Metal crowns are a reliable restoration of the chewing group of teeth. When are coated metal crowns used? Coated metal prostheses

Metal crowns for teeth are still popular, since nothing has yet been invented more reliable and stronger in prosthetics. Such products have been worn by our ancestors since ancient times, and they still continue to serve people with their durability. Although the appearance of the crowns is far from the most attractive, the price and quality correspond to reality.

What it is

A one-piece cast crown is a metal product that is made from various alloys of titanium, chromium-cobalt, chromium-nickel metal, and its design is cast completely. The main area of ​​​​use of this type of crowns is the prosthetics of the chewing type of teeth. This is due to their poor aesthetic component.

A (metal) one-piece crown is considered a high-precision product, which, although it has a metallic color, sits very tightly in the oral cavity. These crowns are an excellent choice for distant teeth.

Advantages of solid products

This material has a number of advantages, namely:

1. Strongly adjoins to tooth tissues.
2. Has safety (teeth do not break and do not chip off).
3. It has a natural anatomical shape.
4. A small price compared to other analogues.
5. Does not erase opposing teeth.
6. Remarkably resumes chewing performance.

Reasons for installation

Experts advise to put metal crowns only in certain cases, if:

• it is those teeth that are responsible for chewing that are destroyed;
• sections of the jaw row are noticeably worn;
• the tooth is severely damaged or injured;
• dental implants.

To put such a product, you need to visit an orthopedic dentist at least twice. First, the doctor will get acquainted with x-rays of the oral jaw, then he will begin caries therapy for those teeth where metal crowns will be installed. From the place where the turning or preparation is planned, the nerve is removed.

Metal crown: types

As a rule, when a patient seeks help from a dentist to place a metal crown, he is offered two options, depending on the method of its production:

1. One piece product. It is made according to special casts by firing in a kiln. Such a crown is characterized by thick walls, which favorably affects its service life. It is produced from base (chromium, nickel, steel alloys) and noble (platinum, palladium, gold, silver) metals. Due to the steel coloring, only the lateral teeth, hidden during conversation, are prosthetized with products. They are optimally suited for prosthetics of chewing teeth, because they can withstand considerable loads.
2. A stamped crown is a typical sleeve that is ground with a special machine to give the product the desired shape.

Modeling of a cast crown

Such a product is considered a reliable option for prosthetics and is installed from a cobalt-chromium alloy. The (metal) crown has an indisputable advantage - it has no solder joints, and this makes it especially strong. It well covers the turned tooth, not allowing the cement mixture to dissolve and reducing the likelihood of penetration of food under it. The period of operation is 15-20 years. The modeling of a one-piece cast crown contains several points:

• casting of the prosthesis;
• tooth preparation (from 0.2 to 0.6 mm of tissue is removed);
• production of a wax cap by stretching;
• finishing, fitting, grinding, polishing of the metal surface;
• creation of casts, including opposite and adjacent teeth.

Samples of such products

Today, solid metal crowns are placed in the office of an orthopedic dentist (reviews about them from most patients can only be heard positive) of several types:

1. Without spraying - simple products of steel color.
2. Sprayed. If such “beauty” does not suit the patient, if he wishes, the crowns can be made with a coating imitating gold.
3. Coated. Products lined with ceramics are considered even more aesthetic. Their front side is covered with a ceramic overlay. However, you should be extremely careful at the time of eating, because ceramics can chip off.
4. Combined. With this prosthetics, part of the crowns is covered with ceramics, while others, which are hidden when smiling, are placed without facing.

Stamped crowns

They are prostheses made from factory sleeves, which are given the necessary shape. Products differ in thin shells, so there is no need to grind a large number of tooth tissues. A crown (metal) is installed if there is no destruction of the roots, and 1/3 of the tooth is preserved. Gold is used for its production

The ease of creation determined not only the low price, but also the short service life of the material. Gold ones are made from an alloy that is 90% gold.

Manufacturing steps

There are certain stages in creating such a crown:

• the patient is given casts of both jaws to model the product, which should be done within 15 minutes, until the raw material is compressed;
• the lines of the prosthesis are marked on the plaster so that it does not come out too wide or narrow;
• then comes modeling with wax, which is applied to the surface of the plaster - thus, the crown (metal) gets an anatomical shape;

• according to the traced model, a steel stamp is created, which is driven into the sleeve;
• external stamping is carried out using a screw press;
• the stamp is removed, and the edges of the product are cut off with special scissors.

During the manufacturing period, firing is repeatedly carried out so that the metal becomes more stubborn and strong. The prosthesis should not have irregularities and cracks.

Indications for the installation of a stamped product

Installation of a metal crown is performed:

• for preliminary prosthetics of a milk tooth before it is replaced by a permanent one;
• for savings;
• as a fundamental component during installation;
• if the tooth is so injured or damaged by caries that it is unrealistic to renew it with a filling.

Crown installation process

Such an event usually occurs in 2 stages:

1. At first, the product is placed temporarily so that the doctor can observe the reaction of the tooth.
2. If the patient does not complain of pain, then at the next visit the crown is removed, cleaned of the preliminary cement and reinstalled, but with zinc phosphate or glass ionomer cement.

If, as a result of the first installation, it is found that the metal crown (photo below) causes discomfort to the patient, then it will be removed and processed again.

What should be a properly installed product

Properly made and placed crown:

• adheres firmly to the shell of the tooth;
• has a smooth, polished shape;
• sags into the periodontal recess by 0.2 mm;
• reproduces the anatomical shape of the molar;
• in contact with adjacent and opposite teeth.

Contraindications for installation

In some cases, it is not recommended to put a metal crown if there is:

• bruxism;
• the presence of an allergic reaction to steel;
• disturbed bite of the dentition;
• tangible damage to a living tooth;
• complex due to poor aesthetics in the prosthetics of the anterior teeth.

What harm is a metal crown

In certain situations, such a product can cause damage:

1. Due to its installation, a galvanic syndrome may appear. This is due to the use of several alloys to create an orthopedic structure. Mixing different materials leads to the formation of a galvanic current. There are headaches, swelling, some diseases, a taste of metal, sleep disturbance, burning in the mouth.
2. A crown (stamped) is not produced from individual casts, and therefore it is not suitable for a sufficient restoration of the functions of a living tooth.
3. The product does not adhere closely to the tooth, creating a gap between the walls, into which food remains penetrate. Therefore, rotting of healthy tissues can occur under it.
4. The one-piece cast crown has good thermal conductivity. If it was placed on a non-pulpless tooth, then during the reception of hot food, unpleasant sensations may appear.

Timeless technology

The manufacture of metal crowns is the “forever young” technology of the last century, which has hardly been modernized in recent years. Along with some modern and fashionable permanent prosthetics, it remains just as popular. And this is not surprising, since the main reason for such relevance is the low cost of the prosthesis with high strength.

What are coated metal crowns? Are such products safe for health and what features distinguish them from other prostheses?

Various types of spraying.

Metal for the production of dentures in dentistry has been used for more than a decade. The choice of alloys for the manufacture of structures is wide: these can be ordinary metals, but if desired, the patient can install a product made of alloys of palladium, silver, gold. Methods for the production of metal crowns differ depending on the type of metal, the location of the prosthetic tooth, but despite these differences, the products always turn out to be strong and wear-resistant.

What is stamping?

Stamped products are a budget option, which has now practically disappeared from dental practice due to a number of shortcomings. literally "stamped" on the basis of the workpiece, and then adjusted to the tooth of a particular patient. The designs are durable, but the teeth on them quickly deteriorate.

How is a cast crown made?

The dentist evaluates the condition of the patient's oral cavity, treats all carious teeth, inflammatory processes, removes dental deposits, and only after such preparation does he start prosthetics. Prosthetic teeth are subject to turning and depulpation, after which impressions are taken from them.

A stamped crown is made in several stages:

• A plaster model is made
• The product is plastered in a special apparatus - an occluder,
• A model is formed from wax,
• Wax is replaced by metal,
• The structure is attached
• Excess material is removed
• The finished product is ground and polished.

Expert opinion. Dentist Evdokimov P.Yu.: “If at any stage the production technology is violated, the product will injure soft tissues and neighboring teeth. Such prostheses have an unaesthetic appearance and are striking if they are installed in the smile line.

What are metal structures?

There are several types of metal crowns:

• without spraying
• with ceramic or plastic veneer to give the crown a more aesthetic appearance,
• sprayed,
• combined prostheses from alloys of metals and ceramics.

What is spraying?

Combined prosthesis.

Metal crowns are necessarily coated with a special coating. The product is covered with a facing layer from all sides at a high temperature in a nitrogen atmosphere. Before this, the structure is degreased, then polished, which allows for a better connection of materials.

Most often, solid crowns are used together with: if a part of the dentition that falls into the smile line is prosthetized with the help of a bridge. The front teeth in such a situation are made of cermet, and those that are not visible are made of metal.

Features of coated crowns

The first coated designs were crowns made of gold, which had an appearance that was far from perfect. Metal prostheses are most often used for prosthetics of the chewing group of teeth, as they withstand high chewing loads and are wear resistant. Indications:

• protection of the tooth from further destruction of the tooth damaged by caries,
• prosthetics of a tooth in which a filling was previously installed,
• for support.

Pros and cons of metal prostheses

One of the main advantages of metal products is their durability. High-quality constructions serve for several decades. It is almost impossible to damage such a structure, and the appearance of cracks and chips is a rarity. Gold crowns fit almost perfectly, as the material is very pliable and elastic and does not cause irritation and allergies.

The only drawback is an unattractive appearance, so such products are not installed on the smile line so as not to spoil its aesthetics. Stamped products can be hazardous to the health of the oral cavity, as there is often a gap between the structure and the gum, in which the infection gradually accumulates, which threatens the development of the inflammatory process.

In appearance, a metal dental crown resembles a cap that is put on a damaged tooth or fixed on an implant if the first one is completely missing. The thickness of the metal crown is 0.2 - 0.3 mm. Its main advantages are the ability to withstand maximum chewing loads, affordable price and durability.

The downside of a metal crown is its aesthetic imperfection - in this sense, metal loses a lot to all other materials for making crowns. Therefore, such structures are installed mainly on the back teeth, where they are securely hidden from prying eyes.

Are metal crowns harmful?

It is fair to say that there is the possibility of galvanic reactions and allergies to metal crowns after they are placed. To avoid such complications, clinics conduct a thorough diagnosis, which allows you to identify the presence of an allergy before a permanent construction is delivered.

Contraindications for metal crowns

There are a number of restrictions under which it is not recommended to put metal crowns on the patient's teeth. Among them:

• bruxism;
• allergy to metals;
• malocclusion;
• resorption of the tooth root (destruction of dentin and bone tissue around the root);
• prosthetics of the anterior teeth.

The last contraindication for metal crowns is included in the list of restrictions solely for aesthetic reasons.

What metal are dental crowns made of?

Modern dentistry offers a fairly large range of materials for metal crowns:

• steel
• chromium and cobalt alloy
• alloy of silver and palladium
• titanium
• gold
• platinum

In Russia, there was a period when dentists preferred gold among all types of metal for dental crowns, because, due to its softness, the structures fit snugly to the teeth and have a sparing effect on neighboring ones. But today they are increasingly preferred alloys that contain platinum or titanium. These materials provide even greater durability and biocompatibility with human tissues.

Coated metal crowns are very popular today in prosthetics. They allow you to recreate the anatomical shape of the tooth with minimal turning of healthy tissues. The plating can be gold, palladium or platinum - at the request of the patient - respectively, resulting in white coated metal crowns or yellow ones. For example, gold-plated dental metal crowns allow you to get a durable result without much damage to your wallet.

Types of metal crowns for teeth

According to the manufacturing technology, metal crowns for teeth are stamped and solid cast.

stamped

This is a budget option. For the manufacture of a stamped metal crown, standard sleeves are used, which are given the necessary shape resembling a case. The preparation of a tooth for a metal stamped crown requires the most minimal, since it has very thin walls. It is not necessary to carry out depulpation for installation. For fixation, at least a third of the dental crown and a healthy root are needed. Of the minuses of the design: incomplete restoration of chewing function, rapid erasure, loose fit to hard tissue.

cast

The production of a cast metal crown is made according to individual casts by casting. These are very strong structures, resistant to corrosion, they are very durable. Since cast crowns are made exclusively, there is no risk of incomplete fit, and therefore the penetration of bacteria under the crown. The downside is that the preparation of teeth for a metal crown in this case is quite substantial.

Types of solid metal crowns:

• simple;
• sprayed;
• with ceramic lining.

*Metal crowns on teeth with white ceramic coating are almost indistinguishable from natural teeth, but their lifespan is significantly less than those made entirely of metal.

About which metal crowns are best for a particular patient and how much it costs to put a metal crown from the selected material, you should consult with your doctor.

Installation of a metal crown

Before the procedure for installing a metal crown, the patient will first be diagnosed with the condition of the oral cavity, professional teeth cleaning, caries treatment and canal filling, if necessary. Only after that you can start fixing the metal crown on the tooth. Installation of all structures takes place in several stages:

1. The damaged tooth is ground or, if the crown is destroyed almost to the base, a special tab is installed on it, on which the structure is then fixed.


2. They take an impression of the tooth under the crown, as well as adjacent teeth.


3. A temporary overlay is installed on the tooth, it will protect it from destruction while the permanent structure is being made.


4. A three-dimensional model is modeled from wax, and a permanent crown is cast on it.


5. The temporary structure is removed and a permanent metal crown is placed on the tooth.

To install a metal crown on a tooth, the patient, as a rule, needs to come to the dental clinic twice: to prepare for prosthetics and only then to fix the microprosthesis.

Service life of a metal crown

Metal crowns have high wear resistance and, in principle, break very rarely. Steel structures can serve a person for 12-15 years, titanium crowns - more than 20 years. If the patient has ceramic-lined crowns, their service life will be 7-8 years. At the same time, the designs do not require additional care and allow you not to change your usual diet, since they can withstand solid food. But we do not recommend experimenting with biting wires and opening bottles with your teeth - everything has a limit. Treat crowns like your natural teeth.

Can the metal crown be removed?

Sometimes during operation it may be necessary to remove the metal crown. This is required when:

• there was a decementation of the crown, as a result of which it became mobile;
• the tooth under the crown began to hurt due to the development of caries;
• there was a need for prosthetics of the adjacent tooth. In this case, it is easier to put a bridge that will solve the problems of several destroyed teeth at once;
• The crown is worn out and needs to be replaced.

To remove a metal crown from a tooth in dentistry, two main methods are used: sawing and using the Kopp apparatus.

If the crown is removed due to the development of caries, then it is first treated, and after that a microprosthesis is installed. If it flew off the patient during operation, then the doctor will conduct an examination and find out why this happened. After the cause is found and eliminated, the metal crown will be put back.

In order not to have to resort to repeated prosthetics with metal dental crowns, one should responsibly approach the choice of a specialist and, of course, monitor the state of oral health - both at home and under the regular supervision of professionals.

Coated metal crowns are popular in dental practice.

And if earlier such structures were distinguished by sparkling steel, today orthopedic dentists have abandoned unaesthetic products, and prefer the installation of coated crowns that do not differ in appearance from the rest of the dentition.

Product characteristics

Due to their wear resistance and biocompatibility, metal alloys are trustworthy as prosthetic products.

A real breakthrough in the dental practice of the past years was the procedure for covering crowns with a special material under the influence of high temperatures. The formed layer on orthopedic products is called spraying.

Sputtered prostheses retained their main feature - a metal frame. And to create a cladding on it, the following materials are used:

• gold;
• ceramics;
• chromecobalt;
• titanium;
• alloy of silver with palladium;
• steel.

The disadvantage of most of the listed materials is the lack of naturalness, tk. in accordance with the main color of the alloy, the finished product acquires the appropriate shade - gold, silver, etc.

Gold-plated products are considered the most antiseptic and durable. They have a smooth surface that prevents the growth of pathogens and prevents food particles from accumulating. But gold structures are very expensive, so they are inaccessible to most patients.

Models with titanium nitride lining distinguished themselves by high aesthetic indicators. Such products are the most popular in modern dentistry.

The appearance of the crowns has the maximum naturalness, therefore, with their help, it is possible to restore not only chewing teeth, but also units from the anterior section. The spraying procedure is carried out using a vacuum-plasma technique.

Coated metal crowns mainly differ from other types of orthopedic structures in endurance, which is characterized by the ability to withstand heavy loads during chewing processes.

The presented products are made in two ways:

• stamping;
• creation of a one-piece cast structure according to an individual impression.

The process of applying titanium nitride to a metal frame consists of the following steps:

1. disinfection of the prosthetic part;
2. polishing of the processed surface;
3. etching of titanium on metal in vacuum under the influence of high temperature.

Remarkable! Titanium nitride is not applied to the marginal part of the crown. However, after installation, this part goes under the gum, so it is invisible to others.

Stamping technique

The product differs not only in the type of metal, but also in the manufacturing method, one of which is stamping. The manufacturing technology by this method is as follows:

• removal of the impression;
• percussion of the optimal shape of the product on a standard blank-sleeve.

A stamped model is a cost-effective option for prosthetics, which is very rarely used in dental practice today.

Products are literally "stamped" on the basis of blanks, and only after that they are adjusted in accordance with the anatomical features of the patient's tooth.

Such structures are very durable, however, the elements of the dentition under them quickly become unusable.

For reference! The wall thickness of a stamped structure depends on the alloy used in the manufacturing process. It is optimal that the wall does not exceed 0.3 mm in width. Otherwise, the specialist will have to grind off a significant amount of hard tissue from the prosthetic tooth.

Design features

Depending on the working material of the crown being made and the selected coating, metal structures for dental prosthetics have advantages and disadvantages.

We will consider the comparative characteristic using the example of a table.

All for and against

Among the general advantages, dentists distinguish the following:

• long service life;
• imitation of the anatomical shape of a natural unit;
• maximum similarity in color with the rest of the dentition (not for all designs);
• excellent biocompatibility;
• preservation of taste sensations;
• minimal risk of cracking;
• good strength in comparison with non-metallic structures;
• full restoration of the functionality of the dentoalveolar apparatus;
• elasticity and pliability of the material;
• no sensation of a foreign object in the mouth due to the tight fit of the product to the tooth.

Flaws:

• ceramic-metal loses in external parameters to ceramic crowns;
• the danger of a gap between the structure and the gum, which contributes to the accumulation of infection (applies to stamped products).

Installation restrictions

It is better to install metal structures to restore the ability of teeth to perform complex chewing functions, i.e. in the side sections.

However, products coated with titanium nitride can be fixed in the frontal zone, where the row elements are not so actively involved in mechanical processes.

According to the installation location, metal frames are used:

• In the anterior region, it is recommended to install a durable steel crown with zirconium coating.
• In the lateral zones - the solid cast frame with any coating becomes the ideal solution in this area. The type of coating for chewing elements does not matter, since they are hidden from prying eyes.

It should be noted that it is not always possible to install a metal crown. Consider the full list of restrictions:

• metal allergy;
• teeth grinding;
• violation of the occlusion of the row;
• serious damage to supporting units;
• periodontitis and severe periodontitis.

In addition to the main contraindications for installation, it is not recommended if the finished product does not meet the basic requirements:

• recreating contact with adjacent units and antagonists;
• exact repetition of the anatomical shape of the prosthetic tooth;
• the optimal height of the structure, not exceeding the dimensions of the remaining elements of the row;
• sufficient density of the girth of the tooth in the neck area.

For this reason, it is important to carefully choose a clinic and an orthopedic dentist who can professionally and efficiently install a prosthetic structure made in accordance with all requirements.

Stages of prosthetics

Before restoring teeth, a thorough preparation is carried out, which includes the following steps:

1. Orthopedic consultation. The specialist examines the patient's oral cavity, determines the presence of supporting elements, assesses the condition of all tissues, identifies contraindications for installation, develops a treatment plan and chooses a prosthetic method.
2. Diagnostics. Before installing an orthopedic product, it is important to undergo an x-ray examination. Based on the picture, the doctor can correctly assess the condition of the teeth.
3. Preparatory treatment. The specialist treats all carious lesions, eliminates inflammation of soft tissues, eliminates hard deposits and bacterial plaque. To avoid burns during the preparation process, the nerve is removed from single-rooted elements.

An important stage of preparation is depulping, which takes place in accordance with the following algorithm of actions:

• removal of the nerve bundle;
• processing and expansion of root canals using special tools;
• the introduction of the filling mass into the channels;
• restoration of the crown part of the tooth with a filling.

With a strong destruction of the tooth crown, the doctor restores it by installing a pin - a rod that performs the function of strengthening. Also for these purposes, more modern designs are used - stump tabs.

The preliminary stage also includes turning the teeth. Using a special diamond bur, the doctor prepares the hard tissues of the tooth, giving it the optimal shape for a snug fit of the crown. The layer of tissue to be removed should not exceed the thickness of the walls of the prosthesis.

Laboratory stage

After the doctor has completed all the preparatory stages for prosthetics, the period of taking casts and making the structure begins. In the dental laboratory, plaster models are made from the finished impressions, on the basis of which the orthopedic product is cast.

For the period of creating a permanent crown, a temporary construction is installed for the patient, which will help to mask the defect and provide protection to the turned tooth.

Surgical stage (required in extreme cases)

Doctors resort to surgical intervention in rare and complex cases when the patient is diagnosed with severe pathologies.

Surgical preparation involves the following activities:

• removal of untreated teeth and their roots;
• excision of hypertrophied gum tissue, scars, pronounced mucosal protrusions;
• immobilization of loose but healthy elements with the help of special orthodontic devices;
• resection of multi-root elements of the dentition;
• surgical elimination of overgrown bone tissue (outgrowths, osteophytes);
• reconstruction of the optimal parameters of the alveolar process.

Remember! Rehabilitation after surgery lasts at least 2 months. Only after complete restoration of tissues can one proceed to prosthetics.

Final stage

Before installing the crown, it is mandatory to try it on. This procedure is necessary to determine the quality of the product, for example, the frame often does not fit snugly on the stump. Try-on manipulations help to eliminate defects before permanent fixation.

After fixing the crown on temporary cement, which is carried out to determine the relationship of the teeth and the reaction of living tissues to metal, the product is permanently fixed on a special adhesive.

On a note! Dentists recommend wearing a product fixed on temporary cement for at least 14 days. If the patient does not complain during this period, the crown is dismantled, cleaned and installed on a permanent dental adhesive.

In the video, the technician explains how to make a metal-ceramic crown.

Life time

Coated metal crowns have a high wear resistance. According to statistics, such products break down in rare cases. Steel structures can be operated without problems for 15-18 years. Gold dentures have a longer service life - at least 25 years.

The lowest service life of crowns with ceramic veneers. Their patients can wear about 10 years.

At the same time, any of the listed designs requires the patient to comply with the rules of hygiene and medical recommendations:

• Timely check for the presence of inflammation of the gums and the root of a living tooth using X-ray examination.
• Minimizing the use of foods that are too hard, which can cause deformation of the orthopedic device.
• Regular hygienic cleaning of teeth with a brush and toothpaste. In this case, brush movements should be carried out down and back with gentle pressure on the teeth.
• After each meal, it is advisable to rinse the mouth with an antiseptic.
• Stop smoking, as nicotine negatively affects the color of ceramic and plastic coatings.

Issue price

Most popular types of coated metal crowns are installed by dentists for 1500-2000 rubles. Let's consider the cost of the cast prosthesis itself with a special composition applied using the table as an example.

The stamped frame itself without spraying, which can be installed on chewing teeth, will cost the patient about 3,000 rubles. Cast structures can be made in clinics of the middle price segment for 4,000-5,000 rubles.

The final price for all treatment, including preparatory measures and the manufacture of a crown, depends on the pricing policy of the dental institution, its prestige, the professionalism and experience of the doctor, as well as the complexity of the clinical case.

The first metal dentures were made of gold or steel. Gold items not only protected badly damaged teeth well, but also positively characterized the material condition of their owner. Steel crowns were both stronger and cheaper, but their appearance left much to be desired. And a compromise was found in the form of a coating imitating gold.

What is spraying?

The coating of metal dentures is carried out with titanium nitride by the vacuum-plasma method. This technology was borrowed by dental technicians from the industry, where it has found wide application for anti-corrosion protection of tools and some parts of machine tools and other units. Therefore, until the doctors acquired their own equipment, the crowns were given for coating to the nearest large plant to the metalworking shop.

Spraying is carried out at high temperature and electric voltage in a nitrogen atmosphere. From one electrode made of titanium nitride, ions rush to another electrode - the actual orthopedic structure, where the yellow alloy settles in a thin layer. The product is pre-polished and degreased, which contributes to a stronger connection of metals.

If in industry the main purpose of spraying is to increase the surface strength and anti-corrosion properties of the product, then in dentistry these qualities were not so in demand. The main thing for dentures is the biological inertness of the coating, low cost and external resemblance to gold. And in the manufacture of brazed bridges, titanium nitride isolated solder joints from contact with saliva, which in some cases significantly extended their service life, reducing the intensity of oxidative processes.

What combinations of coated and uncoated elements of dentures are possible?

First of all, the prosthesis cannot be covered partially, it is sprayed simultaneously from all sides. However, if the bridge or crown is made with plastic parts, facets or other veneering elements can be modeled after coating. In order for the retaining elements of removable dentures not to stand out against the background of yellow crowns, the clasps were also coated with titanium nitride. Later, at the request of the patient, they began to produce sprayed frames. It is possible to cover not only stamped, but also cast crowns and bridges. But this technology turned out to be completely incompatible with metal-ceramics, therefore, if, in order to save money, a part of the prosthesis is made without facing, it remains light and shiny like polished stainless steel.

Currently, the issue of banning metal dentures with coating is being actively discussed. This is mainly due to low aesthetics, uncompetitiveness with ceramic-metal and zirconium products. There are also a number of criticisms regarding stamped crowns, which are most often made with a coating, and are inferior in accuracy to cast ones. However, low cost, manufacturability and high durability will allow for a very long time sprayed crowns to be in demand among the poor in many countries of the world.