WO2011114718A1

WO2011114718A1 - Dental oct device

Info

Publication number: WO2011114718A1
Application number: PCT/JP2011/001518
Authority: WO
Inventors: 角保徳; 小澤総喜
Original assignee: 財団法人ヒューマンサイエンス振興財団
Priority date: 2010-03-16
Filing date: 2011-03-15
Publication date: 2011-09-22

Abstract

Provided is an OCT device capable of accurate diagnosis of proximal and occlusal caries and capable of the inside drawing of tooth root canal without performing an excess root canal enlargement. An OCT probe (140) is inserted into an embrasure and an image of a proximal surface is captured by at least one of rotating and moving forward and backward the OCT probe (140). An image of an occlusal surface is captured by using a horizontally moving means (220) for horizontally moving the OCT probe (140) and a vertically moving means (230) for vertically moving the OCT probe (140). An inside image of tooth root canal is captured by selectively and compatibly using a first OCT probe (101) for irradiating light at a right angle, a second OCT probe (102) for irradiating light toward the tip of a probe, or a third OCT probe for emitting light, the angle of which is equal to an angle between the angle of the first OCT probe and the angle of the second OCT probe.

Description

Dental OCT device

The present invention relates to a dental optical coherence tomography (OCT) apparatus used when acquiring a tomographic image in a root canal. More specifically, the tomographic images of the tooth apex, apical periodontal tissue, and side branches can be acquired and the tissue images can be drawn, and the conventional dental diagnostic imaging equipment is extremely photographed. The present invention relates to a dental OCT apparatus that enables diagnosis and diagnosis of dental diseases such as remnants, pulpal root canals, fractures, and cracks. Moreover, it is related with the dental OCT apparatus which image | photographs a tooth adjacent surface and a tooth occlusion surface.

Caries are a disease that accounts for about 40% of the causes of tooth extraction. As the caries deepen into the tooth, inflammation occurs in the pulp, causing pulpitis. Pulpitis is classified into, for example, acute pulpitis and chronic pulpitis, and in the initial symptoms of acute pulpitis, odontoblasts undergo degenerative atrophy, hyperemia, serous exudation, etc. at the site of inflammation. For deciduous teeth and young people who have a fast progress of touching, the dentin is destroyed almost before and after acute purulent pulpitis, and open total purulent pulpitis occurs, resulting in pulp necrosis. In the case of pulpitis, if left untreated, inflammation or infection may develop in the periodontal tissue including the periodontal ligament, periosteum, and jawbone.

If a bacterial infection spreads to the root pulp and irreversible total pulpitis, a pulpectomy is usually performed, but after removal of the pulp, the metabolism of the teeth (dentin / dental pulp) by the blood vessels is lost. As a result, the dentin becomes brittle and the incidence of fractures or cracks increases. In addition, since nerves are lost due to the degeneration of dental pulp that transmits pain, subjective symptoms cannot be obtained when suffering from dental caries again, making early detection difficult.

When the caries-causing bacteria group enters the dental pulp, the infected pulp undergoes necrosis within the tooth, and the bacterial body enters the jawbone and causes apical periodontitis. For the treatment of apical periodontitis, (1) mechanical cleaning using a reamer or file, (2) chemical sterilization cleaning with hypochlorous acid or hydrogen peroxide, etc. (3) iodine, water Endodontic treatment such as local preparation with calcium oxide, antibiotics and formaldehyde is performed, but there are many cases of recurrence.

Periapical periodontitis has a long period of time compared to pulpitis and the pain symptoms are mild, and it often destroys the jawbone over time with apical periodontal abscess → granulomas → cyst, There are cases that are discovered after becoming serious, such as retrograde infection of surrounding teeth, which is a major cause of tooth loss.

Infected lesions formed in the jawbone continuously infiltrate the whole body blood vessels even when chronic, causing infective endocarditis, myocardial infarction, cerebral infarction, and the like.

On the other hand, the anatomical form of the tooth apex often has side branches and a net-like apex compared to the root body. Since the structures of the side branches and the reticulated apex are fine and complex, and these complex structures vary from person to person, it is extremely difficult to evaluate the side branch and the reticulated apex in vivo. In addition, it is extremely difficult to find an excessively stenotic root canal that is present in the medullary canal that is narrowed with age, which reduces the outcome of endodontic therapy.

Root canal treatment is performed blindly using a reamer and a file, and there is no method for directly confirming the condition inside the root canal or the root canal wall or root apex.

During initial treatment of pulpitis and apical periodontitis, reliable endodontic treatment is indispensable, and preoperative examinations, initial lesions, side branches, and reticulated apex are detected in vivo to ensure it. The development of methods and equipment is being sought. In addition, although objective image inspection methods such as fractures, cracks, deformed excessively stenosed root canals, and the presence or absence of remnants are indispensable, these inspection methods do not yet exist.

Hard tissue examination methods in dental clinics include dental X-ray photography, panoramic X-ray examination, and dental CT, etc., all of which have low resolution and accurate depiction of tooth apex anatomy. It is extremely difficult to depict apical periodontitis, detect fractures of roots, etc.

On the other hand, OCT is a state-of-the-art technology that can acquire tomographic images from the surface layer to the inside of a living tissue at high speed and with high resolution, and has attracted attention as non-invasive imaging including ophthalmology.

For example, Non-Patent Document 1 describes intra-root OCT imaging of the root of the tooth root using OCT for cardiovascular (Light-Lab (registered trademark)). For example, Patent Document 1 describes an OCT probe that acquires a tomographic image of an observation object in the oral cavity using low-coherence light emitted from a light source.

However, in the OCT probe of Non-Patent Document 1, the light emission angle is 90 degrees with respect to the optical fiber, and the diameter of the OCT probe is larger than the root canal diameter. It is possible to depict only the tooth apex and apical periodontal tissue, and excessive root canal enlargement that penetrates the tooth is necessary, and the root apex and root apex without root canal enlargement. It is impossible to visualize the periodontal tissue. The OCT probe of Patent Document 1 also has a light emission angle of 90 degrees with respect to the optical fiber. Even if this OCT probe is applied to intra-root canal imaging, the upper pulp cavity and the root canal body part Although it is possible to depict the tooth apex and the apical periodontal tissue, it is impossible.

Next, there are three major parts of touching, the first is the occlusal surface of the tooth, the second is the cervical part, and the third is the tooth and teeth adjacent to each other. It is a tooth adjacent surface that is a surface that is present.

Caries-causing bacteria and food residues adhere to teeth as plaques. Plaque adheres not only to the gingival margin and the boundary between the dental restorative material and the tooth, but also to the tooth occlusal surface of the molar tooth. Plaque attachment on the tooth occlusal surface is the main cause of contact with the tooth occlusal surface. is there.

Conventionally, in dental occlusal surface diagnosis, an X-ray imaging apparatus, an intraoral camera, a dental camera, X-ray CT, MRI, and the like are used for inspection and examination. Among these, the image obtained by the X-ray imaging apparatus is a transmission image, and it is difficult to know the internal structure of the measurement object three-dimensionally, and X-rays are harmful to the human body. There is a limit to the number of shots. Since the intraoral camera images only the surface of the intraoral tissue, internal information such as teeth cannot be obtained. X-ray CT is harmful to the human body as well as an X-ray imaging apparatus and has a poor resolution. MRI has poor resolution and a large and expensive apparatus.

Therefore, as described above, in recent years, an OCT (Optical Coherence Tomography) apparatus is harmless to the human body and can obtain three-dimensional information of a measurement object with high resolution. In the field of dentistry, an invention using an OCT apparatus has been made.

For example, in Patent Document 2 and Patent Document 3, low-coherent light generating means for irradiating a tooth part of a subject, and means for scanning a predetermined region of the tooth part using the low-coherent light as signal light And OCT means for acquiring an optical tomographic image of a scanning region by interference between reflected light from a predetermined depth in the scanning region and reference light, and describes a low-coherent light as a subject. As a means for irradiating the tooth part, a handpiece type OCT probe attached to the tip of an arm is described. With these techniques, it is possible to photograph the labial and cheek lateral surfaces of the teeth and periodontal tissues and the oral soft tissues that can reach linearly.

However, the maximum opening of a person, which is the distance from the mandibular anterior tooth incision to the maxillary anterior incision, is limited to about 35 to 40 mm for adults. Especially, the average maximum opening for women is about 7 mm than that for men. There are few. Therefore, in the above-described dental diagnosis OCT apparatus, it is difficult to accurately photograph the occlusal surface where the lingual inclination is recognized from the anatomical form of the dentition.

Next, since the tooth adjacent surface is very narrow, it is a site that is less cleanable and self-cleaning than other tooth surfaces, and easily becomes an unclean area, and is therefore considered a touch-prone site.

The contact of the adjacent tooth surface is difficult to observe because the patient's own subjective symptoms are scarce in the initial lesion, and it occurs in a narrow part. It is easy to become.

In the conventional examination of touching the adjacent tooth surface, an adjacent tooth may be slightly opened using an instrument called an interdental opener for visual inspection. However, even if pathologically initial caudal lesions have occurred, it is difficult to find a crust change on the surface by visual inspection, and therefore, it is difficult to find a crust on the adjacent tooth surface.

Therefore, in order to enable detection of tooth internal touch, a dental X-ray examination or a wing-type X-ray examination in which a small X-ray film is attached with a wing and then bitten and fixed to emit X-rays. X-ray imaging of the tooth adjacent surface by the method is performed.

For example, Patent Document 4 describes an X-ray photography holder that enables good positioning for photographing an anterior bite wing. Patent Document 5 describes a receptor positioning device that has a sighting plate that forms a substantially rectangular opening and that is used to take dental dental wing X-rays of a tooth inside a patient's mouth. In Patent Document 6, image processing that improves the contrast of an object and does not deteriorate the graininess is performed, the sharpness of a dental digital X-ray image is improved, and the X-ray photograph image of the adjacent caries is sharpened. An X-ray image acquisition method is described.

However, in X-ray photography, since contrast difference does not occur unless about 70% of the dental minerals disappear, it is difficult to accurately examine the contact of the adjacent tooth surface with these X-ray photography. Especially early detection of early lesions is difficult.

JP 2008-183208 A JP 2004-344260 A JP 2004-344262 A JP 2004-121846 A JP 2005-521510 A JP 2007-029681 A

The present invention has been made in view of such problems, and an object of the present invention is to provide a dental OCT apparatus that enables accurate imaging of the occlusal surface of the tooth and enables accurate examination of the occlusal surface of the tooth. And

It is another object of the present invention to provide a dental OCT apparatus that makes it possible to accurately check the touch of the adjacent tooth surface, and in particular, enables early detection of early lesions.

It is another object of the present invention to provide a dental OCT apparatus that can depict a tooth apex, apical periodontal tissue, and a side branch without excessive root canal enlargement.

In order to achieve the above object, a dental OCT apparatus according to the present invention includes a light source that emits light, a flexible sheath in which at least the distal end side region is transparent, and a probe main body disposed in the sheath, An OCT probe, one end of which is connected to the light source and the other end of which is connected to the probe body, and an image display unit that displays an image of an observation target in the oral cavity. The light guided from the light source through the light guiding unit is emitted to the observation target, the reflected light is swept to the light guiding unit, and an image based on the reflected light is displayed on the image display unit. And

The OCT probe includes a first OCT probe that changes the direction of incident light from the light guide unit to a viewing object while changing the direction to a right angle, a second OCT probe that emits the incident light to the observation object, and the incident light. Of the first OCT probe and the second OCT probe, and a third OCT probe that emits to the observation object at an emission angle between the emission angle by the second OCT probe and the first OCT probe, the second OCT probe, or Since the third OCT probe is configured to be used interchangeably, the root apex, the apical periodontal tissue, and the side branch can be depicted without excessive root canal enlargement.

The OCT probe has a rotating means for rotating the probe main body and a moving means for moving the probe main body back and forth within the sheath, and the OCT probe is located above or below the interdental space. A probe is inserted, the sheath is fixed in the interdental space where the OCT probe is inserted, the probe body is rotated by the rotating means, and the probe is moved by the moving means in the fixed sheath. Since the image of the tooth adjacent surface is imaged with the OCT probe by performing at least one of the main body back and forth movement, it is possible to accurately capture the tooth adjacent surface touch.

Further, a rotating means for rotating the probe body, a forward / backward moving means for moving the probe body back and forth within the sheath, a horizontal moving means for moving the OCT probe horizontally, and the OCT probe vertically Since it is provided with a vertical moving means for moving, it is possible to accurately photograph the tooth occlusal surface.

According to the present invention, it is possible to acquire an image of the upper root canal from the first OCT probe, acquire an image of the tooth apex and the like from the second OCT probe, and acquire an image of the side wall of the root canal from the third OCT probe. The root apex of the tooth, the apical periodontal tissue, and the side branch can be drawn without performing root canal enlargement. Therefore, it is possible to conduct a precise examination at the first treatment of pulpitis and apical periodontitis, and to directly confirm the actual condition inside the root canal and root canal wall and apical lesions. Therefore, root canal treatment can be performed easily and accurately. In addition, objective image inspections such as the presence or absence of fractures, cracks, deformed excessively stenosed root canals, and remnants are possible, making it possible to diagnose and diagnose dental diseases that were extremely difficult with conventional dental imaging equipment. Make it possible.

Further, according to the present invention, an image of the adjacent tooth surface from various directions can be obtained by inserting an OCT probe into the interdental space and performing at least one of rotation and forward / backward movement. In addition, since it is rotated and moved back and forth, the entire tooth adjacent surface can be directly irradiated with light, so that it is possible to accurately photograph the touch of the tooth adjacent surface, and particularly early detection of an initial lesion is possible.

Further, according to the present invention, an OCT probe is inserted in the vicinity of the tooth occlusion surface, and at least one of rotation and back-and-forth movement of the probe body is performed, and OCT imaging is performed according to the surface form of the tooth occlusion surface. Therefore, for example, even a woman with a small maximum opening can accurately photograph a tooth occlusal surface. Further, by disposing the sheath along the undulating form of the tooth occlusal surface, it is possible to perform precise scanning along the surface form of the tooth occlusal surface and to accurately detect the tooth occlusal surface touch.

It is a block diagram which shows the whole structure of the dental OCT apparatus which concerns on this embodiment. It is explanatory drawing explaining an OCT probe. It is a photograph figure of a tooth adjacent surface touch. It is a schematic diagram of the tooth adjacent surface touch. It is a photograph figure of the cheek side view of the tooth contact surface as a comparative example. It is a photograph figure which carries out OCT imaging | photography of the tooth | gear adjacent surface touch as a comparative example from a cheek side surface side. It is a photograph figure of the occlusal surface side of the tooth adjacent surface touch as a comparative example. It is a photograph figure which carries out OCT imaging | photography from the occlusal surface side of the tooth adjacent surface touch as a comparative example. It is a photograph figure of the tongue side surface side of the tooth adjacent surface touch as a comparative example. It is a photograph figure which carries out OCT imaging | photography of the tooth adjacent surface touch as a comparative example from the lingual side surface side. It is explanatory drawing explaining the imaging | photography method of the tooth adjacent surface which concerns on this embodiment from a cheek side. It is explanatory drawing explaining the imaging | photography method of the tooth adjacent surface which concerns on this embodiment from a tongue side surface. It is explanatory drawing explaining the imaging | photography method of the tooth adjacent surface which concerns on this embodiment from an occlusal surface. It is a photograph figure explaining the incidence direction of photography of a tooth adjacent surface concerning this embodiment. It is a photograph figure explaining the position of the section corresponding to each incidence direction about imaging of the tooth adjacent surface concerning this embodiment. It is a tomographic image obtained by rotating the probe main body in imaging of the tooth adjacent surface according to the present embodiment. At shooting tooth adjacent surface according to the present embodiment, a tomographic view obtained by moving the probe body forward or backward, a tomographic photograph of the cross section shown in S ₁ in FIG. 8B. At shooting tooth adjacent surface according to the present embodiment, a tomographic view obtained by moving the probe body forward or backward, a tomography of the cross-section shown in FIG. 8B in S _2. At shooting tooth adjacent surface according to the present embodiment, a tomographic view obtained by moving the probe body forward or backward, a tomographic photograph of the cross-section shown in S ₃ in FIG. 8B. At shooting tooth adjacent surface according to the present embodiment, a tomographic view obtained by moving the probe body forward or backward, a tomographic photograph of the cross section shown in S ₄ in FIG. 8B. It is explanatory drawing of the 2nd probe main body which changes the direction to an acute angle and inject | emits incident light with respect to an optical fiber. It is explanatory drawing of the 3rd probe main body which injects incident light with the direction changed at an obtuse angle with respect to the optical fiber. It is a use mode figure of the OCT probe which uses the 2nd probe main part. It is a use mode figure of the OCT probe which uses the 3rd probe main part. It is explanatory drawing which image | photographs a tooth adjacent surface using the expansion body of the shape closely_contact | adhered to an interdental drum-shaped space | gap. It is explanatory drawing which shows a specific example of the cross section of an expansion body. It is explanatory drawing explaining the OCT probe which has a moving means concerning another embodiment. It is explanatory drawing explaining the horizontal movement means to move an OCT probe horizontally, and the vertical movement means to move an OCT probe vertically. It is explanatory drawing explaining the surface form of the tooth occlusion surface of a maxillary first premolar. It is explanatory drawing explaining the surface form of the tooth occlusal surface of a maxillary 1st molar. It is a photograph figure as a comparative example which carries out OCT imaging | photography of the tooth occlusal surface of a mandibular molar using a handpiece type OCT probe. It is a photograph figure as a comparative example which carries out OCT imaging | photography of the tooth occlusal surface of a maxillary molar using a handpiece type | mold OCT probe. It is a figure explaining the horizontal movement of an OCT probe. It is a figure explaining the vertical movement of an OCT probe. It is explanatory drawing explaining the sheath provided along the uneven | corrugated form of a tooth occlusion surface. It is a figure explaining the usage condition of the OCT probe which uses a 2nd probe main body. It is a figure explaining the usage aspect of the OCT probe which uses a 3rd probe main body. It is explanatory drawing of the container part arrange | positioned in contact with a tooth occlusal surface. It is a block diagram which shows the whole structure of a dental OCT apparatus. It is sectional drawing in the surface containing the central axis of the 6th optical fiber of a 1st OCT probe. It is sectional drawing in the surface containing the central axis of the 6th optical fiber of the 2nd OCT probe which irradiates light to a probe tip direction. It is sectional drawing in the surface containing the central axis of the 6th optical fiber of a 2nd OCT probe in the case of changing the angle of a front end direction. It is sectional drawing of another form of the 2nd OCT probe which inject | emits light to the front end side. It is sectional drawing in the surface containing the central axis of the 6th optical fiber of a 3rd OCT probe. It is explanatory drawing in the case of acquiring the tomographic image of a root canal upper part using a 1st OCT probe. It is explanatory drawing in the case of acquiring the tomographic image of the root apex part of a root canal using a 2nd OCT probe. It is explanatory drawing in the case of acquiring the tomographic image of the intermediate area | region of a root canal side wall using a 3rd OCT probe. It is explanatory drawing which acquires the tomographic image in the case of another form of a 3rd OCT probe. It is explanatory drawing of the 4th probe main body which concerns on another embodiment which can move so that a front-end | tip may face a different direction, and is a case where the 4th probe main body is not bent. It is explanatory drawing of the 4th probe main body which concerns on another embodiment which can move so that a front-end | tip may face a different direction, and is a case where the 4th probe main body is bent.

(Embodiment 1A)
Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. However, the embodiments are for facilitating understanding of the principle of the present invention, and the scope of the present invention is as follows. The present invention is not limited to the embodiments, and other embodiments in which those skilled in the art appropriately replace the configurations of the following embodiments are also included in the scope of the present invention.

The dental OCT apparatus 900 according to the present embodiment photographs the adjacent tooth surface by inserting the OCT probe 140 into the interdental space and performing at least one of rotation and back-and-forth movement.

The OCT device is a device that can measure in vivo tissue with a very high resolution in the micro order. In OCT, by using a near-infrared light source that can reach below the body surface, it is possible to measure not only the surface portion of the subject but also the deep portion. Near-infrared rays are not radiation that is harmful to the living body, such as X-rays (X-rays), so that it is possible to strictly inspect a non-invasive subject.

FIG. 1 is a block diagram showing the overall configuration of a dental OCT apparatus 900 according to this embodiment. The dental OCT apparatus 900 uses a near-infrared light source 110 that oscillates an optical signal in a certain frequency range as a wavelength scanning light source. Since it is a wavelength scanning type OCT, the two-dimensional data collection speed is remarkably fast. The wavelength of the light source 110 is, for example, 700 nm to 2500 nm, and corresponds to the wavelength of near infrared light that enters the living body. The output of the light source 110 is given to an optical fiber 111 as a light guiding means. In the middle portion of the optical fiber 111, a coupling portion 113 is provided for causing another optical fiber 112 to approach and interfere.

An OCT probe 140 is provided at one end of the optical fiber 112 as a light guiding means. The OCT probe 140 includes a sheath 150 and a probe main body 131 disposed in the sheath 150. The sheath 150 is permeable at least in the distal end region and is formed of a flexible material. The probe body 131 emits light guided from the optical fiber 112 to the tooth adjacent surface that is the observation target 200, sweeps the reflected light to the optical fiber 112, and displays an image based on the reflected light on an image display unit 125 described later. indicate.

At the other end of the optical fiber 111, a reference mirror 118 is provided perpendicularly to the optical axis via a collimating lens 117. Here, the optical distance L1 from the coupling portion 113 to the reference mirror 118 and the optical distance L2 from the coupling portion 113 to the surface that is the measurement site of the observation target 200 are set equal. A photodetector 121 is connected to the other end of the optical fiber 112 via a lens 120. The reference mirror 118 interferes with the backscattered light returning from the observation target 200 and generates interference light. The light detector 121 is composed of, for example, a light receiving element or a CCD (Charge Coupled Device) image sensor, and receives the interference light between the reflected light from the reference mirror 118 and the light reflected from the measurement site, thereby converting the beat signal into an electrical signal. Get as. Here, the optical fiber 111, the optical fiber 112, the coupling portion 113, the collimator lens 117, the reference mirror 118, and the lens 120 constitute an interference optical system.

The output of the photodetector 121 is input to the signal processing unit 123 via the amplifier 122. The signal processing unit 123 obtains a tomographic image signal by performing a Fourier transform on the received light signal obtained from the interference optical system. The output from the signal processing unit 123 is given to the image processing unit 124. The image processing unit 124 generates a two-dimensional or three-dimensional image of the observation target 200 based on the output from the signal processing unit 123. The display image generated in this way is displayed by the image display unit 125.

FIG. 2 is an explanatory diagram for explaining the OCT probe 140. As shown in FIG. 2, the OCT probe 140 includes a sheath 150 and a probe main body 131 disposed in the sheath 150. The probe main body 131 is connected to the end face of the optical fiber 112 in an axially aligned state. The probe main body 131 includes a prism 135, a GRIN lens (refractive index inclined lens) 136, and a connection light guide unit 137 that connects the GRIN lens 136 and the optical fiber 112 in order from the distal end side. The prism 135 is, for example, a right-angle prism, and is arranged so that the emission angle of the light guided by the optical fiber 112 is a right angle. The light deflected at a right angle by the prism 135 passes through the sheath 150 and irradiates the observation target 200 existing outside.

The OCT probe 140 is provided with a rotating means 160 at the end on the proximal end side of the probe main body 131. The rotating means 160 has an actuator provided with a motor, and the probe main body 131 is connected to the rotating shaft of the motor. The probe main body 131 is configured to be detachable from the actuator, and is rotated by the actuator of the rotating means 160. The rotating means 160 can be driven by a controller (not shown). The rotating means 160 is not limited to the configuration provided at the proximal end of the probe main body 131. For example, the rotating means 160 is provided at the proximal end of the OCT probe 140 and extends from the rotating means 160 to the distal end. It is also possible to adopt a configuration in which the outgoing optical fiber and the probe main body 131 are rotated.

Also, the OCT probe 140 is provided with a moving means 171 having a guide rail 171b provided along the longitudinal direction inside the sheath 150 and a slider 171a. The slider 171a is provided between the probe main body 131 and the guide rail 171b, supports the probe main body 131, and is movable back and forth along the guide rail 171b. The probe main body 131 can be moved back and forth within the sheath 150 by moving the slider 171a back and forth. The slider 171a can be moved back and forth by a slider cylinder, for example, and can be driven by a controller (not shown). Instead of the slider, it is also possible to provide a roller that supports the probe main body 131 and is movable back and forth along the guide rail 171b. The probe main body 131 is moved in the sheath 150 by moving the roller back and forth. Can be moved back and forth.

Next, an imaging aspect of a tooth adjacent surface using the dental OCT apparatus 900 having the above-described configuration will be described.

FIG. 3A and FIG. 3B are explanatory diagrams for explaining the touch of the adjacent tooth surface. Of these, FIG. 3A is a photographic view of the tooth adjacent surface contact, and FIG. 3B is a schematic view of the tooth adjacent surface contact. As shown in FIGS. 3A and 3B, an interval of about 50 to 80 μm, which does not cause food impaction, is appropriate between teeth, and the interval between adjacent teeth is very narrow. It is difficult to find the touch.

FIG. 4A and FIG. 4B are photographic diagrams as comparative examples in which OCT imaging is performed from the side of the buccal side of the tooth contact surface. 4A is a photograph of the buccal side view, and FIG. 4B is an OCT photograph from the buccal side. When OCT imaging is performed from the side of the cheek so as to pass through the solid line shown in FIG. 4A, the tomographic image shown in FIG. 4B is obtained. As shown in the dotted line in FIG. 4B, a slight touch abnormality is shown.

FIGS. 5A and 5B are photographic views as comparative examples in which OCT imaging is performed from the occlusal surface side of the tooth adjacent surface. 5A is a photograph of the occlusal view, and FIG. 5B is an OCT photograph from the occlusal surface. When OCT imaging is performed from the occlusal surface so as to pass through the solid line shown in FIG. 5A, a tomographic image shown in FIG. 5B is obtained. As shown in the dotted line in FIG. 5B, a slight touch abnormality is shown.

FIGS. 6A and 6B are photographic views as comparative examples in which OCT imaging is performed from the side of the lingual surface of the tooth adjacent surface. 6A is a photograph of the lingual side view, and FIG. 6B is an OCT photograph from the lingual side. When OCT imaging is performed from the side of the tongue so as to pass the solid line shown in FIG. 6A, a tomographic image shown in FIG. 6B is obtained. As shown in the dotted line in FIG. 6B, the abnormal touch findings are hardly understood in the OCT imaging from the side of the tongue.

Next, FIG. 7A, FIG. 7B and FIG. 7C are explanatory views for explaining a method for photographing a tooth adjacent surface according to the present embodiment. 7A is an explanatory view from the cheek side, FIG. 7B is an explanatory view from the tongue side, and FIG. 7C is an explanatory view from the occlusal surface. As shown in FIGS. 7A, 7B, and 7C, the OCT probe 140 is inserted into the upper part or the lower part of the interdental hour space, and the sheath 150 is fixed in the interdental hour space where the OCT probe 140 is inserted. Let Since the sheath 150 is flexible, it is easy to insert the OCT probe 140 into the interdental space and it is difficult to damage periodontal tissue in the vicinity of the interdental space. Then, while rotating the probe main body 131 by the rotating means 160, an image of the tooth adjacent surface is taken by the OCT probe 140. Alternatively, the probe body 131 is moved forward or backward by the moving means 171 in the fixed sheath 150 and an image of the tooth adjacent surface is taken by the OCT probe 140. Alternatively, the probe body 131 is moved forward or backward by the moving means 171 in the fixed sheath 150 while the probe body 131 is rotated by the rotating means 160, and an image of the tooth adjacent surface is taken by the OCT probe 140.

The rotation of the probe body 131 is 360 degrees, but is not limited to this. For example, when the OCT probe 140 is inserted into the upper part of the interdental space, the rotation is 180 degrees downward. For example, when the OCT probe 140 is inserted in the lower part of the interdental space, it can be rotated 180 degrees upward.

In addition, without fixing the sheath 150 in the interdental space, the probe main body 131 can be moved forward or backward together with the sheath 150 and an image of the tooth adjacent surface can be taken with the OCT probe 140. In such a case, a sheath moving means for moving the sheath 150 is provided without providing the moving means 171 for moving the probe main body 131 back and forth within the sheath 150. In addition, the sheath 150 has a double structure formed by an outer sheath and an inner sheath, the outer sheath is fixed in the interdental space, and the probe body 131 is moved forward or backward together with the inner sheath. It is also possible to take an image of the tooth adjacent surface.

FIG. 8A and FIG. 8B are photographic views for explaining photographing of a tooth adjacent surface according to the present embodiment. 8A is a photographic view for explaining the incident direction, and FIG. 8B is a photographic view for explaining the position of the cross section corresponding to each incident direction. The OCT probe 140 is inserted into the upper part of the interdental space, the sheath 150 is fixed, and an image of the adjacent tooth surface is taken while the probe body 131 is rotated as indicated by an arrow R in FIG. 8A. The position of the cross section in such a case is indicated by R in FIG. 8B. Further, the OCT probe 140 is inserted into the upper part of the interdental space, and the sheath 150 is fixed. As shown by arrows S ₁ , S ₂ , S ₃ , and S ₄ in FIG. The main body 131 is moved forward or backward to take an image of the tooth adjacent surface. The position of the cross section in such a case is indicated by S ₁ , S ₂ , S ₃ , and S ₄ in FIG. 8B, respectively.

FIG. 9 is a tomographic image obtained by rotating the probe main body 131 in the imaging of the tooth adjacent surface according to the present embodiment. As shown in FIG. 9, the progress of the touch can be clearly confirmed in the tomographic photograph of the cross section indicated by R in FIG. 8B. 10A, 10B, 10C, and 10D are tomographic photographs obtained by moving the probe main body 131 forward or backward in imaging of a tooth adjacent surface according to the present embodiment. As shown in FIG. 10A, FIG. 10B, FIG. 10C, and FIG. 10D, the tomographic images of the cross sections indicated by S ₁ , S ₂ , S ₃ , and S ₄ in FIG. can do.

In this way, by inserting the OCT probe 140 into the interdental space and performing at least one of rotation and back-and-forth movement, images of adjacent teeth from various directions can be obtained, Since it is rotated and moved back and forth, the entire tooth adjacent surface can be directly irradiated with light, so that it is possible to photograph a very accurate contact with the tooth adjacent surface. Further, according to the present invention, accurate and clear imaging can be performed not only on the tooth adjacent surface but also on the periodontal tissue in the vicinity of the tooth adjacent surface. Periodontal tissue includes gingiva, alveolar bone, cementum, connective fibers, and periodontal ligament.

In the above-described embodiment, the rotation of the probe main body 131 is performed by the rotating means 160 in the imaging of the tooth adjacent surface. However, the rotation is not limited to such an embodiment, and the rotation of the probe main body 131 is not performed by humans. Manual operation is also possible. The probe body 131 is moved back and forth by the moving means 171. However, the probe body 131 is not limited to such an embodiment, and the probe body 131 can be moved back and forth by a human hand.

(Embodiment 1B)
In the above-described embodiment, the probe main body 131 emits incident light from the optical fiber while changing the direction to a right angle (first probe main body). However, the scope of the present invention is not limited to such an embodiment. 11A and 11B are diagrams illustrating the OCT probe according to Embodiment 1B in which the direction of incident light is changed in a direction different from a right angle. FIG. 11A is an explanatory diagram of the second probe main body 132 that emits incident light at an acute angle with respect to the optical fiber, and FIG. 11B emits incident light at an obtuse angle with respect to the optical fiber. It is explanatory drawing of the 3rd probe main body.

As shown in FIG. 11A, in the second probe body, the prism 235 is configured so that the emission angle of the light guided by the optical fiber 112 is irradiated at an acute angle. In this embodiment, the irradiation angle θ is For example, it is 60 degrees. Other configurations are the same as those of the first probe main body 131 described above. As shown in FIG. 11B, in the third probe body, the prism 335 is configured so that the emission angle of the light guided by the optical fiber 112 is irradiated at an obtuse angle. For example, θ is 130 degrees. Other configurations are the same as those of the first probe main body 131 described above.

FIG. 12A and FIG. 12B are diagrams for explaining how to use the OCT probe according to Embodiment 1B. Of these, FIG. 12A shows how the OCT probe uses the second probe body, and FIG. 12B shows how the OCT probe uses the third probe body. In the embodiment 1B, the probe main body includes three types of the first probe main body 131, the second probe main body 132, or the third probe main body 133, and the first probe main body 131, the second probe main body 132, or the third probe main body. The main body 133 is used interchangeably. That is, in the normal usage mode, the first probe body 131 is used. And as FIG. 12A shows, when inserting the OCT probe 140 in the back | inner side of an interdental hourglass-shaped space | gap, and image | photographs a tooth adjacent surface from the back | inner side, the 2nd probe main body 132 is used. In addition, as shown in FIG. 12B, the third probe body 133 is used when it is difficult to insert the OCT probe 140 because the lower part of the interdental drum-shaped gap is narrow. Thereby, even when the lower part of the interdental space is narrow and it is difficult to insert the OCT probe 140, it is possible to accurately photograph the adjacent tooth surface.

(Embodiment 1C)
In the above-described embodiment 1A, when the space between the sheath 150 and the probe main body 131 is air, the difference in the refractive index of each connecting portion between the prism 135 → air and the air → sheath 150. In some cases, optical connection loss due to the occurrence of the loss occurs. In view of this, in this embodiment, the sheath 150 has matching oil for adjusting the refractive index that fills the space between the sheath 150 and the probe main body 131. The refractive index of the matching oil may be the same as or close to the refractive index of the prism 135, or the same or close to the refractive index of the sheath 150 may be used. In addition, when the refractive index of the prism 135 and the refractive index of the sheath 150 are the same or close to each other, it is possible to use the refractive index.

It is preferable that the matching oil filled in the sheath 150 has a viscosity enough to ensure the rotation and back-and-forth movement of the OCT probe 131 smoothly. By using the matching oil for adjusting the refractive index that fills the space between the sheath 150 and the probe main body 131, it is possible to prevent light connection loss and to photograph a clear tooth adjacent surface.

Embodiment 1D
In the above-described embodiment 1A, when the space between the sheath 150 and the observation target 200 is air, the refractive index of each connection portion is different between the sheath 150 → air and the air → observation target 200. In some cases, optical connection loss due to the difference may occur. Therefore, in the present embodiment, matching oil for adjusting the refractive index that fills the space between the sheath 150 and the observation target 200 is disposed around the sheath 150. The refractive index of the matching oil can be the same as or close to the refractive index of the sheath 150.

The matching oil disposed around the sheath 150 is preferably viscous so that it stays in the interdental hour space for a certain period of time, and because it contacts the dental hour space, it may not have any biological harm. is necessary. The type of matching oil disposed around the sheath 150 is not particularly limited, and for example, vegetable oil or the like can be used. By using a matching oil for adjusting the refractive index that fills the space between the sheath 150 and the observation target 200, it is possible to prevent loss of light connection and to capture a clear tooth adjacent surface.

It is also possible to use the expansion body 300 having the cavity portion 310 and having a shape that closely contacts the interdental space when expanded. FIG. 13 is an explanatory view of photographing a tooth adjacent surface using an expanding body 300 having a shape closely contacting with an interdental space. As shown in FIG. 13, an OCT probe 140 is inserted into the inner cavity 310 of the expansion body 300, and an anti-attenuation medium that prevents light attenuation due to a difference in refractive index is injected into the expansion body 300. Then, the expansion body 300 is brought into close contact with the interdental space, and an image of the adjacent tooth surface is taken with the OCT probe 140. Since the anti-attenuation medium is filled in the expansion body 300, it does not matter whether there is any biological harm or no viscosity. The anti-attenuation medium is not particularly limited. For example, water, physiological saline, vegetable oil, or the like can be used. Thereby, the connection loss of the light resulting from the air in the space between the sheath 150 and the observation target 200 can be prevented, and clear imaging of the adjacent tooth surface becomes possible.

FIG. 14 is an explanatory view showing a specific example of a cross section of the expansion body 300. As shown in FIG. 14, it is preferable that the expanded body 300 is formed with a smooth concave curve in which the cross section when expanded is recessed inward. The interdental space is formed by a smooth convex curve that protrudes to the outside. By having such a cross-sectional shape, the interdental space has a shape that can easily adhere to the interdental space when the expansion body 300 expands. Become.

(Embodiment 1E)
In the embodiment 1A described above, the moving means 171 for moving the probe main body 131 back and forth within the sheath 150 includes the slider 171a and the guide rail 171b provided inside the sheath 150. However, the moving means for moving the probe main body 131 back and forth within the sheath 150 is not limited to such an embodiment.

FIG. 15 is an explanatory diagram for explaining an OCT probe having moving means according to another embodiment. As shown in FIG. 15, the end of the probe main body 131 on the proximal end side is provided with a telescopic moving means 179 composed of a multistage rod. When the moving means 179 extends, the probe main body 131 moves to the distal end side in the sheath 150, and when the moving means 179 contracts, the probe main body 131 moves to the proximal end side in the sheath 150. The moving means 179 may be attached to the rotating means 160 located at the proximal end of the probe main body 131 as shown in FIG. 15, or directly to the proximal end of the probe main body 131. It is also possible to attach. The moving means 179 may be formed of a string-like member without being configured as an expandable / contractible multi-stage rod structure, and the string-like member may be wound up by a reel or the like. Note that 179 can exist at the center of probe rotation. According to such a configuration, the probe main body 131 cannot be moved to the distal end side within the sheath 150, but the probe main body 131 can be moved to the proximal end side within the sheath 150 with a simple configuration.

(Embodiment 2A)
The dental OCT apparatus 900 according to the present embodiment inserts an OCT probe 140 in the vicinity of the tooth occlusion surface, performs at least one of rotation and forward / backward movement, and performs OCT imaging according to the surface form of the tooth occlusion surface.

The overall configuration of the dental OCT apparatus 900 according to this embodiment is the same as that of Embodiment 1A as shown in FIG. The observation target 200 is a tooth occlusal surface. The configuration of the OCT probe 140 is the same as that of the embodiment 1A as shown in FIG. The thickness of the probe main body 131 is not particularly limited as long as it is a size that can be inserted into the oral cavity, but is 0.4 to 0.8 mm, for example.

FIG. 16 is an explanatory diagram for explaining the horizontal moving means 220 for moving the OCT probe 140 horizontally and the vertical moving means 230 for moving the OCT probe 140 vertically. In order to avoid the complexity of the figure, the moving means 171 is omitted in FIG. As shown in FIG. 16, support rails 210 are laid on both outer sides of the sheath 150, and the support rails 210 support the OCT probe 140. The horizontal moving means 220 supports the base end portion of the support rail 210 and can freely move the support rail 210 left and right (in the y-axis direction in FIG. 16) or front and rear (in the x-axis direction in FIG. 16). is there. That is, when the OCT probe 140 is moved left and right, the support rail 210 is moved left and right, and when the OCT probe 140 is moved back and forth, the support rail 210 is moved forward or moved backward. As a result, the OCT probe 140 is moved horizontally. Further, the vertical moving unit 230 can move the horizontal moving unit 220 vertically (up and down), and moves the OCT probe 140 vertically (up and down) freely (in the z-axis direction in FIG. 16). In the present embodiment, the vertical moving unit 230 moves the horizontal moving unit 220 vertically. However, the present invention is not limited to such an embodiment. For example, the horizontal moving unit 220 is the vertical moving unit 230. It is also possible to adopt a configuration in which the is moved horizontally.

Next, an imaging aspect of the occlusal surface using the dental OCT apparatus 900 having the above-described configuration will be described.

17A and 17B are explanatory views for explaining the surface form of the occlusal surface of the molar tooth, in which FIG. 17A is the surface form of the occlusal surface of the upper first premolar, and FIG. 17B is the upper first molar tooth. It is the surface form of the tooth occlusal surface. 17A and 17B, 611 is a buccal lateral ridge, 612 is a buccal lateral surface, 613 is a central occlusal ridge, 614 is a corner angle, 615 is a mesial occlusal surface ridge, and 616 is a mesial marginal ridge. , 617 occlusal surface, 618 lingual cusp, 619 lingual side, 620 distal marginal ridge, 621 distal occlusal ridge, 623 incision, 624 buccal cusp, and 625 mesial cheek A side cusp, 626 is an occlusal collateral ridge, 627 is a mesial lingual cusp, 628 is a distal lingual cusp, and 629 is a distal buccal cusp. As shown in FIGS. 17A and 17B, the tooth occlusal surface is a concave surface facing each other between the cusps of the upper and lower molars, and is a ridge, fissure, fossa or the like. It is configured and has a complex form, and realizes a masticatory function by engaging upper and lower teeth. The unevenness of the tooth occlusal surface ensures the function of chewing food, and the spillway assures the function of finely grinding the chewed food. In addition, a tooth occlusal surface is not formed in an anterior tooth part, but a cutting edge part is formed.

FIG. 18A and FIG. 18B are photographic diagrams as comparative examples in which the occlusal surface of the tooth is OCT imaged using a handpiece type OCT probe. 18A is an OCT image of the occlusal surface of the lower molar, and FIG. 18B is an OCT image of the occlusal surface of the upper molar. As shown in FIGS. 18A and 18B, the maximum human opening is limited to about 35 to 40 mm for adults. Therefore, in OCT imaging using a handpiece type OCT probe, light is applied to the tooth occlusal surface. It is extremely difficult to make the light incident vertically. In OCT imaging, differences in the refraction and scattering phenomena occur due to slight differences in the incident angle of light. Therefore, in imaging methods in which light cannot be incident perpendicularly to the tooth occlusal surface, there is a difference in image rendering ability and accuracy. It is difficult to photograph the occlusal surface of the teeth.

Next, FIG. 19A and FIG. 19B are a method for photographing a tooth occlusal surface according to this embodiment. 19A is a view for explaining horizontal movement of the OCT probe 140, and FIG. 19B is a view for explaining vertical movement of the OCT probe 140. In order to avoid the complexity of the drawing, the description of the sheath 150, the rotating means 160, and the moving means 171 is omitted in FIGS. 19A and 19B. The OCT probe 140 is placed in the vicinity of the tooth occlusion surface. Since the sheath 150 is flexible, it is difficult to damage the periodontal tissue. Then, while rotating the probe main body 131 by the rotating means 160, the probe main body 131 is moved forward or backward by the moving means 171 in the sheath 150. The rotation range angle of the probe main body 131 needs to be a rotation range angle that can cover the form of the tooth occlusal surface by the rotation of the probe main body 131 and is not particularly limited, but is, for example, 30 ° to 90 °. is there. It is also possible to rotate the probe main body 131 without moving back and forth and photograph with the OCT probe 140, or move the probe main body 131 back and forth without rotating and photograph with the OCT probe 140. Then, as shown in FIG. 19A, the OCT probe 140 is moved horizontally (front and rear, left and right) by the horizontal moving means 220, and OCT imaging according to the form of the tooth occlusal surface at the horizontal position is performed. Further, as shown in FIG. 19B, the OCT probe 140 is moved vertically (up and down) by the vertical moving means 230, the distance from the observation target 200 is kept constant, and the shape of the tooth occlusal surface is improved with high sensitivity and resolution. Perform OCT imaging.

In this way, the OCT probe is inserted in the vicinity of the tooth occlusal surface, and at least one of rotation and forward / backward movement of the probe body is performed, and OCT imaging is performed according to the surface form of the tooth occlusal surface. It is possible to shoot a proper tooth occlusal surface. Furthermore, according to the present invention, accurate and clear imaging can be performed not only on the occlusal surface of the tooth but also on the tongue side surface and the lingual side of the tooth / periodontal tissue and the lingual side of the tooth.

Note that the OCT probe 140 can also take an image of the tooth occlusal surface by moving the probe body 131 forward or backward together with the sheath 150. In such a case, it is not necessary to provide moving means 171 for moving the probe main body 131 back and forth within the sheath 150. Further, the sheath 150 has a double structure formed by an outer sheath and an inner sheath, the outer sheath is fixed in the vicinity of the tooth occlusion surface, and the probe body 131 is moved forward or backward together with the inner sheath to occlude the tooth. It is also possible to take an image of the surface.

In the above-described embodiment, the rotation of the probe main body 131 is performed by the rotating means 160 in photographing the occlusal surface of the tooth. However, the rotation of the probe main body 131 is not limited to such an embodiment. Manual operation is also possible. The probe body 131 is moved back and forth by the moving means 171. However, the probe body 131 is not limited to such an embodiment, and the probe body 131 can be moved back and forth by a human hand. Similarly, the horizontal and vertical movements of the OCT probe 140 can be operated by human hands.

(Embodiment 2B)
In the embodiment 2B, the sheath 151 is provided by being deformed along the undulation form of the tooth occlusal surface. FIG. 20 is an explanatory diagram for explaining a sheath 151 provided along the undulation form of the tooth occlusal surface. As shown in FIG. 20, the tooth occlusion surface has a complicated shape having a raised portion and a groove bottom portion at the center, and the sheath 151 is arranged at a constant distance from the tooth occlusion surface. The distance between the tooth occlusal surface and the sheath 151 is not particularly limited, and can be, for example, 0 to 10 mm. When the distance is set to 0 mm, the sheath 151 can be fixedly supported while being in close contact with the tooth occlusal surface. The sheath 151 is made of a material that is flexible and plastically deformed. By pressing the sheath 151 against the tooth occlusal surface to be observed 200, the sheath 151 along the undulation form of the tooth occlusion surface can be easily formed. Can do. Although the support rail 210 that supports the sheath 151 is not shown, it can be laid along the form of the sheath 151, for example, and the horizontal moving means 220 supports the proximal end of the support rail 210 and supports the OCT probe 140. The vertical moving means 230 moves the OCT probe 140 vertically freely by moving the horizontal moving means 220 vertically. In addition, without providing the horizontal moving means 220 and the vertical moving means 230, only the sheath 151 provided along the undulating form of the tooth occlusal surface is provided, and the probe main body 131 is rotated in the sheath 151 to move back and forth. It is also possible to photograph the tooth occlusion surface.

By using the sheath 151 provided along the undulation form of the tooth occlusal surface, the distance between the tooth occlusal surface to be observed 200 and the probe main body 131 can be accurately maintained at a constant interval, and the resolution can be further improved. Shooting is possible.

(Embodiment 2C)
In the present embodiment, as shown in Embodiment 1B, the second probe main body 132 that emits incident light with an acute angle changed with respect to the optical fiber, and the incident light emitted with an obtuse angle changed with respect to the optical fiber. And a third probe body 133 to be used.

FIG. 21A and FIG. 21B are diagrams for explaining how to use the OCT probe according to Embodiment 2C. 21A shows how the OCT probe uses the second probe body 132, and FIG. 21B shows how the OCT probe uses the third probe body 133. In the embodiment 2C, the probe main body includes three types of the first probe main body 131, the second probe main body 132, or the third probe main body 133, and the first probe main body 131, the second probe main body 132, or the third probe main body. The main body 133 is used interchangeably. That is, in the normal usage mode, the first probe body 131 is used. Then, as shown in FIG. 21A, when the OCT probe 140 is inserted on the tooth occlusion surface and the tooth occlusion surface is imaged obliquely rearward from the distal end side to the proximal end side, the second probe main body 132 is used. . In addition, as shown in FIG. 21B, the third probe main body 133 is used when photographing the occlusal surface obliquely forward from the proximal end side to the distal end side. As a result, even complex tooth occlusal surfaces can be imaged perpendicularly to the tooth occlusal surface, and resolution differences due to refraction and scattering phenomena can be minimized.

(Embodiment 2D)
In the present embodiment, similar to the above-described embodiment 1C, the sheath 150 has matching oil for adjusting the refractive index that fills the space between the sheath 150 and the probe main body 131.

(Embodiment 2E)
In the present embodiment, matching oil for adjusting the refractive index that fills the space between the sheath 150 and the observation target 200 is disposed around the sheath 150. The refractive index of the matching oil can be the same as or close to the refractive index of the sheath 150.

It is preferable that the matching oil disposed around the sheath 150 has a viscosity that is in contact with the tooth occlusal surface and stagnates for a certain period of time. In contact with the tooth occlusal surface, in the case of the tooth occlusal surface of the lower molar, it is immediately above the tooth occlusal surface, and in the case of the tooth occlusal surface of the upper molar, directly under the tooth occlusal surface. Moreover, since the matching oil arrange | positioned around the sheath 150 contacts a tooth occlusal surface, it is necessary to have no biological harm. The type of matching oil disposed around the sheath 150 is not particularly limited, and for example, vegetable oil or the like can be used. By using the matching oil for adjusting the refractive index that fills the space between the sheath 150 and the observation target 200, it is possible to prevent loss of light connection and to photograph a clear tooth occlusal surface.

FIG. 22 is an explanatory diagram of the vessel portion 301 installed in contact with the tooth occlusal surface. As shown in FIG. 22, a container 301 installed in contact with the tooth occlusal surface may be provided, and the container 301 may be filled with an anti-attenuation medium that prevents light attenuation due to a difference in refractive index. An insertion hole 311 into which the OCT probe 140 can be inserted is formed on the side surface of the vessel portion 301. The OCT probe 140 is inserted into the insertion hole 311 of the vessel part 301. The anti-attenuation medium is not particularly limited as long as it has no biological harm, but for example, water, physiological saline, vegetable oil, or the like can be used. Thereby, the connection loss of the light resulting from the air in the space between the sheath 150 and the observation object 200 can be prevented, and a clear image of the occlusal surface can be obtained.

The insertion hole 311 has a size that allows the OCT probe 140 to move vertically and horizontally. Therefore, when the OCT probe 140 moves vertically and horizontally, a small amount of the anti-attenuation medium filled in the vessel portion 301 may flow out from the insertion hole 311. In order to prevent a disadvantage caused by such outflow, The size of the shape is set such that the insertion hole 311 of the vessel part 301 is located outside the oral cavity. As a result, even if a small amount of the anti-attenuation medium flows out from the insertion hole 311, since it flows out of the oral cavity, there is no possibility of giving discomfort to the patient.

(Embodiment 2F)
Further, as shown in the above-described embodiment 1E, it is also possible to provide moving means 179 for moving the probe main body 131 back and forth within the sheath 150.

(Embodiment 3A)
FIG. 23 is a block diagram showing the overall structure of the dental OCT apparatus 900 of this embodiment. In the OCT main apparatus 800, the path of the electric signal is indicated by a one-dot chain line. As will be described later, the dental OCT apparatus 900 according to this embodiment includes a first OCT probe 101 that externally irradiates the OCT probe so that the light emission angle becomes a right angle, and a first OCT probe 101 that externally irradiates light toward the probe tip. A 2OCT probe 102 and a third OCT probe 103 that performs external irradiation at an irradiation angle between the irradiation angle of the first OCT probe 101 and the irradiation angle of the second OCT probe 102 are configured. These are selected and used interchangeably according to the rendering target position of the tissue in the root canal. In FIG. 23, the first OCT probe 101 is used.

As shown in FIG. 23, the dental OCT apparatus 900 includes a first OCT probe 101, an OCT main apparatus 800, and an image display unit 125, and an intraoral examination body that is an observation target using the first OCT probe 101. A tomographic image relating to a living tissue is acquired. In the following description, the direction approaching the light source of the OCT probe 101 on the optical path is defined as the proximal end side, and the direction away from the light source is defined as the distal end side.

The OCT main device 800 includes a light source 110, a fiber coupler 213, a controller 281, a rotary joint 214, a first actuator 215, a light detection unit 216, a signal processing unit 123, a lens 218, a roof mirror 219, a second actuator 282, and a light guiding unit. First to fourth optical fibers F1 to F4, the first optical fiber F1 connects the light source 110 and the fiber coupler 213, the second optical fiber F2 connects the fiber coupler 213 and the rotary joint 214, The third optical fiber F3 is led out from the fiber coupler 213 to the roof mirror 219, and the fourth optical fiber F4 connects the fiber coupler 213 and the light detection unit 216. Note that the optical fiber of this embodiment is assumed to be a single mode optical fiber.

The controller 281 controls the OCT main apparatus 800 as a whole, specifically turns on and off the light source 110, controls the first actuator 215 and the second actuator 282, and controls the signal processing unit 123. The light source 110 is a near-infrared light source and is a wavelength scanning laser light source that enables OCT. Since it is a wavelength scanning OCT, the two-dimensional data collection speed can be remarkably increased.

The rotary joint 214 is coupled with a fifth optical fiber F5 as a light guide, and a probe attached portion 142 for attaching an OCT probe is provided at the end of the fifth optical fiber F5. The rotary joint 214 rotates the fifth optical fiber F5 and the sixth optical fiber F6.

When the dental OCT apparatus 900 is used, a tomographic image is acquired as follows. First, near-infrared light is irradiated from the light source 110, and the irradiated near-infrared light travels through the first optical fiber F1 and travels to the fiber coupler 213. Near-infrared light incident through the first optical fiber F1 is split by the fiber coupler 213 into light passing through the second optical fiber F2 and light passing through the third optical fiber F3.

The division ratio of the fiber coupler 213 is not particularly limited, and can be set as appropriate so that a tomographic image of the root canal tissue can be clearly obtained. For example, the division ratio of the light toward the second optical fiber F2 The amount can be set to 50% of the amount of incident light, and the amount of light directed to the third optical fiber F3 can be set to 50% of the amount of incident light.

The light that is split by the fiber coupler 213 and travels through the second optical fiber F <b> 2 is then guided to the rotary joint 214 and enters the fifth optical fiber F <b> 5 that is coupled to the rotary joint 214. The rotary joint 214 is driven by the first actuator 215 under the control of the controller 281 to rotate the fifth optical fiber F5, the sixth optical fiber F6, and the first probe body 331 around the center axis of the fiber.

The light traveling through the fifth optical fiber F5 passes through the probe attached portion 142 and the probe attaching portion 141, passes through the sixth optical fiber F6 disposed in the longitudinal direction in the internal space of the sheath 150, and passes through the sixth light. The light enters the first probe body 331 that is joined and arranged in a state of being aligned with the fiber F6. The first probe body 331 irradiates incident light at a right angle. And the light irradiated from the 1st probe main body 331 is inject | emitted from the side surface of the 1st OCT probe 101, and condenses on the root canal tissue Rc which exists outside a probe. Then, by operating the controller 281 to operate the first actuator 215 and rotate the rotary joint 214, the light emitted from the side surface of the first OCT probe 101 is rotated on the tissue circumference in the root canal.

On the other hand, the light that is split by the fiber coupler 213 and travels through the third optical fiber F3 is converted into a parallel light flux through the lens 218, and then reflected by the roof mirror 219. The reflected light from the roof mirror 219 is guided to the fiber coupler 213 by returning through the same optical path as the incident light path.

The third optical fiber F3 has a total length corresponding to the optical path length from the fiber coupler 213 to the tip of the fifth optical fiber F5. The Dach mirror 219 is translated along the central axis of the third optical fiber F3 (in other words, the optical axis of the lens 218) by the second actuator 282 under the control of the controller 281. The optical path length between the roof mirror 219 and the end face F3a of the optical fiber F3 is adjusted.

Both the reflected light from the root canal tissue and the reflected light from the roof mirror 219 are received by the light detection unit 216 via the fiber coupler 213. Here, the roof mirror 219 is moved by a small distance so that the optical path length from the distal end face F3a of the third optical fiber F3 to the roof mirror 219 matches the optical path length from the distal end face of the sixth optical fiber F6 to the root canal tissue. . As a result, the two types of reflected light cause interference.

The photodetector 216 transmits a signal corresponding to the interference pattern detected by receiving the above-described two types of reflected / scattered light to the signal processing unit 123. The signal processing unit 123 generates an image signal related to the root canal tissue based on the signal corresponding to the received interference pattern, and the generated image signal is output to the image display unit 125. The image display unit 125 displays an image corresponding to the image signal.

Next, the configuration of the OCT probe will be described. FIG. 24 is a cross-sectional view of the first OCT probe 101 on a plane including the central axis of the sixth optical fiber F6. As shown in FIG. 24, the first OCT probe 101 has a tube-shaped sheath 150 having flexibility, and a transmission region 155 having light transmittance is provided at the distal end portion of the sheath 150. . In the sheath 150, a sixth optical fiber F6 and a first probe body 331 are provided as light guiding means.

The first probe main body 331 is connected and disposed in a state of being aligned with the end surface of the sixth optical fiber F6. The first probe main body 331 includes a prism 135, a GRIN lens (refractive index tilt lens) 136, and a connection light guide 137 that connects the GRIN lens 136 and the optical fiber F6 in order from the distal end side. As shown in FIG. 24, the prism 135 is arranged so that the emission angle of the light guided by the sixth optical fiber F6 is a right angle.

The light deflected at right angles by the first probe main body 331 is irradiated to the root canal tissue Rc existing outside from the transmission region 155, and the first probe main body 331 is disposed on the outer periphery of the first probe main body 331. For example, a metal coat 138 is provided so as not to be damaged by contact with.

A probe attachment portion 141 that can be attached to the probe attachment portion 142 is provided at the proximal end side of the first OCT probe 101.

Next, FIGS. 25A and 25B are cross-sectional views of the second OCT probe 102 on a plane including the central axis of the sixth optical fiber F6. Of these, FIG. 25A shows the case of irradiation in the probe tip direction, and FIG. 25B shows the case of changing the angle in the injection direction. As shown in FIG. 25A, the second probe main body 332 formed in the second OCT probe 102 includes a micromirror 166, a prism 135, a GRIN lens 136, and a connection light guide 137. That is, in the second probe main body 332, the arrangement of the prism 135 is the same as that of the first OCT probe 101 described above, but the light deflected by the prism 135 is deflected again and travels straight to the distal end side of the second OCT probe 102, It differs from the first OCT probe 101 in that the micromirror 166 is arranged to irradiate the root canal tissue Rc. The micromirror 166 is configured to be rotatable by a predetermined angle around the rotation shaft 161 by the electric power supplied from the power line 162. Other configurations are the same as those of the first OCT probe 101 and the first probe body 331 described above.

As shown in FIG. 25B, by rotating the micromirror 166, it is possible to perform image scanning in the probe tip direction by irradiating the probe tip direction at an oblique angle. When image scanning in the probe tip direction is performed by rotating the micromirror 166, the second probe main body 332 is rotated, and the rotation operation of the micromirror 166 and the rotation operation of the second probe main body 332 are synchronized. Thus, it is also possible to perform image scanning in the probe tip direction.

Note that, as shown in FIG. 26, the second OCT probe 102 that emits light toward the tip side may employ a configuration in which the first OCT probe 101 does not include the prism 135. As shown in FIG. 26, nothing may be provided at the tip of the GRIN lens 136, or a protective glass for protecting the tip of the GRIN lens 136 may be provided.

Next, FIG. 27 is a cross-sectional view of the third OCT probe 103 on a plane including the central axis of the sixth optical fiber F6. As shown in FIG. 27, in the third probe main body 333 formed in the third OCT probe 103, the prism 135 is irradiated with light from the first probe main body 331 so that the emission angle of the light guided by the sixth optical fiber F6 is irradiated. Is arranged so as to irradiate the root canal tissue Rc at an irradiation angle between the irradiation angle to be irradiated and the irradiation angle at which light is irradiated from the second probe main body 332. In the present embodiment, The irradiation angle is 60 degrees, for example. Other configurations are the same as those of the first OCT probe 101 described above.

Next, the procedure for acquiring the image of the observation object in the root canal will be described with reference to FIGS. FIG. 28 is an explanatory diagram when a tomographic image of the upper portion of the root canal 500 is acquired using the first OCT probe 101.

As shown in FIG. 28, the root canal 500 has a main root canal 510 having a hollow shape and a side branch 520 that is a portion branched finely from the main root canal 510. The upper part of dentin 543 is covered with enamel 542 and the lower part is fixed with cementum 540, periodontal ligament 549 and alveolar bone 541. Below the apical portion 530 of the root canal 500 is the apical lesion 560. The apical lesion is also referred to as apical lesion or apical periodontitis, and is a collective term for lesions that occur near the tip of the tooth root (for example, a periodontal granuloma, a root cyst, etc.).

The controller 281 is operated to turn on the light source 110 so that near-infrared light reaches the fiber coupler 213 and is divided into light passing through the second optical fiber F2 and light passing through the third optical fiber F3. The light traveling through the second optical fiber F2 enters the fifth optical fiber F5, then passes through the sixth optical fiber F6, and enters the first probe body 331. Light is emitted from the first probe main body 331 at a right angle, collected on the root canal tissue, and swept by the first probe main body 331 again.

On the other hand, the light traveling through the third optical fiber F3 is reflected by the roof mirror 219, and the reflected light is guided to the fiber coupler 213 again.

Both the reflected light from the root canal tissue and the reflected light from the roof mirror 219 are received by the light detection unit 216 via the fiber coupler 213. Then, the controller 281 moves the roof mirror 219 by a small distance so that the optical path length from the distal end face F3a of the third optical fiber F3 to the roof mirror 219 is changed from the distal end face of the sixth optical fiber F6 to the optical path length between tissues in the root canal. By making them coincide, interference is generated from two kinds of reflected light. The movement of the first OCT probe 101 can be moved up and down while rotating the first probe main body 331 with the sheath 150 fixed, and the sheath 150 can be moved up and down together with the first probe main body 331, for example. Is possible. In this way, a tomographic image of the upper part of the root canal 500 is acquired.

Next, when acquiring an image of the apical portion of the root canal 500, the first OCT probe 101 is removed and the second OCT probe 102 is attached. The second OCT probe 102 is attached, for example, by removing the first probe main body 331 and attaching the second probe main body 332 while keeping the sheath 150 intact. FIG. 29 is an explanatory diagram when a tomographic image of the apical portion of the root canal 500 is acquired using the second OCT probe 102. As described above, the controller 281 is operated in the same manner as the operation of the first OCT probe 101, and as shown in FIG. 29, the light is externally irradiated toward the tip of the probe and collected in the root canal tissue existing outside the probe. Illuminate to obtain a tomographic image of the apex.

Next, when acquiring an image of the root canal side wall in the intermediate region between the root apex and the upper part of the root canal 500, the third OCT probe 103 is attached. The third OCT probe 103 is attached, for example, by removing the second probe main body 332 and attaching the third probe main body 333 while keeping the sheath 150 as it is. FIG. 30 is an explanatory diagram when a tomographic image of an intermediate region of the side wall of the root canal 500 is acquired using the third OCT probe 103. As described above, the controller 281 is operated in the same manner as the operation of the first OCT probe 101, and as shown in FIG. 30, the light is externally irradiated at a predetermined angle and collected on the root canal tissue existing outside the probe. Then, a tomographic image of the intermediate region in the root canal is acquired.

(Embodiment 3B)
In the present embodiment, similar to the above-described embodiment 1C, the sheath 150 has matching oil for adjusting the refractive index that fills the space between the sheath 150 and the probe main body 331. By using a matching oil for adjusting the refractive index that fills the space between the sheath 150 and the probe main body 331, connection loss of light can be prevented, and clear imaging of the root canal tissue Rc is possible. Become.

(Embodiment 3C)
In the present embodiment, matching oil for refractive index adjustment that fills the space between the sheath 150 and the root canal tissue Rc is disposed around the sheath 150. The refractive index of the matching oil can be the same as or close to the refractive index of the sheath 150. By using a matching oil for refractive index adjustment that fills the space between the sheath 150 and the root canal tissue Rc, loss of light connection can be prevented, and clear imaging of the root canal tissue Rc can be performed. It becomes possible.

(Embodiment 3D)
In the above-described embodiment, only one type of third OCT probe is provided. However, the present invention is not limited to the above-described embodiment. For example, a plurality of third OCT probes can be provided. FIG. 31 is a cross-sectional view of the third OCT probe 103a on the plane including the central axis of the sixth optical fiber F6. As shown in FIG. 31, in the third probe main body 333 formed on the third OCT probe 103a, the prism 135 is arranged to be irradiated at an irradiation angle of 30 degrees. Then, by combining with the third OCT probe 103 irradiated at an irradiation angle of 60 degrees shown in FIG. 27, an image of the intermediate region in the root canal can be acquired more accurately.

(Embodiment 3E)
Further, the present invention can also be configured so that the tip of the probe main body can move in different directions within the sheath 150. FIG. 32A and FIG. 32B are explanatory views of a fourth OCT probe according to another embodiment that is movable so that the tip faces in different directions. 32A shows the fourth probe body when not bent, and FIG. 32B shows the fourth probe body when bent. As shown in FIG. 32A, the fourth probe body is connected in order from the distal end side to the prism 135, the GRIN lens (refractive index gradient lens) 136, and the seventh optical fiber F7 that can be bent with flexibility. And a light guide portion 137.

Wire attachment portions

174 and 174 are provided at both ends of the GRIN lens 136, and

wire attachment portions

172 and 172 are also provided at both ends of the connection light guide portion 137. Between these wire attachment portions, A set of wires 173 are each attached. In the state of FIG. 32A, the emission angle of the light guided by the sixth optical fiber F6 and the seventh optical fiber F7 is a right angle.

Then, as shown in FIG. 32B, when one of the wires 173 is reduced, the fourth probe main body moves so as to face the direction of the reduced one wire 173 side. In the state of FIG. 32B, the emission angles of the light guided by the sixth optical fiber F6 and the seventh optical fiber F7 are emitted not at a right angle but at an angle θ obliquely forward. According to the configuration of the present embodiment, the light emission angle can be adjusted by a simple method of adjusting the length of the wire provided in the probe body without changing the shape of the prism 135.

As described above, according to the dental OCT apparatus according to this embodiment as described above, a wide range of tissue images in the root canal can be acquired by combining the first OCT probe 101, the second OCT probe 102, and the third OCT probe 103. In addition to the upper part of the root canal, it is possible to depict the root canal side wall, the apical part, and the apical periodontal tissue part in the intermediate region. Therefore, without operating the file or reamer in a blind state as in the past, the actual condition inside the root canal, specifically the tooth apex, periodontal ligament, cementum, alveolar bone, root canal wall and root By directly confirming the state of the apex, root canal treatment can be performed easily and accurately, and it is possible to detect root fractures, so the benefits obtained by the present invention are immeasurable.

In the above-described embodiment, the swept source OCT (SS-OCT) is used in the Fourier domain OCT (FD-OCT). However, the present invention is not limited to this method. The format proposed in OCT (SD-OCT) may be used, and the OCT apparatus may be in the format proposed in time domain OCT (TD-OCT).

Since early detection of tooth contact and tooth occlusion contact is possible, it can be used beneficially in the fields of dental diagnosis and treatment. In addition, the present invention can be used for drawing a tissue image in the root canal, and can accurately and easily grasp the structures of complex apical parts, apical periodontal tissues, and side branches. In addition, objective image inspections such as the presence or absence of fractures, cracks, deformed excessively stenosed root canals, and remnants are possible, making it possible to diagnose and diagnose dental diseases that were extremely difficult with conventional dental imaging equipment. Make it possible. Therefore, it can be used in the field of examination and diagnosis of dental diseases.

101: First OCT probe (OCT probe)
102: Second OCT probe (OCT probe)
103: Third OCT probe (OCT probe)
110: Light source 111, 112: Optical fiber 113: Coupling unit 117: Collimating lens 118: Reference mirror 120: Lens 121: Photo detector 122: Amplifier 123: Signal processing unit 124: Image processing unit 125: Image display unit 131: Probe Body (first probe body)
132: Second probe main body 133: Third probe main body 135: Prism 136: GRIN lens 137: Connection light guide 140: OCT probe 150, 151: Sheath 160: Rotating means 171: Moving means 171a: Slider 171b: Guide rail 200 : Observation object 210: Support rail 220: Horizontal movement means 230: Vertical movement means 300: Expansion body 301: Container part 310: Internal cavity part 311: Insertion hole 331: First probe main body (probe main body)
332: second probe body (probe body)
333: Third probe body (probe body)
500: Root canal 800: OCT main device 900: Dental OCT device

Claims

A light source that emits light;
An OCT probe having a flexible sheath having at least a distal side region permeable, and a probe body disposed in the sheath;
A light guide means having one end connected to the light source and the other end connected to the probe body;
An image display unit for displaying an image of an observation target in the oral cavity,
The probe main body emits light guided from the light source through the light guide unit to the observation target, sweeps the reflected light to the light guide unit, and displays an image based on the reflected light on the image display unit. Dental OCT device.
The OCT probe includes a first OCT probe that changes the direction of incident light from the light guide unit to a target to be observed by changing the direction to a right angle;
A second OCT probe that linearly emits the incident light and emits it to an observation target;
The incident light is composed of three types: a third OCT probe that emits light to an observation object at an emission angle between an emission angle of the first OCT probe and an emission angle of the second OCT probe,
The dental OCT apparatus according to claim 1, wherein the first OCT probe, the second OCT probe, or the third OCT probe is configured to be used interchangeably.
The dental OCT apparatus according to claim 2, wherein the observation object in the oral cavity is a tooth apex, an apical periodontal tissue, or a side branch in a root canal.
The dental OCT apparatus according to claim 2, wherein the object to be observed in the oral cavity is a remnant pulp, a pulpal root canal, a fracture, a crack, or a deformed excessively narrowed root canal.
The dental OCT apparatus according to claim 1, further comprising a matching oil that fills a space between the sheath and the probe body in the sheath.
The dental OCT apparatus according to claim 1, further comprising a matching oil that fills a space between the observation target and the sheath.
The observation object is a tooth adjacent surface,
The OCT probe has rotating means for rotationally driving the probe main body, and moving means for moving the probe main body back and forth within the sheath,
The OCT probe is inserted into the upper part or the lower part of the interdental space, the sheath is fixed in the interdental space where the OCT probe is inserted, and the probe body is rotated and fixed by the rotating means. The dental adjacent surface according to claim 1, wherein an image of a tooth adjacent surface is taken with an OCT probe by performing at least one of the back and forth movement of the probe body by the moving means in the sheath. OCT device.
Having an inflatable body having a cavity portion and in close contact with the interdental space when inflated;
The OCT probe is inserted into the lumen of the inflatable body;
An anti-attenuation medium for preventing light attenuation due to a difference in refractive index is injected into the expansion body, thereby bringing the expansion body into close contact with the interdental space and taking an image of a tooth adjacent surface with an OCT probe. The dental OCT apparatus according to claim 7.
The observation object is a tooth occlusal surface,
Rotating means for rotationally driving the probe body;
Back and forth moving means for moving the probe body back and forth within the sheath;
Horizontal moving means for moving the OCT probe horizontally;
The dental OCT apparatus according to claim 1, further comprising a vertical moving unit that vertically moves the OCT probe.
The dental OCT apparatus according to claim 9, wherein the sheath disposed in the vicinity of the tooth occlusal surface is provided by being deformed along the undulation form of the tooth occlusal surface.
The probe main body is a first probe main body that emits incident light from the light guiding means at a right angle to the observation target;
A second probe body that changes the direction of the incident light at an acute angle with respect to the light guide means and emits the incident light to an observation target;
The incident light consists of three types: a third probe body that changes the direction to an obtuse angle with respect to the light guide means and emits the incident light to an observation target;
The dental OCT apparatus according to claim 7 or 9, wherein the first probe main body, the second probe main body, or the third probe main body is configured to be used interchangeably.
It is placed in contact with the tooth occlusal surface, and has a vessel portion filled with an anti-attenuation medium that prevents attenuation of light due to a difference in refractive index,
The side of the vessel has an insertion hole into which the OCT probe can be inserted,
The OCT probe is inserted into the insertion hole of the vessel part,
The dental OCT apparatus according to claim 9, wherein an image of a tooth occlusal surface is taken with an OCT probe by injecting the anti-attenuation medium into the vessel portion.