Crowns on the teeth. What's better
Tooth crown is a non-removable prosthesis that is used in cases of tooth decay of more than 50 percent in order to restore the functional function and aesthetics of the tooth. In other words, it is a denture that imitates a real tooth.
Dental Crowns - Types and Features
Crowns can be divided into groups: temporary and permanent
For manufacturing: stamped, cast, pressed according to the material: metal, plastic, composite, ceramic, zirconium and combined
By fixing: Cemented, yaws are screwed, pin on supporting elements: single, supporting in bridge-like prosthesis or component of telescopic by the method of manufacture: direct (made directly in the oral cavity of the patient) and indirect (produces a technician in the laboratory).
Stages of manufacturing crowns almost always the same, and consist of two main: medical and laboratory.
Toothbrushing, as a rule, is removed from 1 to 3 mm of tooth tissue, depending on the crown.
If the tooth is dead or it needs to heal the canals (depulpate), then the tooth often pins (reinforces), which gives him the strength and reliability of the future design. Pins can be standard: titanium, fiberglass, steel, carbon or cast: steel, titanium, silver, gold and combined. Molded: zirconium or metal.
Removing the print - the historically most accurate imprint was from plaster, due to the fact that it did not have shrinkage. But he was not comfortable at work. And in the nineteenth and twentieth centuries, silicones and polyvinylsiloxanes appeared - it was a breakthrough in dentistry. But they had a shrinkage that had a very bad effect on the final result of the work.
After receiving the imprint, the work falls on the table to the dental technician, in the laboratory, and the technician begins to make models: working and auxiliary. After the gypsum is frozen, the next stage is the simulation of a future tooth from the wax under a single crown or under a cap for applying ceramics, plastics or composites.
Then the work is transferred to the foundry laboratory, where the founder soldered to the wax and molds the metal prosthesis.
Then the work returns to the dental technician again, where he cuts off the elderly, adjusts the prosthesis on the gypsum model and transfers the doctor to the clinic for a pill.
After the prosthesis is installed, if there is no remark in the patient and the doctor, the work returns to the laboratory for polishing and polishing, if it is a metal prosthesis and for applying ceramics / plastics / composite, if this is a combined work and then transferred to the officer again.
Medical stage - fixing the finished crown on the tooth.
So, we will try to understand each kind of crowns and choose the best option.
It is modeled from wax, and then cast out of metal, after polishing to a mirror luster. And just as you can apply a damp spray or make it out of gold.
Pros: available price 20-40 euros, durability.
Cons: Low aesthetic performance.
Conclusion: economy crown, which may well fulfill its function.
Note: most often used on the upper upper chewing teeth (as the patients themselves say - "where they are not visible"). You can not use these crowns if the crowns-anthogonists are ceramic or metal-ceramic - this leads to chopping ceramics.
Often made of plastic for a short time. For a while, a dentist makes a permanent crown.
Pros: the optimal level of aesthetics and the cost of 20-30EU.
Cons: fragility, porosity and the presence of a residual monomer that destroys the gums and, in some cases, causes allergies in patients. That is, technically, the powder (polymer) and the liquid (monomer) are mixed and polymerized to the final result. However, the residual monomer (solvent) still stays. The need for fitting the design in the mouth of the patient (due to the features of the crown). Most often, getting the perfect result when using this type of crown is problematic. With prolonged use, due to residual monomer can cause gum inflammation (gingivitis or periodontitis).
However, there is an alternative to a temporary crown of plastic.
In the center of iStomatolog, temporary crowns are milled and / or printed on a special PMMA composite - polymethylmethacrylate, thermoplastic, synthetic material or PEEK-polyetherethereton, biocompatible and wear-resistant material that is strong as a human bone.
Pros: accuracy and time of manufacture at the expense of digital technologies, strength through the composition of the material. Absence of residual monomer and absence of allergic reactions Inert material resistant to oxidation is light and it is important that these materials are inert chemically and biologically, which allows them to be disposed of without danger to the environment.
Cons: used as a temporary construction.
Conclusion: a temporary crown is indicated for replacement of the lost tooth for a short time. You should pay attention to how it is made, in order to avoid further problems with the gums and not to cause an allergic reaction. The cost of this work is approximately 30 euros
These crowns are metalloplasmas, metal composites, and metal ceramics.
The principle and purpose of these crowns is practically the same. The goal is to satisfy the aesthetic need of the patient. So to say a compromise between aesthetics and strength. Principle of manufacture: the preparation of a tooth, from it is removed from the clips and transmitted to the laboratory technique. The technician pours a collapsible model and models a wax cap that is subsequently replaced with metal. Further, the metal is processed and applied to it either plastic (read below the disadvantages), composite (short-lived) or applied ceramics and sintered.
Pros: aesthetics, conditional strength (refers to metal ceramics, approximately 50-70 MPa). Relatively low cost from 50 to 250 EU depending on the qualification of the equipment and ceramic mass.
Cons: too many tissues are evaporated and, as a result, in this type of structures, the tooth usually depulps (removes the nerve) and pinches. The presence of bluish gums subsequently at the expense of the edge of the crown that enters the gums and thereafter there is a recession of gums (lowering of the gums), in the manufacture of such a design, there should be a normal clinical height of his tooth and there should be no deep bite. At the expense of multi-stage execution of work - lack of accuracy due to probable errors at each stage.
Conclusion: The crown is durable, it can last 5-8 years, but with aesthetics inferior to metal bezelnymi crowns. And in 2-4 years, the cyanosis of the gum may appear around the crown.
Note: It is important to pay attention to what material your other crowns (if any) were made to avoid oxidation and galvanosia.
These are crowns of E.M. (disilicate of lithium), of zirconium oxide, ceramic zirconia, feldspar ceramics.
Crown of feldspar (ceramics)
Has proven good on the market of dentistry. Typically, it is milled by special equipment and done about 30 minutes, then cemented on the tooth. This is precisely the version of the crown that is used in the anterior group of teeth to achieve the aesthetic needs of the patient.
Cons: the cost of 150-250 EU, the impossibility of combining bridge construction.
Pros: high aesthetic result, service life more than 8 years. No need to be baked in a special oven. Wide color gamut, biocompatibility and excellent transluscence (chameleon effect), refraction of light is appropriate for your teeth, do not need to decapulate the tooth.
Conclusion: excellent replacement of metal ceramic crown on the front teeth.
Note: made only on special equipment (Frazer).
Dental crowns E.mah (disilicate lithium)
Very durable material and is used for the manufacture of dental crowns, inserts, linings, veneers and luminaries. Their strength is about 400 MPa.
Cons: high cost (250-500 EU).
Pros: high aesthetics and durability, almost completely repeats the color and structure of the natural tooth. Minimal preparation of teeth, and in some cases - without preparation. Biocompatibility and lack of allergy in patients.
Conclusion: this is precisely the variant of crowns, which does not distinguish from the real teeth even a dentist. Service life is 10 years.
Note: the entire process of selecting the form and color of the tooth can be observed by the patient, these crowns are also milled on special equipment and due to this they have high accuracy.
Zirconium oxide crowns
Excellent alternative to metal ceramics. You can make both anatomical crowns and a cap for applying ceramics.
Cons: the cost is 150-400 EU.
Pros: strength 600-1400 MPa. Aesthetics (due to a wide range of shades). Ability to make bridges, lack of allergic reactions, biocompatibility, do not need to decapulate the tooth. Service life is 10 years.
After reading the short characteristics of crowns, we can conclude that the main requirements for dental crowns are:
- high strength
- biocompatibility with periodontal tissues (gums, tooth tissues)
- lifetime and warranty (as well as the term of manufacturing)
What kind of toothpick to choose?
Returning to the question of choice (metal ceramics or ceramics?), The manufacture of metal-ceramic dental crown is:
- the cost of depulping the tooth,
- the cost of manufacturing a tab (pin)
- the cost of the crown itself
- for the same money you can install a ceramic (non-metal) crown.
This will allow:
- to maintain the vitality of the tooth
- get the aesthetically correct solution (no cyan gums)
- get higher durability of the structure (approx. 10-20 times)
- will allow to avoid allergic reactions in the future.
Our digital laboratory uses CEREC equipment, which will allow you to create a ceramic crown as quickly and accurately as possible. Usually, it is performed for one visit of the patient.
For all works on ceramic crowns (zirconium dioxide, E.MAX, feldspar), we give a guarantee for 3 years, subject to all the recommendations of the doctor. Contact us.