JP2018153383A - Dental plaque inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of accurately detecting an adhesion state (quantity) of dental plaque adhering to teeth, which is not accurately detected due to that dental plaque sometimes adheres to a detection unit and a light guide surface in a method with a conventional dental plaque inspection device.SOLUTION: A dental plaque inspection device 100 as an inspection device which irradiates teeth 1 with light, and detects a state of dental plaque 2 adhering to the teeth on the basis of intensity of fluorescent light emitted from the teeth includes: a light emission part 3 for emitting light to be radiated onto the teeth; a detection unit (light head part 6) for detecting fluorescent light emitted when irradiating the teeth with light; receiving parts 8,9 for receiving detected fluorescent light; and a control part 20 for performing signal processing on the basis of fluorescent light intensity detected by the receiving parts. The control part detects a change in fluorescent light intensity emitted from dental plaque due to irradiating dental plaque adhering to the detection unit with light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dental plaque inspection apparatus that measures the intensity of fluorescence generated from dental plaques attached to the teeth by irradiating the teeth with light, and determines adhesion of plaques based on the measured fluorescence intensity.

  2. Description of the Related Art Conventionally, a dental plaque inspection apparatus is known that irradiates teeth with light and easily and quantitatively detects the adhesion state (amount) of plaque adhered to the teeth based on the reflected light. . An irradiating unit that irradiates light on the teeth and a light receiving unit that receives the reflected light are provided in the immediate vicinity of the teeth, and includes a detecting unit that detects the state of plaque based on the reflected light. It has been proposed to detect the adhesion state (amount) of plaque by detecting the wavelength distribution. (For example, refer to Patent Document 1).

  In addition, as a device for detecting biological deposits on the tooth surface, the teeth emit light that emits autofluorescence, and the intensity of the fluorescence is compared with the intensity of autofluorescence from the clean tooth surface. Toothbrushes have been proposed that relate to the amount of deposits. Light irradiation to the tooth and autofluorescence emission from the tooth are guided by a light guide, and a structure in which the surface (end face) of the light guide is installed near the tooth surface has been proposed. (For example, refer to Patent Document 2).

Japanese Patent Laying-Open No. 2003-210497 (first page, FIG. 1) JP 2002-515276 A (first page, FIG. 1)

  However, in the conventional dental plaque inspection apparatus or the toothbrush provided with the fluorescence means described above, the method of detecting the adhesion state (amount) of plaque or biological deposits attached to the teeth is not limited to the light receiving unit or irradiation. Since the surface of the light guide that guides light and fluorescence emission needs to be installed near the surface of the teeth, plaque and biological deposits may adhere to the surface of the light receiving unit and the light guide. Therefore, when light is applied to the teeth, it is reflected light or fluorescent light from plaque or biological deposits attached to the teeth. It was not possible to determine whether the light was from the deposits, and it was not possible to accurately detect the plaque attached to the teeth and the attached state (amount) of biological deposits.

  In addition, if the amount of plaque or biological deposits attached to the surface of the light receiving unit or light guide is small, it will be difficult to visually check for the presence or absence of adhesion, and the light receiving unit and light guide will be inspected each time inspection is performed. It was necessary to always clean the surface of this, and the work at the time of inspection was complicated.

  The plaque inspection device of the present invention was created to solve the conventional problems, and the plaque adhering to the teeth is detected with high accuracy on the surface of the light receiving unit and the light guide installed near the tooth surface. It is an object of the present invention to provide a dental plaque inspection apparatus capable of doing this.

  In order to achieve the above object, the dental plaque inspection apparatus of the present invention employs the following configuration.

A dental plaque inspection device that detects the state of plaque adhering to a tooth based on the intensity of fluorescence emitted from the tooth or plaque by irradiating the tooth with light, and a light emitting unit that emits light and the tooth A detection unit for detecting fluorescence generated when light is irradiated, a light receiving unit for receiving fluorescence, and a control unit for performing signal processing based on the fluorescence intensity received by the light receiving unit The control unit is characterized by detecting a change in fluorescence intensity emitted from the plaque adhering to the detection unit when the plaque adhering to the detection unit is irradiated with light.

  The light emitting unit is controlled so that the energy of light applied to the plaque adhering to the detection unit is higher than the energy of the light applied when detecting the state of the plaque adhering to the tooth.

The control unit includes a storage unit for storing the fluorescence intensity of the plaque adhered to the detection unit, and detects a change in the fluorescence intensity based on the fluorescence intensity stored in the storage unit.
Further, the present invention is characterized in that light is applied to the plaque adhering to the detection unit until it is detected that the fluorescence intensity becomes smaller than a predetermined value.

  The light applied to the teeth is characterized by having a wavelength band of 380 nm to 440 nm. The light receiving unit receives fluorescence in the first wavelength band and fluorescence in the second wavelength band. The first wavelength band is a wavelength band from 625 nm to 655 nm, and the second wavelength band is from 580 nm to 580 nm. The wavelength band is 620 nm, and the difference between the fluorescence intensity in the first wavelength band and the fluorescence intensity in the second wavelength band is stored in the storage unit as the fluorescence intensity of plaque adhered to the detection unit.

  By using the plaque inspection apparatus of the present invention, even when plaque adheres to the detection unit installed near the surface of the tooth, it can accurately detect the adhesion state of the plaque adhered to the tooth. Therefore, plaque can be inspected efficiently with good workability.

It is a block block diagram which shows the structure inside the plaque inspection apparatus of this invention. It is the spectrum figure which showed the characteristic of the fluorescence emission obtained when detecting the plaque adhering to a tooth | gear in the plaque inspection apparatus of this invention. FIG. 2 is a configuration diagram showing a state when detecting plaque adhering to the optical head unit in the plaque inspection apparatus of the present invention, and characteristics of fluorescence emission obtained when detecting plaque adhering to the optical head unit. It is the shown spectrum figure. It is a spectrum figure explaining the control of a light emission part with respect to the plaque adhering to the optical head part in the plaque inspection apparatus of this invention.

  Hereinafter, the plaque inspection apparatus of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the invention described in the claims and equivalents thereof.

  FIG. 1 is a block diagram showing the internal configuration of the dental plaque inspection apparatus of the present invention.

As shown in FIG. 1, the dental plaque inspection apparatus 100 according to the present invention includes a light emitting unit 3, a first light receiving unit 8, a second light receiving unit 9, and a reflection mirror 7 that reflects light emitted from the light emitting unit 3 in a prescribed direction. And a waveguide 4 like an optical fiber that transmits the irradiation light of the light emitting unit 3, and a waveguide 5 similar to the waveguide 4 that transmits detection light from the plaque to the first light receiving unit 8 and the second light receiving unit 9. , A calculation unit 21 that calculates the signals detected by the first light receiving unit 8 and the second light receiving unit 9, a storage unit 22 that stores the calculated information, and a control unit 20 that outputs a signal for controlling the light emitting unit 3. The power supply unit 23 is used to operate these installed electronic components. The waveguide 4 includes an optical head unit 6 that also serves as an irradiation unit that irradiates the irradiation light transmitted from the light emitting unit 3 and a detection unit that receives detection light from dental plaque. 1 and the structure which can be installed in the position close to the plaque 2 attached to the tooth 1.

  Therefore, the light from the light emitting unit 3 is reflected by the reflecting mirror 7 and is irradiated from the waveguide 4 to the teeth 1 and the plaque 2 through the optical head unit 6. In addition, the fluorescence or reflected light of the tooth 1 or the plaque 2 is incident from the optical head unit 6 and irradiated to the first light receiving unit 8 and the second light receiving unit 9 through the waveguide 4, the reflection mirror 7, and the waveguide 5. Thus, detection of dental plaque 2 can be made possible.

  The light emitting unit 3 emits light when detecting plaque, and may be an LED light source or a laser light source. Further, the wavelength of the light to be irradiated is desirably a wavelength in a band (for example, about 380 nm to 440 nm) in which a component contained in dental plaque absorbs light and exhibits a fluorescence reaction.

  The first light receiving unit 8 includes a light receiving element (for example, a photodiode) that can detect the intensity of a wavelength band (for example, about 625 nm to 655 nm) indicating the fluorescence peak of the fluorescence emitted from the plaque, and the second light receiving unit 9. Is preferably a light receiving element (for example, a photodiode) that can detect the intensity of a wavelength band (for example, about 580 nm to 620 nm) shorter than the wavelength band indicating the fluorescence peak of fluorescence emitted from dental plaque. The presence or absence of plaque may be identified by the difference in the color of fluorescence emitted from the plaque by an element (for example, a CMOS element).

Further, it is desirable that the reflection mirror 7 is a device that reflects light of a specific wavelength and transmits light of other wavelengths, such as a dichroic mirror, and emits irradiation light of a wavelength band described in this embodiment. When used, for example, a reflection mirror that reflects less than 500 nm and transmits more than 500 nm can be used. However, the wavelength characteristics of the reflection mirror to be used are not limited to the wavelength characteristics shown above.
The control unit 20 can compare the fluorescence intensities detected by the first light receiving unit 8 and the second light receiving unit 9, and can control the irradiation time of the light emitting unit 3 from the result of the compared fluorescence intensity.

  In the plaque inspection apparatus 100 shown in FIG. 1, the transmission of irradiation light from the light emitting unit 3 to the optical head unit 6 and the transmission of detection light from the optical head unit 6 to the reflection mirror 7 are performed via the same waveguide 4. The coaxial transmission to be performed is illustrated, but this embodiment is an example, and a configuration in which a waveguide that transmits irradiation light and a waveguide that transmits detection light are separated, or a waveguide 4 is used. Instead, the light emitting unit 3, the first light receiving unit 8, and the second light receiving unit 9 may be arranged at the tip of the optical head unit 6.

  Next, detection of plaque 2 and control of the light emitting unit 3 in the plaque inspection apparatus 100 of the present invention will be described with reference to FIGS. 1, 2, and 3.

  FIG. 2 is a spectrum diagram showing the fluorescence emission characteristics obtained when detecting plaque 2 attached to the tooth 1, where the vertical axis represents the relative value (dimensionless amount) of the fluorescence intensity, and the horizontal axis represents Wavelength (nm) is shown. FIG. 2 shows that the optical head portion 6 is inserted into the mouth so that the optical head portion 6 is in contact with the surface portion of the tooth 1 or the interdental portion, or the boundary portion between the tooth 1 and the gingiva, or in the vicinity thereof. It will be explained on the assumption. FIG. 3A is a configuration diagram showing a state when the plaque 2 attached to the optical head unit 6 is detected by the plaque inspection apparatus 100 of the present invention, and FIG. 3B is an optical head. FIG. 6 is a spectrum diagram showing the fluorescence emission characteristics obtained when detecting the plaque 2 attached to the part 6. Further, the spectrum diagrams showing the characteristics of the fluorescence emission shown in FIG. 2 and FIG. 3B are the wavelength characteristics when the intensity of the irradiation light in the optical head unit 6 is about 4.35 mW. Further, FIG. 3 will be described on the assumption that the optical head unit 6 is out of the mouth. Whether the optical head unit 6 is inserted into the mouth or out of the mouth is determined by the user of the dental plaque inspection apparatus 100 according to the present invention, and by the dental plaque inspection apparatus 100 automatically. Either method can be used.

First, the detection of the plaque 2 attached to the tooth 1 and the control of the light emitting unit 3 in the plaque inspection apparatus 100 of the present invention will be described with reference to FIGS. 1 and 2. As described above, the detection of the plaque 2 attached to the tooth 1 is performed when the optical head unit 6 is inserted into the mouth.

  Irradiation light (for example, about 380 nm to 440 nm) of the light emitting unit 3 is transmitted through the waveguide 4 via the reflection mirror 7 and irradiated from the optical head unit 6 to the plaque 2 attached to the tooth 1. The plaque 2 causes an excitation reaction by absorbing the irradiation light, and fluoresces the detection light 30 having the optical characteristics shown in FIG. The fluorescent detection light 30 enters from the optical head unit 6, is transmitted through the waveguide 4, the reflection mirror 7, and the waveguide 5, and is applied to the first light receiving unit 8 and the second light receiving unit 9. In the first light receiving unit 8 and the second light receiving unit 9, the irradiated light is converted into an electric signal according to the intensity, and the electric signal is transmitted to the control unit 20. The first light receiving unit 8 is a light receiving element that can detect the light intensity of only a first wavelength band 41 (for example, 625 nm to 655 nm), which is a wavelength band indicating a fluorescence peak of fluorescence emitted from dental plaque, The second light receiving unit 9 is a light receiving element capable of detecting the light intensity of only the second wavelength band 42 (for example, 580 nm to 620 nm) which is a shorter wavelength band than the first wavelength band. By calculating the electric signal from the unit 9 by the calculation unit 21 of the control unit 20, the adhesion state of the plaque is determined.

  Next, detection and control of the light emitting unit 3 in a state where the plaque 2 is attached to the optical head unit 6 in the plaque inspection apparatus 100 of the present invention will be described with reference to FIG. As described above, the detection in the state where the plaque 2 is attached to the optical head unit 6 is performed when the optical head unit 6 is out of the mouth.

  Transmission of irradiation light from the light emitting unit 3 to the optical head unit 6 is the same as that described in FIG. The irradiated light reaching the optical head unit 6 is applied to the plaque 2 attached to the optical head unit 6, and the plaque 2 absorbs the light to cause an excitation reaction. As in FIG. As shown in FIG. Similarly to the description of FIG. 2, the detection light 32 that has emitted fluorescence is applied to the first light receiving unit 8 and the second light receiving unit 9, and the first light receiving unit 8 has the light intensity of the first wavelength band 41 and the second light receiving unit. 9 converts the light intensity of the second wavelength band 42 into an electric signal, and the electric signal is calculated by the calculation unit 21 of the control unit 20 to determine the adhesion state of the plaque.

  As a method for determining the adhesion state of plaque, for example, the fluorescence intensity P1 of the first wavelength band 41 detected in the first light receiving unit 8 is set as the fluorescence intensity P1, and the second wavelength detected in the second light receiving unit 9 is used. The fluorescence intensity of the band 42 is set as the fluorescence intensity P2, and the fluorescence intensity P of the plaque 2 attached to the optical head unit 6 is obtained by the calculation unit 21 as the difference between the fluorescence intensity P1 and the fluorescence intensity P2 (P = P1-P2). Can do. The fluorescence intensity P is stored in the storage unit 22. The fluorescence intensity P1 can be obtained by setting the fluorescence intensity P1 to be the maximum value of the fluorescence intensity in the first wavelength band 41 and the fluorescence intensity P2 being the minimum value of the fluorescence intensity in the second wavelength band 42. . In addition, since it is only necessary to know that the fluorescence intensity of the attached plaque is attenuated to some extent, the setting method of the fluorescence intensity P1 and the fluorescence intensity P2 is determined in a predetermined manner in the first wavelength band 41 and the second wavelength band 42. The value of the fluorescence intensity at a wavelength (for example, the median value of the range) may be used, or the integrated value of the fluorescence intensity P1 may be obtained as the fluorescence intensity of the attached plaque, and a change in the value may be detected. It is not limited. Furthermore, the method of determining the adhesion state of the plaque 2 shown in this embodiment is an example, and the calculation method is not limited to this.

  Next, the control of the light emitting unit 3 when the adhesion of plaque to the optical head unit 6 is detected outside the mouth of the plaque inspection apparatus according to the present invention will be described with reference to FIG.

FIG. 4 shows detection light 32 showing the wavelength characteristic of fluorescence emission immediately after irradiating the plaque 2 attached to the optical head unit 6 with irradiation light, and wavelength of fluorescence emission after irradiating irradiation light for a certain period of time. It is the spectrum figure of the detection light 34 which showed the characteristic. The spectrum of the fluorescence emission characteristic shown in the detection light 34 is a wavelength characteristic after irradiation with irradiation light having the same intensity (about 4.35 mW in the optical head unit 6) as when the detection light 32 is detected for 10 seconds.

  First, as shown in FIG. 4, when the plaque 2 is attached to the optical head unit 6 outside the mouth, the spectrum of the detection light 32 shown in FIG. 3B is obtained and attached to the optical head unit 6. The fluorescence intensity P of the plaque 2 is obtained by the calculation unit 21. Further, the fluorescence intensity P at this time is stored in the storage unit 22.

  Next, the control unit 20 controls the light emitting unit 3 so that the irradiation light is continuously emitted. Irradiation light is continuously irradiated to the plaque 2 of the optical head unit 6, and the fluorescent substance (for example, protoporphyrin) contained in the plaque 2 absorbs a lot of light energy by being exposed to the irradiation light for a long time. Causes photobleaching. The detection light 34 shown in FIG. 4 is a spectrum of the wavelength characteristic of fluorescence emission after the irradiation light is irradiated on the plaque 2 for 10 seconds, and the fluorescence intensity P1 detected by the first light receiving unit 8 of the detection light 32 is By decreasing due to light fading, the fluorescence intensity P1 ′ is obtained, approaches the intensity of the fluorescence intensity P2 ′ detected by the second light receiving unit 9, and eventually becomes less than the fluorescence intensity P2 ′.

  The phenomenon in which the fluorescent material absorbs light energy and photobleachs is a phenomenon that occurs when exposed to irradiation light that excites the fluorescent material for a long period of time or when exposed to strong irradiation light. In addition to the means for photobleaching according to the irradiation time shown in (2), means for making the fluorescent material absorb more light energy by increasing the energy of light per unit area is also effective. When irradiating strong irradiation light, for example, a function for controlling the output of irradiation light of the light emitting unit 3 may be added to the control unit 20 and the control unit 20 may perform control. It is not limited to this. Moreover, combining these means is also effective, and is not limited to one.

  The control of the continuous irradiation of the light emitting unit 3 by the control unit 20 is such that the intensity of the detection light of the fluorescence intensity P1 ′ detected by the first light receiving unit 8 is the intensity of the detection light of the fluorescence intensity P2 ′ detected by the second light receiving unit 9. Continue until smaller than. That is, the calculation unit 21 detects the change in the fluorescence intensity emitted from the plaque by calculating the fluorescence intensity P (P = P1′−P2 ′) and storing the value of the fluorescence intensity P in the storage unit 22. can do. Then, the control unit 20 determines that the fluorescence emitted from the plaque is no longer detected because the stored value of the fluorescence intensity P becomes smaller than zero as a predetermined value, for example. Thus, until the fluorescence emitted from the dental plaque is not detected, the light emitting unit irradiates the dental plaque with light. The fluorescent material contained in the above-mentioned plaque is irreversibly photobleached, and the photobleached fluorescent material does not emit fluorescence again.

  Confirmation of the adhesion of the plaque 2 to the optical head unit 6 outside the mouth is performed when the apparatus is started up when using the plaque inspection apparatus 100 of the present invention, or the plaque 2 adhered to the tooth 1 is confirmed. This is to be done when the optical head unit 6 is taken out from the mouth to the outside of the mouth, and the operation of the optical head unit 6 being taken out from the mouth to the outside is detected and automatically performed. Also good.

  As described above, the plaque inspection apparatus 100 according to the present embodiment attenuates the fluorescence emission of the plaque 2 attached to the optical head unit 6, so that even if the plaque is attached to the optical head unit 6, It is a device that can confirm adhering plaque without erroneous detection, and can accurately detect the adhering state (amount) of plaque adhering to a tooth.

  In addition, the structure of the plaque inspection apparatus 100 of this embodiment mentioned above is an example of this invention. For this reason, the installation position of each optical system member, the installation method, the shape of the waveguide and the optical head unit are not limited to the above-described embodiment, and the gist of the invention is not changed even in other embodiments. Various modifications are possible within the range.

DESCRIPTION OF SYMBOLS 1 Tooth 2 Dental plaque 3 Light emission part 6 Optical head part 8 1st light-receiving part 9 2nd light-receiving part 20 Control part 30,32,34 Detection light 41 1st wavelength band 42 2nd wavelength band 100 Dental plaque inspection apparatus

Claims (6)

A dental plaque inspection apparatus that detects the state of plaque adhering to the tooth based on the intensity of fluorescence generated from the tooth by irradiating light on the tooth,
A light emitting unit that emits light;
A detection unit for detecting the fluorescence generated when the teeth are irradiated with light;
A light receiving portion for receiving the fluorescence;
A control unit that performs signal processing based on the fluorescence intensity received by the light receiving unit,
The control unit detects a change in the fluorescence intensity emitted from the plaque adhering to the detection unit when light is applied to the plaque adhering to the detection unit. apparatus. The light emitting unit is controlled so that the energy of light applied to the plaque adhering to the detection unit is higher than the energy of light applied when detecting the state of plaque adhering to the tooth. The plaque inspection apparatus according to claim 1. The control unit includes a storage unit for storing the fluorescence intensity of plaque adhered to the detection unit, and detects a change in the fluorescence intensity based on the fluorescence intensity stored in the storage unit. The plaque inspection apparatus according to claim 1 or 2. The plaque examination according to any one of claims 1 to 3, wherein the plaque adhered to the detection unit is irradiated with light until it is detected that the fluorescence intensity becomes smaller than a predetermined value. apparatus. The plaque inspection apparatus according to any one of claims 1 to 4, wherein the light applied to the teeth has a wavelength band of 380 nm to 440 nm. The light receiving unit receives fluorescence in a first wavelength band and fluorescence in a second wavelength band, the first wavelength band is a wavelength band of 625 nm to 655 nm, and the second wavelength band is 580 nm. A wavelength band of ˜620 nm,
The difference between the fluorescence intensity in the first wavelength band and the fluorescence intensity in the second wavelength band is stored in the storage unit as the fluorescence intensity of plaque adhered to the detection unit. The plaque inspection apparatus according to any one of claims 1 to 5.

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