To save even very neglected teeth and to return the former attractiveness to a smile, installation will help dental crowns. Today, there are materials and technologies that allow you to make the appearance of the tooth with a crown absolutely similar to the present.
Content
Dental crown: types and indications
Before the material is processed, it is similar to ordinary metal cap. The technological process of manufacturing is carried out in a dental laboratory. The dentist, in turn, takes pictures in order to carry out a working model, and also makes further installation of the crown on the tooth for the purpose of fitting.
Crowns can also be part of a large denture. For example, in the absence of several teeth, they are replaced by artificial ones. In this case, the crowns play the role of supporting the neighboring elements, which are pre-grinded to ensure the necessary conditions for fixing the entire structure.
In this case, crown surrounds a tooth as well as ground enamel. It is necessary to take into account the differences in the anatomical structure of each group of teeth in order to ensure not only the protection of hard tissue, but also the usual process of chewing.
The use of such an orthopedic construction is possible when natural crowns are already destroyed by 70 percent or more. Damage of this kind is not eliminated by filling materials or inlays, as this may lead to a split of the tooth and its further removal.
Types of crowns
Today designs differ in types of materialfrom which are executed:
- metal, made from an alloy of metals, including precious ones;
- metal-ceramic, the inner part of which is made of metal, and the outer part is made of ceramic;
- all-ceramic, which include zirconium dioxide, so that they are not inferior in strength to metal.
Indications
Such elements are used to restore the teeth, with the loss of a significant amount of their hard tissues. The cause of this situation can be caries, injuries, as well as changes in the color of enamel. There are cases of failure in the development of enamel, which entails the appearance of a large number of pits on a surface. Less often you can find such indications:
- location anomalies;
- closed gap between teeth;
- support crowns installed for bridge prosthesis or as retaining elements.
How to put the crowns
There are several stages in the manufacture of such structures and their installation directly on the places prepared in advance.
Consultation and treatment plan definition
During the preliminary consultation, the dentist draws up a treatment planand also discusses with the patient all possible prosthetics. By offering specific materials, the doctor focuses on the results of X-rays and the clinical situation in the oral cavity.
The treatment plan may include the following steps:
- removal of nonviable teeth;
- preparation of all elements of the jaw under the crowns, such as the treatment of pulpitis, caries, periodontitis, and canal filling;
- determination of the final terms of prosthetics and preliminary cost of all treatment and manufacturing.
Preparation of teeth for prosthetics
In preparing multiroot chewing teeth for prosthetics, doctors try to keep the pulpas crowns are best placed on live teeth. In addition, the enamel of such teeth is denser, which significantly reduces the risk of burns of the pulp during the turning process. For single-root teeth, nerve removal and root canal filling are performed.
Mandatory before prosthetics is treatment of carious processes, pulpitis and periodontitis. This is done as follows:
- If there is evidence, the nerves are removed.
- Root canals are processed and expanded.
- The prepared canals are filled with gutta-percha.
- Put a seal on the crown area.
In case of significant destruction of an important part of the tooth, before the start of prosthetics, it is necessary not just cure, but recover. The process is carried out in two ways:
- Pin installation. The method involves screwing into the pre-sealed root canal of a special pin, which is the basis for the restoration of the crown of the tooth. After the restoration is completed, the tooth is turned under a future crown.
- The use of the stump tabs. In this method, a special stump insert molded from metal is used, which is installed into the tooth. This design includes the root tab in the form of a tooth, machined under the crown, sufficiently tightly fixed in the crown part and the dental canal.
After this, preparation is carried out, which is the process of turning the teeth in order to give them the desired shape for fixing the structure. The orthopedic surgeon performs the procedure with the help of a drill. Focusing on the type of crown, he removes from 1.5 to 2.5 mm of hard tissue on each side of the tooth. When grinding live teeth, the use of local anesthesia is recommended, as the process is quite painful.
Manufacturing and installation of crowns
The next step will be formation of casts with pre-grinded teeth, using a special impression mass. In the future, with the obtained impressions, the laboratory creates plaster models, which are an exact replica of the patient's jaw.
Such a model should reflect all elements of the jaw, including those machined. It is on gypsum copies that a technician makes crowns.
Until permanent crowns are made, as a rule, they install temporary plastic elements that perform not only an aesthetic function, but also protect the grinded teeth from the effects of the aggressive environment of the oral cavity.
Before finishing the job it is necessary to try on the prepared elements to assess the quality of the cast metal frame. If the outcome of the fitting is positive, the doctor produces a ceramic mass for the frame.
Before the crowns are fixed on a permanent cement, it is recommended to wait a while and follow the behavior of the tooth. For this, the crown or bridge is placed on temporary cement, which is distinguished by the possibility of easy dismantling of the crown without compromising the integrity of the tooth, as well as the crown itself. When fixing the structure to a permanent cement immediately, it will be possible to remove it only after sawing.
After 2-4 weeks and in the absence of complaints from the patient, the structures are removed, the temporary cement is cleaned and fixed on a permanent basis.
Removal of dental crowns
Sometimes there are situations in which there is the need to remove installed itemsregardless of the level of dental treatment. The reasons may be:
- Poor tooth preparation before installing the crown. We are talking about the poor quality of the canal filling, which over time can lead to the development of the inflammatory process.Consequently, an already installed crown is removed for a new tooth treatment or its removal.
- The pain arising under the crown. The reason may be the holes formed under it, into which bacteria have penetrated. The accumulation of harmful microorganisms provokes the development of the inflammatory process.
- Laboratory errors in the manufacturing process.
- Insufficient adherence of the structure to the neck, distorting the bite and causing other physiological or aesthetic problems.
- Planned or urgent replacement of an already installed item. Each design has a certain service life, regardless of the material of manufacture. If the prosthesis is performed sufficiently qualitatively, the patient may not think about a repeated procedure for about 10 years. After this time, the crown will need to be replaced. In case of damage, the occurrence of cracks, holes in the place of the washed cement, an urgent replacement is necessary.
The process of removing the design make using special discs and burssawing it under anesthesia. The procedure is rather unpleasant, even for a dead tooth.
Of course, the final choice of material for dental crowns, the place of their installation is made directly by the patient. However, he should definitely listen to the opinion of the dentist, as well as accurately follow his recommendations to obtain the best result.