RU2532886C2 - Device for controlling and correcting angular displacement of dental instrument - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to dentistry, particularly to dental orthopaedics, dental therapy and dental surgery. A device comprises a dental handpiece with a working instrument; a laser emitter with a laser beam former is attached to the dental handpiece; a laser emission plane is orthogonal to an axis of symmetry of the dental instrument; an optical receiver connected to a data collection and processing system wireless connected to an indication system are arranged at an equal space from the emitter and from each other.

EFFECT: structural improvement.

9 cl, 6 dwg

Description

The invention relates to dentistry, in particular to orthopedic dentistry, therapeutic dentistry, surgical dentistry, and is directed to the preparation of abutment teeth for fixed structures, the preparation of the jaws for implant systems, the installation of implant systems in the jaw, the preparation of hard tissues of teeth in therapeutic dentistry, obtaining parallelism in dental laboratory.

The dentist at any position of the chair provides visual control over the operative field in the oral cavity, being somewhat on the side of the patient. In this situation, it is difficult to navigate both with respect to the midline of the patient’s face and to make sure that the axes of the treated teeth coincide.

When setting crowns, parallel retention points on the abutment teeth are necessary.

Modern publications on the preparation of teeth using CEREC CAD / CAM technology indicate that the angle of 6 ° is considered the optimal angle of convergence of the walls of the prepared tooth for fixed structures.

Clinical observations and laboratory studies have shown that in real clinical conditions, the average angle of convergence of the prepared teeth is 20-25 °.

The human eye cannot, in a clinical situation, detect the difference between parallel preparation and bevelling of the lines of the lateral walls of the stump, having a height of 5-7 mm, up to 10 °.

An error of 10 ° and bringing the angle of convergence of the prepared tooth walls to 30 ° or more can increase the percentage of rollover of the entire structure of a fixed bridge or a single crown.

This leads to numerous misalignment of single crowns and fixed bridges, resulting in complications of the caries process.

A device for parallel preparation of teeth is known, which is taken as a prototype (RF patent 2080099, IPC A61C 3/02, publ. 05.27.1997), containing a dental tip with a head for securing and rotating the cutting tool, an actuator, which is structurally a controlled hinge, equipped with two microservomotors. In this case, the control of the actuator is provided by the control unit by means of electronic logic comparison circuits.

The disadvantage of this device is the lack of accuracy in determining parallel surfaces of the preparation of the teeth, which contributes to the low reliability and durability of the bridge structure of the prosthesis.

The basis of the invention is the task to improve the accuracy of determining the parallelism of the surfaces of the prepared teeth and, as a result, increase the reliability and durability of the bridge tooth structure.

The problem is solved due to the fact that in the device for monitoring and correcting angular deviations of a dental instrument containing a dental handpiece with a working tool according to the invention, a laser emitter with a laser beam former is mounted on the dental handpiece, the laser radiation plane being orthogonal to the axis of symmetry of the dental tool, and at equidistant distance from the emitter and between each other there are photodetectors connected to a data acquisition and processing system, Commercially wireless communication with the display system, wherein the laser emitter is mounted on a dental handpiece for rotation in three planes.

In addition, the laser beam former is made in the form of a cylindrical lens.

Each photodetector has a photosensitive layer, consisting of photosensitive sensors along the entire length, such as photodiodes.

A glass filter is installed in front of the photosensitive layer of the photodetector.

Each photodetector is mounted on the chassis and mounted on a telescopic leg with stand.

The number of photodetectors must be at least two.

Each photosensitive photodetector sensor is connected to a data acquisition and processing system.

The display system is a video glasses, for example epson moverio bt-100.

The device is illustrated by drawings, where

Figure 1 presents a diagram of a device

figure 2 presents the photodetector,

figure 3 schematically shows the location of the emitter and photodetectors,

figure 4 - the angular deviation of the working tool and the change in the place of incidence of the beam on the photodetectors,

figure 5 - information about the angular deviation on the video glasses.

figure 6 is a structural diagram of data collection.

The device consists of a dental tip 1 with a working tool 2. A laser emitter 3 with a flat radiation shaper 4 is mounted on the dental tip 4. Photodetectors 5 are located at an equal distance from the emitter 3. Each photodetector has a photosensitive layer consisting of photosensitive sensors 6 along the entire length. The photosensitive layer is closed by a protective glass filter 7. Each photodetector 6 is mounted on a telescopic leg 8 with a stand. The number of photodetectors must be at least two. The photodetectors are connected to an information collection and processing system 9, consisting of a data acquisition unit 10 and a personal computer (PC) 11. The data acquisition and processing system has a wireless connection with an indication system 12, which is a doctor’s video glasses, for example epson moverio bt-100. Flat laser beam 13. The data acquisition unit 10 reads the readings from the photodetectors 5 and consists of series-connected: the input and data matching port 14, the microcontroller 15 and the data transfer interface to the PC 16.

The device operates as follows.

The laser emitter 3, mounted on the dental tip 1, generates and emits a beam 11, which simultaneously falls on the photodetectors 5. A laser beam 11 is formed by passing through a cylindrical glass lens 4.

For the entire system to work, one condition must be met: the plane of the laser radiation must be strictly orthogonal to the axis of symmetry O _{1 of the} instrument. This is achieved by using special fasteners, which allows you to rotate the laser emitter 3 in three planes and adjust the beam plane for each specific tool on a particular dental tip. Each photodetector 5 is a vertical rack with photosensitive sensors along the entire length 6. The device can be made in two versions - using two photodetectors, and three or more photodetectors. Since the axis O _{1 of the} tool 2 is orthogonal to the plane of the laser beam 11, to uniquely determine the angular position of the axis of the tool 2, it is necessary to determine the position of the plane of the laser beam in space. In order to determine the position of a plane in space, you need to know at least three points that belong to this plane. Such “known points in space” will be the illuminated areas of each of the photodetectors 5, at the point of incidence on each photodetector, the beam 11 will illuminate a small area of photosensitive sensors. Information about the position of the illuminated region from each photodetector falls on the data acquisition and processing system 9, i.e. at the doctor’s video. Based on the information received from the photodetectors, the data collection and processing system 9 concludes the current angular position of the beam plane in space relative to the specified one (i.e., it actually concludes the degree of deviation of the beam from the given plane). The plane of the beam is associated with the position of the doctor’s working tool and does not change during operation, the system for receiving and processing data 9 from photodetectors calculates the current angular deviation of the doctor’s working tool relative to the specified one. This information is transmitted to the doctor through the data collection unit 10, PC 11 and the indication system 12.

When testing this device, two photodetectors 5 were installed, spaced 1 meter apart. At the same time, two photodetectors are equidistant from the emitter 3 by a distance of 1 meter (the accuracy and the range of variation of the angular deviations of the device will depend on these distances, the larger these distances, the greater the measurement accuracy and the smaller the measurement range). As a result, the relative position of the complex, the working tool, the first photodetector and the second photodetector, is described using a triangle (if all the distances between the elements of the complex are equal, as in our case, the triangle is equilateral), where the vertices of the triangle are the photodetectors and emitter.

With this arrangement of the complex working tool - photodetectors, it is possible to measure the angular deviation of the working tool, based on changes in the place of incidence of the beam on the photodetectors (figure 4).

The case using two photodetectors of figure 3. If the working tool 2 throughout the work will remain in the same area (at the same distance from the photodetectors), and the laser beam 13 will fall on the photodetectors 5 throughout the work, then all the angular deviations of the working tool in all planes (except the plane perpendicular to the plane of the boron) will change the place where the laser beam falls on the photodetectors. By changing the illuminated area on the photodetector, one can judge the change in the angular position of the working tool.

The data collection and processing unit 9 monitors which area and on which photodetector is illuminated. The personal computer processes the information received from the data collection and processing unit as follows:

X ₀ - zero (initial) position of the beam on the photodetector 1 (coordinate of the illuminated area on the photodetector);

Y _{0 —} zero (initial) position of the beam on the photodetector 2 (coordinate of the illuminated region on the photodetector);

X ₀ + Y ₀ = a - zero (initial) roll;

X ₀ -Y ₀ = b - zero (initial) pitch.

During tip deviations, the roll and pitch values increment (the terminology used here to determine the angular position of the tip in space, similar to that used in aviation, the tip is simply presented instead of the plane), the number of the illuminated crystal on each leg changes from the initial X ₀ ( Y ₀ ) until new X ₁ (Y ₁ ):

_.

_.

k ₁ - the magnitude of the increment of the position of the beam on the first leg (number of crystals).

k ₂ - the magnitude of the increment of the position of the beam on the second leg (number of crystals).

[(k] ₁ + k ₂ ) - pitch increments.

[(k] -k ₂ ) - roll increment.

The resulting value of the angle of deviation of the roll and pitch from the zero position:

The dependence of the angle of the indicator on the angle γ:

It is proposed to use transparent video glasses (for example epson moverio bt-100) as an indication system showing the doctor the current deviation of the working tool. The use of transparent video glasses will allow the doctor to take information about the current angular deviation of the working tool relative to a given position without taking his eyes off the field of work. Information on these video glasses comes from a personal computer (in accordance with the functionality of the video glasses).

Information about the angular deviation of the video glasses is proposed to transmit in the following form (Figure 5).

The center of the fixed circle is the zero point 17, the small circle 18 describes the deviation of the working tool from the zero point, the goal of the doctor to perform work, choosing the position of the working tool in which the centers of these circles were aligned. In this case, the deviation of the working tool from a given axis will be minimal. The information comes to the video glasses in the form of a cross on a black background, through the black background of the video glasses, the field of work for the doctor was easily seen.

A flat laser beam simultaneously hits two or more photodetectors. With known distances between the tip and both photodetectors, and between two photodetectors, we get the opportunity to measure the angular deviation of the working tool. To measure the angular deviation, you first need to set the "zero position" - the position of the working tool, relative to which the angular deviation in space will be calculated. The angular deviation of the working tool from the “zero position” will be calculated whenever a laser beam hits two photodetectors simultaneously. In the case of using two photodetectors, it is necessary to set the zero position near the turning location, in this case, the error accumulated in connection with the deviation from the zero position is small enough. With increasing distance from the place of assignment of the "zero position" to the place of work, the error in determining the deviation of the angular position of the working tool will increase in proportion to this distance. In the case of using three photodetectors, the error in determining the angular deviation will depend on the distance between the place of assignment of the "zero position" and the place of work.

This device allows the doctor to control and measure the angular position of the tool during operation, improves the accuracy of determining the parallelism of the surfaces of the prepared teeth, and as a result, the reliability and durability of the bridge tooth structure increases.

Claims (9)

1. A device for monitoring and correcting angular deviations of a dental instrument, comprising a dental tip with a working tool, characterized in that a laser emitter with a laser beam former is mounted on the dental tip, the laser radiation plane being orthogonal to the axis of symmetry of the dental instrument, and at an equidistant distance from the emitter and between themselves are photodetectors connected to a data acquisition and processing system that has wireless communication with the system my display, wherein the laser transmitter is mounted on a dental handpiece for rotation in three planes. 2. The device according to claim 1 or 2, characterized in that the laser beam former is made in the form of a cylindrical lens. 3. The device according to claim 1, characterized in that each photodetector has a photosensitive layer consisting of photosensitive sensors along the entire length, for example photodiodes. 4. The device according to claim 1 or 4, characterized in that a glass filter is installed in front of the photosensitive layer of the photodetector. 5. The device according to claim 5, characterized in that the photodetector is mounted on the chassis and mounted on a telescopic leg with a stand. 6. The device according to claim 6, characterized in that the number of photodetectors must be at least two. 7. The device according to claim 7, characterized in that each photosensitive sensor of the photodetector is connected to a data acquisition and processing system. 8. The device according to claim 1, characterized in that the data acquisition and processing system consists of a data acquisition unit and a PC. 9. The device according to claim 1, characterized in that the display system is a doctor’s video glasses, for example epson moverio bt-100.

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