Single crown. Cementation of permanent zirconia restorations with glass ionomer cement - an alternative to metal-ceramic restorations

Modern dental practice, combined with extensive experience in the field of dental prosthetics, today is based on the use of gentle materials with a neutral impact in the form of crowns.

At first, various metals or alloys from precious metals, which, however, are not completely safe and can cause allergies.
Then, to solve this problem, experts found another material for crowns that is neutral - ceramics. However, its significant drawback was fragility.
And finally, scientists were able to combine strength and hypoallergenicity in one product - crowns based on zirconium dioxide, which are, today, the safest and most comfortable means of dental prosthetics.

In the photo: zirconium oxide crowns

What it is

A metal-free ceramic crown based on zirconium is the most modern way prosthetics, characterized by high durability and aesthetics.

Moreover, zirconium is often called “white gold” because it has the same strength and durability as this precious metal.

Proof of this is the special method of manufacturing zirconium teeth, which involves the use of special equipment. Moreover, manual processing of this material is completely excluded, since it is initially very hard.

In general, a ceramic crown on zirconium dioxide is an indispensable choice of prosthetics for people with increased allergic reaction to traditional metals.

Which crowns are better: zirconium, metal-ceramic, porcelain

Choice in favor certain type crowns depend, first of all, on the group of teeth (chewing or anterior) requiring restoration, as well as on the budget (the higher the aesthetics of the product, the higher the price). Let's look at the three most common types of dental crowns: metal-ceramic, porcelain and zirconium.

Metal-ceramic

The use of products of this type is most common when restoring anterior teeth. The reason for this is not so much the high quality as low price this method of prosthetics, which, moreover, has good aesthetics.

pros:

satisfactory visual qualities;
durability (on average 8-10 years, and sometimes more);
relatively low price, which occupies a middle position between the cost of conventional metal crowns and metal-free ceramics.

Minuses:

the need for sufficiently strong grinding of dental tissues;
frequent need for depulpation of teeth(removal of nerves followed by canal filling) especially for crowns.

Porcelain

Porcelain crowns can have various properties, which depend on the chosen method of their production.

There are two manufacturing technologies: layer-by-layer application of porcelain mass and injection molding under high temperature and pressure.

This is important to consider, since porcelain crowns obtained by pressing have more high rate strength than non-pressed products. In the case of manufacturing using the layering method, there is a risk of ceramic chipping, which affects the overall reliability of the crowns.

Advantages:

Aesthetics. The visual qualities of porcelain (as well as other metal-free ceramics) are very close in optical properties and structure to natural tooth enamel. This allows you to achieve maximum similarity of shade and translucency with natural dental tissue.
Long-term preservation of its original appearance. Porcelain is a material that does not darken or tarnish and retains its original aesthetic characteristics even after for a long time. Due to this, its use in to a large extent superior in quality to conventional filling material, which will inevitably change its original appearance over time.

Flaws:

Relatively high price.
Such a product is not suitable for creating bridges, limiting its scope of application to the restoration of only one tooth.

Zirconium ceramics

Zirconium dioxide is the most modern material, used for the production of bridges and single crowns. In terms of its strength, it is not inferior to metals, but unlike them it has excellent aesthetic qualities.

If we compare porcelain and zirconium crowns, it will become obvious that the main advantage of such products is their reliability and durability.

However, the aesthetic qualities of these two materials are identical. Therefore, we can say that the choice in favor of zirconium largely depends on the budget, since preparations from it require greater costs than in the case of porcelain.

Also, speaking about this material, it should be mentioned that zirconium crowns are lighter than metal-ceramics and are not capable of causing allergies. But, again, they cost much more, because in this case, metal ceramics are the most affordable option. The price of a zirconium dioxide crown in a Moscow clinic is 9,900 rubles. on promotion.

Zirconium teeth are the most reliable, but also the most expensive solution, porcelain crowns are very aesthetic, but also have a high price, and metal ceramics are a budget, but traumatic type of prosthetics. The final choice of one type of crown or another depends on the decision of the specialist and the financial capabilities of the patient.

Metal-free zirconium crowns are the most minimally traumatic type of prosthetics

Advantages and disadvantages

The balance between the pros and cons of zirconium crowns is the main reason for choosing or rejecting them. Let's take a closer look at these qualities.

pros

Naturalness appearance . Zirconium bridges and crowns are visually very similar to natural teeth. Moreover, this effect is initial, but is enhanced after coating the products with a special composition;
Density of contact with the gum. Only crowns and dentures made of zirconium are suitable for a careful fit to the gum. This, in turn, cannot be achieved when using metal, since its pressing into the gums can lead to the development of inflammation and complications. Therefore, if you want to achieve an ideal dentition, the choice in favor of zirconium crowns is obvious;
Long service life. A special method for installing zirconium oxide prostheses ensures their reliable fastening and eliminates the occurrence of loosening. According to statistics, the service life of such crowns or bridges is 15-20 years, but can be significantly increased with regular compliance with standards basic hygiene. The minimum period for wearing products is considered to be 5 years, since it is for this time that the manufacturer gives its personal guarantee. In addition, this material has antibacterial properties, which prevents the development of caries on neighboring teeth and protects them from destruction;
Perfect match to the structure natural tooth . To achieve maximum resemblance of a zirconium crown to natural teeth, specialists carefully select a shade that would match the natural color enamel, and use CAD/CAM modeling to create an element completely similar in shape to real teeth;
Convenient installation. Due to the fact that the prosthesis is initially endowed with high strength, and the installed frame has a minimum thickness, the area of tooth tissue preparation is reduced to a minimum. This helps eliminate many problematic nuances that cause inconvenience to both the patient and the doctor. Also, using this technique, the need for adjustments during the procedure is eliminated, since each tooth is modeled individually and is guaranteed to fit into place. This fact is confirmed by many cases when patients with zirconium crowns turn to a third-party dentist, who, in turn, accepts artificial teeth for real ones.

Minuses

Of the disadvantages of the prosthetic technique using zirconium dioxide, perhaps only one can be highlighted - significant cost. However, this is quite understandable, since in this case the specialist will use high-quality and expensive material, which, moreover, is very difficult to process.

High aesthetics is one of the main advantages of zirconium crowns

Duration and installation method

Before the procedure begins, a softening gel is applied to the patient’s lips. Then around the tooth, under the edge of the gum, they inject special thread, designed to protect gingival tissue from microtrauma during the treatment process. At the end of preparation for the installation of crowns, the teeth are turned for zirconium using diamond, calibrated tools, which make it possible to make this process more gentle.

When preparatory stage finished, the specialist begins the procedure according to the following method:

The tooth is being treated for a crown. The shape and color indicators of the future product are determined. Using a soft silicone mass, impressions are taken and sent to a dental laboratory. Previously created temporary crowns made of plastic are fixed on prepared teeth;
During the second visit, the specialist verifies the accuracy of the crown made and also adjusts it (if necessary). Next, color and aesthetic indicators are assessed. After this, the crown is sent back to the dental laboratory for the final manufacturing stage;
During the third visit, the zirconium crowns are fixed with permanent cement. Existing excess fixation material is removed and the procedure comes to an end.

On average, when using zirconium crowns, the installation time ranges from 30 minutes to 3 hours per procedure. However, the final value of this indicator depends on the complexity and volume of work.

Life time

With proper use and compliance with hygiene standards, the average service life of such crowns is more than 15 years. This, in turn, is twice as much as metal-ceramic products. However, it should be understood that this indicator largely depends on the patient’s personal preferences, as well as on the frequency of his visits to the dentist.

On the other hand, many manufacturers provide a 5-year warranty on their products, which at least protects the wearers of zirconium bridges and crowns from unforeseen circumstances.

Technology and manufacturing stages

Abutment teeth undergo therapeutic preparation: low-quality fillings are replaced, root canals those requiring treatment are cleaned and filled, and caries is treated.
The specialist grinds the supporting teeth for future crowns.
The prepared teeth are scanned to subsequently create a three-dimensional model on a computer.
Through special program Based on the scanned three-dimensional model, a similar model of future crowns is created. Moreover, in this case, it is necessary to create two volumetric layers: firstly, a layer with a three-dimensional model of the zirconium frame, and secondly, with a porcelain-based lining of the frame.
The finished three-dimensional model of the zirconium frame is loaded into a milling machine, which automatic mode produces “sawing” of the product from the workpiece.
The finished frame is fired in a special oven, which makes it possible to give it the strength of metal.
The dental technician carefully layers the porcelain mixture onto the frame. After this, the workpiece is placed in the oven, where high temperature The porcelain layers are “sintered” together.
Specially selected dyes are applied to the crowns and the final firing is carried out. At this stage, the creation of zirconium crowns is completed.

Indications and contraindications for use

Indications:

defect of dentition;
violations in hard tissues tooth;
installation on implants immediately after the corresponding operation in the absence of all teeth.

Contraindications:

low clinical height of natural teeth (small teeth) in the area of bridge-type prosthesis connectors;
bruxism (involuntary grinding of teeth);
deep bite

How to care

If, before starting zirconium prosthetics, the patient paid due attention to hygiene oral cavity, then no difficulties should arise after the procedure, since zirconium crowns and bridges do not require special care and shopping expensive funds. However, the effectiveness of brushing your teeth can be increased if, together with a toothbrush, you also use special miniature brushes designed to remove food particles from hard-to-reach areas.

For supporting normal condition zirconium elements and natural teeth in general, it is mandatory to visit the dentist at least several times a year.

Is it worth installing a zirconium oxide core inlay?

This issue is of concern not only for patients, but also for doctors, since the stump inlay made of zirconium dioxide began to be used relatively recently. On the other hand, there are already hundreds of operations performed using this particular material, confirming its undoubted quality. Thus, the decision to install a zirconium core depends only on the condition of the rhizome of a particular patient’s tooth, as well as on the advisability of its use in a particular case.

Zirconium coating

Installing zirconium crowns on chewing or front teeth is a rather expensive procedure that not many people can afford. However, there is no longer any need to abandon this material in favor of the cheapest, but hazardous metals, because the use modern technologies makes it possible to avoid negative influence traditional crowns even on a small budget.

The spraying technique involves the creation of a zirconium coating on metal crowns, which can provide adequate protection against particles of the base material of the crown entering the oral cavity. This, in turn, helps avoid the development of allergies and other negative consequences caused by metals.

Thus, zirconium sputtering is the most a budget option install cast crowns, which, although it does not have all the advantages of such, is endowed with their most basic advantages.

Thanks to affordable price metal ceramic crowns are in great demand. They are durable and quite aesthetic, and with proper care their service life will be as long as possible.

Contraindications for dental prosthetics

Before undergoing dental prosthetics, familiarize yourself with the available contraindications. Sometimes, in order to install crowns or dentures, it is necessary to carry out dental preparation of the oral cavity and eliminate inflammatory processes.

Temporary removable dentures

Temporary removable dentures are still actively used in dentistry. They are divided into several groups and are used when it is impossible to use fixed prosthetics.

Composite Tabs

Composite inlays are made from high-quality filling material. Their cost is acceptable for many patients. Unlike fillings, which quickly stain, wear out and fall out, a composite inlay is much more durable and comfortable.

We place zirconium dioxide crowns

New dental methods Prosthetics greatly facilitate the dentist’s work and improve the patient’s quality of life. One of best options solutions aesthetic problems are zirconium crowns.

Nylon prosthetics - a new word in prosthetics

Dental prosthetics with nylon dentures is a compromise between aesthetics and reliability. Nylon dentures They are beautiful and aesthetically pleasing, although they have some disadvantages that you should know about before using this prosthetic technique.

Jaw in a glass? Forget it!

Removable prosthetics is an outdated and unpromising method of correcting dental defects. Metal-ceramic and metal-free ceramic crowns open limitless possibilities for dental excellence.

Ceramic crowns

Metal-free ceramic crowns allow you to achieve high aesthetics prosthetics. Unlike metal-ceramics, they are no different from natural teeth, although they are considered less durable.

Bridges

Adhesive bridge prosthetics using French technologies using modern European materials. You will not feel pain and will not notice how the installation of the prosthesis has been completed.

Removable dentures

Removable dentures are dentures that can be removed temporarily (usually at night). As a rule, they require special care, without which they begin to ooze bad smell, change color, which negatively affects their aesthetic properties.

Zirconium abutments

Zirconium abutments are in great demand in modern dentistry. The use of zirconium dioxide for the production of structures that are used in dental prosthetics solves many problems, including aesthetic ones.

Temporary crowns for front teeth

Temporary crowns on the front teeth are actively used in prosthetics. Making a prosthesis can take more than one week, and during this time patients cannot walk around with unsightly ground teeth. Temporary structures preserve the aesthetics of teeth and allow you to feel comfortable during the intermediate stage of prosthetics.

Temporary crown for implant

A temporary crown is installed on the implant immediately after implantation of the artificial root. And it helps the gums accept the required form, form a beautiful relief, restore the chewing load and increase the patient’s comfort during communication.

Plastic for making temporary crowns

Plastic for the manufacture of temporary crowns is used in the intermediate period of prosthetics, when the patient is waiting permanent crowns and bridges. The materials used can be of either low or high quality. The better the temporary plastic crown, the more comfortable it will be for the patient to get used to permanent artificial teeth.

Installation of ataments in dentistry

The installation of abutments in dentistry is most often carried out after the artificial root has fused with the patient’s bone tissue. After screwing in the abutment and final healing of the tissues, you can begin the final stage of prosthetics.

Locking fastening of clasp and bridge prostheses

The locking fastening of clasp and bridge prostheses reliably fixes prosthetic structures, removes excess load from the teeth and ensures stable aesthetics of the smile. Today, dentists have the opportunity to select individual micro-locks that are suitable for each specific clinical case.

What types of dental injuries are there?

Even the most calm people Those living a measured life run the risk of getting bruised or wounded. We need to talk separately about children - their love of movement and restlessness is often the reason various kinds damage. Moreover, not only children’s knees are injured; teeth are often the object of impact. Dental injuries will be discussed below.

Pathology of hard dental tissues in orthopedics

According to the principle of the origin of the pathology, they are divided into lesions of carious and non-carious origin, including both congenital and acquired phenomena. Dental caries is a disease that appears on the teeth after their eruption, and is expressed in demineralization, softening of dental tissue and the subsequent formation of a defect, expressed in the form of a pathological cavity.

Dental orthopedics. Which prosthesis to choose

Today dentistry uses several types of dentures, attached both to the upper and to the lower jaw, and when choosing a method and type, take into account individual characteristics the patient, his state of health and in particular bone tissue jaws. The installation process is the same removable dentures does not involve taking into account the condition of bone tissue. How to decide on the choice of prosthesis?

Life with dentures

Long gone are the days when dentures were associated with grandma's iron jaws left on the bedside table at night. A modern denture is practically indistinguishable from healthy tooth. But the importance of dental prosthetics is not only aesthetics.

“What happened once may never happen again. What happened twice will happen again” - “The Alchemist”, Coelho

Cases with single crowns in the frontal area are always very important for the patient. As a rule, having had a negative experience, they try not to step on the rake again - they carefully choose a doctor, the material of the crown and the time of its manufacture. For a doctor, such cases are very labor-intensive, and how much is a matter of concept and philosophy. I have already shown how difficult it can be to solve such a problem. And in this post, we’ll solve it again.

Appearance of the patient's smile. The task is very simple - improve your appearance.

To understand what we are faced with, we need to make a calculation. The crown differs from your own tooth in color, shape, transparency, and width. The formation of the zenith of the artificial crown is exactly in the middle, despite the fact that the zenith of the natural tooth is shifted laterally. This “makes” the shape of the tooth - a sign of the curvature of the crown. Under the crown is an elaborate inlay in an empty channel. At the apex there is a vacuum.

We determine the main shade of the tooth using an individual scale - the technician bakes a ceramic blank similar in color onto the zirconium frame. This does not always happen and not for everyone.

We begin to cut the crown.

Crown fit plus/minus kilometer. The root actively resists, but there is already circular caries.

Since the tooth was processed without a ledge, the fixing cement flowed into the gingival groove. The gums are inflamed.

Using a curette at 15X magnification, we remove cement and tartar from the groove.

To bring the gum back to normal, we will make a ledge and a temporary crown around the tooth. Healing cap.

The ledge is ready. The inlay is underprocessed in the anteroposterior direction. There is no place for ceramics and frames here.

After 2 weeks, there are no traces of inflammation left - you can continue working.

Lateral reduction of the cobalt/chrome insert is a pleasure...

Use a thin file to apply cement around the perimeter.

Using the MAXI nozzle we sound the tab.

All that remains is to remove it with tweezers. Video of how it happened:

Something in the channels. Let's clean it.

Now you can take it to the endodontist.

After refilling the canal and getting rid of caries, we will make a new inlay and temporary crown.

Copy and finished tab.

Adhesion without cement. 44x magnification.

Fuji luting cement. They talk a lot about it, they put a lot of structures on it - objectively, the thickness of its film is almost 30 microns, versus 20 microns for Unicem-2. This does not harm the quality of work, but when working with high magnification it is definitely not suitable, despite the ultrasonic fixation of the inlay.

Let's move on to polishing the ledge.

Let's take KERR Opticlean.

We will use the right diamond to finish its working edge.

Before and after.

Continuity of polishing burs according to the shape of the ledge.

The ledge after the standard bur with blue markings. These grooves will be reflected on the impression, but when the frame is seated, they will disappear on the working model. And on the test model after the first putting on of the cap. As a result, the finished crown will rest against these grooves with its edge and will not reach their height. This is an “extra” 20-30 microns of loss of fit quality.