Metal crowns on teeth are still popular, as they haven’t come up with anything more reliable and stronger in prosthetics. Our ancestors wore such products since ancient times, and they still continue to serve people with their longevity. Although the appearance of crowns is far from the most attractive, but the price and quality are true.
What it is
A one-piece crown is a metal product, which is made from various alloys of titanium metal, chromocobalt, chromium-nickel, and its design is completely cast. The main area of use for this variety of crowns is prosthetics of the chewing type of teeth. This is due to their poor aesthetic component.
All-cast crown (metal) is considered a high-precision product, which, although it is distinguished by a metallic color, but sits very tightly in the oral cavity. Such crowns are an excellent choice for distant teeth.
The advantages of solid products
Such material has a number of advantages, namely:
- Tightly adheres to dental tissues.
- It has safety (teeth do not break and do not break).
- It has a natural anatomical shape.
- Low price compared to other analogues.
- Does not erase opposing teeth.
- Remarkably resumes chewing performance.
Installation reasons
Experts advise to put metal crowns only in certain cases, if:
- those teeth that are responsible for chewing are destroyed;
- sections of the jaw row are noticeably worn;
- the tooth is severely damaged or injured;
- implants are on the teeth.
To deliver such a product, you need to visit a orthopedic dentist at least twice. First, the doctor will get acquainted with x-rays of the oral jaw, then he will begin the therapy of caries of 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 put a metal crown, he is offered two options, depending on the method of its production:
- One piece cast. It is made according to special casts by the method of burning in a furnace. Such a crown has thick walls, which favorably affects its service life. It is produced from base metals (alloys of chromium, nickel, steel) and precious metals (platinum, palladium, gold, silver). Due to the steel coloring, only the lateral teeth hidden during the conversation are prosthetized. They are optimally suited for prosthetics of chewing teeth, because they withstand considerable loads.
- The stamped crown is a typical sleeve that is ground with a special machine to give the product the desired shape.
Solid cast modeling
Such a product is considered a reliable option for prosthetics and is installed in cobalt-chrome alloy. The solid cast crown (metal) has undeniable superiority - it does not have soldered joints, and this makes it especially strong. It well covers a sharpened tooth, preventing the cement mixture from absorbing and reducing the likelihood of food penetrating under it. The operation period is 15-20 years. The modeling of a one-piece crown accommodates several points:
- casting a prosthesis;
- tooth preparation (removed from 0.2 to 0.6 mm of tissue);
- production of a wax cap by tightening;
- finishing, fitting, grinding, polishing the surface of the metal;
- creating casts, including opposite and adjacent teeth.
Samples of such products
Today in the orthopedic dentist’s office put solid metal crowns (reviews about them from most patients can be heard only positive) of several types:
- No spraying - simple steel color products.
- With a dusting. If such a “beauty” does not suit the patient, if he wants, the crowns can be made with a dusting imitating gold.
- Coated. Ceramic lined products 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 be chipped.
- Combined. With this prosthetics, some of the crowns are covered with ceramics, while others that are hidden by a smile are placed without facing.
Stamped crowns
Are prostheses made from factory sleeves, which give the necessary shape. Products differ in thin shells, so there is no need to grind a large number of tooth tissues. The crown (metal) is installed if there is no destruction of the roots, and 1/3 of the tooth is saved. For its production, gold or stainless steel is used.
The ease of creation determined not only the low price, but also the short life of the material. Gold stamped crowns are made of alloy, which accounts for 90% of gold.
Manufacturing steps
There are certain stages in creating such a crown:
- the patient has casts of both jaws to simulate the product, which should be performed for 15 minutes, until the compression of the raw material has occurred;
- the lines of the prosthesis are marked on the gypsum so that it does not come out too wide or narrow;
- then wax modeling takes place, which is applied to the surface of the gypsum - thus, the crown (metal) gets an anatomical shape;
- according to the traced model, a steel die is created, which is inserted into the sleeve;
- external stamping is carried out using a screw press;
- the stamp is removed, and the edges of the product are cut with special scissors.
During the manufacturing period, firing is repeatedly performed so that the metal becomes more intractable and strong. The prosthesis should not have bumps or cracks.
Indications for the installation of a stamped product
Installation of a metal crown is carried out:
- for preliminary prosthetics of a milk tooth before its permanent change;
- to save a healthy tooth ;
- as a fundamental component when installing a bridge ;
- if the tooth is so injured or damaged by caries that it is unrealistic to renew the filling.
Crowns installation process
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 already by means of zinc-phosphate or glass-ionomer cement.
If as a result of the first installation it is found that the metal crown (photo below) causes the patient discomfort, then it will be removed and treated again.
What should be a properly installed product
Correctly crafted and delivered crown:
- firmly attached to the tooth shell;
- has a smooth, polished shape;
- sags into the periodontal cavity by 0.2 mm;
- reproduces the anatomical shape of the molar;
- in contact with adjacent and opposite teeth.
Contraindications to installation
In some cases, putting a metal crown is not recommended if there is:
- bruxism;
- the presence of an allergic reaction to steel;
- broken bite of the dentition;
- tangible damage to a living tooth;
- complex due to poor aesthetics for prosthetics of the front teeth.
What harm does a metal crown
In certain situations, such a product may cause damage:
- Due to its installation, 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 galvanic current. There are headaches, swelling, some diseases, a taste of metal, sleep disturbance, burning in the mouth.
- The crown (stamped) is not produced according to individual casts, in this regard, it is unsuitable for a sufficient restoration of the functions of a living tooth.
- The product does not closely adhere to the tooth, creating a gap between the walls, into which the remnants of food penetrate. Therefore, under it, decay of healthy tissues can occur.
- The one-piece crown has good thermal conductivity. If it was placed on an unselected tooth, then unpleasant sensations may appear while eating hot food.
Ageless Technology
The manufacture of metal crowns is a “forever young” technology of the last century, which has not been practically modernized lately. Along with some modern and fashionable methods of permanent prosthetics, it remains all the same popular. And this is not surprising, since the main reason for this relevance is the low cost of the prosthesis with high strength.