Zirconium oxide: properties, contraindications and features of application in stomatology
Zirconium oxide has been used for a long time in dentistry and is distinguished by its strength and compatibility with the natural environment. All this is confirmed by numerous clinical studies.
skeletons Zirconium oxide is used in the construction of many structures, in particular, skeletons based on it have surprising accuracy. All this is done thanks to the use of modern medical technologies. Products based on this material are durable, apparently no one will distinguish an artificial product from real teeth.
The frame made of zirconium oxide is lined with a special porcelain mass, which has a natural origin. All this makes the product just perfect, in comparison with the usual metal-ceramic constructions used in dentistry.
The zirconium oxide pad, dentures, veneers and bridges are all valued for a durable and biocompatible material.
And the frame based on this material is able to reduce the thickness of the crown walls, respectively, the depth of processing of hard dental tissues is also reduced. Thanks to this, the supports in the mouth can be saved, and the prosthesis can be made easier.
Features of non-metal ceramics
Zirconium oxide is used to create crowns, to which aluminum is added. They are also called metal-free. In prosthetics today they are quite widespread and differ in their high strength. Their main feature is the lack of metal components and a high aesthetical design.
The non-metal crown on zirconium and aluminum oxide is the result of the introduction of modern high technologies into the field of dentistry. It is not only strong, biologically compatible with teeth, but also light-permeable. Outwardly, no one will think that this is just a crown, so naturally it looks.
Creating a crown without metal
This ceramic is widely used in the manufacture of not only whole crowns, but also inlays and veneers. If the previously installed seals darkened or the old crown changed color, then the zirconium oxide, which lies at its base, will certainly help to update them.
When making the frame, the doctor removes the impression from the tooth row of his patient, then a wax model is made on his basis. It is scanned and stored on a computer, then later created in a three-dimensional form and constructed taking into account future shrinkage. Then the frame is placed in a special milling machine, where it is ground on the basis of zirconium oxide.
The structure is then sintered in the furnace, acquiring strength. And finally the frame is faced with a ceramic mass. As a result, biocompatible crowns are obtained on the teeth, zirconium oxide plays an important role in this characteristic.
Prostheses made of zirconium oxide are generally perceived positively by the human body. They are strong and reliable, there is no risk of rejection and infection.
Imitation of natural teeth is achieved due to the fact that the zirconium oxide compound has a white tint. When installing a metal-ceramic crown, this can not be obtained, because the frame structure will have a metallic color. And that the metal does not shine through the ceramics, the crowns are equipped with a special coating. As a result, such prostheses do not transmit light, and the color depth is not there. The gums from the inside are not illuminated, as in a natural form, and the presence of a foreign body in the mouth becomes obvious.
The advantage of the automatic production mode
The more so that the metal-free crown is manufactured using a special technology that is completely different from the manual casting of metal-ceramic products. All processes are carried out automatically.
The permissible clearance between the prosthesis and the tooth itself can be from 100 to 300 μm. Through the latest technology used in the creation of products of zirconium oxide, it was reduced to 30 microns. This means maximum accuracy in the joints between the teeth and the prosthesis.
Manufacturing of bridges
Even such a specific type of prosthesis can be made without a metal-based skeleton. A bridge made of zirconium oxide can also be made, but it can not be as long as usual. Its framework, unlike metallic, will be transparent.
In addition, zirconium oxide can be used during prosthetics on implants if the patient needs a high level of aesthetics. And, as mentioned earlier, it can be used to make any kind of prosthesis.
One of the key advantages of zirconia based crowns is their natural appearance and attractiveness. If the cermet prosthesis has always a characteristic shade, in this case it can be selected at the level of the frame to completely imitate the color of the patient's teeth. Regardless of the type of lighting, the tooth will remain transparent. In addition, unlike metal, which with time tend to darken and deform, zirconium oxide even for many years will be the same.
Also, many often complain about changing the color of the gums next to the cermets. This happens because the frame structure negatively affects the adjacent tissue. Of course, the gums blush or get cyanotic not in all cases, but often enough. Prostheses using zirconia completely exclude such a phenomenon.
Zirconium oxide is good in that it has a hypoallergenic property. Before this material was used in dentistry, it was often used in the manufacture of heads for hip joint prostheses to increase their strength.
Allergic manifestations in patients with the installation of artificial teeth or tabs usually occur quite often. Moreover, such reactions can be present even when noble metal species are used( gold, platinum, palladium and others).Crowns or bridges based on zirconium oxide for many suffering from allergies are the only possible solution to bring your teeth in order.
Often the problem and sensitivity of the teeth. During prosthetics, this phenomenon can prevent you from installing everything you need. So, when installing crowns without using metal, the sensitivity threshold changes noticeably for the better. All this is due to the fact that zirconium oxide is an excellent natural heat insulator and is able to protect the teeth from changes in temperature. If it is used to make a cultic insert, the patient will not be exposed to thermal irritation.
Other advantages of
Zirconium oxide is partly enriched with aluminum and stabilized by yttrium, which subsequently makes the products based on it strong and light. In addition, when microcracks appear on the surface, the surface structure is self-healing at the level of molecules.
Crowns made of zirconium are made not only on the front teeth, but also on the side.
This material, among other things, is considered the most ideal for fixing the height of the bite. It has no porosity, unlike cermet, so the erasure of antagonists has lower values.
And the fact that the anatomical crowns can be milled allows the specialized specialists to successfully apply them during prosthetics by means of counter crowns that fix the height of the occlusion.
Treatment of hard dental tissues for the installation of non-metal prostheses is minimal. The framework for teeth based on zirconium oxide has a thickness of only 0.4 millimeters. Due to this, it is possible to grind them to a minimum and even make a prosthetics for the living.
Disadvantages and contraindications
Like any other product used for dental purposes, prostheses based on zirconium oxide have their contraindications. Although in this case there are only two of them, which are not so common:
- pronounced deep bite.
In other cases, you can install crowns, even if the patient brings a certificate of having an allergy to certain components of the prosthesis. It will not apply to metal-free.
As for the shortcomings of products based on zirconium oxide, they actually are not. However, the key and the only one is their high cost. This price is formed not only through the use of certain components, but also the complexity of making the crown. Here, the technician must have a high level of skill and be trained in a special technique at a high level.
If a patient does not have funds for an expensive product based on zirconium oxide, then they can offer him a budget option based on glass processing. Crowns that are stabilized with yttrium oxide are much more expensive.
As you can see, modern developments in the field of dentistry can significantly improve the lives of those who need dentures and do not tolerate them.