Work correctly functional occlusion what. Dental occlusion: an abnormal development of the teeth. The Importance of Normal Occlusion

By the word ceramic-metal, we usually mean orthopedic constructions - crowns and bridges, made by the method of spraying or casting ceramics on a metal frame. This is a hypoallergenic biocompatible material, which in most cases, with rare exceptions, such as allergies, is not rejected by the human body. Metal-ceramic prostheses are used in dentistry mainly for prosthetics of chewing teeth, where aesthetics are not so important as function.

The best cermet

The question “Which cermet is better?” must be decided based on the service life and strength of structures based on various metals. In this case, the best cermet is, perhaps, the one that is made on a gold-platinum alloy frame. Such structures serve up to 15 years. As an alternative, zirconia crowns can be offered, which have an even longer service life of 20 years.

The most popular is metal ceramics on a gold alloy, which can also include platinum and palladium, but gold still prevails in percentage terms. Ceramic-metal on gold is preferable to other types of structures due to the fact that gold is not oxidized by saliva and is one of the most biocompatible metals, that is, it is not rejected by the body.

Metal-ceramic prosthetics

Metal-ceramic dental prosthetics can be used both in the frontal zone of the smile and in the lateral sections.

Prosthetics of the anterior teeth

Metal ceramics can be placed on the front teeth, but from the point of view of aesthetics, such a solution would not be the best option. The fact is that in the frontal zone, the transparency of the tooth enamel is greater than in the lateral zone, so the metal frame can shine through the ceramic coating. Therefore, for prosthetics in the smile area, as a rule, all-ceramics or ceramics on a zirconium frame are used. However, at the request of the patient, cermets can still be installed on the front teeth. At the same time, if the prostheses are carefully and regularly looked after, the service life of metal ceramics on the front teeth, according to patients, can be more than 10 years.

Photo of metal-ceramic prosthetics on the front teeth

Prosthetics of chewing teeth

The most popular is metal-ceramic for chewing teeth in the posterior regions, where strength is more important than appearance. However, it cannot be said that cermets on chewing teeth look unaesthetic. These prostheses mimic the structure and shades of natural dental tissue well. But their main advantage is still the ability to withstand any chewing load.

Metal-ceramic prostheses

Metal-ceramic dentures are frames made of non-precious, semi-precious or precious metal, on which special dental hypoallergenic ceramics are sprayed or poured (depending on the manufacturing method). The material is able to reproduce the color and structure of natural dental tissue, while it does not fade and does not absorb coloring matter. There are the following types of metal-ceramic prostheses.

1. Crowns. They are mainly used for prosthetics in the lateral zone to restore teeth that have been destroyed by more than 2/3. Read more in the article.


2. Dental bridges. Serve to replace several missing teeth in a row. The most reliable bridge structures consist of two crowns and two artificial teeth between them.


3. Clasp prostheses. Removable structures, in which the arch (clasp) and the frames of the crowns attached to it are made of metal. They are used when fixed prosthetics for one reason or another is impossible.

Photo of a metal-ceramic prosthesis

Pros and cons of cermets

Many patients who decide on prosthetics are concerned about the question: “Is metal-ceramics harmful?”. Subject to all manufacturing and installation standards, the harm to cermet itself is minimized and practically eliminated. Modern materials do not contain any toxins. However, it is worth remembering that different types of materials may behave differently in the oral cavity. So, in the case of chromium-nickel alloys in the framework of the crown, nickel allergy is common, and some base metals can oxidize over time under the influence of saliva. Among the advantages of cermets are high strength and long service life, and the disadvantages of cermets are the possibility of exposing the metal frame when lowering the gums (the exception will be crowns made of zirconium dioxide), the transmission of the frame through ceramics and the need for a rather strong turning of living tooth tissues under the crown, up to depulpation living tooth without direct evidence.

Strength

Currently, metal-ceramic dentures, both single and bridge-like, are in most cases used on teeth that have a significant chewing load. Although until recently they were the undisputed leader, regardless of what types of dental prosthetics were used. Ceramic crowns, on the contrary, were not popular for a long time due to the increased fragility of the structure and therefore were used only for prosthetics of the frontal group of teeth. However, with the advent of frameworks made of zirconium dioxide or aluminum dioxide, more and more dentists and patients prefer these modern materials for prosthetics of both chewing and, in some cases, anterior teeth.

It should be noted that the excellent strength of metal-ceramic prosthetics can negatively affect the surface of the teeth adjoining them and lead to their excessive abrasion. At the same time, non-metal ceramic prostheses have a hardness coefficient close to that of natural teeth, which makes it possible not to injure opposing teeth.

Allergy to cermet

The ceramic used for the manufacture of crowns is absolutely hypoallergenic, however, the metals used in the framework in rare cases can cause an allergic reaction. Symptoms of an allergy to ceramic-metal are a burning sensation in the mouth, in the area of ​​​​both the gums and the tongue, a metallic bite, swelling of the gums in the area of ​​​​contact with the crown and swelling. If after the installation of the crown, the phenomena described above are observed, it is necessary to consult a doctor. In such cases, it is recommended to replace the cermet with an all-ceramic crown.

Service life of sintered metal

One of the saddest misconceptions of patients is that a metal-ceramic crown does not require replacement and will last the rest of your life. Unfortunately, this is not the case, and the service life of cermets is limited. On average, a metal-ceramic denture can last 10-12 years if the frame is made of an alloy of base metals, and 15 years or more if a gold-platinum alloy is used. However, it should be borne in mind that the prosthesis must be made strictly according to individual casts, and the patient, when wearing such a fixed or partially removable structure, must follow all recommendations for care. The warranty for cermets is valid on average from one to three years, depending on the frame material. At the same time, the warranty conditions imply that the crown will retain its integrity and will not be destroyed by mechanical impact within the specified period, while the most common cause of crowns falling out is secondary caries that develops at the junction of the tooth and the crown. In order to avoid such situations, it is necessary to regularly undergo preventive examinations and timely replace old orthopedic structures with new ones. Remember: the prosthesis has a service life, failure to comply with which can lead to tooth loss.

Color of cermet

The ceramic used for the manufacture of metal-ceramic crowns allows you to imitate the color and structure of natural enamel, making the prosthetic tooth as similar as possible to the adjacent, natural teeth of the patient. The color of ceramic-metal is selected according to the Vita scale, it does not fade and does not change with time, since, unlike natural enamel and composite materials (for example, fillings), ceramics do not absorb coloring substances from food and drinks, therefore whitening of ceramic-metal is not required. If it seems to you that the time has come to whiten the ceramic-metal installed in your oral cavity, most likely you need to visit a hygienist to remove stained plaque.

Metal-ceramics or ceramics?

If you decide to resort to prosthetics with crowns or bridges, then sooner or later you will face the question: "Which is better - ceramics or metal-ceramics?". What is the difference Metal ceramics and metal-free ceramics differ in their aesthetic and functional properties. Metal-ceramic prostheses are more durable, but have significant aesthetic flaws, which play an important role in the restoration of teeth in the smile zone. Therefore, for prosthetics of the anterior dentition, all-ceramic orthopedic structures will be the preferred option. However, it should be borne in mind that ceramic prostheses are mostly very expensive. In the case when chewing teeth are being restored, metal-ceramic is quite acceptable, since its aesthetic flaws are invisible in the lateral sections.

Metal-ceramic or metal-plastic?

Modern dentistry offers many different options for the manufacture of crowns, the main difference of which lies in the materials for the manufacture of the framework and the anatomical shape of the tooth. Some materials are more expensive, others are cheaper, but the quality of crowns, as you might guess, directly depends on the price, since the most durable and aesthetic designs are made from more expensive materials. To the question: "Which is better - cermet or metal-plastic?" The answer is unequivocal, of course, cermets. Despite the fact that modern dental plastic is of decent quality and hypoallergenic and, just like ceramics, is able to imitate the natural color of teeth, it still loses in many ways, so the choice - metal-plastic or cermet - is decided in favor of the latter. Plastic is inferior to ceramics both in strength and in the ability to imitate natural enamel. Therefore, plastic in modern dentistry is used exclusively for the manufacture of temporary crowns, those that the patient wears while permanent structures are being made in the dental laboratory or while the implant is healing. The manufacture of permanent crowns from plastic, and even on a metal frame, is absolutely unprofitable, the service life of metal and plastic is different, and their connection is not justified.

Sintered metal or metal?

Also today, all-metal crowns are available to patients, but this is the most unaesthetic type of orthopedic structures, which, unlike metal-ceramics and ceramics, are in principle not able to imitate a natural tooth in anything other than anatomical shape. However, metal crowns are noticeably cheaper than metal ceramics, but inferior to it in most parameters. In addition, metal structures can cause increased abrasion of the teeth with which they come into contact.

Metal-ceramic or zirconium?

Above, we have already considered the difference between cermet and ceramic-coated zirconium. If you are faced with a choice: zirconium dioxide or metal-ceramic, then in the case of anterior teeth prosthetics, the advantage, of course, is on the side of ceramic crowns on a zirconium frame. As for the teeth in the chewing zone, zirconium oxide or cermet is not so important, they are not inferior to each other in strength, and the aesthetic side in the posterior region is not as important as the functional one.

Installation of cermet

Now let's talk about how to put cermets.

If you decide to install cermet, first of all you need to undergo a diagnosis.

The procedure for preparing teeth for metal-ceramic. Contrary to popular belief, the installation of metal ceramics on a living tooth is quite possible. However, in most cases there is a need to depulp the tooth under metal-ceramic.

After that, the orthopedist will be able to take casts from the turned teeth, which are necessary for the manufacture of individual designs.

Fixation of the prosthesis.

Many patients are interested in how teeth are turned under metal-plastic - prostheses with a metal frame and a plastic coating on top. The preparation technique is the same as when installing ceramic-metal structures, but the tooth undergoes a much more significant turning due to the massiveness of the metal-plastic structures.

If you decide to install ceramic-metal prostheses, choose proven dentistry.

Grinding of teeth for metal-ceramic

In prosthetics, there are several ways to prepare for metal-ceramic. Grinding of teeth for metal-ceramic can be carried out in two ways, described below.

Cermet with ledge

The orthopedist, grinding the dental tissues, forms a circular ledge along the lower edge, which avoids contact of the metal frame with the gum, and, as a result, minimizes the risk of edema, irritation, bleeding and allergies. With such a turning, to improve aesthetics, it is possible to use cermet with a shoulder mass. The shoulder mass is applied in the area of ​​the ledge under the metal-ceramic and serves to hide the strip of gray metal that shows through the enamel at the base of the crown. Installing a cermet with a ledge and a shoulder mass is usually more expensive, but these costs are fully justified and allow you to avoid many problems with a denture. In addition, cermet grinding with a ledge extends the life of the crown by several years.

Turning for cermet without shoulder

This is an outdated method that was previously used to install stamped steel dentures or metal-plastic crowns. However, some doctors still use it for metal-ceramic preparation, which leads to negative consequences. The preparation of a tooth without a ledge does not provide enough space for the crown, so the contours of the gums are disturbed. The outer perimeter of an artificial crown is larger than that of a natural tooth. As a result, a space is formed between the cermet and the gum where plaque accumulates, the bare edge of the prosthesis looks unaesthetic, and the design itself constantly injures the surrounding soft tissues. In this regard, if the doctor grinds the teeth for metal-ceramic without a ledge, the crown will need to be changed after 5-6 years.

Metal-ceramic dental care

Daily oral hygiene after the installation of ceramic-metal is no different from the usual one. Caring for cermets involves brushing your teeth in the morning and evening, and, if possible, after each meal. At the same time, it is necessary to follow the rules of cleaning: the sweeping movements of the brush should be directed from the gum to the cutting edge, the care of teeth made of metal-ceramic should be completed with dental floss, and ideally with irrigator treatment. If you are interested in the question of how to clean metal ceramics, then everything is simple here: the same as your own teeth, that is, with a soft brush that does not harm the gums, and a paste that your dentist will help you choose based on your individual characteristics of the oral cavity. If, during cleaning or at any other time, you feel that your teeth hurt under ceramic-metal, immediately consult a dentist, perhaps secondary caries has developed under the crown, or the carious cavity has not been carefully processed.

Very often, people who have metal-ceramic crowns in their mouths are concerned about the question: how do MRI and metal-ceramics compare. We hasten to reassure you: metal-ceramic crowns do not deform and do not move under the influence of a magnetic resonance tomograph, however, they can provoke an image defect in the image, so always warn the doctor who prescribes an MRI for you about the presence of metal-ceramics.

Situations are different, and sometimes restoration of cermets is required. This happens when the crown is mechanically damaged. If the cermet in your mouth has broken off, the orthopedist will first of all assess the extent of the problem - how large a piece was broken off. And here he is primarily interested in whether the metal frame is exposed or not. The fact is that it is quite possible to restore an insignificant cleavage of cermet, including the use of composite materials. At the same time, the restoration of cermets in the oral cavity, when the framework was exposed, is no longer possible in most cases. In such a situation, most likely, it will be necessary to remove the cermet and install new structures. Also, do not forget that the timely replacement of metal ceramics will help to avoid unforeseen problems, such as falling crowns or their splitting.

Warranty for cermet

As with any other types of prostheses, each clinic provides a guarantee for metal ceramics for teeth. Of course, its period is short, and how long the guarantee for ceramic-metal lasts depends mainly on the decision of the management of dentistry. What kind of warranty is usually provided for cermets? This is a period of one to three years, during which you can see a doctor for a free repair of your prosthesis. Taking into account the fact that structures made of this material are recommended to be changed after 5-7 years, such a guarantee can be called acceptable.

Prices for dental prosthetics with ceramic-metal

The price of cermets is much lower than that of all-ceramic structures. The price includes the manufacture of an orthopedic structure in a dental laboratory, tooth grinding and installation by an orthopedist. So how much does cermet teeth cost? Depending on the price category of the clinic and the frame material, the price of metal ceramics for teeth in Moscow varies from 7,000 rubles per tooth in economy dentistry to 40,000 rubles in a premium class clinic. In the Price section, you can find out the cost of cermets in various clinics in the city.

Metal-ceramic is the most popular material for dental prosthetics. It is relatively inexpensive, durable and has good aesthetic qualities.

However, metal-ceramic prostheses are not ideal. What are their advantages and disadvantages, what are the nuances of restoring the anterior and chewing teeth with these structures, is it worth putting them in and are there better options - described in the article.

Metal-ceramic prostheses, what is it?

Metal-ceramics are used to make crowns and bridges. Such structures consist of two parts:

• frame: 0.3-0.5 mm thick, it is cast or milled from metal alloys - base or precious;
• lining: its thickness reaches 1-1.5 mm, it is represented by dental ceramics, which is applied by spraying or casting and baked at a temperature of about 900 ° C.

It is thanks to the combination of a metal frame and a ceramic coating that both strength and good imitation of natural teeth are ensured.

Metal-ceramic is a compromise between low-aesthetic all-cast metal prostheses and expensive structures made of glass-ceramic and zirconium dioxide.

Kinds

When choosing ceramic-metal prostheses, keep in mind that they vary greatly in strength, aesthetics and price depending on the variety. So check 3 things:

• what metal alloys for the framework the dental technician uses;
• ceramics of which company will veneer the prosthesis;
• what technology will be used to make the structure.

To figure out which metal-ceramic crowns and prostheses are the best, you need to know their types. These products are classified according to 3 criteria.

By material:

1. Made of cobalt-chromium alloy. It is used most often, because. inexpensive, has good strength and good biocompatibility.
2. Made of nickel-chromium alloy. More plastic than the previous material, but wears out faster and more often causes allergies.
3. From titanium. It is expensive, but it is very durable, does not corrode, lasts longer than other materials, and is bioinert.
4. From precious alloys. Such prostheses are also called gold-ceramic. Composed of 85% gold, 9% platinum, 4% palladium and 2% other metals. The most expensive, but valued for their hypoallergenicity and the ability to accurately imitate real teeth: the gold frame slightly shines through the outer layer of ceramics and gives it a natural yellowish tint.

By form:

1. Ordinary. They do not have the lower metal part, which is in contact with the gum, covered with ceramics. Over time, constant contact of the metal with the mucosa causes it to turn blue, and the inevitable periodontium leads to the exposure of the dark metal edge of the crown.
2. With shoulder mass. Such prostheses are also called ceramic-metal crowns of increased aesthetics. They have a lower edge lined with glass ceramics - around the entire circumference or only on the front side, which is visible when smiling. This avoids blue gums and exposing the edge of the metal frame.

Manufacturing method:

1. Solid cast. Produced by casting from molten metal. The use of this technique requires a high level of professionalism of the orthopedic dentist and dental technician: inexperienced masters make mistakes when taking impressions and making the framework, due to which the prosthesis does not fit snugly against the stump and does not correspond to the bite. Such misses affect the stability and durability of the structure.
2. Milled using CAD/CAM technology. They are made using automatic installations: casts are taken by an intraoral (intraoral) camera, and the frame is made on a programmed machine. This method almost completely eliminates manual work and reduces the likelihood of errors due to human factors to a minimum.

The best porcelain-fused-to-metal crowns are of increased aesthetics, made of gold-containing alloys, made using CAD / CAM technology. But the prices for such prostheses go through the roof. Most often, one-piece cast structures made of cobalt- or nickel-chromium and without shoulder masses are installed. Such products cost 3-4 times cheaper.

Pros and cons

Metal-ceramic prostheses are chosen because of the numerous advantages:

• good aesthetics: cermet is not ideal in this regard, but it is not noticeable in the mouth for interlocutors - you can determine it only by looking closely;
• high strength: structures made of this material easily withstand chewing loads and do not deform: you can eat hard and sticky food without fear;
• long service life - 8-12 years;
• hygiene - bacteria do not accumulate on the ceramic lining;
• stability - the material does not absorb pigments and nicotine resins, does not change color, it does not need to be bleached;
• ease of care - it is not much different from the hygiene of your own teeth;
• Affordable price: you can choose the most cost-effective variety of cermets.

It is worth considering the disadvantages of crowns and bridges made of metal-ceramic:

• cobalt and nickel-chromium alloys cause allergies in 5% of patients ();
• due to the metal frame, dentures cannot convey the translucency natural for enamel (the ability to transmit light) and stand out against the background of natural teeth;
• in 0.1% of cases, oxidation of the metal frame is possible;
• the metal in the composition conducts heat and cold - because of this, hypersensitivity to thermal stimuli is possible;
• patients with already installed metal structures in their mouths should be careful - if crown frames are made from other alloys, they will cause galvanic currents in the mouth, this situation occurs especially often in smokers;
• cyanosis of the gums - it inevitably develops after a few months / a couple of years due to the contact of the metal edge of the frame with the mucous membrane, the problem is solved by installing crowns with a shoulder mass;
• exposure of the metal edge at the neck of the tooth - due to the inevitable recession of the gums, the non-veneered part of the crown becomes exposed over time and becomes noticeable in the mouth, metal-ceramic crowns of increased aesthetics are deprived of this drawback;
• the need to strongly prepare the teeth: the wall thickness of metal-ceramic crowns is 1.5-2 mm, the same volume is removed from each side of the supporting stump;
• often it is necessary to depulp a tooth - due to the large volume of tissues being ground down, it is not possible to keep units “alive”.

But even significant disadvantages do not reduce the popularity of metal-ceramic crowns. Middle-class patients can choose inexpensive ones with acceptable aesthetics. And if money is not a problem, you can make construction types that are indistinguishable from your own teeth.

Indications and contraindications for installation

Metal-ceramic is installed at:

• destruction of crowns by 2/3 or more;
• fractures;
• pathological abrasion of enamel and dentin;
• slight curvature of the front teeth - sometimes bite defects are hidden under the crowns, although most dentists do not recommend doing this;
• the absence of 1-2 teeth - in this case, a bridge is made.

An important nuance: the root must be intact, and the channels must be completely passed and sealed up to the top (apex). Otherwise, inflammation will soon develop and the remains of the tooth with an expensive metal-ceramic prosthesis will have to be removed.

It is forbidden to fix metal-ceramic dentures when:

• under the age of 21 - before this period, the processes of formation of the dentoalveolar arch and mineralization of teeth are still ongoing;
• end defects: the bridge cannot be fixed if the last tooth in the row is removed, the installation of an implant - dental or basal - will help here;
• extended included defects - if 3 or more adjacent teeth are missing, it is better to put a removable denture;
• severe violations of occlusion - open, cross bite;
• allergies to metal alloys - this applies only to cobalt- and nickel-chromium, and titanium and gold do not cause hypersensitivity;
• severe osteoporosis;
• severe diseases of the central nervous system and mental disorders.

There are also conditions that are relatively contraindicated for prosthetics: pregnancy, inflammatory processes in the oral cavity and any systemic pathologies in the acute phase. In the first case, they wait until the birth of the child (ideally, until the end of breastfeeding).

In other situations, diseases are first eliminated or remissions are achieved, and then prostheses are made.

Stages of prosthetics

Restoration of teeth with ceramic-metal includes 3 main stages:

• preparatory - a key stage: the quality of the prosthesis depends on how well the teeth are treated, crowns are turned and casts are taken;
• laboratory - on which the structure is made;
• final - consists directly in the installation of a crown or bridge.

A minimum of 2 weeks for prosthetics. If long-term preparation is required or the dental laboratory is heavily loaded, the terms increase.

Preparation for prosthetics

Ceramics is 3 times more expensive than cermets

Another drawback is that cermets are 2-3 times more expensive. For one unit, you will have to pay an average of 27,000 rubles. True, if you put a ceramic-metal prosthesis on a frame made of noble alloys or with a shoulder mass, the cost is approximately the same.

Metal-ceramic or zirconium?

The strength of zirconium crowns is even higher than that of metal-ceramic ones. It is 1,200 MPa (data from Ivoclar Vivadent - https://www.ivoclarvivadent.ru/ru/p/dental-professional/ips-emax-zircad-chairside). Whereas the minimum indicator for cermets is from 250 MPa (according to GOST 31575-2012 “Stomatological cermets for dental prosthetics.

Technical requirements. Test methods” – http://docs.cntd.ru/document/1200100320). But the metal has higher elasticity and endurance to deforming and bending loads, especially angular ones.

Zirconium dioxide prostheses restore the anterior and chewing teeth. They have many advantages over metal-ceramic crowns:

• biocompatibility;
• there is no cyanosis of the gums, because in prostheses made of zirconium dioxide there are no metal elements with which the mucosa is in contact;
• long service life - fixed structures made of zirconium dioxide will stand for 15 years or more, it is highly likely that they will last until the end of their lives;
• a smaller volume of tissues being prepared - 0.3 mm is removed for the anterior teeth and 0.6-1 mm for the chewing ones.

Zirconia is usually a bright milky color

However, there are 2 nuances:

1. Zirconia crowns are not always highly aesthetic. 90% of zirconia restorations look unnatural - they are a bright milky color. Most zirconia blocks are opaque and do not convey the translucency of the enamel. The problem is solved by using pre-colored or translucent blocks, but they are rarely used.
2. Frequent chips. According to the medical portal “24Stoma” (https://24stoma.ru/cirkonievye-koronki.html), the ceramic lining of zirconium structures is chipped in 6% of patients after 3 years, and in 10% after 5 years.

But in metal-ceramic prostheses, cracks in porcelain masses occur 2 times less often - in 10% of patients over 10 years. This feature does not apply to artificial teeth made of monolithic zirconia blocks. But more often they are not used, but crowns on a frame with ceramic coating.

In addition, zirconium oxide is expensive. One unit costs an average of 21,000 rubles.

Metal-plastic does not look very aesthetically pleasing

Metal-ceramic or metal-plastic?

Metal-plastic or metal-composite prostheses were invented as a cheap alternative to metal-ceramic ones. They also have a metal frame. Only it is faced not with ceramics, but with plastic masses.

The main advantage of metal-plastic structures is low cost. The average price for one unit is 2-3 thousand rubles. They are installed by people with low incomes who want to achieve at least some similarity of artificial crowns with real enamel.

However, this is where the advantages of metal-composite products end. They have the same disadvantages as cermets, and a bunch of their own disadvantages:

• plastic causes allergies;
• lining often chipped;
• the top layer is colored under the action of food pigments and nicotine resins;
• low strength;
• short service life - up to 5 years;
• low aesthetics - plastic crowns look unnatural, which is noticeable even to strangers.

Metal crowns are strong but unaesthetic

Sintered metal or metal?

- the first type of fixed prostheses that began to be used in dentistry. Today they are considered obsolete and almost never used. The exception is state dentistry, where they are installed en masse.

Cermet is an artificial material that consists of an alloy of metals and a ceramic coating. In dentistry, it is used to restore the functionality of the dentition and their aesthetic appearance. Metal-ceramic prosthesis consists of crowns and bridges. The metal base repeats the shape of the tooth, a thin layer of ceramic is applied on top of it.

In this article, we will answer the main questions that may arise before installing metal-ceramic crowns:

Indications for metal-ceramic prosthetics

The installation of cermet is necessary if you have any of the following symptoms:

• Changes in the shape or color of teeth due to caries, trauma, or taking certain medications.
• The presence of such a strong destruction of the dentition that the use of veneers or inlays is impossible.
• Absence of teeth. However, the installation of a prosthesis will become unacceptable if there are no more than 3 teeth in a row.
• The presence of an anomaly of the jaw (non-standard size, shape, structure of the teeth).
• Hereditary pathological conditions of enamel detected during the diagnosis.
• The occurrence of an allergic reaction to the already installed plastic elements of fixed prostheses.

When it comes to modern dental prosthetics, more and more often the process is associated with metal-ceramic crowns. Such prosthetics combines all the positive properties of the materials in the composition, is the most aesthetic and practical solution. In this article, we will look at how crowns are inserted on the teeth, their main advantages and care features.

A strong, durable and wear-resistant composite makes the crown resistant to any external factors and damage, which is very convenient for busy people who have no time to renew dentures every year.

In order to decipher the name of the product, you should look deeper into the structure of the structure itself and the material, figure out what a metal-ceramic crown looks like (before and after photos are shown below).

Such systems consist of a dense one-piece cast frame made of a medical alloy (cobalt and chromium, chromium and nickel, etc.). In some cases, elite compounds from non-ferrous metals (platinum, gold, palladium, etc.) are used, which makes the system even more reliable and less allergenic. The use of gold for the manufacture of the frame allows you to choose the most natural color of the crown, so this design is often used for prosthetics of the front teeth.

Metal-ceramic crown: photo before and after installation

Ceramic is applied to the frame layer by layer. This work is performed by technologists according to your individual casts, which allows you to make teeth from metal-ceramic (before and after photos are given above) as accurately and naturally as possible. After creating the product, it is fired in a furnace at 800-900 °, which strengthens the chemical bond of all materials in its base.

Prosthetic technology

Before installing metal-ceramic crowns, the doctor must prepare the oral cavity in the area where the system will be fixed.

To begin with, a dental x-ray is taken and we get a picture of the area. The dentist studies whether there are active diseases or pathological processes in the root of the tooth, at its base.

When diagnosing diseases, the tooth should be treated, get rid of caries and dark plaque, and restore soft tissues.

The next step is depulpation of the abutment tooth. It is necessary when detecting root inflammation, illiterate previous filling, damage and destruction of the tooth. Also, a mandatory removal of the nerve in the front teeth is carried out.

In the case when half of the abutment tooth is destroyed or severely damaged, a pin is installed in the canal. The missing coronal part is built up on it with the help of a dental composite for filling. If, before dental prosthetics with ceramic-metal, the tooth was damaged or destroyed to the base or has thinned walls, then it can only be restored using a stump tab.

After sanitation of the oral cavity and restoration of the surface of the supporting tooth, they proceed to turning it, giving the volume of the future crown. The dentist grinds the surface until a suitable stump is formed. An individual cast is then taken from it and sent to the laboratory for the production of a prosthesis.

Metal-ceramic crown on the back teeth before and after

At this time, the patient is offered to install temporary plastic prostheses for aesthetic restoration of the dentition, protection of a weakened turned tooth and for personal comfort. The manufacture of metal-ceramic crowns (photos before and after installation are given above) can take from 2 to 3 weeks.

When the system is ready, it should be fixed in the patient's mouth. First, there is a fitting, the patient describes the sensations of using a new tooth. To do this, the dentist fixes the crown with temporary cement for several months. If the patient is comfortable, he does not feel the presence of a foreign body in the oral cavity and additional fitting of the prosthesis is not needed, then the temporary cement is replaced with a long-term one.

Denture care

After fixing the metal-ceramic crown, the dentist will definitely consult on the issues of regular oral hygiene and the peculiarities of caring for the implant.

First of all, regular care includes brushing your teeth after every meal. You should clean your teeth and crown correctly: perform sweeping movements from the base to the cutting end, as well as circular movements. You can pick up any brush, but it is forbidden to use it for more than the recommended period, which is determined by the color indicator on the bristles. By the way, the bristles should be soft enough, and the paste should not contain abrasive components.

Be sure to use an interdental brush and dental floss after brushing.

Several times a week, treat the oral cavity with an irrigator filled with a disinfectant solution or herbal decoction.

The service life of ceramic-metal after prosthetics varies from 7 to 15 years, depending on the operating conditions and the quality of hygiene. But during trauma, mechanical damage, strong chewing loads, crumbling of the material or its chipping may occur. In this situation, the restoration of the product will be required.

The service life of cermets ranges from 7 to 15 years

If a metal frame is exposed during the destruction process, then the crown will have to be replaced with a new one. If a small element has broken off, then it can be restored using a filling composite, as in the case of a living tooth.

Regular visits to the dentist and timely replacement of the product will help to avoid chips, loosening and loss of the implant in the future.

Advantages of metal-ceramic prosthetics

Metal-ceramic crowns have their pros and cons.

Let's look at the positive aspects of this type of prosthetics.

In addition to the advantages, metal-ceramic crowns also have disadvantages, unfortunately.

1. The metal pin at the base of the crown does not let the natural color through. This can become noticeable when adjacent to a live glossy tooth, so metal-ceramic is rarely used for prosthetics of a single front tooth.
2. Before installing the prosthesis, it is necessary to grind a healthy tooth, which severely damages its tissues.
3. The increased strength of ceramics is not always a plus. Teeth located on the opposite jaw can destroy and wear off when in contact with the surface of the prosthesis, which leads to pain, hypersensitivity, chips and destruction. Also, despite the declared wear resistance, the ceramic coating is still subject to destruction and chipping.
4. Sometimes, when prosthetics with metal ceramics, a metal frame can show through (this often happens when the gums are lowered). This worsens the aesthetic performance of the model.

   

   Chipped metal-ceramic crown

5. Many patients are allergic to metals, including noble ones.
6. The impossibility of bleaching the product. Many patients are interested in whether it is possible to whiten ceramic-metal teeth (photo below) during long-term operation. Unfortunately, all dental products only penetrate natural enamel, so you can match it to the color of the implant or spend more time choosing the perfect ceramic color. You should also periodically carry out professional cleaning of the teeth, which produces the effect of whitening and restores aesthetics and shine to the smile. Do not forget to polish the implants (and this is possible), removing traces of limescale, tartar.

   

   Tooth color selection

We examined how teeth made of metal-ceramic are inserted, what advantages and disadvantages they have, as well as the nuances of care. It can be concluded that such crowns, by modern standards, are considered the most aesthetic, strong and durable, fully restore the functionality of the oral cavity and repeat the anatomical shape of the tooth. With proper care and regular visits to the dentist (once every six months or a year), they will serve you for more than ten years without chips or damage.