Zirconia Dental Crowns

When dental crowns needs to be done, it is necessary to use biologically compatible substances in the mouth. After many years of using plastic biodent materials on metal, the use of porcelain over metal became popular in the 1980s. Porcelain construction on metal as porcelain tooth crown in the last 30 years in particular has become widespread throughout the world.

However, the metal under porcelain sometimes causes allergic reactions in some people. The problem of gum morphology, which causes aesthetic problems in the front tooth region, also comes from the disadvantages of metal-based porcelain tooth crowns. For this reason, intensive studies have been started on porcelains strengthened with full ceramics in 1990s. However, no matter how much the porcelain material is strengthened, the use of ceramics in the application of dental bridges without infrastructure material has not been successful.

At this point, the use of zirconium material, which takes the place of the metal infrastructure, has been introduced and within a short period of time the properties of the zirconium infrastructure have been developed, making it possible to apply more aesthetic substructure than metal supported porcelain crowns.

Zirconia is used as an infill material in the tooth coverings of the upper part of the tooth which turns around and covers the damaged teeth.

Traditional porcelain crowns can be attached to the teeth with metal support, while durable and aesthetic dental crowns can be achieved without metal by zirconia crowns.

Computerized Zirconia Tooth Design

The dentist prepares the problematic teeth in the mouth for the operation. After completing the necessary dental treatments and restorations, they prepare temporary teeth (crowns). Before creating final zirconia crowns, exact measures decided by oral silicone substance for covering the tooth. This measure must be error-free. The laboratory transfers the measurement taken by the dentist to the computer environment. Computer-aided design, called CAD-CAM, and computer-aided production phase of new zirconia porcelain crowns begin. The dental technician prepares the zirconium infrastructure design to be used on this scale. The gap between the tooth  in the mouth  and new zirconia crown, the thickness of the material, and the points where the crowns joins the gum should be carefully calculated and entered to the computer program.  This operation should be done by trained and experienced dental technicians.

Today, there are applications that are called as monolithic zirconium and the finished tooth shape is determined by computer design. In monolithic zirconium, the zirconium coming out of the scraper machine is only polished and attached. We do not generally prefer monolithic zirconium tooth coatings and bridges since we get more excellent results when a porcelain is aesthetically treated with zirconia crowns.

Preparation of Zirconia Crowns

Zirconium material is used as a cylindrical zirconium block in dentistry. Computer aided manufacturing (CAM) machines used to scrape operation on these blocks. The zirconium base, which needs to have a high physical property to give strength  to dental crown, gets to its final durability with a hardening process called sintering.

The material is softer and easier to process before sintering. For this reason, the dental crown is eroded from the zirconium blocks before the curing process. It is then subjected to special heat treatment to obtain durability, ie, sintered.

After this step the dental technician will now work on the form and color to give the dental aesthetic properties on this infrastructure.

Properties of Zirconia Crown Tooth

Zirconium is used for two purposes in cometic dentistry or dental treatment:

1. Zirconium Crown: Crown is the term for dentistry given to the upper part of the tooth that appears in the mouth. Zirconium crowns are tooth coverings which are made of zirconium, that is used to cover the damaged teeth or as the substructure of the upper part of the teeth. When called zirconium crowns, zirconium tooth coatings are expressed. Conventional porcelain crowns can be attached to the root of the tooth with metal support, and aesthetic appearance without metal support can be achieved with zirconium for porcelain crowns.
2. Zirconium Bridge: Tooth bridges are connecting two real teeth in the mouth that are next to the missing tooth with a dental crown. While porcelain bridges require metal support, zirconium bridges are the first choice for an aesthetic smile design because it allows bridges to be made without metal.

Advantages of Zirconia Crown Bridges

• Zirconium is the first choice for tooth bridges in cosmetic dentistry because it allows zirconium to be made in natural tooth color and metal-free bridges instead of porcelains that have to be used with metal.
• Zirconium bridges are strong enough to be used without any problems even in the teeth of the rear part of the mount. They can be used as a good alternative to metal bridges.
• Zirconium has a very natural appearance, not only as a tooth color, but also structurally. It is difficult to distinguish between natural teeth and zirconium tooth bridges.
• It is therefore helpful to have a natural smile in cases where one tooth is missing. 
• Zirconium bridges allow you to have a more photogenic smile design than metal supported porcelain bridges. On zirconium bridges, opaque colors do not occur when you take pictures (flash or natural light) whereas opaque colors are unwanted result of metal-supported porcelain bridges on pictures. 
• Zirconium full ceramic bridges are a non-allergenic material. 
• Zirconium does not cause gum bruises in gum disease. The gray colored layer formed over time around the tooth and gum does not occur in the zirconium bridges. 
• Gum bruises, which are common in gum diseases and gingival recessions, do not appear in zirconia. 
• The zirconium teeth isolate the heat very well, thus avoiding the sensitivities that can be encountered in extreme hot / cold changes. 
• Zirconium bridges are made from ceramics, so they are lighter than metal-supported porcelain. 
• Zirconium crowns with their full ceramic structures do not cause deterioration of metal taste perceptions, where as metal-backed porcelain causes metal taste perceptions problems.