Orthopedics

An inlay is – an artificial restoration that fills a tooth defect. In fact, it is an ideal filling made outside the mouth, in a dental laboratory. Inlays are indicated for the restoration of large cavities in the chewing teeth. They are made of high-strength ceramics or composite material.

The advantages of tabs in comparison with fillings are the ability to restore the anatomy and function of the interdental contact point and their strength in the restoration of this area in the masticatory teeth.

If the front teeth have an ugly shape or discolored, you can use beautiful overlays – veneers. (Veneer is a microprosthesis that covers the vestibular surface of the front teeth.) Like inlays, veneers are made in the laboratory. With the help of veneers, the lost shape and color of the teeth so much color that it is almost impossible to distinguish them from real teeth.

If you can’t save a smile with the help of inlays and veneers, you can restore a damaged tooth with a crown. An artificial crown is a non-removable structure that is installed on its roots and replaces the natural crown of the tooth.

Restoration of teeth with artificial crowns is used in cases where it is not possible to restore a tooth with a filling or tab. All-metal, metal-ceramic and all-ceramic crowns are currently used. Plastic crowns are used only as temporary structures.

Solid metal crown is made by high-precision casting of various metal alloys, including precious ones.

The undoubted advantage of these crowns is the homogeneity of the metal and the lack of solder when connecting them with artificial teeth. The crown is very strong and durable.

The only drawback is its low aesthetics, high thermal conductivity, ie when eating hot food can be unpleasant. The crown is very close to the machined tooth and does not allow to clog food, resorb cement and break down the tooth. In the manufacture of cast bridges, the destruction of the structure at the junction of individual teeth is virtually eliminated. With the help of these crowns it is possible to create an anatomical shape of the tooth, as close as possible to the natural one.

All-ceramic crowns come in two types – porcelain and zirconium oxide crowns (so-called zirconium crowns). They are distinguished from metal-ceramic ones precisely by the fact that they do not contain metal, ie they are metal-free structures.

Porcelain crowns are made of special porcelain by injection molding under pressure and at high temperatures. Under such conditions, the ceramic acquires special strength and does not require a metal frame. Such ceramics is more aesthetic than metal ceramics and in its physical and optical properties is more consistent with the natural tooth.

Advantages of extruded porcelain ceramics:

• Excellent aesthetics, which completely conveys the shades and transparency of the natural tissues of the tooth
• High stability of aesthetic properties, which guarantees excellent aesthetics for a very long period of time.

Disadvantages of extruded porcelain ceramics

• Suitable for the manufacture of only single crowns – due to the fact that inside the porcelain crowns there is no frame – the manufacture of porcelain bridges is contraindicated.

These are crowns made of zirconium dioxide, which is the most modern material today for the manufacture of crowns, inlays and bridges. In the professional language of dentists, such crowns pretend to be metal frame ceramics. The aesthetics of such structures is as consistent as possible with the aesthetics of real healthy teeth.

Zirconium crowns consist of a high-strength framework of zirconium dioxide and sintered on it porcelain mass. This framework is only slightly inferior to metal in strength, but has a light transmission that is not inherent in the metal.

The frame of zirconium dioxide is made by “CAD / CAM technology”, which means:

• Computer simulation of the future crown
• Milling with an automatic machine

Advantages of zirconium crowns:

• Excellent aesthetics, which fully conveys the shades and transparency of the natural tissues of the tooth.
• High strength due to the zirconium dioxide frame.
• Quality and reliability – thanks to modern materials and manufacturing technologies.

Disadvantages of zirconium crowns

• High cost – zirconium dental crowns are expensive due to the very high cost of equipment, consumables and labor costs.

Metal-ceramic crowns are a budget compromise today between strength, aesthetics and cost in dental prosthetics.

Metal-ceramic crowns inside have a cast frame made of a specially designed alloy, the main elements of which are chromium and cobalt (or nickel). This frame has a thickness of 0.3 – 0.5 mm. It is also possible to use alloys of precious metals, consisting of gold, platinum, palladium, and others.

For the manufacture of metal-ceramic crowns, the dental technician first makes a metal frame, then after fitting the frame it is applied ceramics. Therefore, metal-ceramic crowns have a natural appearance. Metal-ceramic crowns adhere to the tooth with good accuracy.

Advantages of metal-ceramic crowns:

• Good aesthetics
• Durability and strength

Disadvantages of metal-ceramic crowns:

• The need for grinding a large volume of hard tissues of the tooth

A bridge prosthesis is a fixed orthopedic structure that resembles a bridge that is attached to the teeth with crowns, crowns with pins, inlays. It can be made of the same materials and the same technology as the crown. Their distinctive feature is the presence of an intermediate part in the form of artificial teeth. It is used to replace one or more missing teeth.

If the bridge is metal-ceramic, then in the laboratory first make a metal base of the bridge – a metal frame. In the clinic, the frame is tried on the teeth, and, making sure that it corresponds exactly to them, again sent to the dental laboratory to cover it with a special ceramic mass, due to which the teeth will look like the color of natural teeth.

Depending on the method of fixation in the oral cavity, dentures are removable and non-removable. What kind of prosthesis is indicated for a particular patient, decides the dentist-orthopedist.

Non-removable prostheses include artificial crowns and bridges (see above).

Removable prostheses are prostheses that the patient can remove from the mouth and install in the mouth themselves. Removable dentures are indicated for partial loss of teeth, when it is impossible to make bridges or restore the integrity of the dentition with implants, as well as complete loss of teeth. Removable prosthetics are considered to be one of the most difficult methods of orthopedic treatment.

Removable dentures are divided into lamellar and clasp (arc). Lamellar ones in turn distinguish between partial and complete.

The lamellar prosthesis is made of artificial teeth located on the plate, which in turn is made of special plastic under the color of the gums. Due to this, the prosthesis is quite light and relatively cheap. Lamellar prostheses are partial and complete.

Partial lamellar prosthesis (PSP) is used in cases where one or more teeth are lost, when it is not possible to use a masticatory tooth as a support for a bridge, due to its absence or poor stability of the latter in the jaw bones. Also indications for prosthetics with removable partial dentures are defects of dentitions of great length. Partial removable dentures can also be made in the absence of some teeth or a single tooth and the patient’s unwillingness to grind healthy teeth to fix the bridge or as a temporary denture.

Unfortunately, in the lower jaw, in contrast to the upper, such a prosthesis is poorly kept. You can improve the fixation of these prostheses by placing implants.

Clasp prosthesis (from him. “Bugel” – “arch”) – an arcuate prosthesis that allows you to use your own teeth and gums for suppor, which allows you to evenly distribute the masticatory load between the mucous membrane and the remaining teeth.

The clasp prosthesis has saddle-shaped parts, artificial teeth, an arch and support-retaining elements (clamps, lock fastenings and sometimes splinting elements). Saddle-shaped parts cover only toothless areas, leaving free the palate and the part where there are natural teeth. Saddles are interconnected by an arc – a clasp. The basis of the clasp prosthesis is a metal frame (arc, clasps, etc.).

There are clasp prostheses with support-retaining clasps (special hooks) and locking fasteners (attachments).

• In clasp dentures with clasps, the denture is held on the teeth with hooks of different shapes, which are selected individually for each tooth. Clamps tightly cover the tooth, but due to their elasticity do not damage the enamel.
• Clasp prostheses with locks have a very strong prosthesis attachment. According to the principles of attachment, such prostheses resemble bridges. This means that part of the pressure during chewing is transferred to the abutment teeth. Such teeth are usually covered with all-metal or cermet crowns. The fastening is hidden inside the clasp prosthesis, which means that the clasps and other metal elements of the structure are not visible from the outside.

Modern clasp prostheses ;are high-tech designs that solve two tasks at once (splinting and prosthetics), which have a lot of advantages and a minimum of disadvantages.

Advantages of clasp prostheses:

• More comfortable than plate prostheses (due to the fact that they take up less space in the mouth).
• Strong
• More aesthetic than CSPP
• Better fixed on the teeth
• Do not disrupt taste sensitivity
• Evenly distribute the load between the teeth and the mucous membrane
• Durable

Disadvantages of clasp prostheses:

• More expensive than ChSPP
• Require periodic relocation once every 6-12 months.
• If you do not follow the rules of using these dentures and untimely relocation can overload the abutment teeth.
• When making clasp dentures with attachments, it is necessary to cover the abutment teeth with crowns.

Adaptation to removable dentures

Removable dentures are a foreign body in the oral cavity, so in the first two or three weeks of using the prosthesis may be profuse salivation.

ChSPP transfer a significant portion of the masticatory pressure to the oral mucosa, which is not physiological. Therefore, removable dentures can cause pain, which requires mandatory correction by a dentist.

At the first time of use of prostheses the function of language is broken. This problem is solved by reading aloud and sucking lollipops.

On average, the period of adaptation to prostheses is 3 weeks.

Care of removable dentures

• Removable dentures require mandatory removal at night.
• It is necessary to store prostheses in capacity with 100% humidity, for additional cleaning in the container with water it is desirable to add special soluble tablets (PROTEFIX, COREGA).
• After each meal, dentures require removal, rinsing under running water and rinsing the mouth.
• Twice a day (morning and evening) dentures should be cleaned with a toothbrush and toothpaste.

The average service life of prostheses is 4 years.

Clasp dentures are much more durable if you follow the rules of care and timely relocation.

At considerable destruction of a crown part of a tooth before filling, the tooth is strengthened by a metal or fiberglass pin. When restoring a tooth on a pin, the condition of the tooth root is very important – it must be strong, the root canal must be well sealed. Restoration of a tooth on a pin is especially durable if the tooth after such restoration will be covered with a dental crown.

Installation of dental pins

The cast metal inlay ;is a pin collapsible or monolithic design which is made in laboratory and is installed in the tooth channel. It consists of a pin and a stump, which allows you to simulate the crown part, which is covered with a crown. Collapsible structures are used to restore teeth with two or more roots.

Another indisputable advantage of the inlay is its ability not only to restore the tooth, but also to become a reliable support, both for a single crown and for a bridge. For application of this method of treatment it is necessary to fulfill two conditions: healthy periodontal tissues and well-sealend root canals.