SU1482670A1 - Method of diagnosis of focal demineralization of tooth enamel - Google Patents

Abstract

This invention relates to medicine, in particular to therapeutic dentistry. The proposed method allows one to quantify the degree of focal demineralization of tooth enamel by detecting the intensity of reflected light from its surface. The purpose of the invention is to improve the accuracy of the method. The intensity of the reflected light from the affected and healthy area is measured. Their attitude is calculated and, if its value is greater than one, they diagnose focal demineralization. The method is carried out using a device comprising a light source and a light guide, at the working end of which there is a nozzle including a collecting lens, a dividing plate, a diaphragm and a photoreceiver optically conjugated with a dividing plate, as well as a photo-EMF recorder. In order to more efficiently focus the light beam emerging from the light guide, a low-intensity laser is used as the light source. The nozzle aperture is attached to the tooth surface in the affected and intact area, the photo-EMF reading is recorded and the relationship between the values obtained is determined. 1 il.

Description

one

This invention relates to medicine, in particular to therapeutic dentistry.

The aim of the invention is to improve the accuracy of the method.

The drawing shows a diagram of the device for implementing the proposed method.

To implement the proposed method, a device is used comprising a light source and a light guide in which there is a nozzle at the working end of the fiber, including a collecting lens arranged successively along the beam, a dividing plate, a diaphragm and a photodetector optically coupled to the dividing plate and connected to the recorder photo-emf, and in order to more effectively focus the light beam emerging from the light guide, a low-intensity laser is used as the light source.

The method is carried out in the following manner,

After turning on the laser light source and the EMF recorder, they record the recorder's readings, which

314

represent a background. Then the nozzle aperture is attached to the affected part of the earth and the readings of the recorder are recorded, after which the same takes place in the healthy part. From the last two readings, the first (background) is subtracted and the digital relation between the values obtained is determined, which indicates the degree of demineralization.

For the implementation of the method using a continuous argon laser ILA-120 with a wavelength of 514 nm. The radiation power used before the light enters the fiber is 20 and 2 mW. As a light guide, a regular fiber bundle (60 lines per 1 mm) with a diameter of 2 mm and a length of 270 mm is used. A lens with a focal length of 1 mm and a relative aperture of 1: 2.5 is used to focus the light beam on the object under study. A photodiode FD-11K operating in photodiode mode is used as a photodetector, and a B7-21 voltmeter is used as a photo EMF recorder.

A device for implementing the proposed method contains an argon laser 1, a light guide 2, a lens 3, a dividing plate 4 (oriented at an angle of 45 ° to the axis of propagation of light), a diaphragm 5, a photodetector 6, a EMF recorder 7, the object under study (tooth) 8.

The study material was medically removed intact teeth, on the enamels of which focal demineralization areas were simulated. The intensity of demineralization depended on the residence time of the teeth (exposure) in a demineralizing environment.

Example 1 A molar with a focal demineralization area on the buccal surface of the crown (3 mm diameter, exposure in a demineralizing medium — 3 weeks) was placed in front of the aperture of the diaphragm. With the help of radiation of 20 mW, the photo-emf readings were: background - 51 mV, affected area 115 mV, healthy area - 83 mV. Therefore, the degree of demineralization was

 2

(one)

EXAMPLE 2. The same mole r was investigated. Before the aperture of the diaphragm

a demineralization site located on the luminous surface of the crown (diameter 3 mm, exposure to a demineralizing medium — 2 weeks) was placed. With the same radiation power, the photo-emf readings were: background - 51 mV, affected area - 87 mV, intact - 80 mV, Demineralization degree was

 1.24

(2)

five

0

five

five

0

five

0

0

Comparison of indicators (1) and (2) demonstrates a greater degree of focal demineralization in case (1). The application of the dye to the tooth surface led to the termination of the source of demineralization only on the buccal surface (a 2% aqueous solution of methylene sigieg was used, application for 3 minutes). Thus, the proposed method for determining the degree of focal demineralization of enamel is superior in its sensitivity to the method of vital staining.

Example A mole with a plot of focal demineralization on the buccal surface of the crown (diameter 3 mm, exposure in a demineralizing medium — 18 days) was studied at a radiation power of 20 mW and 2 mW. With a power of 20 mW, the photo-emf readings were: background - 51 mV, affected area - 99 mV, intact - 83 mV. With a radiation power of 2 mW, the photo-emf readings were respectively: background - 15 mV, affected area - 24 mV, intact - 21 mV. Thus, the degree of focal demineralization in both cases was 1.5, from which it can be concluded that a change in the power of the laser source leads to a change in the absolute values of photovoltage without affecting the digital ratio between these values.

Example 4. A mol p with a plot of focal demineralization on the buccal surface of a crown (diameter 3 mm, exposure in a demineralizing medium — 20 days) was investigated before and after treatment with a mineralizing solution. With the help of radiation of 20 mW, 5 photo-emf readings were as follows: background - 51 mV, affected area - 114 mV, intact area - 86 mV. After a 10-minute application of an 8% alcoholic solution of chloride ... calcium and drying

air, the photoelectric indices of steel became, respectively: background - 51 mV, affected area - 108 mV, intact - 85 mV. Consequently, the degree of focal demineralization after the effect of the remineralizing solution decreased from 1.8 to 1.68, which indicates the presence of a remineralization effect.

These examples show that the proposed method for determining the degree of focal demineralization of tooth enamel and a device for its implementation provide an opportunity to quantitatively characterize the degree of focal demineralization.

Example-5. Patient M., 13 years old, in the prhepeecal third of the vestibular surface of the tooth crown had a focal demineralization area of 1.5x3 mm. The research indicators using the proposed method were: background - 25 mV, demineralization section - 50 mV, intact area - 35 mV. Thus, the demineralization rate was

35 - 25 -

The tooth is removed by orthodontic indications (labial position 3). The tooth was cut through the area of demineralization under study, the preparation was painted with a 2% solution of methylene blue. A tooth cut was examined

ten

15

20

using a BMI-1 microscope to measure the depth of demineralization. The depth of demineralization was 395 microns.

Example 6. Patient P., 23 years old, removed G8 due to pericoronaritis. On the buccal surface there was a focal demineralization area of 2 x 2.5 mm. The EMF indices were: background - 25 mV, demineralization section - 79 mV, intact area - 40 mV. Thus, the demineralization rate was

79-25

A stained tooth cut was examined with a BMI-1 microscope. The depth of demineralization was 1276 microns.

Thus, a higher demineralization rate corresponds to a greater depth of damage.

Claims (1)

Invention Formula A method for diagnosing the focal demineralization of tooth enamel, including the delivery of a light beam to the affected and healthy area through a light guide, which, in order to improve the accuracy of the method, records the intensity of the reflected sing from each segment, determines the ratio between the values obtained and when the ratio is significant, large units diagnose focal demilization.