The choice of dentures is now quite large, butwith incomplete tooth fracture, the most popular dental crowns, which allow to refuse removal. They are made in different ways, from different materials, and sometimes it is difficult to choose the right option.
What is a crown and why is it needed?
Crown is the type of fixed denture.Outwardly, it repeats the shape of the tooth and becomes indistinguishable from healthy teeth during installation. It is used for incomplete tooth fracture to restore its masticatory functions and aesthetic appearance, as well as to prevent further destruction. Crowns are distinguished depending on the material for their manufacture. They are metal, cermet, plastic and ceramic. Metallic in modern clinics are rarely used, because they have a non-aesthetic appearance, and for prosthetics of the front teeth are completely unsuitable.
Ceramic have a natural appearance.This is the most expensive kind of crowns, they are made of zirconium oxide. Plastic crowns are used mainly as temporary dentures, as they do not have durability and durability, they are easily damaged and damaged. This is the cheapest kind. Metal-ceramic crowns combine beauty and strength, are most popular in comparison with other species due to their practicality. Dental crowns are also distinguished according to the manufacturing method: the crown can be stamped and cast.
Stamped crowns. Principles of manufacturing
The production of stamped crowns is already appliedfor over a hundred years, many dentists consider this process a relic of the past, but, nevertheless, it is still applied, because it is very cheap. Stainless steel makes cylindrical billets of different diameters, from which they stamp metal crowns on special machines. Such a product should have some qualities for proper installation and comfortable wearing.
The crown must be clearlythe size of the tooth, tightly cover it, without gaps and voids. Otherwise, it will provoke inflammation of the gum, as a result, it can lead to atrophy. For a more dense fit of the crown to the tooth and its fixation, a special dental cement is used. The crown should not go deep into the gum, it can cause gum disease, for example, periodontitis. In addition, it must conform to the shape of a healthy tooth, so as not to violate the integrity of the series, and to have an appropriate size to avoid injury. The product is designed to restore the functions of the tooth.
Stages of manufacturing a stamped metal crown
- first the impression of the jaw is made, all completely.
- then the desired product is modeled
- 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 the use of stamped crowns
Stamped metal crowns are used:
- With incomplete fracture of the tooth. In this case, the tooth is grinded to the desired size, all its defects and carious lesions are eliminated in order to exclude further destruction.
- If you will install removable dentures, for example, clasp, or bridges. To protect the supporting teeth, set the crowns.
- To restore a destroyed baby tooth
There are some contraindications to their use:
- Bruxism (grinding teeth, in which the enamel is destroyed).
- Complete destruction of the tooth, in which there is nothing to save.
- Infectious diseases of the oral cavity.
Pros and cons of stamped crowns
Advantages of stamped crowns:
- Preparation of the tooth does not require much time, turningis carried out at a minimum, since the walls of the crown are thin. This is especially important if the product is attached to a healthy tooth that will support the removable prosthesis.
- This is a therapeutic procedure that allows you to keep a healthy tooth and avoid removal.
- Crown stamped can be used in thosecases where other types of prosthetics are not possible (for example, the use of implants can not be carried out because of diabetes mellitus or other patient illness).
- This is a cheap way of manufacturing and prosthetics, so it becomes a rescue for people with low incomes.
- Use for a long time leads to the attrition of the crown and its failure. Subsequently, the product will have to be changed to a new one.
- Cement, which holds the crown, over timeresolves, which leads to a loose fit to the tooth and gum. This, in turn, can lead to damage, the formation of caries and the destruction of the tooth due to ingestion of food.
- If the tooth is completely destroyed, the crown will not help to perform the chewing functions.
- The stamped bridge bridge contains soldered parts that shorten the life of the bridge.
Solid cast crowns
Modern casting method allowed to makehigh-quality thin-walled crowns. Whole-crown is used to restore the shape of the damaged tooth, its safety, as a support for bridges and removable dentures. It is cast from cobalt-chrome alloy, as a result, one-piece product without adhesions. Even with the creation of bridges, no soldering of the elements is required, the structure is poured out entirely. Such crowns can have different manufacturing options.
- Conventional crown without sputtering, polished metal.
- Crown with gold plating. May cause an allergic reaction. When wearing for a long time, the spraying process is erased.
- Solid cast crowns. They have a cast metal frame and a plastic cover for giving an aesthetic look of natural teeth. With long or careless wearing, chipped plastic is possible.
- Metalloceramics. The most expensive kind of crowns, has a durability and a natural appearance.
- Significant damage to the teeth.
- The pathology of the shape of the teeth or its location.
- Anomaly of tooth size.
- Support for removable and bridge prostheses.
- Prevention of abrasion of teeth, bruxism.
Advantages of cast crowns
- The possibility of a single-piece production of not only individual crowns, but also bridges, which provides strength and durability of products.
- Durability. Wearing such crowns can last up to 10 years, if the quality of the material and the installation are carried out at a high level.
- Fast and easy manufacture.
- Whole-crown is performed individually for each tooth and fits perfectly into the dentition, without causing discomfort in wearing.
- The accuracy of the design allows you to tightly install the crown without gaps, which protects against the ingress of bacteria and food under it.
- For the front teeth, it is possible to produce crowns with a coating or lining for aesthetic appearance. Crown stamped does not provide such an opportunity.
Disadvantages of cast crowns
- When preparing for the installation of the crown, a fairly large layer of a healthy tooth is grinding off.
- Crown molding must be precise, otherwise installation and wearing will be problematic.
- When taking hot or cold food, unpleasant sensations are possible because of the high thermal conductivity of the material.
- The price of such products is much higher than that of stamped crowns.