JP5376447B2 - Root canal treatment system - Google Patents

Description

  The present invention relates to a root canal treatment system using a CT image and a root canal treatment instrument.

  Conventionally, in dental root canal treatment, a root canal length measuring device that measures the length of the root canal electrically measures the length of the root canal. This is because, for example, an electrical signal is given between the measurement electrode to be inserted into the root canal and the oral electrode placed in the oral cavity, and the tip of the measurement electrode has reached the root apex (apical position). It is to detect. As described above, many techniques for electrically measuring the length of the root canal are publicly known and disclosed in Patent Document 1 and the like.

  However, this root canal length measuring instrument does not actually measure the length of the root canal, but only detects the apex. In order to measure the actual length of the root canal, after detecting the apex portion with a root canal length measuring instrument, a stopper provided in advance on the measurement electrode is lowered until it hits the tooth. And once the measurement electrode was extracted from the root canal, the length of the root canal was measured by measuring the distance from the stopper to the tip of the measurement electrode.

  The root canal length measuring instrument disclosed in Patent Document 2 can detect the apex and further has a function of displaying that the tip of the measurement electrode has reached the set reference position. Then, whether or not the tip of the measurement electrode is approaching the apex or the reference position is displayed by an instruction dot. However, this display is only a guide, and the position of the measurement electrode cannot be specifically understood.

  By the way, the number of root canals varies from person to person even in teeth of the same site. For example, in the first premolars, the number of root canals is one or two, and there are cases of single roots and multiple roots. In the second molar, the number of root canals is 2-4. In addition, the shape of the root canal is not necessarily linear, and there are some that are greatly curved. Further, the root canal may have a side branch (branch of the root canal) and may have a complicated shape.

  Doing root canal treatment without accurately knowing the length of the root canal, the number of root canals, the shape of the root canal, etc. This can cause lesions, resulting in the need for root canal treatment again or forced extraction.

  Therefore, in root canal treatment, it is necessary to accurately grasp the length of the root canal in advance and grasp the shape of the root canal such as the number of root canals, the presence or absence of side branches, the width of the root canal, and the curvature of the root canal. Furthermore, it is preferable to specifically grasp where the tip of the root canal treatment instrument is present in the root canal during root canal treatment.

JP-A-6-181938 Japanese Patent No. 3113095

  Therefore, in view of the above problems, the present invention can confirm the shape of the root canal before root canal treatment, can accurately measure the distance from the reference position to the apex, and further, during root canal treatment, Provided is a root canal treatment system capable of displaying in real time the distance that the distal end of a tube treatment instrument has moved from a reference position.

In order to solve the above problems, a root canal treatment system according to the present invention is based on an image display means for displaying a CT image of a tooth to be a root canal treatment, and a CT image displayed on the image display means in advance. CT image length measuring means for measuring the length from the set reference position to the apex of the root canal of the subject tooth, a root canal treatment instrument for treating the root canal of the subject tooth, and a root canal treatment instrument A guide means for guiding the root canal to the root canal, and a treatment instrument distance measuring means for measuring the distance the tip of the root canal treatment instrument has moved from the reference position ,
The guide means is formed with a guide hole penetrating vertically and has a base installed on the crown portion of the target tooth. The treatment instrument distance measuring means is attached at one end to the upper part of the root canal treatment instrument and has the other end Is guided to the outside through the base, and a linear member for transmitting the vertical movement of the root canal treatment instrument, and a detecting means for detecting the movement amount of the other end of the linear member that moves in accordance with the vertical movement of the root canal treatment instrument And comprising.

Preferably, the root canal treatment instrument is provided on a lower side of the handle part, a support member to which one end of the linear member is detachably attached, and a lower side of the support member. A cutting portion for removing the pulp and enlarging the root canal, and the guide means guides the cutting portion to the root canal, and the treatment instrument distance measuring means has the tip of the cutting portion from the reference position. Measure the distance traveled.

  Preferably, the image display means simultaneously displays a plurality of axial position images up to the apex portion of the target tooth in order to confirm the number of root canals or the shape of the root canals.

Preferably, the image display means is a virtual endoscopic image generated based on a CT image, wherein the viewpoint position is the position of the tip of the root canal treatment instrument, the line-of-sight direction is the direction toward the apical side of the root canal, and Is displayed.

  Preferably, the image display means displays a point indicating the position of the tip of the root canal treatment instrument on the CT image, and the point displayed on the CT image corresponds to the distance measured by the treatment instrument distance measurement means. , Move on the CT image.

Preferably, a length display means for displaying the length measured by the CT image length measurement means, and a distance display means for displaying the distance measured by the treatment instrument distance measurement means are provided.

  In the root canal treatment system according to the present invention, a CT image of an arbitrary cross section such as an axial image, a coronal image, a sagittal image, or the like of a tooth to be subjected to a root canal treatment is displayed on the image display means. Thus, the shape of the root canal can be accurately confirmed, such as the number of root canals and the presence or absence of side branches. Furthermore, since the distance from the reference position (for example, root canal mouth, crown part, etc.) to the apex can be measured by CT image, the measurement electrode is inserted into the root canal before treatment as in the past. There is no need to do.

  At the time of treatment, it is possible to measure how far the distal end of the root canal treatment instrument has moved from the reference position by the treatment instrument distance measuring means. You can see exactly where it is in real time.

It is a figure showing one embodiment of a root canal treatment system concerning the present invention. It is a figure which shows CT image of the some cross section in an object tooth. It is a figure which shows the axial position image at equal intervals to the root apex part of an object tooth. It is a figure which shows the virtual endoscopic image of an object tooth. FIG. 4A to FIG. 4H show the state of passing through the inside of the root canal of the target tooth and reaching the apex. It is a figure which shows the virtual endoscopic image of an object tooth. FIG. B is a diagram showing a state in which the viewpoint position is advanced from FIG. A toward the root canal. It is a figure which shows a mode that the length from a reference position to a root apex part is measured based on CT image. It is a figure which shows a root canal treatment instrument, a guide means, and a treatment instrument distance measurement means. FIG. 7A is a diagram showing a state in which the tip of the root canal treatment instrument is aligned with the reference position (dental crown), and FIG. 7B shows a state in which the tip of the root canal treatment instrument is inserted into the root canal from the reference position. FIG. It is a figure which shows the example of a detection means, Comprising: FIG. 8A shows the detection by a rotary encoder, FIG. 8B shows the detection by a linear encoder. FIGS. 9A and 9B are diagrams showing examples of detection means, in which FIG. 9A shows detection by a variable resistor, and FIG. 9B shows detection by an optical triangulation method. It is a figure showing a mode that the point which shows the position of a front-end | tip on a CT image moves with the movement of the front-end | tip of a root canal treatment instrument. It is a figure which shows a mode that the CT image which showed the position of the front-end | tip of a root canal treatment instrument and the virtual endoscopic image of the root canal in the position of the front-end | tip of a root canal treatment instrument were displayed on the image display means. It is a figure which shows the apex part detection means which detects an apex part electrically.

  Embodiments of the present invention will be described below with reference to the drawings.

  The entire root canal treatment system of the present invention will be described with reference to FIG. The root canal treatment system includes a conbeam CT apparatus (CBCT apparatus) 10 for performing CT imaging of a tooth 7 to be treated.

  The root canal treatment system includes a control unit 2 for performing various processes such as image processing and length measurement. The control unit 2 includes image data acquisition means 21 that acquires CT image data from the CBCT apparatus 10. The control unit 2 includes image reconstruction means 22 that performs image processing on image data and reconstructs a CT image. The control unit 2 includes virtual endoscopic image generation means 23 that generates a virtual endoscopic image based on the CT image. Furthermore, the control unit 2 includes CT image length measurement means 24 that measures the length from the reference position through the root canal 73 to the apex portion 72 (apical position) based on the CT image. Here, the reference position is a position that is set in advance by the operator during treatment, and is, for example, the crown 71 or the root canal.

  The root canal treatment system includes a root canal treatment instrument 3 that removes the pulp in the root canal 73 and enlarges the root canal 73. The root canal treatment system includes guide means 4 for guiding the root canal treatment instrument 3 to the root canal 73 to be treated.

  The root canal treatment system includes a treatment instrument distance measuring means 5 that measures the distance that the distal end 32a of the root canal treatment instrument 3 has moved from the reference position. The therapeutic instrument distance measuring means 5 includes a linear member 51 for transmitting the vertical movement of the root canal therapeutic instrument 3. The therapeutic instrument distance measuring means 5 includes a detecting means 52 that detects the vertical movement of the root canal therapeutic instrument 3. Furthermore, the treatment instrument distance measuring means 5 includes a distance calculation means 53 that calculates the distance that the distal end 32a of the root canal treatment instrument 3 has moved from the reference position based on the detection signal from the detection means 52.

  The root canal treatment system includes a display unit 6 that displays images, measurement distances, and the like. The display unit 6 includes display means 61 that displays CT images and virtual endoscopic images. The display unit 6 includes a length display unit 62 that displays the length measured by the CT image length measurement unit 24. The display unit 6 includes distance display means 63 that displays the distance measured by the treatment instrument distance measurement means 5. Further, the root canal treatment system includes an operation unit 11 for an operator to perform an operation such as selecting an image to be displayed on the image display unit 61.

  In performing root canal treatment, the operator cuts the crown portion 71 of the tooth 7 to be subjected to root canal treatment in advance to enlarge the crown portion 71 until the dental pulp cavity can be confirmed. Then, the CBCT apparatus 10 irradiates the target tooth 7 on which the dental crown portion 71 is enlarged with an X-ray beam, and performs CT imaging of the target tooth 7. In addition to the above, a simulation for enlarging and forming on an image reconstructed by performing CT imaging first may be performed.

  In the reconstructed CT image, in order to clarify the reference position determined by the operator, for example, when the crown part 71 is used as the reference position, the reference position is used when the crown part 71 is enlarged. The crown portion 71 may be cut flat. The surgeon can easily confirm the reference position on the CT image by finding the portion of the CT image cut to the flat of the tooth 7. Further, by performing CT imaging with a plate-like object such as a metal plate placed at the reference position, the reference position can be clarified on the CT image. However, in the case of a metal plate, an artifact problem may occur, so it is preferable to use a metal that is less affected by the artifact. As long as the reference position is clear in the reconstructed CT image, other materials may be used instead of metal. In addition, the reference position may be clarified in the reconstructed CT image by previously installing the guide unit 4 on the crown portion 71 and performing CT imaging.

  Image data obtained by CT imaging is acquired by the image data acquisition means 21. The image reconstruction unit 22 performs image processing on the acquired image data to reconstruct a CT image. The image reconstruction unit 22 reconstructs a two-dimensional image and a three-dimensional image of an arbitrary cross section in addition to an axial image, a sagittal image, and a coronal image. The CT image reconstructed in this way is displayed on the image display means 61.

  The surgeon confirms the number of root canals 73 of the target tooth 7 and the shape of the root canal 73 from the CT image displayed by the image display means 61. When the target tooth 7 has a plurality of roots, the surgeon specifies the root canal 73 to be treated from the CT image. As shown in FIG. 2, the image display means 61 not only displays a single CT image, but also, for example, an axial image, a sagittal image, and a coronal image at an arbitrary point of the target tooth 7. In addition, arbitrary cross sections can be displayed simultaneously. Further, as shown in FIG. 3, a plurality of axial position images at regular intervals from the reference position to the apex portion 72 can be displayed simultaneously. The interval between axial positions is 0.5 mm or 1.0 mm, for example, or a plurality of axial positions may be displayed at finer intervals according to the resolution of the CT image. The surgeon continuously observes a plurality of axial position images from the reference position to the apex portion 72, so that the shape of the root canal 73 such as a change in the width of the root canal 73 and a curvature of the root canal 73 is obtained. Easy to understand.

  Further, the CT image displayed on the image display means 61 may be freely rotated by the operation means 11 so that the shape of the root canal 73 can be easily understood.

  Further, the virtual endoscopic image generation unit 23 generates a virtual endoscopic image based on the CT image, and displays the virtual endoscopic image on the image display unit 61. Unlike the CT image shown previously, by using a virtual endoscopic image as shown in FIGS. 4 and 5, the root canal 73 to be treated can be observed from the inside.

  In the virtual endoscopic image, the viewpoint position and the line-of-sight direction can be arbitrarily changed by the operation means 11. As shown in FIG. 4, the image enters the inside of the root canal 73 while changing the viewpoint position and the line-of-sight direction toward the root canal 73 from the image (FIG. 4A) in which the target tooth 7 can be confirmed from the outside (FIG. 4B and FIG. 4C The root canal 72 can be confirmed (FIGS. 4D to 4H), and the shape of the root canal 73 from the root canal 73 to the apex 72 can be grasped from the inside. Furthermore, from such a virtual endoscopic image, a moving image from the outside of the target tooth 7 to the inside of the root canal 73 and reaching the root apex 72 is created, and the width of the root canal 73 and the root canal 73 are determined by the moving image. It is also possible to confirm the shape of the root canal 73, such as the curvature of the.

  Further, when the surgeon moves the viewpoint position from the virtual endoscopic image shown in FIG. 5A toward the root canal 73a with the operating means 11, the virtual endoscopic image shown in FIG. 5B is displayed. The root canal 73b can be confirmed. The surgeon can confirm the number of root canals from the virtual endoscopic image, further identify the root canal 73 to be treated, advance the viewpoint position to the apex 72, and confirm the shape of the root canal 73. .

  As shown in FIG. 6, the surgeon confirms the shape of the root canal 73 to be treated from the CT image, and then displays an image of the CT image in which the root apex 72 of the root canal 73 to be treated appears. It is displayed on the means 61. Then, for example, on the CT image, the line 91 can be drawn by superimposing the CT image on the CT image by the operation means 11, and the operator can start the root to be treated from the reference position (for example, the crown portion 71). A line 91 is drawn through the tube 73 to the apex 72. The CT image length measuring means 24 measures the length from the reference position side 91a of the line 91 drawn on the CT image to the apex portion 91b to the apex portion 72 from the actual reference position. Is calculated. This length calculation is performed based on the fact that the imaging area of CT imaging by the CBCT apparatus 10 and the magnification of the displayed CT image are known in advance.

  In the above method, when the root canal 73 is greatly curved in three dimensions, measurement cannot be performed in consideration of the depth of the root canal 73 that does not appear on the CT image. Therefore, as shown in FIG. 6, the vertical axis 81 a and the horizontal axis 81 b are displayed on the image display unit 61, and the operation unit 11 freely rotates the image about the vertical axis 81 a or the horizontal axis 81 b as a central axis. Enable to display CT images of different cross sections.

  Then, the operator plots the reference position (for example, the crown portion 71) by the operation means 11 and plots the position of the root canal 73 to be treated up to the apex portion 72 along the curvature of the root canal 73. I will do it. In the middle, when approaching a curved portion that does not appear in the CT image, the operating means 11 rotates the image about the vertical axis 81a or the horizontal axis 81b as the central axis, and the root canal 73 that did not appear in the previously displayed CT image. A CT image showing the curved portion is displayed, and the position of the root canal 73 is plotted. If necessary, the CT image to be rotated and displayed is changed each time, and plotting is performed until the apex 72 is reached. The CT image length measuring unit 24 calculates the length from the actual reference position to the apex 72 based on the length of the line drawn through the positions plotted from the reference position to the apex 72 in order. In this way, by measuring the length from the reference position to the apex portion 72 in consideration of the depth of the root canal 73, an accurate length can be obtained even when the root canal 73 is greatly curved in three dimensions. Can be measured.

  In addition to this, as shown in FIG. 3, in a plurality of axial position images extending from the reference position to the apex portion 72, the surgeon can treat the root canal as a treatment target displayed at the reference position and each axial position image. Plot 73 positions. Then, the CT image length measuring unit 24 sequentially determines the actual length of the axial length image passing through the positions plotted on the axial position images from the reference position to the apex portion 72 (for example, 0.5 mm). ) And the plot position, and can also be measured.

  The CT image length measuring unit 24 measures not only the measurement from the reference position to the apex 72 but also the distance from the reference position to the side branch when, for example, a side branch is confirmed on the CT image. Can do. In addition, an arbitrary distance on the CT image such as the length of the root canal 73 and the width of the root canal 73 can be measured.

  The control unit 2 causes the length display unit 62 to display the length measured by the CT image length measurement unit 24.

  Next, the root canal treatment instrument 3, the guide means 4, and the treatment instrument distance measurement means 5 will be described with reference to FIG. The root canal treatment instrument 3 is a reamer, a file, or the like. The root canal treatment instrument 3 includes a handle 31 for an operator to operate the root canal treatment instrument 3. The surgeon grasps the handle 31 to move the root canal treatment device 3 up and down, horizontally and rotationally. Further, the root canal treatment instrument 3 includes a cutting portion 32 for removing the dental pulp and enlarging the root canal 73. The cutting part 32 is formed in a taper shape. The length of the cutting part 32 is about 20 mm to 25 mm, and the thickness of the cutting part 32 also varies.

  The guide means 4 includes a base 44 installed on the crown portion 71. The base 44 includes a guide hole 41 for guiding the cutting portion 32 of the root canal treatment instrument 3 to be inserted into the root canal 73. The guide hole 41 is formed in a taper shape, and the diameter of the hole decreases from the upper surface side toward the lower surface side, so that the cutting portion 32 can be easily inserted into the root canal 73.

  The therapeutic instrument distance measuring means 5 is configured as follows. One end 51 a of the linear member 51 is attached to a support member 33 provided under the handle 31 of the root canal treatment instrument 3. Since the root canal treatment instrument 3 to be used has different lengths and thicknesses of the cutting portion 32 and is used in accordance with the length and shape of the root canal 73 to be treated, the linear member 51 is It is preferable that the root canal treatment instrument 3 is detachably attached. A through hole 42 is formed in the base 44 from the upper surface to the side surface. The other end 51 b of the linear member 51 is guided to the outside through the through hole 42. The other end 51b led to the outside is connected to detection means 52 that detects the amount of movement of the other end 51b. Based on the detection signal from the detection means 52, the distance calculation means 53 calculates the distance from the reference position to the distal end 32a of the root canal treatment instrument.

  The linear member 51 may have a circular cross section or a band cross section. The linear member 51 is, for example, a SUS wire, a shape memory alloy, a nickel titanium alloy wire, a titanium wire, a titanium alloy wire, or the like.

  As the surgeon moves the root canal treatment instrument 3 up and down to treat the root canal 73, the entire linear member 51 attached to the support member 33 moves through the guide means 4. That is, as the root canal treatment instrument 3 moves up and down, the one end 51a moves up and down and the other end 51b moves forward and backward, so that the movement of the root canal treatment instrument 3 is transmitted to the other end 51b. Thereby, for example, when the crown portion 71 is set as the reference position, as shown in FIG. 7A, the other end 51b when the distal end 32a of the root canal treatment device 3 is located at the crown portion 71 (reference position) as shown in FIG. By measuring the distance of the other end 51b when the distal end 32a of the root canal treatment instrument 3 is inserted into the root canal 73 as shown in FIG. 3, the distance from the reference position to the position where the distal end 32a has entered is measured. Can do.

  The tube 43 may be attached to the inlet on the side surface side of the through hole 42, and the other end 51 b of the linear member 51 may be guided to the outside through the through hole 42 and the tube 43. The tube 43 extends from the inlet on the side surface side of the through hole 42 to the detection means 52, and guides the linear member 51 to the detection means 52. The tube 43 is made of rubber, coil spring, plastic or the like and is flexible, and the linear member 51 is smoothly guided to the outside by the tube 43 without being bent halfway. For the tube 43, for example, it is preferable to use a material used for a catheter (including a microcatheter) used in the medical field.

  The support member 33 supports the cutting part 32 rotatably. Thereby, although the support member 33 moves up and down with the vertical movement of the root canal treatment instrument 3, it can be prevented from rotating with respect to the rotational movement of the root canal treatment instrument 3. Therefore, even if the surgeon holds the handle 31 and rotates the cutting part 32, the linear member 51 does not rotate, so that it is possible to prevent an erroneous distance from being measured due to the rotation.

  The detection means 52 includes, for example, an encoder as shown in FIG. As shown in FIG. 8A, the other end 51 b is connected to the rotary encoder 12. The amount of movement of the other end 51b is detected from the amount of displacement that rotates as the other end 51b moves. Moreover, FIG. 8B is the linear encoder 13, and the other end 51b is connected to the scale 13a. The amount of movement of the other end 51b from the amount of displacement of the scale 13a is detected.

  Further, a variable resistor 14 may be used as shown in FIG. 9A. The other end 51 b of the linear member is connected to the movable terminal 14 a of the variable resistor 14. As the root canal treatment instrument 3 moves up and down, the movable terminal 14a connected to the other end 51a moves, so that the resistance value changes. The amount of movement of the other end 51b can be detected from the changing resistance value.

  The amount of movement of the other end 51b can also be detected by the principle of optical triangulation as shown in FIG. 9B. The light from the light projecting element 15 passes through the light projecting lens 16 and is irradiated to the detection body 17 attached to the other end 51b. The light applied to the detection body 17 is reflected, and the reflected light passes through the light receiving lens 18 to form a spot on the position detection element 19. When the position of the detection body 17 attached to the other end 51b moves from 17a to 17b, the position of the spot on the position detection element 19 moves from 19a to 19b. Therefore, the amount of movement of the other end 51b can be detected by detecting the position change of the spot of the position detecting element 19.

  The distance measured by the treatment instrument distance measuring unit 5 as described above is displayed on the distance display unit 63 by the control unit 2. That is, as shown in FIG. 7A, 0 mm is displayed when the distal end 32 a of the root canal treatment instrument 3 is aligned with the reference position (in this case, the crown portion 71), and as the distal end 32 a approaches the apical portion 72. The display distance gradually increases, and the display distance gradually decreases as the tip 32a moves away from the apex 72. In this way, the surgeon can accurately grasp the distance from the reference position to the position where the distal end 32a of the root canal treatment instrument 3 has entered in real time and accurately during root canal treatment. Then, the distance from the reference position displayed by the length display unit 62 to the apex 72 and the distance displayed by the distance display 63 indicate how close the tip 32 a is to the apex 72. .

  Next, an example in which the position of the distal end 32a of the root canal treatment device 3 is displayed on the CT image in real time during the treatment of the root canal 73 will be described with reference to FIG.

  First, the point 92 is superimposed and displayed on the reference position side 91a of the line 91 drawn on the CT image in a state where the tip 32a of the actual root canal treatment instrument 3 is aligned with the reference position. Then, by moving the root canal treatment instrument 3 up and down, the treatment instrument distance measuring means 5 measures the distance, and the control unit 2 moves to a position on the line advanced by an amount corresponding to the measurement distance from the reference position side 91a. Point 92 is displayed. In this way, the actual position of the tip 32a of the root canal treatment instrument 3 matches the position of the point 92 on the CT image. When the tip 32a is brought close to the apex portion 72, the measurement distance increases, and the displayed point 92 moves on the line 91 by an amount corresponding to the increase amount toward the apex side 91b. When the tip 32a is moved away from the apex portion 72, the measurement distance is decreased, so that the displayed point 92 moves on the line 91 toward the reference position side 91a by an amount corresponding to the amount of decrease.

  As described above, the point 92 indicating the position of the distal end 32 a is displayed on the CT image, and the point 92 is moved from the reference position to the root through the root canal 73 corresponding to the vertical movement of the root canal treatment instrument 3. The CT image can be moved to the apex 72. Thereby, the surgeon can understand in real time which position of the tip 32a of the root canal treatment instrument 3 is present in the root canal 73 at the time of treatment. By knowing the position of the distal end 32a in this way, for example, when the operator confirms that the distal end 32a has approached the vicinity of the curved root canal 73, the force applied to the root canal treatment instrument 3 is adjusted. For example, the cutting part 32 can be smoothly inserted into the curvature of the root canal 73.

  In addition, as shown in FIG. 11, a CT image of the target tooth 7 showing the position of the tip 32a of the root canal treatment instrument 3 in real time on one image display means 61 at the time of treatment of the root canal 73, and the tip 32a You may display simultaneously the virtual endoscopic image which shows the root canal 73 in a position in real time. In FIG. 11, an image A is a CT image of a cross section of the target tooth 7 showing the root canal 73 to be treated, and displays the position of the tip 32a in real time. The line 93 indicates the height at which the tip 32a exists, and the intersection 94 of the line 91 and the line 93 indicates the position of the tip 32a. The image B is a CT image of the target tooth 7 and displays the position of the distal end 32a of the root canal treatment device 3 in real time by a point 92. Image C is a virtual endoscopic image of the root canal 73 to be treated.

  The viewpoint position of the virtual endoscopic image of the image C is the position of the distal end 32a of the root canal treatment instrument 3, and the line-of-sight direction is the direction toward the apical portion 72 side. As described above, the viewpoint position is set to the distal end 32a based on the fact that the position of the distal end 32a can be measured in real time by the therapeutic instrument distance measuring means 5 or the like. Further, setting the line-of-sight direction to the direction toward the apex 72 is performed based on a line 91 drawn by the operator from the reference position to the apex 72 on the CT image. That is, the line-of-sight direction is a tangential direction at the point 92 of the line 91 and is a direction in which the point 92 on the line 91 moves to the apex 72 side.

  By doing in this way, the operator can confirm the shape inside the root canal 73 in the position of the front-end | tip 32a in real time by the virtual endoscopic image at the time of the treatment of the root canal 73. Since the line-of-sight direction is the direction that advances toward the apical portion 72, the surgeon inserts the distal end 32 a of the root canal treatment device 3 toward the apex portion 72. It will be easier to grasp whether or not to operate. Furthermore, by simultaneously displaying the CT image of the root canal 73 and the virtual endoscopic image, the operator can perform treatment while understanding the shape of the root canal 73 more accurately.

  The root canal treatment system may further include a conventional apex detection means 95 for electrically detecting the apex as shown in FIG. A measurement electrode 95a is provided in the root canal treatment instrument 3, and an oral electrode 95b is provided in the oral cavity. The detection means 95c measures electrical characteristics such as an impedance value between the measurement electrode 95a and the oral electrode 95b. Since the impedance value to be measured becomes a predetermined value, the detection unit 95c detects that the tip of the measurement electrode 95a has reached the apex 72.

  When the position of the tip 32a of the actual root canal treatment instrument 3 and the position of the point 92 displayed on the CT image are deviated for some reason, the actual tip 32a has already reached the root apex 72. The point 92 on the CT image may not reach the apex 72 on the CT image. At this time, if the surgeon determines that the tip 32a has not yet reached the apex 72 and forcibly inserts the root canal treatment instrument 3, the apex 72 is damaged. Therefore, the apex detection means 95 detects that the tip 32a of the root canal treatment instrument 3 has reached the apex 72, and displays the detection on the display unit 6 so that the operator can detect the apex. The part can be prevented from being damaged. Note that the operator may be audibly informed to the surgeon that the tip 32a has reached the apex 72.

24 CT image length measurement means 3 Root canal treatment instrument 32a Root canal treatment instrument tip 4 Guide means 5 Treatment instrument distance measurement means 51 Linear member 51a Linear member one end 51b Linear member other end 52 Detection means 61 Image Display means 7 Tooth 71 Crown part 72 Root apex 73 Root canal 92 Point 95 Root apex detection means

Claims (6)

Image display means for displaying a CT image of a tooth to be subjected to root canal treatment;
CT image length measuring means for measuring the length from a preset reference position to the root apex of the root canal of the target tooth based on the CT image displayed on the image display means;
And root canal treatment instrument for performing treatment of the root canal of the subject tooth,
And guide means for guiding the front Kinekan treatment instrument into the root canal,
A treatment instrument distance measuring means for measuring a distance by which the distal end of the root canal treatment instrument has moved from the reference position ,
The guide means includes a base in which a guide hole penetrating vertically is formed and installed on a crown portion of the target tooth,
The treatment instrument distance measuring means has one end attached to the upper part of the root canal treatment instrument and the other end guided to the outside through the base, and a linear member for transmitting the vertical movement of the root canal treatment instrument; A root canal treatment system comprising: a detecting unit that detects a movement amount of the other end of the linear member that moves in accordance with the vertical movement of the root canal treatment instrument . The root canal treatment instrument includes a handle for a surgeon to hold, a support member provided on the lower side of the handle, and the one end of the linear member is detachably attached, and a lower part of the support member A cutting portion provided on the side for removing the pulp and enlarging the root canal,
The guide means guides the cutting part to the root canal,
The root canal treatment system according to claim 1, wherein the treatment instrument distance measurement unit measures a distance by which a tip of the cutting unit has moved from the reference position. The image display means simultaneously displays a plurality of axial position images of the target tooth to the apex in order to confirm the number of root canals or the shape of the root canals. The root canal treatment system according to claim 1 or 2. In the image display means, the viewpoint position is the position of the distal end of the root canal treatment instrument, the line-of-sight direction is a direction toward the root apex side of the root canal, and a virtual interior generated based on the CT image The endoscopic treatment system according to any one of claims 1 to 3, wherein an endoscopic image is displayed. The image display means displays the point indicating the position of the tip of the root canal treatment instrument on the CT image,
The points that are displayed on the CT image, the treatment instrument distance according to the distance measured by the measuring means, any one of claims 1 to 4, characterized in that moves on the CT image The root canal treatment system according to Item . A length display means for displaying a length measured by the CT image length measurement means, and a distance display means for displaying a distance measured by the treatment instrument distance measurement means. The root canal treatment system according to any one of claims 1 to 5.