is relatively rare. The most popular type of crowns being used currently are porcelain crowns. These ceramic crowns are incredibly natural-looking, biocompatible, and toxin-free, but they are not as durable as their metal counterparts and tend to cost considerably more.
Porcelain-fused-to-metal (PFM) crowns combine the strength of metal with the aesthetics of porcelain, using a metal cap that is coated in porcelain. While these PFM crowns cost less than porcelain and are more durable, they can create an unusually visible gray line at the gums where the metal appears below the porcelain. PFM crowns are also contraindicated for people who grind or clench their teeth, as the porcelain can wear down quickly and leave the metal exposed.
While it hasn’t been used for dental restorations as long as other materials, zirconia shows great promise in combining extreme durability and top-shelf aesthetics. Zirconia is luminous and translucent, just like the natural teeth, and zirconia crowns are strong, long-lasting, and biocompatible, which means they are very unlikely to cause allergic reactions. Zirconia dental crowns may be more rigid or prone to fracture than other types of implants; because they are relatively new on the dental scene, evidence of their durability is still being gathered.
The most innovative type of dental crown currently in use is made of lithium disilicate, branded as E-max. E-max crowns are very thin, light, and realistic-looking, demonstrating excellent durability and strength when used in both the fronts and backs of the mouths. Like with zirconia, however, E-max is new enough that longer-term failures could occur as more longitudinal evidence arises, and the higher cost of E-max may make the idea of these possible failures even more daunting. Generally speaking, a dental crown should be considered a long-term investment, and the type of dental crown you choose can play a pretty big part in your expected return, so make sure to review your options in greater depth with your dentist.
