Different Types of Dental Crowns

As technology progresses, the field of dentistry gains new materials, techniques and services. However, we rarely stumble upon a magic "one size fits all" approach. This is particularly true of the advancements in dental crowns. There are nearly hundreds of different crown materials and manufacturers, each with their own specific use. In this article, we will discuss four general types of dental crowns and why we use them. Enjoy!

Porcelain fused to metal- These crowns combine the esthetic properties of porcelain with the adaptability of metal. A metal framework is cast to a stone model of the prepared tooth. Afterwords, layers of porcelain are baked on, creating the look of a natural enamel. These crowns are typically used in the back of the mouth, as they are durable and resist wear to the opposing teeth. However, the metal substructure can make these crowns too opaque to be used in cosmetic applications.  

Gold- Gold crowns are less frequently used in modern dentistry due to the availability of newer, more esthetic materials. However, gold is one of the most adaptable materials available, allowing for a near seamless junction between tooth and crown. It also requires the least amount of tooth structure to be removed, but this becomes irrelevant in instances of severe decay, chips and fractures. 

Lithium Disilicate "Emax": Emax is an extremely durable and esthetic material. It can be used in nearly all areas of the mouth, although we tend to use it in cosmetic areas. Since these crowns are made from a single type of material, they transmit light very well and perfectly match natural enamel. Emax can even be stained or painted to match imperfections in the surrounding teeth!

Zirconia "BruxZir": Like Emax, BruxZir crowns are made from a single type of material (engineered zirconia). However, they trade cosmetic advantages for extreme fracture resistance and durability. BruxZir crowns are best used in patients with strong jaws or grinding problems, where other materials will not last. In fact, these crowns are hard enough to wear enamel, meaning that they need to be used judiciously and only when necessary. 

An important note is that Thousand Oaks Family Dentistry charges the same crown fee regardless of material used. We want our patients to know that we are focused on the best long term outcomes for their dental care- be it from the newest technology or tried and true methods!

Cosmetic Reconstruction With Emax Crowns and Veneers

Today's case is a great example of the importance of color and translucency when designing a crown or veneer in the anterior region. This patient came to our office dissatisfied with their current dental restorations and overall smile esthetics. The crowned teeth appeared unnaturally opaque and presented with a sharp change in color where the teeth met the gum tissue. These crowns were created using porcelain fused to metal (PFM), a classic technique for fabricating tooth colored crowns. While they make very functional restorations, PFMs take away from the natural translucency of teeth due to their solid metal underpinnings. This patient's condition was exacerbated by gingival recession, which revealed contrasting natural tooth structure underneath the crown.

To create a completely natural smile, we utilized Emax lithium disilicate crowns and veneers across the maxillary and mandibular teeth. These crowns are made of a single type of translucent material, and thus transmit light like natural enamel. Similarly, the single piece construction makes these crown very strong, allowing us to replace the PFMs in the posterior region as well. By working closely with our dental lab, we created a set of crowns and veneers that are uniform in shape, color and shade. The final product is a natural and youthful smile designed to stand the test of time! If you would like to know more about crowns, veneers or any other esthetic service offered by our office, please give us a call. 

Emax Lithium Disilicate Crowns

    When it comes to dental crown materials, there are many different options to suit a multitude of different scenarios. Some, like full porcelain crowns, provide excellent esthetic results. Others, such as full gold units, provide extreme durability along with desirable tooth-like physical properties. However, what options offer both beautiful cosmetic results along with enduring strength?

For many years, porcelain-fused-to-metal (or “PFM”) crowns were the cornerstone of “form meets function” in crown materials. These units are made by taking an alloy metal core and attaching a thin layer of porcelain over it, resulting in a durable tooth colored restoration. Unfortunately, this process is not without it’s downfalls. The porcelain has a tendency to crack and break between the opposing tooth and the hard metal sublayer. Additionally, the alloy substructure is extremely opaque, and prevents the overall crown from having the translucency of a natural tooth. This detracts from the overall esthetics of the final product.

While PFM crown still have a very useful place in dentistry (and are still regularly placed at our office for various reasons), modern technology has provided us with newer and more elegant solutions. Today, we can offer Emax as a means of creating a beautiful crown or bridge with long term durability.

An example of a finished Emax dental bridge (right) and crown (left)

Emax is a lithium disilicate material that combines the translucency of porcelain with incredible strength. On average, these restorations can withstand 360-400 megapascals of force before breaking. What does this mean? Essentially, you could hammer a crown made of Emax into a plywood board and pull it out without damaging the structure. This incredible resilience means that Emax can be placed in almost any location in the mouth with extreme confidence.

In terms of esthetics, Emax rivals porcelain in that it provides an incredibly toothlike translucency. One of the most obvious “tells” of a dental crown is poor transmittance of light. Crown that do not respond to ambient light like natural teeth are just as visually jarring as poor tooth shade matching. Emax offers this low opacity in conjunction with the ability to have natural artifacts “baked” into the crown’s surface. Surface lines, color gradients and staining can be added to the crown to blend it perfectly with the adjoining teeth. Overall, this step helps detract from the “chiclet gum” look that is imparted to certain crown.

Of course, Emax in only one of the excellent crown options offered at our office. While it has some great properties, it can be a poor choice of restoration depending on a number of factors. Your crown material should take into account mouth location, neighboring teeth and your personal expectations. We regularly work with a number of different materials because our patients regularly need a number of different materials. If you have any questions Emax, or any other materials we offer at our office, please let us know at your next appointment!