Metal-ceramic crown: photo, service life, feedback and recommendations
Dentists around the world in their medical practice for a long time use metal ceramics, which is many times superior to plastic. It is a durable material used to create inlays, fixed and removable prostheses and bridges.
Crown of metal-ceramic
Metal-ceramic crown is a very common type of fixed dental prosthesis developed individually. Simply put, such a material is a cover for a tooth damaged under certain circumstances.
The great popularity of metal-ceramic crowns is associated with their high strength and external characteristics of the finished prosthesis. The color of the product resembles the enamel of a living tooth, which makes the smile natural.
The metal-ceramic crown itself consists of a cast metal frame with a thickness of up to 0.5 mm and an outer ceramic part.The base is made of special alloys that are not susceptible to oxidation under the influence of saliva. Although about one hundred types of such alloys are used in modern dentistry, they necessarily include the following metals:
The total amount of noble metals in the finished crown should be equal to 98%. If the prosthesis is made, for example, of gold, platinum and palladium, then their ratio will be as follows: 85%: 9%: 4%, respectively.
The metal-ceramic crown per tooth has the following properties:
- high degree of adhesion of the surface of the crown and tooth;
- resistance to shifts of different nature;
- long service life (from ten to fifteen years);
- anatomically correct form;
- one hundred percent hit in the color of the desired shade.
Dental indications for the use of crowns:
- restoration of the entire dentition;
- restoration of single teeth;
- recreation of the tooth chewing function;
- restoration of the natural form;
- congenital anomaly in the structure of the tooth;
- development of periodontal disease;
- carrying out splinting procedure (strengthening of mobile teeth);
- allergies to fixed prostheses of metal.
It is impossible to install a metal-ceramic crown under such circumstances:
- chronic periodontitis;
- broken bite;
- the presence of untreated inflammatory processes in the oral cavity;
- bruxism (night gnashing of teeth);
- any mental disorders and illnesses;
- immunity weakened after illness.
Installation of metal-ceramic crowns begins with your first visit to the dentist on this issue. This procedure takes place in four stages, the duration of each is from one to several sessions, it all depends on the individual characteristics:
- preparatory (therapeutic) stage;
- teeth preparation stage;
- imprint of the dentition and the manufacture of metal-ceramic crown;
- temporary fixation of a metal-ceramic crown;
- the final stage of installation (full fixation).
Therapeutic tooth preparation
It is simply impossible and wrong to put in a ceramic-metal crown without first conducting a full dental examination. This is fraught with serious consequences.
The dentist-therapist must fully assess the clinical picture and the condition of the patient’s mouth. If necessary, treat inflamed gums, caries, periodontitis and other diseases, and then replace the old fillings with fresh ones. For this, in some cases, an X-ray is taken. It can be used to determine the quality of previously filled canals (if any) and make sure that there are no inflammatory lesions inside the tooth.
At the end of the preparatory stage, the dentist performs a tooth depulpation (removal of the pulp - neurovascular bundle). This is necessary to prevent further inflammatory diseases.
Metal-ceramic crowns - preparation
Teeth preparation is the grinding of their hard tissues: enamels and dentin. Under metal ceramics, the toothing layer can be up to two millimeters thick.
Objectives of preparation:
- creating favorable conditions for fixing the crown on the abutment tooth;
- the formation of a special prosthetic space for crowns;
- guarantee the correct contact of the edges of the crown and tooth tissue.
The preparation procedure is performed under local anesthesia using drugs such as lidocaine, mepivacaine, articaine, and their varieties. This is necessary for the anesthesia of both the tooth itself and its adjacent soft tissues, that is, the gums.
After anesthesia, the dentist creates longitudinal or transverse grooves of the required depth. This is done in order to control the thickness of the sanding layer of enamel and dentin.
Next, the orthopedic dentist begins to gently grind the hard tissues of the tooth, and under the gum itself, in the lower part, makes a ledge. Its width is closely related to the aesthetic properties and durability of the crown during further use. A ground tooth should be tapered for convenient donning of the crown. As a result of the preparation, when the crown is installed, it will be shorter on average up to a quarter of its original length.
When the preparation of the tooth is completed, the doctor makes an impression of the dentition, to finally begin the process of making the prosthesis.
Crown manufacturing process
The main stages of the manufacture of metal-ceramic crowns:
- creation of a print of a tooth row;
- frame making;
- frame fitting;
- the creation of a dentition.
If we consider in more detail, the manufacture of metal-ceramic crowns is as follows:
- with the help of a special solidifying mass, an impression of the tooth row is made, which in all details repeats the features of the tooth structure;
- when the print is ready, a gypsum model of the dentition is made on its basis;
- then the future metal frame is poured from the wax;
- in the workshop on the basis of the frame make the metal base of the prosthesis:
- there is a fitting of the frame by the patient to make sure of the correctness and convenience of its shape;
- if there is no need to finish the frame, then it is sent to the dental laboratory for applying several layers of porcelain, and after each layer the crown is heat treated (fired) in a special oven at a temperature of 800-950 degrees;
- Finally, enamel is applied to the porcelain to imitate the color of the natural tooth.
The color of metal-ceramic crowns directly depends on the tone of the enamel of the patient’s natural teeth, so it is selected individually.This allows you to make the crown indistinguishable from a real tooth, not only in shape, but also in color.
Selection of color occurs according to the scale of Vita, which is also used during the procedure of teeth whitening.
The scale has four color ranges:
A - brown-orange;
B - yellow-orange;
C - gray-brown;
D - gray-orange.
In addition, each group is divided by the degree of brightness from one to four, where the unit is the highest brightness. Based on this, the color of the teeth is indicated by an alphanumeric code, for example, C2.
In order to choose the right shade, the dentist conditionally divides a tooth into three mutually perpendicular vertical and horizontal planes, which, in turn, are divided into surfaces:
- cervical, the color of which depends on the state of periodontal tissues;
In the most advanced dentistry, it is possible to use special spectrometers of such companies: DeguDent, VITA Easyshade and SHOFU.
Their undoubted advantage is that the results of the analysis do not depend on the conditions of its conduct (for example, on the type of lighting devices).
Temporary fixation and closing step
After the metal-ceramic crown is made and applied, the tooth is treated with a special paste, which contains fluorine, to protect it from damage under the prosthesis.
After that, the cermets are fixed with temporary cement for up to three months. This is necessary so that the person gets used to the prosthesis, and if necessary it can be corrected. This process takes from fifteen minutes to half an hour.
At the end of the quarter, the crown is already finally installed and fixed. For this:
- the prosthesis is removed from the temporary cement and cleaned;
- a place under the crown is treated with a special apparatus, in order to give roughness for better bonding with the crown;
- the final fitting of the denture takes place;
- special dental cement is applied in the middle;
- metal ceramic crown is put in place and helps it to harden with a special lamp.
After this, changing the color of the enamel or a serious correction of the prosthesis becomes impossible without removing it.
If the condition of the oral cavity was satisfactory, then the total number of visits to the dentist required to install the metal-ceramic crown is three to four visits.
Features of the metal-ceramic crown on the implant
The crown on the implant differs from the prosthesis on the honed tooth only in the type of production and fixation. Externally, it has the same look.
Metal-ceramic crown on the implant is fixed in two ways:
The screw fixation is that first an abutment is connected to the crown (the link between the implant and the prosthetic structure). After that, the entire prosthesis, which was assembled outside the oral cavity, is inserted into the implant and is then fixed with a screw. Under it, the doctor first makes a through hole in the crown, which, upon completion of the fixation procedure, is closed with a seal.
With cement fixation, the abutment is screwed first to the implant, and not to the crown (as is the case with the screw method). After that, the metal-ceramic crown is fixed with a cement mortar (composite glue).
In practice, both types of fixation are used. But it is worth noting that the screw is more secure and reliable. In this case, almost any corrections are easily passed. The doctor needs only to remove the seal, drill out the screw and remove the crown, and after carrying out the reconstruction, put everything back.
When the crown is fixed in the cement method, the situation is more complicated, so it is most often used for the installation of bridges.
The price of the metal-ceramic crown depends closely not only on the material used for its manufacture, but also on where it is placed - on the tooth or implant.Metal-ceramic crown - price depending on the place of fixation
Average price for 1 crown
From 5 thousand rubles
From 10 thousand rubles
Cobalt and chrome
Gold and palladium or gold and platinum
Average price for 1 crown
From 5 to 8 thousand rubles
15 thousand rubles
Also, the country affecting the manufacturer of the metal-ceramic crown also influences the price: a Russian or Belarusian prosthesis will cost about two thousand rubles less than a Japanese or German metal-ceramic crown.
The prestige of the clinic and the professionalism of the doctors are also not in last place in the formation of value.
In some dentistry, the price for a temporary prosthesis (one that is set for three months) is not included in the total cost of the cermet prosthesis.It is somewhere from 1 to 1.5 thousand rubles.
In order to avoid unforeseen situations, the patient is recommended to get all the details from his dentist in advance and with all the details.
Sintered crowns: reviews
As it was said earlier, metal ceramics are in great demand both among dentists and among patients themselves.
Positive feedback describing many of the advantages of metal-ceramic crowns:
- relatively affordable price, especially when compared with the service life;
- reliable fastening;
- long service life;
- high hygiene, because the crown is resistant to bacteria and microorganisms;
- visual similarity with a real tooth;
- the color of the crown does not tarnish even with time;
- there is no discomfort during chewing;
- suitable for implant placement;
- the same care as for real teeth;
- there is no food under the crowns;
- if the metal-ceramic crown was placed on the tooth, then it protects it from further destruction;
- excellent combination of price and quality.
Also among the reviews and dentists, and patients noted how ideal metal-ceramic crown on the front tooth. This prosthesis is durable and quite aesthetic.
But it would be dishonest to say that the crowns of this variety have absolutely no flaws. Patients notice that:
- if the denture is in contact with the tooth, the tooth may eventually erase;
- lowering of the gums is possible, after which the metal base becomes noticeable;
- before installing the prosthesis, a lot of hard dental tissue is removed;
- extremely rarely, pain and even swelling under the bridge.
In general, patient reviews about the metal-ceramic crown consist of the following items:
- high quality tooth preparation for the procedure of prosthetics;
- professional skills of the dentist-orthopedist, because a good result largely depends on how competently he conducted the tooth preparation procedure;
- the literacy of the dental technician, because the second component of the success of the prosthesis consists of how well the metal crown is recreated according to the impression given.
If you need dental care, experts recommend you to find a good clinic with positive reviews, which already has a therapist, orthopedic surgeon and a highly qualified technician.Treat your teeth in time so that you don’t have to pay in the future with health and material means.