BruxZir Crowns

At our office, we want all of our dental work to be beautiful, functional and enduring. Many times, finding the intersection point of these three qualities requires us to turn to new technologies and developments in dental materials. In the case of dental crowns, we utilize BruxZir milled zirconia as a beautiful restorative solution that stands up to even the toughest conditions.

In the human mouth, the farther back a tooth is, the more relative force it will receive during a regular day. Teeth closest to the jaw joint are situated right next to the masseter, the muscle responsible for chewing, biting and closing the mouth. This muscle can generate incredible amounts of force, enough to crack or fracture your own teeth. Because of this, many types of crowns will chip, break or fail in the rear of the mouth.

A diagram highlighting the masseter muscle. 

In the past, porcelain fused to metal (PFM) crowns were the best tooth colored solution for posterior teeth, as their solid metal underpinnings are incredibly durable. However, the baked on porcelain can fracture and break during normal wear, requiring replacement or adjustment. Gold crowns were popular as well, so long as the patient was comfortable without a tooth colored restoration. Other materials, such as full porcelain crowns, are simply too fragile to be placed in such a functional position.

In contrast, Bruxzir crowns combine longevity, strength and natural beauty. They are milled out of a solid piece of engineered zirconia to match the color and shape of the original tooth. Since it is a single piece of material, it better matches the light characteristics of natural teeth. There is no metal backbone block out and less tooth structure has to be removed to accommodate the newly made crown.

While some materials (such as Emax) offer better translucency and color properties, nothing can stand up to BruxZir’s durability. They are essential chip, grind and crack proof. Even with heavy grinders and clenchers, the single piece zirconia will not fail or erode. No other material can offer this level of endurance in an esthetic, tooth colored package.

Even taking a hammer to a BruxZir crown will not ruin it's structural integrity. 

We typically only place BruxZir crowns on molars and more rearward teeth. While these units are esthetically superior to PFMs, they are not as cosmetically versatile as Emax crowns. In essence, their incredible strength comes with the price of poorer relative translucency. For front teeth experiencing less average force and wear, we will typically place this more esthetic material. Of course, we still place PFM and gold crowns, but most patients are eligible and more willing to be fitted with these state-of-the-art units.

If you have any further questions about BruxZir crowns, or any other crown materials at our office, please give us a call. We would love to talk you through your crown options, and which material would work best for you personally!

Crowns and Bridges

Hands down, dental crowns and bridges are the most versatile restorative tools at our office. Whether going on previously decayed teeth, root-canaled teeth or a dental implant, they offer convenience, beauty and excellent flexibility. Please take a moment and read why we love crowns and bridges at Thousand Oaks Family Dentistry!

In it’s simplest form, a dental crown is a hard, solid object that replaces the natural “crown” of the tooth. It can add structural rigidity, biting function or esthetic value to any damaged or decayed teeth. Similarly, bridges are three (or more) crowns made in tandem, were the outermost two units are attached to your natural teeth (or implants). The goal is to “bridge” the gap created by a tooth that was previously removed. Both crowns and bridges are prepared using the same techniques.

Crowns and Bridges are placed for a number of reasons. Crowns can be used to fix teeth that have too much decay to be rebuilt with a dental filling. They can also restore structure after a tooth becomes cracked (depending on the nature of the crack). Bridges are used to replace once-missing teeth in almost any area of the mouth. All that is required is that the gap is “surrounded” by viable teeth for the bridge to be mounted to. Likewise, implant crowns are the final restorative step in implant surgery and give the implant its beauty and functional ability.

The basics of how a tooth is prepared for a crown. (Read top left to lower right)

To prepare a tooth for a crown or bridge, we essentially remove a ~1.5mm gap from around all surfaces of the tooth, in addition to any defects or decay. The walls of the teeth are slightly tapered, so that the crown can be placed easily and has ample tooth structure to hold on to. At the gumline, a distinct ridge (called the “margin”) is created to give an explicit surface for the crown to be cemented against. In the case of bridges, this step is done on two separate teeth, with special care given to making both teeth completely parallel. For implant crowns, these steps and designs are built into the shape of the abutment, which is essentially a manufactured “undertooth” made at an off site dental lab.

1) A natural tooth is broken/decayed and cannot be repaired with a filling 2) The tooth is prepared for a crown, giving it clearance for the new unit and proper structure. 3) The final crown is cemented and delivered. 

Preparing and delivering bridges is done with much the same technique. However, a missing tooth is replaced in the process. 

After your tooth is prepared, we have a number of material options for making your crown or bridge. In nearly every case, we will use tooth colored materials and restorations. We can match almost any esthetic concerns, from color to matching staining patterns and the shape of adjacent teeth. For front teeth, we often use eMAX lithium disilicate crowns for their excellent esthetic properties and strength. In molars and back teeth, we typically place a material called Bruxzir. Bruxzir is an engineered zirconia that surpasses all other crown materials in terms of hardness and durability. We also have a number of more traditional crown materials at our disposal, ranging from gold to zirconia and porcelain fused to metal (PFM). Picking a crown material is a discussion between you and Dr. Kari that considers your whole-mouth condition and your specific wants and needs.

An example of an eMAX bridge/crown. 

At a crown preparation appointment, we start by getting you numb and taking an initial impression for our temporary crown. We then prepare the teeth, taking care to provide ample clearance for the new unit. Once the tooth is fully prepared, we take a final impression and make notes for the lab. Finally, we use our first impression to make an acrylic temporary. While this will not be as strong as your final crown, it will allow you to leave with a fully shaped tooth. This is important for esthetics, chewing function and for maintaining the space between the prepared tooth and the opposing tooth. After two weeks, the lab will deliver your crown, which will be adjusted, seated and cemented in a quick follow up appointment. The process for implant crowns is slightly different, but still requires appointments for initial impressions followed by the actual crown delivery.

If you have any further questions concerning dental crowns, please give our office a call. We place and deliver crowns almost every day and can walk you through your unique needs. There should be no confusion, fear or apprehension surrounding your crown or bridge treatment!