JP2017153582A - Dental light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dental light irradiation device that can be inserted into a narrow place such as a root canal of a tooth and a periodontal pocket, and can efficiently condense and apply an irradiation light from an LED light source.SOLUTION: A dental light irradiation device includes a slender tip chip that can be inserted into a narrow place in an oral cavity, a handpiece body with the tip chip attached to the distal side end part, an LED light source attached to the inside on the distal side of the handpiece body, and a lens body for receiving an irradiation light from the LED light source and guiding it the tip chip. A light receiving surface for the irradiation light from the LED light source of the lens body is formed by an aspherical surface, and the tip chip includes a taper-shaped light guide part which is tapered, and an irradiation part formed integrally at the tip of the light guide part so as to emit the light guided at the light guide part.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a light irradiation apparatus used for photobacterial treatment in dentistry, etc., particularly a tip such as a tip that can efficiently irradiate a narrow part of the oral cavity with a desired intensity at the tip of a handpiece using an LED as a light source. The present invention relates to a dental light irradiation apparatus having

  Irradiating a narrow part such as a tooth root canal or a periodontal pocket is extremely effective for medical treatment of such a part. As the prior art that can irradiate light even to a narrow part of a tooth in this way, the techniques disclosed in Patent Documents 1 to 4 can be cited. Patent Documents 1 to 4 disclose a technical idea of irradiating a narrow part such as a tooth root canal or a periodontal pocket.

  However, these are commonly configured to guide light from a light source through a light guide or an equivalent (including a condensing member) and irradiate the target site. When the light is guided through the light source, it is inevitable that light irradiation unevenness and attenuation of the light amount occur, and in order to obtain a sufficient light amount at the irradiation end, it is necessary to use a light source with a large capacity. In addition, associated equipment is increased in size or power consumption is increased. In particular, in a dental light irradiator, the light source and related equipment are incorporated in a handpiece type grip part, etc., and therefore the grip part etc. is naturally increased in size, which causes a reduction in handling suitability. .

  In order to solve such a problem, in Patent Document 4, a light source is attached to the distal end portion of an elongated member 7 that can be inserted into a narrow site such as a tooth root canal or a periodontal pocket, and the medical site is directly irradiated. Although a handpiece type light irradiation device having a configuration is provided, in this device, since the light source is provided at the tip, it is not possible to make the tip sharp, but conversely, if the tip is made thinner, the strength like an LED The problem is that the irradiation intensity is insufficient with a weak light source.

Special table 2003-525072 gazette Japanese Patent Laid-Open No. 2003-310641 JP 2004-321422 A JP 2011-135973 A

Therefore, the present invention has been created to solve the above-mentioned problems, and can be inserted into a narrow space such as a tooth root canal or a periodontal pocket, and can efficiently radiate light from an LED light source. It aims at providing the dental light irradiation apparatus which can condense and irradiate.

The dental light irradiation apparatus of the present invention is
An elongated tip (for example, the tip 15 in the present embodiment) that can be inserted into a narrow portion in the oral cavity;
A handpiece body (for example, the body 12 and the head 13 in the present embodiment) in which the tip is attached to the distal end;
An LED light source (for example, the LED light source 16 in the present embodiment) attached to the distal side of the handpiece body;
A lens body that receives irradiation light from the LED light source and guides it to the tip chip (for example, the lens body 17 in the present embodiment);
The lens body has an aspherical light receiving surface from the LED light source,
The tip has a tapered light guide portion that tapers (for example, the tapered portion 15a in the present embodiment), and an irradiation portion that emits light guided by the light guide portion (for example, the elongated portion 15b in the present embodiment). It is characterized by having.

  When the dental light irradiation apparatus of the present invention is used for light sterilization treatment or the like, a tip tip having an LED as a light source is inserted into a narrow portion such as a tooth root canal or a periodontal pocket to irradiate light. According to this dental light irradiation device, since the LED light source is used at the distal end of the handpiece, the light guide path from the light source is close to the tip, and the attenuation and decrease in intensity of irradiation light are small. On the other hand, since the light source is not provided in the tip, the tip can be reduced in size and lengthened, and insertion and light irradiation can be performed even in a narrower part. The tip and the lens body may be formed as separate members or may be molded integrally with each other.

  Further, according to the dental light irradiation apparatus, the end surface of the lens body that receives the irradiation light from the LED light source is configured as an aspherical surface (in this specification, the aspherical surface does not include a plane). Therefore, the main beam of light from the LED light source can be changed into parallel light and guided in the lens body. Therefore, the light from the LED light source can be emitted from the tip chip with maximum efficiency.

  The irradiation surface of the lens body may also be aspherical.

  The inside of the lens body is generally guided by parallel light, but if the irradiation surface to the tip is also aspherical, it is focused in the tip tip toward the central axis and depends on light guide by reflection in the tip tip Even if not, the number of reflections can be reduced and light can be guided to the irradiated portion. Especially when it is an ultra-fine tip that inserts the irradiated part into a particularly narrow part such as a tooth root canal or periodontal pocket, and the taper angle of the light guiding part cannot be made too large. It is good.

In the dental light irradiation device of the present invention,
The lens body may be formed such that the light receiving surface of the irradiation light from the LED light source is flat and the irradiation surface is aspherical.

  In the above-described dental light irradiation apparatus described above, the light receiving surface of the lens body is aspherical. However, the same applies if the light receiving surface of the lens body is flat and the irradiation surface side is aspherical.

  Moreover, it is preferable that the taper-shaped angle of the light guide portion of the tip is an acute angle so as to be substantially totally reflected on the inner surface.

  According to this configuration, the taper angle of the light guide portion of the tip chip that receives light from the lens body is set to an acute angle, and is configured to be totally totally reflected inside the light guide portion. When such a configuration is adopted, when light is applied to the inner surface (inner wall) of the tip end more than the total reflection angle, it has the property of being totally reflected without being transmitted to the outside. Also, as the number of reflections increases, the optical path becomes longer and the attenuation of light increases, which is disadvantageous for efficiency. Therefore, the smaller the number of reflections, the higher the light guide efficiency. Therefore, in the present invention, the parallel light received from the lens body is substantially totally reflected internally as a light guide portion having an acute taper angle (tapered), and the number of reflections (ideally about twice at most) is reduced. doing.

  Moreover, it is preferable that the light receiving surface of the lens body is positioned within an irradiation angle range including a predetermined ratio or more of the luminous flux of the irradiation light from the LED light source.

  Although the irradiation light from the LED light source diffuses, in practice, most of the light flux is included in the range of the predetermined irradiation angle. Therefore, it has been found that it is preferable to irradiate the light receiving surface of the lens body directly from the LED light source with effective light rather than providing a reflector or a separate light guide in order to obtain high intensity irradiation light. Therefore, in this dental light irradiation apparatus, it is comprised so that a light-receiving surface may be located in the effective irradiation angle range.

  Furthermore, the light receiving surface on the lens body side of the tip may be formed as an aspherical surface.

  In the previous example, the irradiation surface side of the lens body was formed as an aspheric surface, and was condensed in the light guide part of the tip chip. In this example, the shape of the light receiving surface side of the tip chip is aspherical. The same effect is intended.

According to the dental light irradiation apparatus of the present invention, it is a rechargeable handpiece that uses an LED light source, but can be inserted into a narrow part such as a tooth root canal or a periodontal pocket. At the same time, it is possible to efficiently condense and irradiate without reducing the intensity of the irradiation light from the LED light source. For example, when this dental light irradiation device is used for photo-sterilization treatment or the like, rapid and effective photo-sterilization can be performed.

FIG. 1 is a perspective view showing an overall configuration of a dental light irradiation apparatus 1 as an embodiment of the present invention. A plan view of the handpiece of FIG. 1 is shown in (a), and a front view is shown in (b). The figure which modeled the LED light source, the lens body, and the chip | tip is shown. (A) shows a schematic plan view of the LED light source, and (b) shows the result of the directional distribution of the light emission. (A) is a schematic diagram shown about the simulation of the light ray which injects into a lens body from an LED light source, (b) is a schematic diagram which shows the mode of selection about the light emission part of an LED light source, when evaluating a simulation result. Actually, for the three types of lens bodies shown in (a), graphs evaluated by comparing the light beam simulation results of FIG. 5 are shown in (b) and (c). It is an example of a combination of a lens body and a chip with high efficiency of light guiding. (A) is an aspherical upper part on the LED light source side and flat on the lower part, and (b) is non-planar on the LED light source side. In the spherical shape, the lower part on the chip side is also aspherical, and in (c), the upper part on the LED light source side is aspherical and the upper part of the chip is aspherical. 7A is a modified example of FIG. 7A, the upper part on the LED light source side is planar and the lower part is aspherical, and FIG. 7B is the upper part on the LED light source side planar and the lower part is aspherical. The upper part is also aspheric.

  FIG. 1 is a perspective view of the entire cylindrical hand piece including the light irradiation device 10 of the present invention, and FIG. 2 is a plan view of the hand piece (FIG. 2 (a)) and a front view (FIG. 2 (b)). It is shown. FIG. 1 is a perspective view showing an overall configuration of a dental light irradiation apparatus 10 as an embodiment of the present invention. The dental light irradiation device 10 shown in FIG. 1 is configured in a cordless handpiece type that can mainly irradiate the root canal and periodontal pocket of a tooth. The dental light irradiation apparatus 10 includes a grip-shaped main body 12 which is a part held by a surgeon during dental treatment, and a head 13 which is detachably attached to the front side portion of the main body 12. . The main body 12 is provided with a charging battery for supplying power to the LED light source 12. Since the LED light source 12 is disposed in the head 13, although not shown in FIGS. 1 to 2, the approximate position is indicated by a point 16 in FIG. 2 (hereinafter also referred to as the LED light source 12).

  Further, the head 13 includes a head base portion 13a and a head front end portion 13b attached to the front end of the head base portion 13a, and a chip 15 is detachably attached to the head front end portion 13b. On the surface of the head 12, an operation / display unit 14 is provided for displaying the irradiation time and illumination intensity, the set irradiation time and remaining irradiation time, the remaining battery level, and the like. Inside the head base 13a, there is an electric control unit (not shown) that controls the start / stop of the light irradiation of the LED light source 16 by receiving the operation from the operation / display unit 14 and the power supply from the battery in the main body 12. It is arranged.

  Further, the head tip portion 13b is inclined upward at a predetermined inclination angle (θ = 25 ° in the example of FIG. 2) with respect to the axes of the main body 12 and the head base portion 13a. A lens body 17 that guides irradiation light from the internal LED light source 16 to the chip 15 is attached to the head tip portion 13b. The chip 15 is attached to the head end portion 13b by being directly attached to the lens body 17. With such a configuration, the chip 15 is irradiated with light.

  The surgeon grasps the main body 12 of the handpiece 10 having the above-described configuration, puts the head tip portion 13b into the oral cavity, inserts the tip of the tip 15 into the root canal of the tooth, periodontal pocket, etc., and irradiates with light. Photosterilization treatment and the like can be performed. Hereinafter, the configuration and light guide of the chip 15 serving as a light irradiation portion, the LED light source 16 that supplies light to the chip 15, and the lens body 17 that guides light from the LED light source 16 to the chip 15 will be described by way of example.

  FIG. 3 schematically shows the LED light source 16, the lens body 17, and the chip 15. In the dental light irradiation apparatus of the present invention, it was examined how to efficiently guide the light emission power of the LED light source 16 to the chip 15. Specifically, Condition (1) The power of the LED light source 16 is captured by the lens body 17 with high efficiency. Condition (2) Light incident on the captured lens body 17 is guided to the lower part (chip side) with high efficiency. Condition (3) A configuration in which incident light from the lens body 17 to the chip 15 is diffused in a highly efficient and non-directional manner was studied.

In this verification, the following polycarbonates were used as the lens body 17 and the chip 15 that serve as the light receiving and light guiding elements.
Density: 1.20 g / cm3
Available temperature: − 100 ° C to +180 ° C
Melting point: about 250 ° C
Refractive index: 1.585 ± 0.001
Light transmittance: 90% ± 1% (3mm)
Line attenuation coefficient μ: 0.3512 cm-1
Thermal conductivity: 0.19 W / mK
Total internal reflection angle: 39.1 °

As the LED light source 16, an LED engine LED (model number: LZ4-00R208) having the following specifications was used.
Lighting color: Red
Wavelength: 660nm
Luminous intensity: 2.6cd
Luminous flux / radiant flux: 2.6W
If-forward current: 700mA
Vf-forward voltage: 10.5V
Power rating: 7.4W
Maximum / minimum operating temperature: + 125 ° C / -40 ° C
Viewing angle: 95deg

  As will be described in detail later, first, the irradiation light from the LED light source 16 is incident on the upper portion of the lens body 17. Although the irradiation light from the LED light source 16 is diffused, it is desirable that most of the diffused light is incident on the lens body 17 in view of the condition (1). A method of condensing diffused light by providing a reflecting plate around is also conceivable. However, in consideration of the utilization rate of reflected light, here, from the LED light source 16 to the LED light source 16 and the lens body 17 based on the directivity of irradiation light. The distance l and the diameter r1 of the upper part 17a of the lens body 17 are set. Note that the diameter r1 of the lens body 17 is preferably small. This is for interference with peripheral members, downsizing of the device, and sharpening of the taper angle α of the chip 17 described later.

The lens body 17 is integrally molded, but its upper portion 17a is an aspheric lens. As a result, the main beam of incident light is made parallel to the axial direction, the sub beam at the center is also sharpened to promote internal reflection, and emission to the outside is reduced. The incident light of the parallel light is guided through the lens body 17 as it is,
The aspherical shape of the upper portion 17a of the lens body 17 may be a convex shape upward or a concave shape that opens upward.

  The light guided in the lens body 17 is emitted from the lower portion 17b. In the example of FIG. 3, the lower portion 17b has a planar shape, but may have an aspherical shape as shown in FIG.

  The light emitted from the lower portion 17b of the lens body 17 is incident on the chip 15 as it is. The chip 15 is attached to the lower portion 17 b of the lens body 17. The tip 15 includes a tapered portion 15a having a diameter r2 that decreases downward, and an elongated portion 17b that extends downward by integral molding with the tapered portion 15a. The elongated portion 15b is directly inserted into a tooth root canal or a periodontal pocket, and the lower end of the elongated portion 15b may be sharp, but the lower end is not shown in FIG. 3 (the lower end is shown in FIG. (See example in FIG. 2).

  The light incident on the tapered portion 15a is preferably guided to the elongated portion 15b with a small decrease in intensity, and is preferably totally reflected by the inner surface and less reflected (ideally reflected at most). 2 times). Therefore, the taper angle α needs to be small and acute, and the elongated portion 15b preferably has a large diameter r3. On the other hand, the diameter r3 desired by the treatment site is set as the diameter of the elongated portion 15b.

Thus, in order to utilize the total reflection on the inner surface, specifically, the following relationship is established.
Total reflection angle> K + 2nα
(Total reflection angle = 90-critical angle)
K: incident light angle n: number of reflections (n = 2 at most ideal)
α: taper angle critical angle = smallest incident angle at which total reflection occurs

Next, the details of the LED light source 16, the lens body 17, and the chip 15 will be described.
4A is a schematic plan view of the LED light source 16, and FIG. 4B shows the result of the directional distribution of light emission. The LED light source 16 has a light emitter 16 a supported by the LED base 16. The light emitter 16a is formed with rotational symmetry about the central axis. As can be seen from the light emitter 16a, the LED light source 16 is not a point light source, but has an infinite number of light source points in a finite range (the distance in the width direction of the light emitter 16a) as shown by the arrows. Light is radiated to Therefore, it is necessary to consider the directivity distribution of light.

  Here, assuming that the irradiation light from the surface light emitter issued from the lower surface of the LED base portion 16b has passed through the light emitter 16a which is a spherical glass lens, The angle was tracked and calculated. As a result, the calculated directivity distribution of the light emitter 16a (LED light source 16) is shown in FIG. From this figure, it can be seen that the LED light source 16 includes 97% or more of light flux in the range of the D irradiation angle β = 110 °, and it is ideal to capture the irradiation light in this range.

  Next, a simulation of a light beam irradiated from the LED light source 16 and incident on the lens body 17 will be outlined with reference to FIG. First, an arbitrary point on the surface of the light emitter 16a of the LED light source 16 is set as the light emission point (1). Next, the angle (incident angle) at which the light beam (2) emitted from the set light emitting point (1) is incident on the upper portion 17a of the lens body 17 is calculated. Based on the calculated incident angle, refraction is calculated when incident light enters the surface of the upper portion 17a of the lens body 17. Refracted light is traced and reflected when it reaches the wall surface (17c or 15a), but it is evaluated whether the critical angle (= 90 ° -total reflection angle) can be maintained even if reflection occurs. . If the critical angle cannot be maintained, it is determined that this ray does not reach the tip. A ray that can maintain a critical angle after reflection is continuously traced, and if this ray finally reaches the upper side of the tip 15b, it is considered good. This evaluation is performed for all rays. At this time, the light emitting portion of the light emitting body 16a is selected, and it is determined that a predetermined radius or less emits light as shown in (1) to (4) in FIG. In the actual simulation, the radius is chopped finely, a large number of light spots are evaluated, and the simulation accuracy is improved.

Evaluation as a light beam (high-efficiency light beam) with a small intensity drop in the lens body 17 calculates and evaluates the total efficiency Te as shown in Equation 1.
In Equation 1,
Beam area ratio coefficient at radius r: Sr (proportional to the square of the beam angle determined by radius r)
Ray distribution rate at radius r: Dr (proportional to the circumference determined by radius r)
Number of rays to be evaluated at radius r: Nr
Number of rays reaching the tip of radius r: Mr
It is said.

FIG. 6 shows a result of actually comparing and evaluating the above-described light beam simulation results with three types of lens bodies 17. As shown in FIG. 6 (a), (1) is a planar lens body 17 for both the upper and lower parts, and (2) is a spherical upper part 17a on the LED light source side and a planar lower part 17b on the chip side. (3) shows an upper surface 17a on the LED light source side that is aspherical, and a lower portion 17b on the chip side that is a planar lens body 17. Here, the lens body diameter is evaluated from 4 mm to 8 mm. Below the lens body, there is no side portion 17c, and the length immediately becomes a 16 mm taper portion, and the tip diameter is 0.5 mm. (See FIG. 3).

In FIG. 6 (b), Te in the lens body 17 of (1) to (3) of FIG. 6 (a) is shown on the left side and the right side, respectively. As can be seen from this graph, the overall efficiency of the lens body 17 of (1) is about 0.15 at most, and the maximum efficiency of about 0.25 for the lens body of (2). In (3), the higher one is over 0.35,
From this figure, it can be understood that the light incident from the LED light source 16 to the aspherical lens body 17 is guided to the chip 15 with higher efficiency. At this time, it is understood that the lens diameter should be about 4.5 mm in order to optimize the LED light source.
FIG. 6C shows a change in the overall efficiency of the aspherical lens of (3) when the tip diameter is changed. As can be seen, a change of 0.05 mm also affects the efficiency, indicating that the overall efficiency is proportional to the tip diameter. It can be seen that the tip diameter should be as thick as possible within a practical range.

  FIG. 7 shows three types of combinations of the lens body 17 and the chip 15 with high efficiency of light guiding. (A) The upper part 17a on the LED light source side is aspherical, the lower part 17b on the chip 15 side is a planar lens body 17, and (b) is the upper part 17a on the LED light source side is aspherical. In addition, the lower part 17b on the chip 15 side is also an aspherical lens body 17, and in FIG. 8C, the upper part 17a on the LED light source side is aspherical and the upper part 15c of the chip 15 is aspherical.

  In the example of FIG. 7A, the light incident on the upper portion 17a of the lens body 17 is refracted to become parallel light, is incident on the chip 15 as parallel light, and is guided in the tapered portion 15a. . The parallel light is substantially totally reflected and reaches the elongated portion 15b while maintaining a critical angle in the tapered portion 15a.

  In the example of FIG. 7B, the light incident on the upper portion 17a of the lens body 17 is refracted and temporarily becomes parallel light as shown in FIG. 7A (not shown), but the length of the lower portion 17b of the lens body 17 is reduced. It can be seen that the light is focused on the aspherical surface of the focal point, enters the chip 15, and is guided through the tapered portion 15a. The condensed light converges on the spot region 19 near the boundary between the tapered portion 15a and the elongated portion 17 and reaches the elongated portion 15b. This example is advantageous when there is a limit to the acute shape of the taper angle or when it is difficult to maintain the critical angle. This can be said to be a method for reducing the number of reflections to 0 as much as possible.

  The example of FIG. 7C is a modification of FIG. 7B, and the light incident on the upper portion 17a of the lens body 17 is refracted and becomes a parallel light once, but at the upper portion 15c of the chip 15 ( It can be seen that the light is condensed by the same long focal aspherical surface as the lower portion 17b of b) and guided in the tapered portion 15a. The condensed light converges on the spot region 19 near the boundary between the tapered portion 15a and the elongated portion 17 and reaches the elongated portion 15b.

FIG. 8A is a modification of FIG. 7A, in which the upper portion 17 on the LED light source side is planar and the lower portion is aspherical. FIG. 8B is a modification of FIG. 7C, in which the upper part on the LED light source side is planar, the lower part is aspherical, and the upper part of the chip is also aspherical. 7A and 7C, the irradiation light from the LED light source 16 is changed to parallel light at the upper portion 17a of the lens body 17, but in the example of FIGS. 8A and 8B, at the lower portion 17b of the lens body 17. It is supposed to change to parallel light.
7 to 8, the side surface 17c of the lens body 17 is provided with a vertical surface, but the side portion 17c may not be provided.

As mentioned above, although embodiment of this invention was described based on drawing, a specific structure is not limited to these embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and all modifications within the meaning and scope equivalent to the scope of claims for patent are included.

DESCRIPTION OF SYMBOLS 10 Dental light irradiation apparatus 12 Main body 13 Head 13a Head base part 13b Head front-end | tip part 14 Operation display part 15 Tip 15a Taper part 15b Elongated part 15c Chip upper part 16 LED light source 16a Light-emitting body 16b LED base part 17 Lens body 17a Upper part 17b Lower part 17c side Part 19 Spot area

Claims (6)

An elongated tip that can be inserted into a narrow spot in the oral cavity;
A handpiece body with the tip attached to the distal end;
An LED light source mounted inside the distal side of the handpiece body;
A lens body that receives irradiation light from the LED light source and guides it to the tip chip;
The lens body has an aspherical light receiving surface from the LED light source,
The tip light tip includes a tapered light guide portion that tapers and an irradiation portion that emits light guided by the light guide portion.   The dental light irradiation device according to claim 1, wherein an irradiation surface of the lens body is formed as an aspherical surface. An elongated tip that can be inserted into a narrow spot in the oral cavity;
A handpiece body with the tip attached to the distal end;
An LED light source mounted inside the distal side of the handpiece body;
A lens body that receives irradiation light from the LED light source and guides it to the tip chip;
The lens body is formed such that the light receiving surface of the irradiation light from the LED light source is flat and the irradiation surface is aspherical,
The tip light tip includes a tapered light guide portion that tapers and an irradiation portion that emits light guided by the light guide portion.   The dental light irradiation apparatus according to claim 1, wherein the light receiving surface on the lens body side of the tip is formed as an aspherical surface.   The dental light irradiation apparatus according to any one of claims 1 to 4, wherein the angle of the tapered shape of the light guide portion of the tip is an acute angle so as to be substantially totally reflected by the inner surface thereof. . The light receiving surface of the lens body is positioned within an irradiation angle range including a predetermined ratio or more of a light flux of irradiation light from the LED light source. Dental irradiation equipment.