The choice of dentures is now quite large, but with incomplete tooth destruction, dental crowns are the most popular, which allow you to refuse to remove. They are made in different ways, from different materials, and sometimes it can be difficult to choose the right one.
What is a crown and why is it needed?
A crown is a type of fixed denture. Outwardly, it repeats the shape of the tooth and, when installed, becomes indistinguishable from he althy teeth. It is used in case of incomplete destruction of the tooth to restore its chewing functions and aesthetic appearance, as well as to prevent further destruction. Crowns are distinguished depending on the material for their manufacture. They are metal, ceramic-metal, plastic and ceramic. Metal ones are rarely used in modern clinics, as they have an unaesthetic appearance, and are completely unsuitable for prosthetics of the front teeth.
Ceramic have a natural appearance. This is the most expensive type of crowns, they are made of zirconium oxide. Plastic crownsare used mainly as temporary prostheses, since they do not have durability and wear resistance, they are easily subjected to mechanical damage and fail. This is the cheapest kind. Porcelain-fused-to-metal crowns combine beauty and strength, are the most popular compared to other types because of their practicality. Dental crowns are also distinguished by the way they are made: there is a stamped and one-piece crown.
Stamped crowns. Manufacturing principles
The production of stamped crowns has been used for over a hundred years, many dentists consider this process a relic of the past, but, nevertheless, it is still used, as it is very cheap. Cylindrical blanks of different diameters are made of stainless steel, from which metal crowns are stamped on special machines. Such a product must have some qualities for their proper installation and comfortable wearing.
The stamped crown should fit exactly the size of the tooth, cover it tightly, without gaps and voids. Otherwise, it will provoke inflammation of the gums, as a result, this can lead to atrophy. For a tighter fit of the crown to the tooth and its fixation, special dental cement is used. The crown should not go deep into the gum, this can cause gum disease, such as periodontitis. In addition, it must match the shape of a he althy tooth so as not to disturb the integrity of the row, and be of the appropriate size to avoid injury. Productdesigned to restore tooth function.
Steps in making a stamped metal crown
- First, an impression of the jaw is taken, completely.
- next, the desired product is modeled
- receiving stamps
- the crown itself is made
- the product is polished and polished
- The finished crown is put on a pre-prepared tooth and fixed with cement.
Indications and contraindications for stamped crowns
Stamped metal crowns use:
- In case of incomplete destruction of the tooth. In this case, the tooth is ground to the desired size, all its defects and carious lesions are eliminated in order to prevent further destruction.
- If removable dentures, such as clasp or bridges, will be installed. To protect the supporting teeth, crowns are installed.
- To restore a broken baby tooth
There are some contraindications to their use:
- Bruxism (teeth grinding that breaks down enamel).
- Complete destruction of the tooth, in which there is nothing to save.
- Infectious diseases of the oral cavity.
Pros and cons of punched crowns
Advantages of punched crowns:
- Preparation of the tooth does not require much time, turning is carried out to a minimum, since the walls of the crown are thin. This is especially important if the product is attached to a he althy tooth that will support a removable denture.
- This is a treatmentallowing you to keep a he althy tooth and avoid extraction.
- A stamped crown can be used in cases where other types of prosthetics are not possible (for example, the use of implants cannot be carried out due to diabetes mellitus or other illness of the patient).
- This is a cheap way to make and prosthetics, so it becomes a lifesaver for low-income people.
Disadvantages of stamped crowns:
- Using for a long time will wear the crown and cause it to fail. Subsequently, the product will have to be replaced with a new one.
- The cement on which the crown is held dissolves over time, which leads to a loose fit to the tooth and gum. This, in turn, can lead to damage, cavities and tooth decay due to ingestion of food.
- If the tooth is completely destroyed, the crown will not help to perform chewing functions.
- A stamped bridge contains brazed parts that shorten its life.
Full cast crowns
The modern method of casting has made it possible to produce high-quality thin-walled crowns. A one-piece cast crown is used to restore the shape of a damaged tooth, its preservation, as a support for bridges and removable dentures. It is cast from a cob alt-chromium alloy, resulting in a one-piece product without adhesions. Even when creating bridges, soldering of the elements is not required, the structure is cast as a whole. Such crowns may havevarious manufacturing options.
- Regular crown without coating, polished metal.
- Gold plated crown. May cause allergic reactions. With prolonged wear, the coating is erased.
- One-piece plastic crowns. They have a cast metal frame and a plastic overlay to give an aesthetic appearance to natural teeth. If worn for a long time or carelessly, plastic chips may occur.
- Metal ceramics. The most expensive type of crown, durable and natural looking.
Indications for cast crowns:
- Significant damage to teeth.
- Pathology of tooth shape or location.
- Mistake.
- Tooth size anomaly.
- Support for removable and bridge dentures.
- Prevention of tooth abrasion, bruxism.
Advantages of cast crowns
- The possibility of one-piece manufacturing of not only individual crowns, but also bridges, which ensures the strength and wear resistance of products.
- Durability. Wearing such crowns can last up to 10 years if the quality of the material and installation are performed at a high level.
- Quick and easy to make.
- One-piece cast crown is made individually for each tooth and fits perfectly into the dentition without causing discomfort to wear.
- The precision of the design allows you to tightly install the crown without gaps, which protects against the ingress of bacteria and food underher.
- For anterior teeth, crowns can be coated or veneered for an aesthetic appearance. A stamped crown does not provide such an opportunity.
Disadvantages of cast crowns
- In preparation for the installation of the crown, a rather large layer of a he althy tooth is ground off.
- The casting of the crown must be extremely accurate, otherwise installation and wearing will be problematic.
- When eating hot or cold food, discomfort may occur due to the high thermal conductivity of the material.
- The price of such products is much higher than that of stamped crowns.
