For the preparation of carious cavities, special equipment and tools are used. A key element of the equipment of a modern dental office is a dental unit, which is part of the workplace of a dentist.
dental unit is a complex of electrical, mechanical and hydraulic elements that converts external energy into the energy of dental instruments and is designed to provide the necessary conditions for dental treatment (Shmigirilov V.M., 2002). Currently, in therapeutic dentistry, universal dental units of domestic and foreign production are most often used.
(see Fig. 28) has an electric and air drive for handpiece operation, an oil-free compressor, it is connected to the water supply and sewage system, equipped with an air and driven bur cooling system, an aspiration system (saliva ejector, “vacuum cleaner”), etc. The dental lamp should have sufficient power, at the same time, its light should not cause spontaneous polymerization of light-cured materials. The dental chair should provide comfort for the doctor and the patient during treatment, both in the position of the patient "lying" and in the position of the patient "sitting". In addition, the installations can be equipped with additional devices and equipment: a carious cavity illumination system through the tip, a built-in lamp for the polymerization of light-curing materials, a computer, a radiovisiograph, an endodontic microscope, etc.
The dental unit must meet the following requirements:
- the design of the unit must meet the requirements of ergonomics and correspond as much as possible to the individual physiological characteristics of the dentist (the doctor should be comfortable working);
- the design of the unit must meet the requirements of a particular treatment process (there are enough “necessary” functions; there are no redundant, “unnecessary” functions);
- the installation should be comfortable and safe for the patient, its appearance and comfort should positively influence the patient's subjective perception of the quality of the dental care provided to him;
- the cost and design of the unit must correspond to the price category and the general interior of the clinic, as well as the personal taste of the doctor;
- the brand, design and construction of the unit should help to improve the professional image of the doctor both in the eyes of patients and in the eyes of fellow dentists;
- the installation must be reliable, the risk of equipment failure must be minimal;
- the unit should be easy to repair, it should have an affordable service, the delivery time of spare parts should be minimal.
In accordance with this requirement, when purchasing a unit, it is necessary to provide for the possibility and availability of after-sales service, warranty and post-warranty repairs. Dental units currently on the Russian market, depending on their configuration, design, clinical capabilities and price group, can be divided into three classes. Let's take a look at this division using KaVo's dental units as an example.
1. Economy class. In the lot class, you can include installations of relatively low cost, of sufficiently high quality, but limited by the minimum number of functions required by the doctor. In addition, they are convenient for the doctor and the patient, functional, but not distinguished by an exclusive or "advanced" design. An example is the "Unik T Standard" (KaVo) installation (see Fig. 29).
Rice. 29. Universal dental unit "Unik T Standart" (KaVo)
2. Business Class. The lot class should include installations of an average price category, improved quality, allowing you to use any tool and achieve the required adjustments. Such installations have additional functions and are equipped with additional tools (photopolymerization device, ultrasonic piezoelectric scaler, tip illumination, etc.). In addition, such units are equipped with a more convenient and ergonomic control system with programming functions. An example is the "KaVo PRIMUS 1058 S" (KaVo) installation (see Fig. 30).
Rice. thirty. Universal business-class dental unit "KaVo PRIMUS 1058 S" (KaVo).
3. Elite class. This class includes installations of a high price category, created on the basis of the latest technologies and original design and design solutions. Such installations have a number of additional functions, are equipped with additional tools, a computer and a control system with programming functions. The comfort of such devices for the doctor and the patient is increased, they are highly functional, they are distinguished by an exclusive, "advanced" design. An example is the installation "KaVo ESTETICA E80 T" (KaVo) (see Fig. 31)
Rice. 31. Universal dental unit "KaVo ESTETICA E80 T" (KaVo).
The workplace of a dentist (see Fig. 32), in addition to the installation, is equipped with a dental chair to accommodate the patient; chairs for the doctor and assistant; furniture to accommodate tools, instruments, materials and medicines; other equipment, depending on the specialization, qualifications, individual preferences of the doctor and the capabilities of the medical institution. The workplace of a dentist is equipped in accordance with the principles of ergonomics.
Rice. 32. The workplace of a dentist based on a modern universal dental unit.
Modern dental units have various drive types(see Table 7). From the drive, rotation is transmitted to the cutting tool with the help of a tip.
Dental handpiece- this is a tool that directly converts the energy of the compressed air flow, the rotation of the micromotor or electric current into the corresponding movements of the working tool (bur, endodontic file, scaler, etc.). The first dental handpiece was created in 1919, the first electric drill appeared in 1926, and the air turbine appeared in 1959.
Rice. 33. Turbine tip
In therapeutic dentistry, turbine, contra-angle and straight handpieces are used to prepare hard tissues of teeth and process fillings. In the turbine handpiece (fig. 33), the bur is driven by compressed air, which is supplied to the turbine rotor located inside the handpiece head (fig. 34).
Turbine handpieces are currently the most commonly used in restorative dentistry. Their main advantage is the high speed of rotation of the bur, reaching 160-400 thousand rpm. These tips provide fast and efficient preparation of hard tissues, primarily tooth enamel. However, the low mechanical power of the turbine handpiece leads to the fact that an increase in burr pressure on the treated tissue causes its rotation to slow down or even stop (“jamming”). In addition, it should be remembered that increased lateral loads that occur with excessive pressure on the drill during the preparation process lead to accelerated wear of the turbine handpiece rotor group. Reducing the force of pressure on the bur reduces the efficiency of cutting hard tissues. Therefore, when working with a turbine handpiece, you should constantly control the pressing force on the bur. The pressure force on the drill should be minimal, similar to stroking. When using a sharp bur and the tip is in good condition, this force is quite sufficient for effective preparation of hard tissues of the tooth. The air pressure supplied to the turbine should also not be exceeded. This, although it increases the speed of preparation, leads to rapid wear of the handpiece. Another possible problem in the process of preparation with a turbine handpiece is a violation of the mode of cooling of the tooth tissues. This can lead to damage to parietal enamel and dentin (thermal necrosis), pulp burns, as well as soft tissues surrounding the tooth. It is our deep conviction that the preparation of hard tooth tissues without sufficient air-water cooling is unacceptable. The turbine handpiece is connected to the drill by means of a rubber hose having a mouthpiece with holes (connector) at the end. The types of connectors most common in our country are shown in Table 8. In addition, there are special adapters that allow you to connect, for example, a Midwest tip to a Borden connector, etc. Turbine handpiece burs have a shank diameter of 1.60 mm (Fig. 35). In the tip, the burs are fixed with a collet device or a special key.
contra-angles(Fig. 36) are low speed. Their main feature is the variety of working tools used and types of movements during preparation. A conventional micromotor handpiece with 1:1 gearing provides bur rotation speeds from 1,000 to 40,000 rpm. Increasing tips are also produced with a gear ratio of 1:2-1:10, the speed of rotation of the bur in them is 5,000-230,000 rpm. Reducing handpieces usually have a ratio of 4:1 and are used primarily in endodontic procedures. The speed of rotation of the drill in the lowering tip is 10-10,000 rpm.
Rice. 36. contra-angle
Straight handpieces(Fig. 37) have approximately the same speed characteristics as angular ones, however, due to their design features, they allow more pressure to be exerted on the set without the appearance of tool vibration. They are used mainly by dental surgeons, dentists and orthopedists and dental technicians. The straight handpiece burs have a shaft diameter of 2.35 mm (Fig. 35) and are fixed in the handpiece with a collet. The rotating parts of the tips wear out over time. Signs of wear are: the appearance of vibration and beating of the bur during rotation, deterioration of the fixation of the bur in the tip, heating of the tip, the appearance of unusual sounds during operation. In this case, repair or replacement of the tip is required.
Rice. 37. Straight handpiece
It is necessary to constantly monitor the technical condition of the tips. Of great importance in ensuring their long-term operation is proper care for them. Handpieces should be cleaned and disinfected after each patient intake. It is recommended to lubricate the handpieces at least twice per shift, on average - after receiving 4-5 patients of a therapeutic profile and always before sterilization. Lubrication is carried out either with liquid oil using a grease can, or with a special pressurized aerosol lubricant (spray). The use of a spray is considered more effective, as it allows not only to lubricate the tip more effectively, but also to remove contaminants from its internal channels. After lubrication, the tips should be stored head down in a special container. Do not leave a lubricated handpiece on the unit, as this can lead to oil leakage into the micromotor and failure of the latter. Before starting work, excess oil is removed from the surface of the handpiece, and the handpiece is "blown": it is turned on outside the patient's mouth for 15-20 seconds. It should be remembered that some turbine handpieces, in order to extend the life of the rotor group, require the supply of oil along with the drive air. When working with such a tip, it is necessary to constantly monitor the presence of oil in a special reservoir inside the unit and one hundred flow to the compressor. Most modern turbine handpieces, on the other hand, require the absence of oil in the drive air and the use of oil-free compressors. The speed handpiece should be stored with the bur clamped into it. This lengthens the life of the collet. When working with a contra-angle, care must be taken when inserting a bur into it, since inserting a bur to a shallower depth leads to damage to the locking latch and the need to repair the tip. The above recommendations are of a general nature. In cases where the manufacturer gives other instructions, it is necessary to follow the instructions attached to the tip.
There are various brands of dental units on the market from economy class to VIP equipment. When purchasing this or that device, always focus on your audience and its needs. The budget class includes installations of Chinese and Brazilian manufacturers, the middle class is South Korean equipment and part of the series from Italian, German brands. The Hi-End segment is represented by Japanese, German and Italian manufacturers.
Of the inexpensive brands, we can recommend Premier, Fona, Azimut, Luck, Diplomat. For the middle class, the economy Excellence series from the German brand Ritter is quite suitable, as well as the Slovak brands Chiromega, Mediprogress, Slovadent, Chirana Dental and the South Korean Hallim Dentech, as well as a number of lower models A-dec, OMS and Takara Belmont. For high-level dentistry, take OMS, the top series Ritter and A-dec, Takara Belmont, as well as Castellini, Morita and Kavo.
Types of dental units are most often classified according to their configuration.
For the arrangement of the patient chair:
- Hydraulic (lower reliability, lower price).
- Electromechanical (high reliability, high price).
According to the types of doctor's block:
- Installations with the top type of giving of tools. (Pluses: the presence of a convenient mechanism for returning the instrument to its original position. Minuses - sleeves limited in length can hamper the doctor's work.)
- Installations with the bottom giving of tools. (Pros: more freedom of movement for the dentist. Cons: the dentist makes sure that the handpiece does not fall out of the socket. The part is subject to imperceptible contamination.)
Drive type:
- Air - for installation of turbine, micromotor, laser tips. The tools of the pneumatic drill and the turbine drill are equipped with an air-water cooling system.
- Electric - for mounting electric micromotors and piezoelectric scalers.
According to the device of the assistant's block:
- With a vacuum suction system designed to collect saliva, solid particles, blood from the patient's mouth. The vacuum system requires the installation of a suction separator.
- With injector suction system. (Designed for higher compressor power consumption).
For hydroblock equipment:
- With spitting bowl equipped with a swivel mechanism (hygienic and comfortable for the assistant).
- With a stationary glass bowl (has a lower cost).
By the number of control pedals:
- With two main pedals that allow you to adjust the patient chair, control instruments.
- With additional pedals (facilitate and speed up the work of the dentist, but increase the installation price).
Dental equipment can also be classified according to the way it is located:
- Stationary installations that are rigidly fixed to the cabinet floor;
- Portable, where the medical unit is free from a rigid connection with the chair.
The equipment of such manufacturers has proven itself well among Russian buyers:
Chirana Dental, Chirastar 501, Chirana Medical Smile 02 and 04. from Slovakia; SDS 1750, A-DEC 2000 from the USA, Darta 3000 of Russian-American production, Puma Eli 5 line, Castellini.Tempo 9 Italy, Siger (S30, S60, S90) from China. Economy class equipment is also popular China: AJAX AJ 11, AJAX AJ 12 Slovakia: Smile Chirana, Germany: Ritter (lower price segment from Chinese components).
How much does a dental unit cost
The Chinese dental unit Azimut 500 A costs $4555, the South Korean HALLIM Challenge Ever unit costs $7400, the Italian OMS Tempo 9 ELX KART costs $13800, the price of the German Ritter Contact World S is $22500, the Japanese Takara Belmont Clesta II A-type is $19800.
Dentistry as a separate branch of medicine was formed in the 20s of the last century. At the same time, the first drills were produced, comparable in size to a perforator, and their sound resembled the roar of a bomber.
In the 21st century, medicine can afford not only compact drills, but also portable dental units that fit in a suitcase.
A dental unit is a complex of all the tools that are necessary for most dental procedures. The device of the dental unit includes:
- patient chair;
- tool table;
- instrument block;
- illuminator;
- for air supply;
- water and air heating unit;
- spittoon bowl.
Types of dental units
There are two types of such equipment:
- Stationary. All equipment is located on an area of 3-4 square meters. m and has a rigid attachment to the floor. These designs are distinguished by a large set of tools and instruments, but low mobility and bulkiness.
- Portable. The doctor's module does not have rigid connections with the patient's chair. Such equipment is compact and highly mobile.
Smart installation choice
When choosing any dental equipment, you should pay attention to the reliability and power of the tools that it comes with.
For example, the patient chair may be equipped with a hydraulic or electric lifting mechanism. The first option has a low price, but is more prone to wear and, as a result, breakdowns.
Attention! Because of the high cost, clinics often prefer used equipment. But the fact is that it is sold without any warranty and service. It is better to purchase new equipment from an official supplier who will provide not only its setup, but also technical support and repairs.
When buying such equipment, it is important to give preference to proven manufacturers: KaVo (Germany), Diplomat (Slovakia), Sirona (Germany), Darta (Russia), FONA (China, Slovakia), Azimut (China).
Installation, repair and maintenance
Installation of a dental unit will not bring many problems if you strictly follow the instructions that are always included in the kit. The whole difficulty lies only in moving this structure, and it is caused by its mass - 200-250 kg. 
Maintenance of equipment is carried out once a month and consists of computer diagnostics and technical inspection. This is done by professionals, because the wrong setting entails problems that can lead to a complete failure of the dental unit.
The cost of repairs depends on the nature of the damage. For the most minimal repair, the owner of the equipment will be forced to pay the master about 2,000 rubles (and this is only for the work itself). Therefore, the purchase of new equipment, which will be under warranty, is more beneficial for the clinic.
Overview of the most popular models
Dental units "Darta" (Darta) are widely known in Russia, as they are produced in our country.
Darta 1600 M is one of the most popular models on the dental equipment market. Manufacturers have tried on the design and ensured ease of operation. Also, the developers themselves noted that when designing the unit, all the preferences of doctors and their assistants were taken into account. However, the Darta 1600 M is a bottom-feed device, and according to experts, this leads to the fact that the doctor has to make sure that the tip does not fall out of the socket. Also, this part is subject to imperceptible contamination.
Sirona Intego is the brainchild of a German company that was part of Siemens until 1997. The manufacturer himself calls this equipment the best in its class. And doctors note the convenience of working chairs and increased freedom of action. However, it is worth noting that Sirona is also more expensive than the products of its competitors.
Dental unit "Diplomat" (Diplomat Adept DA110A)- This is another popular model that has managed to establish itself in the market. Country of origin - Slovakia. Adept DA110A is a stationary device with bottom feed of tools. The equipment is compact and lightweight - depending on the variant - 50-70 kg. Experts speak positively about this model and the manufacturer as a whole due to the good balance between price and quality of the products offered.
Conclusion
The dental unit, along with the competent work of the doctor, makes up a large part of the successful operation of the clinic. Therefore, the selection of equipment must be approached thoroughly.
It is worth giving preference to manufacturers who have proven themselves in the market. It will be beneficial to purchase new equipment from an official representative of the company, which will provide warranty repairs and maintenance of the dental unit.
1. According to the method of location in the office:
· stationary rigidly fixed to the cabinet floor
dental unit
· portable , in which the doctor's unit does not have a rigid connection with the chair, which allows it to be optimally positioned during the patient's appointment.
In some cases, the portable unit allows you to upgrade older dental units.
The appearance of a portable installation
2. By the number of service personnel:
· only for the doctor;
· for simultaneous work of a doctor and an assistant - the so-called principle of work in "four hands".
Workplace of a dentist
3. According to the way the tool block is located:
· mobile trolleys , represent the most simplified and less expensive tool feed system. They can be moved based on the need for location, performance and aesthetics, and can be automated.
Appearance of mobile medical modules
· cabinet built-in brackets – suitable for rear and side feed of the tool. Arms are the most expensive and least mobile of all tool delivery systems and can be built into furniture. The patient, sitting down in a chair, does not see the instrument.
· a doctor's table mounted on a pantographic holder with instruments and a halogen lamp less aesthetic than other types, but provides a large radius of action: the table moves in horizontal and vertical planes, which ensures its convenient location relative to the doctor and patient, and is also equipped with negatoscope , to view x-rays.
4. According to the method of attaching the hoses:
· T - type
Modules per unit are arranged vertically - bottom feed.
dental unit
· S-type
Modules are arranged horizontally - top feed.
5. Depending on the configuration, dental complexes are divided into three main classes:
· economical;
· average;
· high class.
Economy class dental complexes completed
the minimum necessary a set of equipment, instruments and accessories that are used for basic therapeutic and orthopedic operations.
As part of the complex of economical class includes:
· patient chair; (see below.)
· mounted dental unit;
· clean water system;
· dental compressor;
· doctor's chair.
Mounted dental unit as part of the dental complex, it is intended for therapeutic and orthopedic operations when providing dental care to the patient, it is mounted on the side panel of the chair using a special adapter. Installation
consists of the following main blocks:
- tip holders (turbine tip, micromotor, gun);
- dental lamp;
- spittoons with saliva ejector and foot control pedal;
- water and air supply systems.
Tip holder block includes:
A three-functional gun that supplies water, air or a mixture of them to the tooth treatment area;
Pneumatic turbine handpiece with a bur rotation frequency of at least 300,000 rpm and water-air cooling of the tooth treatment zone;
- pneumatic micromotor with a burr speed of up to 20,000 rpm.
Pneumohydraulic equipment that provides the supply of working and cooling air, as well as cooling water to the tips.
On the block panel the handles for adjusting the spray pattern of the cooling mixture, the pressure of the working air, as well as the main toggle switch for turning the unit into operation, are removed. To control the working air pressure, the unit is equipped with a manometer.
The block is mounted on a pantograph device, which, at the physician's discretion, can hold it in any position within a range of at least 400 mm vertically and rotate freely in two planes.
Dental light unit provides an adjustable degree of illumination of the tooth in the range from 10 to 20 kLux. The lamp is mounted on its own pantograph device, which ensures its movement in three planes and retention in any position chosen by the doctor.
spittoon block with a saliva ejector and a foot control pedal provides washing of the bowl of the spittoon, supplying water to the patient's mouthwash cup and suction of saliva during therapeutic or orthopedic operations. Washing the bowl has an automatic time adjustment of the flow of water into the bowl, achieved through the use of a pneumatic time switch in the design. Filling the glass with water is carried out after pressing the corresponding button.
The design of the saliva ejector has an ejector that runs on compressed air. It is switched on by pressing the foot pedal. Depending on the impact force, the performance of the saliva ejector is regulated.
All of the above units are mounted on a common rack, which provides the necessary access for maintenance, diagnostics and sanitization.
Clean water system. To increase the durability of the tips and the complex as a whole, as well as to exclude patient infection, a system was introduced into the design of the dental unit that supplies clean distilled water to the tips to cool the tooth treatment area, as well as a three-functional dental gun.
Dental compressor is designed to supply the dental complex with compressed air purified from chemical and mechanical impurities. The design of the compressor is equipped with its own system for reducing and purifying air from mechanical impurities and condensed moisture. The compressor is powered from an alternating current network with a voltage of 220 V, a frequency of 50 Hz. The sound pressure level of the operating compressor does not exceed 40 dBA.
Chair for a dentist. The chair contains:
Base;
Rack on which the seat is attached;
To provide qualified assistance, the most important equipment is a dental unit. Dental unit is a hardware complex that allows you to perform basic dental interventions.
Currently, the concept of installation means a complete set, including the installation itself, a chair, a compressor, a doctor's table, a doctor's chair and an assistant's chair.
Dental unit device
The dental unit consists of functional blocks, each of which has its own purpose. Depending on the configuration of the installation, the set of blocks may vary.
The main blocks of the dental unit
- Toolbox the main unit of the dental unit contains instruments for manipulations in the oral cavity. It can be equipped with a lighting unit for tools with fiber optic illuminators.
- low speed motors provide rotation speed of the rotary tool from 10,000 to 30,000 revolutions per minute.
- High speed rotary(turbine) tools provide rotary tool rotation speeds from 300,000 to 500,000 rpm. Usually two tips: therapeutic and orthopedic.
- Other tools scaler (a tool for removing dental deposits), polymerization lamp (for polymerization of photopolymers), etc.
- Control block consists of a pedal and a control panel, it is used to control all systems of the installation (position of the chair, speed of rotation of instruments and other parameters).
- Hydroblock.
- Spittoon designed to dispose of saliva and other liquids in the sewer system, equipped with a flush system.
- glass shell designed to fill a glass with water for rinsing the mouth. Equipped with a filter to clean the incoming water.
- Saliva ejector designed to dispose of saliva and other fluids directly from the patient's mouth into the sewer system.
- A vacuum cleaner is intended for utilization of the aerosol mixture formed in the oral cavity during the operation of high-speed (turbine) handpieces.
- Water-air gun It is intended for drying with a jet of air and irrigation of the oral cavity with water or an air mixture.
- Lighting block consists of a halogen lighting lamp for lighting the working field and a bracket that allows you to raise, lower, turn in a horizontal plane and hold the lamp in a given position.
- Dentist chair designed to accommodate the patient. Moves in a vertical plane (raises and falls) to provide a height convenient for
