Crown made of solid: thickness, photo, production steps
In the lateral areas of the oral cavity, the crown is often cast. This is necessary to restore the anatomical integrity of the dentition, when due to various reasons a person loses one or more teeth. This type of prosthetics allows to preserve the functions of the jaw apparatus.
What materials are used to make the crown
Alloys with high strength are used for the production of cast crowns. In modern dentistry materials are used based on chromium, additionally doped with nickel, cobalt. The use of titanium has proven successful. This metal has a high resistance to aggressive environment, it does not darken, besides it has a high biocompatibility. A crown of one-piece can have precious metals in its composition. Gold crowns allow you to make the most accurate fit, as the metal has a high plasticity. They are good in operation, they rarely break. However, the gold crown still wears out, besides it has a high cost. The main indications for prosthetics with solid crowns are the complete loss of one or more teeth, restoration of the functionality of the dentition.
The main types of
solid-cast dentures To date, these types of cast crowns are distinguished:
- Prostheses without sputtering have the appearance of a parent metal, polished to shine.
- All-piece crown with sputtering( mostly golden).This type also has a disadvantage - sputtering does not have a very favorable effect on the mucous membrane of the oral cavity.
- The third type is crowns with lining. As a lining material, plastic or cermet is used. Special pads cover the surface of the prosthesis in the area of a smile. Despite a good aesthetic appearance, such pads can be cleaved. In addition, their cost is significantly increased due to the use of expensive materials.
The first two types are used to replace the lateral teeth. If it is necessary to replace the front of the dentition, the third kind is best suited. It is worth noting that the walls of the crown are rather thin( up to 1 mm).This significantly affects the preliminary diameter of the living tooth.
Production of cast crown. First clinical and laboratory stages of
First of all, the dentist is obliged to conduct an oral examination. If there are affected areas, they need to be sanitized. The first clinical stage involves obtaining an impression of the dentition and directly the tooth for further casting. To do this, often use a special silicone mass, which allows you to fully display all the anatomical features. During this period, the patient can install special temporary structures. Their task is to accelerate the habituation of the gums, to create an aesthetic effect. At the first laboratory stage, a demountable gypsum model is manufactured. Next, the gypsum is implanted in the occludator, a wax crown is modeled. After that, the wax is replaced with metal( in a special foundry laboratory).Then the whole-crown is processed properly.
Second clinical and laboratory stage
In the second stage( clinical), the product is fit. In addition, the tooth is grinded for a quality crown installation. The prosthesis is filled with wax, applied to the installation site. Excess material leaves through a pre-drilled hole. Then the crown is removed, all inaccuracies are smoothed, the occlusal relationships are checked. The prepared product is transferred to the laboratory. Here, polishing, polishing is carried out. The accuracy of the production is verified on a gypsum model. It is also important to evaluate how the prosthesis is joined with parallel antagonist teeth. It should be noted that the work requires a lot of attention. Even a small discrepancy in size can cause difficulties when wearing a crown, constant pain and discomfort.
Final installation of
The crown is fixed in the oral cavity. In this case, the immersion of the end of the prosthesis under the gum should be minimal. The quality of the installation is also checked by the tightness of the patient's tooth. Also, when the antagonists are closed, there should be no discomfort. If necessary, you may need to grind a part of the material. Also, with a lack of material, the crown can be sent back to the laboratory. If the denture is suitable, the person does not feel it, then permanent fixation takes place. It should be noted that if solid crowns are installed, the manufacturing stages take quite a long time - up to several weeks.
The main advantages of these crowns
First of all cast crowns have a long service life. Since this technology allows you to fully display all the nuances of the anatomical structure, the prosthesis organically fits into the dentition, food does not get under them, etc. All this allows you to wear them for more than 10 years. When manufacturing bridges, soldering is not used, and this additionally strengthens the crowns and extends the life of the crowns. Another advantage - under the crown retains more dental tissue( in contrast to cermets).Since the thickness of the whole-crown is less than 0.3-1 mm, the tooth is less subject to grinding. As a consequence, his life is prolonged. In addition, such prostheses are easy to manufacture. And, of course, the solid crown( the photo below) is more accessible, its cost is relatively low.
solid-cast structures Of course, for the front teeth, such crowns do not work. The minimum choice of color - golden, silver - is one of the significant disadvantages of such prosthetics. The metal has a high thermal conductivity, this can cause unpleasant sensations in the mouth of the patient. Since in the manufacture of hard alloys, crowns can provoke wear, deformation of the dentition of the opposite jaw. In addition, the production of solid crowns requires a high qualification of a specialist.