Dental Prosthetics

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Dental prosthetics is the process of artificially re-creating them, when they were previously lost for any reason. Tooth loss can be caused by injuries, illnesses and other factors. Therefore, the prosthetics service is quite in demand in dental practice.

There are many ways to restore a lost tooth or teeth. To determine the specific technology, the doctor must examine the condition of the bone tissue, the degree of neglect of the disease, assess the integrity of the dentition and the health of the gums. In addition, the financial side of the issue is no less important when choosing a denture.

Content:

Necessary examinations before starting prosthetics

Removable dentures

Fixed dentures

Prosthetics in the absence of a large number of teeth

Necessary examinations before starting prosthetics

Modern dental prosthetics is, first of all, a comprehensive examination of a patient who comes to the clinic. For diagnostics, modern equipment should be used. The more thoroughly and fully the doctor performs the initial assessment of the condition of the teeth and oral cavity, the better the patient will receive in the long run.

Diagnostics before choosing a method of dental prosthetics must necessarily include:

Visual examination of the oral cavity, as well as the patient's maxillofacial apparatus. An orthopedic dentist should assess the health of the teeth, the quality of their hygiene, the condition of the oral mucosa, the degree of neglect of existing diseases, etc. In addition, the doctor assesses the functioning of the masticatory muscles, the condition of the temporomandibular joint and the patient's posture;
Taking an X-ray. This will allow visualizing the state of the periodontium, as well as the alveolar processes in the upper and lower jaw. X-ray examination also makes it possible to assess the length and direction of growth of the roots of interest to the doctor, the size of the tooth cavity, the condition of the canals and roots;
Assessment of the tone of the masticatory muscles and their activity is carried out using diagnostic methods such as electromyography and electromyotonometry;
Taking impressions, which will be used to model the future project. Studying the resulting model will allow you to work out the features of the bite, perform preliminary turning, etc.

After the examination, the doctor discusses the possible types of prosthetics with the patient.

There are two main types of dentures: removable and non-removable. Each of these species, in turn, is divided into subspecies with certain disadvantages and advantages.

Removable dentures

Removable prosthetics are used most often when the patient has a lack of several teeth: three or more. Moreover, the missing teeth must go in a row, one after another. The main feature of a removable denture lies in its name, that is, it must be periodically removed from the mouth to carry out hygiene procedures.

Removable dentures can be of the following types:

Clasp;
Acrylic plastic plate;
Nylon.

Clasp removable dentures

The phrase "clasp prosthetics" has German roots. "Bugel" in translation from German means "arc", it is its shape that the prosthesis repeats. This type of prosthetics can be used only when the patient has at least two of his teeth in the mouth, since it will be attached to them.

The materials serving as the basis for the manufacture of a removable clasp prosthesis can be as follows: titanium, nylon, acetal, chromium-cobalt alloy, zirconium, cermet.

Such a prosthesis can be fixed using various devices:

Attachments are double attachments, when one half of the micro-lock is located in the inner part of the prosthesis, and the other is in the metal-ceramic crown, which is put on the supporting tooth. The lock closes when putting on the prosthesis. In this case, the prosthesis is reliably fixed, the locks are not visible when smiling and while eating, and the service life of such prostheses varies from 5 to 7 years. However, clasp prostheses on attachments will cost more than their counterparts with other types of attachment. The fact is that attachments are imported from the USA and Germany, which determines their high cost;
Clasps are hooks made of metal. They are a continuation of the arch of the prosthesis itself and are fixed directly at the base of the teeth that serve as support. The undoubted advantages of such prostheses are their low cost and preservation of the integrity of the tooth enamel. However, such designs have their drawbacks. First of all, this concerns the aesthetic side, since often the clasp can be installed only on the front surface of the abutment tooth. In this case, it falls into the smile line and will be noticeable when teeth are exposed;
Telescopic crowns. This type of clasp prosthetics is the most expensive. The prosthesis is made by a high-level orthopedic dentist and has maximum aesthetics. Crowns of this type are motionlessly fixed on the patient's own teeth with the lower part, and a prosthesis is put on them. It fits with great precision and fits directly into the recesses in the crowns. When the alignment is achieved, all that remains is to click the locks, which allows you to securely fix the structure;
Splinting clasp prostheses are used in the absence of a support tooth on one side of the jaw, with periodontal disease, with displacement of teeth in the conditions of the dentition, with exposure of the roots of the teeth. The design will be made in an arched shape, and the clasps will fix each tooth separately. The advantages of the splinting type of attachment are that the gums and mucous membrane of the oral cavity will be protected from mechanical damage while chewing food, the teeth will not loosen. The disadvantages of such prostheses are that they are rather difficult to manufacture, and this will certainly affect the price;
Clasp prostheses with implant fixation are applicable when the patient does not have end teeth. Instead of missing teeth, in the presence of a jaw bone of the required thickness, implants are inserted into a person. They subsequently act as a support for the clasp prosthesis.

The undoubted advantages of clasp prostheses are:

Low cost;
Reliable fixation in the mouth;
Possibility of installation in the presence of movable teeth;
Structural strength;
No need to remove the prosthesis during a night's rest;
Easy to care for;
Long service life if used correctly.

However, removable clasp processes have the following disadvantages:

This type of prosthesis cannot be installed if there are no healthy teeth in the oral cavity that follow one after another;
Often these prostheses take a long time to get used to them, sometimes the adaptation period is delayed up to several weeks;
The gums can rub against the denture attachments.

Indications for the use of clasp prostheses are:

Replacement of one or more teeth;
The presence of a defect in the dentition;
The presence of an end defect;
The need to correct the curvature of the dentition;
Periodontal therapy using splinting technology.

Contraindications to clasp prosthetics are:

Lack of teeth that act as support;
Diabetes mellitus, oncological diseases;
Acute stage of diseases of the cardiovascular system;
Mental disorders;
Inflammatory processes in the oral cavity in the acute stage;
Diseases of the respiratory system in the acute stage.

Acrylic dentures

Dentures made from acrylic are traditional removable dentures.

They can be divided into several types:

Full removable. This type of prosthesis is installed if the patient has no teeth completely. Instead of the abutment tooth, the alveolar ridge of the lower jaw is used. On the upper jaw, the prosthesis is additionally fixed behind the palate. At the same time, the fixation of such a prosthesis is not entirely reliable, since a person has no teeth.
Partially removable acrylic dentures can be used when the patient has at least one healthy tooth. Naturally, it will act as a support.
Conditionally removable or cover dentures with implant fixation. These prostheses will hold onto mini-implants previously implanted into the patient's jaw. Their number is calculated on a case-by-case basis.

Naturally, acrylic dentures have both advantages and disadvantages. Among the advantages are:

Low weight of the prosthesis;
Variety of shades;
No need for pre-facing;
Easy to operate;
Ease of implementation of hygiene measures;
Low cost;
Ease of repair;
The maximum service life is up to 5 years.

The disadvantages of acrylic dentures include:

Fragility of the prosthesis;
Long time of adaptation of the patient to the prosthesis;
Possibility of developing an allergic reaction to the components of the prosthesis;
Change of diction;
Decreased sensitivity;
The presence of a porous structure, which is a favorable breeding ground for bacteria;
The likelihood of injury to the soft tissues of the oral cavity, the risk increases parallel to the number of missing teeth;
Destruction of the abutment tooth over time.

Indications for the use of an acrylic prosthesis:

Partial and complete adentia;
Correction of bite in childhood with untimely loss of milk teeth;
Temporary replacement of the dentition with non-removable prosthetics.

Contraindications to the use of an acrylic prosthesis:

The presence of an allergic reaction to the components of the prosthesis;
Severe resorption of the jawbone, leading to flattening of the alveolar part (the prosthesis simply will not hold);
Pronounced gag reflex in the patient.

Nylon dentures

Nylon dentures about 20 years ago replaced the plastic dentures that were used as replacement teeth for people with no teeth.

Dental nylon allows you to quite accurately simulate the gums, since the material itself is soft, elastic, translucent. This makes it much more comfortable to use compared to rigid plastic dentures.

Dental crowns that are attached to a nylon denture are made from either ceramic or zirconia.

The dentist will fix the finished prosthesis in one of the following ways, depending on the condition of the patient's oral cavity:

If your own row of teeth is completely absent, then the prosthesis will be attached to the gum. Reliability of fixation is provided by the suction effect after applying a special gel to the prosthesis;
If the prosthesis replaces only part of the teeth, then the nylon structure is equipped with several hooks from a similar material. They are attached to the abutment teeth, directly near their base. At the same time, abutment teeth do not need such a painful procedure as turning.

The undoubted advantage of nylon prostheses is that they get used to them after a week of regular wearing. The material has hypoallergenic properties, does not stain over time and does not require complex care manipulations. If the rules for using the product are not violated, then such a prosthesis can last up to 8 years.

High aesthetic characteristics of the prosthesis are ensured by the fact that the clasps have the color of the gums and are practically invisible on the teeth. Therefore, nylon prostheses are often called invisible prostheses.

However, it is worth noting separately the disadvantages of dentures made of nylon, including:

Injury to the gums located in the area of the extreme teeth. Since the clasps will not be made of metal, but of nylon, they are not able to fully transfer the pressure that is exerted on the base tooth during the chewing process. Therefore, the pressure falls on the mucous membrane of the prosthesis bed. This will lead to destruction of the bone tissue underneath, and the height of the gums will decrease. As a result, the prosthesis will sag in this very place, and its clasps will cut into the mucous membrane of the remaining teeth. As a result - the development of the inflammatory process, the appearance of pain;
The larger the prosthesis, the stronger its elastic deformation will be during chewing food. That is, due to the softness of the nylon prosthesis, the load will be distributed only on the side of the jaw that the person chews on. As a result, the bone tissue will atrophy on this side more quickly, and the process of chewing and biting off food will begin to cause discomfort, causing pain. However, if a nylon prosthesis replaces only 2 teeth, then the patient will not feel such a deficiency;
Accelerated subsidence of the prosthesis as a result of atrophy of the bone tissue under it;
Difficulty polishing the denture. Inside, the prosthesis is not polished at all, which is incorporated by the technology itself. As a result, if it is not subjected to thorough hygiene, microbial plaque will accumulate under it and dental deposits will appear. This, in turn, will provoke an unpleasant odor from the prosthesis and it will be impossible to insert it into the mouth;
High manufacturing cost;
Multiple correction due to sagging gums.

Indications for the use of nylon prostheses:

The absence of 1-2 teeth in the event that the patient does not want to grind the base tooth;
Partial or complete absence of teeth;
Allergic reactions to the components that make up acrylic dentures;
Prosthetic stomatitis.

Contraindications to the use of nylon prostheses:

Periodontal disease, periodontitis;
Insufficient height of the existing teeth;
Mobility of the mucous membrane covering the gums;
Gum atrophy more than 20%.

Fixed dentures

Fixed dentures can be fixed either on a tooth that is located nearby, or on an artificial tooth root - on an implant.

Fixed dentures can be of the following types:

Dental crowns, which are a cap on a tooth, completely imitating its shape. Dental crowns can also be worn on dentures that are fixed on artificial roots;
Bridges are a complex of dental crowns that are put on the patient's teeth, or on the roots of the teeth;
Implants are titanium or zirconium roots. They are installed in order to subsequently put on a crown or bridge;
Inlays, veneers, lumineers are non-removable structures, the main purpose of which is to improve the appearance of a tooth or dentition.

Dental crowns

A dental crown is a tooth prosthesis made according to its anatomical shape and fixed to a tooth-stump.

They can be made from the following materials:

Crowns made of metal. They are made from various alloys, as well as precious metals. All-metal crowns can be installed if there is a need to restore molars.

Distinguish:
1. Solid metal crowns, the basis for them is an alloy of chrome and cobalt, sometimes such crowns are coated with gold plating, the main disadvantage is considered to be low aesthetic characteristics;
2. Stamped crowns are made from a sleeve, which is shaped into a tooth with a hammer. They have a lot of disadvantages, lead to various diseases of the oral cavity (they are practically not used in modern dentistry);
3. Gold crowns, which are very expensive, can only be installed by government clinics.
Crowns made of cermet. They are strong enough, they look aesthetically pleasing, which makes it possible to install them on the front teeth. However, to install such a crown, you will need to sharpen the tooth and remove the nerve from it. The service life of such a crown can be up to 10 years;
All-ceramic crowns made of ceramic mass, the base for which is either porcelain or zirconia. Porcelain crowns are very aesthetically pleasing, but they are very expensive and can only be produced singly. Zirconia crowns also resemble natural teeth, but in addition they are strong and durable. The only drawback of such a crown is its high price;
Metal-composite crowns are an alloy of chromium and cobalt, the front part is covered with plastic. They have excellent aesthetic qualities and are inexpensive. Among the shortcomings, one can single out the fragility of the structure, the possibility of developing allergic reactions, the rapid loss of the original color and the appearance of bad breath due to the high absorbency of the liquid;
One of the undoubted advantages of metal-plastic crowns is a low cost, however, the service life of such a crown will not exceed 5 years. The fact is that a layer of plastic is applied to a metal frame and after a short time it changes its original color. Another common disadvantage of these crowns is the rapid delamination of the plastic.

Read more: Crown on a tooth: what are they, how they are placed, does it hurt?

Bridge prostheses

A dental bridge is a structure that is fixed by means of supports on natural or implanted bases. The size of the bridge varies depending on how many missing teeth need to be replaced.

By the method of fixation, it is customary to distinguish between bridge prostheses:

With attachment to healthy adjacent teeth (preliminary grinding is required);
With attachment to implants (without prior turning);
Attached to special plates - adhesive bridges (turning is not needed, but the service life of such prostheses does not exceed 5 years);
Lockable when tooth or implant support is not required.

Depending on what material is used to make the bridge, there are:

Sintered bridges. Their base consists of metal, which is covered with ceramics on top. The service life of such products is up to 7 years;
Metal-plastic bridges with a metal base, which is covered with plastic on top. The service life of such products is usually limited to three years;
Combined bridges. Such structures can be made from zirconium oxide, from aluminum. These are the most modern prostheses that serve for a long time, up to 15 years, and are distinguished by high quality materials.

The main advantage of installing a bridge is the ability to compensate for the lack of several teeth at once. In addition, high-quality bridges will serve for a long period of time, provided that all medical recommendations and care rules are followed. The rest of the advantages and disadvantages will depend on the type of material from which the prosthesis is made. The pros and cons of metal-plastic, metal-ceramic and other types of bridge prostheses are similar to the pros and cons of dental crowns made of the same materials.

If we consider the disadvantages of bridges in general, they will be as follows:

Grinding of natural teeth used as a support. This is required by the installation of any bridge other than the adhesive. He, in turn, is not so reliable fastening;
The need to have your own healthy teeth, or to install an implant;
The development of the mobility of those teeth that act as support. This is due to excessive stress on them;
Possible atrophy of the part of the jaw, which is located under the bridge.

Dental implantation

Dental implantation is the installation of a pin, which will perform the function of a tooth root, and then a crown will be put on and fixed on top of it. As a result, the person will acquire a durable new artificial tooth. In 99% of cases, it takes root well and does not cause any undesirable health effects. The materials from which dental implants are made are metals (chrome alloy, titanium, stainless steel) and ceramics.

The shape of the implant itself resembles the root of a natural human tooth (more about implants). It is screwed into the jaw, and after engraftment, an intermediate part (abutment) is installed, on top of which a crown from the selected material is fixed.

The positive aspects of implant placement are:

Elimination of the defect without harm to the health of the teeth located in the neighborhood;
High aesthetic properties;
Long service life (up to 15 years or more);
Stopping the process of bone resorption due to the absence of a tooth.

The disadvantages of the implantation procedure are:

Long time of implant engraftment, which can be up to six months;
The development of complications in the form of tissue edema, pain, the development of bleeding, foreign body rejection;
A large number of contraindications.

The indications for implantation are:

Loss of one or more teeth;
Terminal defects of the dentition;
Lack of teeth (complete adentia);
Intolerance of removable dentures due to a pronounced gag reflex or in the presence of individual hypersensitivity to plastics.

Absolute contraindications for implant placement:

Psycho-emotional disorders (depression, hypochondria, psychopathy, psychosis);
Seropositive infections (syphilis, tuberculosis, etc.);
Systemic diseases of the blood, bone and connective tissue;
Endocrine pathologies;
Diseases of the heart and blood vessels of a chronic course;
Oncological processes of a malignant nature.
Diseases of the oral mucosa.

Read more: dental implantation - types of implantation, complications and contraindications

Inlays, veneers, lumineers

A separate type of prosthetics is dental microprosthetics, for which methods such as the installation of inlays, veneers and lumineers are used. These products belong to fixed prostheses and can last for a long time, sometimes up to 10 years. None of the microprostheses can replace a lost tooth; they are aimed at restoring it, eliminating the defect and improving aesthetic qualities.

So, dental inlays are microprostheses that can be either restorative (restore the color and shape of the tooth) or stump (the crown part of the tooth is restored).

They are:

Made of metal (used on chewing teeth) and they are not visible when talking or smiling;
All-ceramic made of zirconium dioxide or pressed ceramic;
Sintered metal;
Composite.

The service life of such tabs can reach 10 years, which is their undoubted advantage. In addition, tabs are often used when a tooth is chipped.

Veneers are the thinnest plates that are attached to the front of the teeth in the smile zone. These onlays can be made of composite, porcelain, or zirconia. They are designed to hide a huge number of aesthetic violations: chips, discoloration of enamel, gaps between teeth, scratches, curvatures. It is the attractive appearance of the teeth after the installation of veneers on them that is their main advantage.

The disadvantages of veneers are as follows:

The fragility of the structure;
Pre-grinding of the frontal teeth, as a result of which they will never be the same;
The need to wear veneers throughout life, or replace your own teeth with prostheses.

Lumineers are a type of veneers, but their distinctive feature is their increased strength. Lumineers last longer than veneers and can be installed for 20 years. Depending on the patient's wishes, the lumineers can be fixed without prior facing. The disadvantage of these dentures is their high cost.

What type of prosthesis is better for dental prosthetics?

The choice of the best prosthesis will depend on a number of factors. First of all, this is the performance of the main function of the prosthesis - chewing. In addition, it must have aesthetic appeal. The issue of price is also important for most patients.

The choice of the type of prosthesis depends on the number of missing teeth, on the condition of the patient's oral cavity, etc. Therefore, it is possible to decide which type of prosthesis is better for prosthetics only in the dentist's office.