Metal crowns for teeth are still popular, as nothing more reliable and stronger in prosthetics has yet been invented. 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 is this
One-piece cast crown is a metal product that is made from various alloys of titanium metal, chromium-cob alt, chromium-nickel, 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 aesthetics.
A (metal) cast 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 castings
This material has a number of advantages, namely:
- Firmly adheres to dental tissues.
- Safety (teeth won't break or chip).
- Features a natural anatomical shape.
- Small price compared to other peers.
- Does not erase opposing teeth.
- Great for resuming chewing performance.
Reasons for installation
Experts advise placing metal crowns only in certain cases if:
- destroyed precisely those teeth that are responsible for chewing;
- jaw line sections visibly worn;
- tooth badly damaged or injured;
- Implants are on my teeth.
To deliver 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:
- One-piece casting. 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, products are prostheticonly lateral teeth hidden during conversation. They are optimally suited for prosthetics of chewing teeth, because they can withstand considerable loads.
- A stamped crown is a typical sleeve that is ground by a special machine to give the product the desired shape.
Modeling a solid crown
Such a product is considered a reliable option for prosthetics and is installed from a cob alt-chromium alloy. The (metal) crown has an indisputable advantage - it does not have soldered 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 design of a one-piece crown contains several items:
- prosthesis casting;
- tooth preparation (removed from 0.2 to 0.6 mm of tissue);
- production of wax cap by wrapping;
- finishing, fitting, grinding, polishing the metal surface;
- Creating impressions including opposing and adjacent teeth.
Samples of such products
Today, solid metal crowns are placed in the orthopedic dentist's office (reviews about them from most patients can only be heard positive) of several types:
- No spraying - simple steel-colored items.
- Sprayed. If such “beauty” does not suit the patient, if he wishes, the crowns can be made with a coating imitating gold.
- 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 when eating, because ceramics can be chipped.
- Combined. With this prosthetics, some of the crowns are covered with ceramics, while others that are hidden when smiling are placed without veneer.
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 or stainless steel is used for its production.
Ease of creation determined not only the low price, but also the short life of the material. Gold forged crowns are made from an alloy that is 90% gold.
Production steps
There are certain steps 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;
- prosthesis lines 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;
- a steel die is created according to the drawn model, which is driven into the sleeve;
- external stamping is done with a screw press;
- the stamp is removed, and the edges of the product are cut off with special scissors.
During the production 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
The metal crown is being installed:
- for preliminary prosthetics of a milk tooth before its replacement with a permanent one;
- to save a he althy tooth;
- as a fundamental part of a bridge;
- if the tooth is so traumatized or damaged by caries that it is unrealistic to renew it with a filling.
The process of installing crowns
Such an event usually takes place in 2 stages:
- At first, the product is placed temporarily so that the doctor can observe the reaction of the tooth.
- If the patient does not complain of pain, then at the next visit the crown is removed, cleaned of 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
Correctly Produced and Deliveredcrown:
- attaches firmly to the shell of the tooth;
- has a smooth, polished shape;
- sinks into the periodontal recess by 0.2 mm;
- reproduces the anatomical shape of the molar;
- contacts adjacent and opposite teeth.
Contraindications for installation
In some cases, it is not recommended to put a metal crown, if any:
- bruxism;
- presence of an allergic reaction to steel;
- malocclusion of the dentition;
- tangible damage to a living tooth;
- complex due to poor aesthetics in front teeth prosthetics.
What harm is a metal crown
In certain situations, this product may cause damage:
- Due to its installation, galvanic syndrome may occur. 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.
- The crown (stamped) is not produced from individual casts, and therefore it is not suitable for sufficient restoration of the functions of a living tooth.
- The product does not fit closely to the tooth, creating a gap between the walls, into which food remains penetrate. Therefore, rotting of he althy tissues can occur under it.
- The solid crown has good thermal conductivity. If she wasplaced on a non-depulped tooth, then during the reception of hot food, unpleasant sensations may appear.
Timeless technology
The production 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 as popular as ever. And this is not surprising, since the main reason for such relevance is the low cost of the prosthesis with high strength.
