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!