JP2019129969A - Cutting tool for collateral-detectable root canal enlarging device and root canal enlarging device - Google Patents

Abstract

To provide a cutting tool for collateral-detectable root canal enlarging device capable of detecting the collateral with higher accuracy.SOLUTION: A cutting tool 3 for a root canal enlarging device 1 for enlarging a root canal b of teeth includes the conductive metal for forming this cutting tool 3, and an insulating film 32 for covering the conductive metal. An opening for detecting the collateral direction is provided in a portion of the insulating film 32. The insulating film 32 is formed of an insulation material having the cutting hardness capable of enlarging the root canal b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cutting tool for a root canal detection device capable of detecting a side branch that can be used to detect a side branch extending from the root canal of a tooth to a periodontal ligament cavity, and a root canal expansion device.

  Conventionally, as a device for detecting a side branch extending from a root canal of a tooth to a periodontal cavity, a side branch detection device described in Patent Documents 1 and 2 is known. The side branch detection device described in Patent Literatures 1 and 2 includes a measurement electrode inserted into the root canal, an oral electrode disposed on the intraoral surface, a power source for applying a plurality of measurement signals to the measurement electrode, and measurement. A data processing unit that outputs display data indicating the presence or absence of a side branch extending from the root canal to the periodontal ligament cavity based on measurement data detected between the electrode and the oral electrode; and a display unit that displays the display data , Is composed of.

  The side branch detection device is a device that displays the presence or absence of a side branch on the display unit based on the waveform of the transition of display data that changes as the measurement electrode is inserted into the root canal. As the measurement electrode used in the side branch detection device, a reamer that is held by an operator with a hand to cut a root canal of a tooth, or a manual cutting tool including a file is used. The measurement electrode includes a conductive metal part that forms the measurement electrode, an insulating film covering the conductive metal part, an opening in a state where the insulating film located near the tip of the conductive metal part is isolated, And a handle portion that a person grips by hand.

  Further, when the nerve of the tooth is removed, it is necessary to remove the infectious substance and the dentin between the opening end in the root canal and the apex of the tip with a canal cleanser (extracting needle) after the treatment. In that case, a root canal length measuring instrument is used to measure the distance (root canal length) from the open end (measurement reference point) of the root canal to the apex. After measuring the root canal length, the dentin and the like in the root canal are removed by a so-called root canal enlargement motor.

Japanese Patent No. 5058713 Japanese Patent No. 6035390

  However, the side branch detection devices described in Patent Literatures 1 and 2 use a hand cutting tool made of a reamer or a file as a measurement electrode, and the measurement electrode is manually moved, so that the detection accuracy of the side branch is low. There was a problem.

  Therefore, an object of the present invention is to provide a cutting tool for a root canal enlargement device and a root canal enlargement device that can detect a side branch with higher accuracy.

  In order to solve the above-mentioned problem, a cutting tool for a root canal enlargement device capable of detecting a side branch according to the present invention is a cutting tool for a root canal enlargement device that enlarges a root canal of a tooth, and the cutting tool includes: A conductive metal that forms the cutting tool and an insulating film that covers the conductive metal are provided, and an opening for detecting a side branch direction is provided in a part of the insulating film.

  The root canal enlargement apparatus according to the present invention is a root canal enlargement apparatus that expands the root canal by attaching a cutting tool for detecting a side branch that detects a side branch extending from the root canal of a tooth to the periodontal ligament cavity. The cutting tool includes a conductive metal that forms the cutting tool, and an insulating film that covers the conductive metal, and an opening for detecting a side branch direction is provided in a part of the insulating film. Side branch opening position where the relationship between the position of the opening of the cutting tool provided in the axial direction of the cutting tool and the position of the handpiece head part holding the driving body having the chuck on which the cutting tool is mounted can be confirmed A confirmation means is provided.

  The present invention can provide a cutting tool for a root canal enlargement device and a root canal enlargement device capable of detecting a side branch with higher accuracy.

It is explanatory drawing which shows an example of the cutting tool for root canal expansion apparatuses and the root canal expansion apparatus which can detect the side branch which concerns on embodiment of this invention. (A) is the principal part enlarged side view of the handpiece head part of the root canal enlargement device showing the attachment state of the cutting tool, (b) is an AA enlarged sectional view of (a), (c) is of (a). BB expanded sectional drawing, (d) is CC expanded sectional view of (c). It is a line graph which shows the measurement data according to each measurement frequency of the to-be-inspected tooth which does not have a side branch and has an apical hole. It is a line graph which shows the measurement data according to each measurement frequency of the to-be-inspected tooth which has a side branch and a apical hole. It is a line graph which shows the measurement data according to each measurement frequency of the to-be-inspected tooth which has a side branch and does not have a apical hole. It is a line graph which shows the waveform of transition of the ratio of the measurement signal obtained using measurement signal 2KHz and 500Hz. It is a line graph which shows the waveform of transition of the difference of the measurement signal obtained using measurement signal 2KHz and 500Hz.

First, a cutting tool for a root canal enlargement device and a root canal enlargement device capable of detecting a side branch according to an embodiment of the present invention will be described with reference to the accompanying drawings.
In the present embodiment, in the root canal enlargement apparatus 1 shown in FIG. 1, the handpiece head 22 side of the handpiece 2 is assumed to be the front direction, the connection portion 23 side is the rear direction, and the inspected tooth a side is the lower direction. To do.

≪Root canal enlargement device≫
As shown in FIG. 1, a root canal enlargement apparatus 1 is equipped with a side branch detection cutting tool 3 for detecting a side branch e extending from a root canal b of a tooth (inspected tooth a) to a periodontal ligament space h. A cutting device for enlarging the tube b. Further, the root canal enlargement device 1 extends from the position of the opening 32a to the periodontal cavity h when the peak of the current value flowing through the opening 32a for side branch direction detection (see FIG. 2A) is detected. It is possible to detect the position of the side branch e in the root canal axis radial direction. The root canal enlargement device 1 includes a power source 7, a control device 8, a hand piece 2, a cutting tool 3 attached to the hand piece 2, an electrode terminal 5, a connection tool 6, and a root canal length with a side branch detection function. Measuring instrument 4 (hereinafter referred to as “root canal length measuring instrument 4” as appropriate) is mainly provided.

<Power supply>
The power supply 7 outputs one or a plurality of measurement signals Pn having different frequencies. For example, the power source 7 outputs measurement signals Pn having two frequencies of 500 Hz and 2 KHz.

<Control device>
The control device 8 is a device capable of detecting the value of the current flowing through the side branch direction detection opening 32a and controlling the rotational speed of the drive body 25 (electric motor). The control device 8 selects or switches the frequency of 500 Hz or 2 KHz and sequentially converts the measurement signal to be sent to the measuring electrode cutting tool 3 into a safe voltage. The control device 8 includes an amplifying unit that converts measurement data (measurement current) obtained from the electrode terminal 5 arranged on the gingiva d of the tooth a to be inspected a into a measurement current and amplifies it, and a conversion unit that converts the measurement current into a DC voltage. And a control unit for controlling each element of the root canal length measuring device 4, a storage unit, a data processing unit, a notification means driving unit, and the like.

≪Handpiece≫
As shown in FIG. 1, the handpiece 2 is a dental medical device used for dental treatment. The handpiece 2 includes a grip part 21, a handpiece head part 22, a connection part 23, a chuck 24, a driving body 25, a side branch opening position confirmation means 26 having a detection member 27, an attachment / detachment operation part 28, It is configured with. The handpiece 2 is used by connecting the connecting portion 23 to the control device 8 and attaching the desired cutting tool 3 to the handpiece head portion 22.

  The grip part 21 is a member that forms a handpiece body. The grip portion 21 may be a pipe or a core material that is formed of an insulating material such as a synthetic resin material, or a grip material that is formed of a conductive material such as a metal material. However, when formed using a conductive material, it is important to apply an insulating film or the like. As a result, even when the tissue in the oral cavity is touched, root canal length measurement, detection of the side branch e, etc. can be performed without hindrance.

  The handpiece head portion 22 is a substantially cylindrical portion that is provided at the front end portion of the grip portion 21 and to which the cutting tool 3 is detachably attached. The handpiece head part 22 and the connection part 23 are made of metal such as stainless steel. The handpiece head unit 22 is provided with an opening hole (not shown) of the chuck 24 to which the cutting tool 3 formed on the lower side is attached and detached, and a drive body 25 that rotationally drives the cutting tool 3.

  The connecting part 23 is a part provided at the rear end of the grip part 21 and connected to the control device 8 and a lead wire 92 connected to a dental unit (not shown). It is not limited.

As shown in FIG. 2A, the chuck 24 is a tightening portion to which the holding member 33 provided at the upper end portion of the cutting tool 3 is detachably attached. The chuck 24 is configured such that the holding member 33 can be fixed to or detached from the chuck 24 by pressing the attachment / detachment operation portion 28 provided at the upper end portion of the handpiece head portion 22. Yes.
The attachment / detachment operation unit 28 includes a push-button switch for performing an operation that enables the attachment / detachment of the holding member 33 by increasing or decreasing the inner diameter of the chuck 24 by a pressing operation.

The driving body 25 includes a motor that rotates the cutting tool 3 to cut the tooth to be inspected a, or an ultrasonic vibrator that cuts the tooth to be inspected a by vibrating the cutting tool 3 ultrasonically. Hereinafter, the case where the driving body 25 is a motor will be described as an example.
In this case, the drive body 25 is composed of an electric motor that can rotate the cutting tool 3 at a low speed or a high speed.
In this description, the driving body 25 is provided on the handpiece head portion 22, but the present invention is not limited to this, and the driving body 25 is provided on the grip portion 21 using a drive coupling mechanism such as a gear. The cutting tool 3 inside the piece head 22 may be driven.

<Side branch opening position confirmation means>
The side branch opening position confirmation means 26 is a means capable of automatically recognizing the position of the side branch direction detection opening 32a. The side branch opening position confirmation means 26 holds the drive body 25 having the position of the opening 32 a provided in the insulating film 32 of the cutting tool 3 in the axial diameter direction of the cutting tool 3 and the chuck 24 on which the cutting tool 3 is mounted. This is a detection device capable of confirming the positional relationship with the position of the handpiece head unit 22. The side branch opening position confirming means 26 includes a cutting tool 3 or a detected member 34 provided on a holding member 33 fixed to the cutting tool 3 and a handpiece head so that the position of the opening 32a can be confirmed. And a detection member 27 that is provided in the section 22 and detects the member to be detected 34.

  As shown in FIG. 2A, the detection member 27 detects the member to be detected 34. For example, when the member 34 to be detected is a magnet, the detection member 27 is a Hall element that can detect the magnetism of the magnet. When the member to be detected 34 is a light emitting element, the detection member 27 is a light receiving element such as a photodiode that receives light from a light emitting element such as a light emitting diode and detects the light. The detection member 27 may be a light detection unit such as a light sensor or a light reflection sensor when the member to be detected 34 is a light emitting element. The detection member 27 is a camera that detects the presence or absence of a marker when the member to be detected 34 is a marker. The detection member 27 may be a color detector that detects the color of the marker when the member to be detected 34 is a colored marker.

<Detection member>
The detected member 34 described above is provided at a circumferential position corresponding to the opening 32 a provided in the cutting tool 3 or a circumferential position corresponding to the opening 32 a of the holding member 33 fixed to the cutting tool 3. These are magnets, electronic elements, markers, and the like serving as marks.

≪Cutting tool≫
As shown in FIG. 1, the cutting tool 3 is attached to a root canal enlargement device 1 for enlarging a root canal b of a tooth (inspected tooth a) and used as a root canal cutting tool. It is a member used as a measurement electrode during tube length measurement. The cutting tool 3 is composed of a member formed in a drill shape called a reamer or a file.
As shown in FIGS. 2A to 2D, the cutting tool 3 includes a conductive metal 31, an insulating film 32, a side branch direction detection opening 32a, a holding member 33, and a member to be detected 34 ( A marker) and a stopper 35. When the cutting tool 3 is rotationally driven to expand the root canal b, the cutting tool 3 is attached to the driving body 25 and rotated at a high speed, and when the root canal b and the side branch e are displayed, the cutting tool 3 is driven at a low side rotation. Is done.

<Conductive metal>
The conductive metal 31 is a metal that forms the cutting tool body. The conductive metal 31 is made of stainless steel, super hard steel, nickel / titanium alloy (NiTi), or the like. The conductive metal 31 is not particularly limited as long as it is made of a conductive metal.

<Insulating film>
The insulating film 32 is made of a thin film of an insulating insulating material that covers at least the surface of the conductive metal 31 to be inserted into the root canal b. The insulating film 32 is formed of an insulating material having a cutting hardness capable of expanding the root canal b. A part of the insulating film 32 is provided with an opening 32a for detecting the side branch direction. The insulating material is made of diamond-like carbon (DLC), ceramic coating or the like. Specific examples of the insulating material include PVD coating (physical vapor deposition) of hard coating such as titanium nitride (TiN), titanium carbonitride (TiCN), titanium nitride aluminum (TiAIN), and chromium nitride (CrN). Method) or titanium coating. Note that titanium nitride (TiN) is most suitable as an insulating material.

<Opening>
The opening 32a is a conductive portion for exposing a part of the conductive metal 31 to conduct electricity. The opening 32 a is provided in a state where the insulating film 32 is peeled off at a position near the tip of the cutting tool 3. The opening 32a is a hole formed by peeling the insulating film 32. The conductive metal 31 can be electrically connected to the external environment of the insulating film 32 through the opening 32a. By making the opening 32a provided in the insulating film 32 a small opening, the opening direction of the side branch e can be detected with high sensitivity, but it is required to accurately align the opening 32a with the side branch position. If the opening 32a is a large opening, the detection sensitivity is lowered, but the accuracy of aligning the cutting tool 3 with the side branch position can be lowered. The size of the opening 32a can be, for example, a circle having a diameter of 0.5 mm to 1 mm, or a non-circular shape having a side of 0.5 mm to 1 mm.

<Holding member>
The holding member 33 is a part for inserting and fixing the cutting tool 3 in the chuck 24. The holding member 33 is a columnar member fixed to the upper end of the cutting tool 3. The holding member 33 is provided with a member to be detected 34 on a cylindrical outer peripheral portion. The detected member 34 is disposed in the same axial direction as the opening 32a when the holding member 33 is viewed from above.

<Stopper>
The stopper 35 is a member for regulating the insertion amount of the cutting tool 3 to be inserted into the root canal b. The stopper 35 is fixed to the cutting tool 3 so as to be movable to a position near the upper end. The stopper 35 may be appropriately provided as necessary, and may not be provided.

<Electrode terminal and connector>
The electrode terminal 5 is an electrical connection terminal that is attached so as to hang on the gingiva d. The electrode terminal 5 is also referred to as a “counter electrode clip holder”. The electrode terminal 5 is not limited to the usage on the gingiva d, but may be used by being gripped by the subject in a shape that the subject can easily grip. Therefore, the contact position of the electrode terminal 5 is not limited to the gingiva d on the oral cavity surface, and may be a part of the body of the subject. When the contact position of the electrode terminal 5 is other than the oral cavity, a wide treatment space in the oral cavity region can be secured.
The connection tool 6 is an electrical connection tool that is electrically connected to the electrode terminal 5. The connection tool 6 is connected to a substrate (not shown) in the root canal length measuring device 4 via a lead wire 91.

≪Root canal length measuring instrument with side branch detection function≫
The root canal length measuring device 4 with a side branch detection function shown in FIG. 1 measures the root canal length, which is performed prior to root canal treatment, when the root canal b of a tooth (inspected tooth a) is treated. This is a measurement display device that performs the detection of the presence or absence of the light and the display indicating the position of the side branch e. The root canal length measuring device 4 also functions as notifying means 40 for notifying the position of the side branch direction detection opening 32a (see FIG. 2A). The root canal length measuring device 4 (notifying means 40) is configured to detect the tip position of the cutting tool 3 as a measurement electrode inserted into the root canal b of the tooth to be inspected and display it on the display unit 41. ing. Further, the root canal length measuring device 4 is configured to notify the icon 32 of the notification means 40 when the opening 32a of the cutting tool 3 is near the side branch e.

  The root canal length measuring instrument 4 includes a board (not shown) on which electronic components and the like are mounted, a switch unit (not shown) provided on the board, and lead wires 91 and 92. The lead wire 91 has one end connected to the substrate and the other end connected to the electrode terminal 5 via the connector 6. The lead wire 92 has one end connected to the substrate and the other end connected to the handpiece 2 via the control device 8.

<Display section>
The display unit 41 is a monitor that displays predetermined information such as a measurement result of the root canal length measuring instrument 4. The display unit 41 is composed of, for example, a liquid crystal panel. By observing the display on the display unit 41, the surgeon can accurately grasp the situation in which the opening 32a (see FIG. 2D) at the tip of the cutting tool 3 approaches the apex position. For example, the surgeon inspects the inspected tooth a having the side branch e, and the side branch e is displayed on the inspected tooth display unit 42 by the “LC (Lateral Canal)” display on the display unit 46 with side branch of the display unit 41. The position of the side branch e can be confirmed by the presence and the distance display of the side branch distance display unit 48. The display unit 41 displays a measurement result based on the DC voltage Vdc and / or emits a warning sound according to an instruction from the control device 8.
The display unit 41 when the power source 7 is ON includes, for example, a notification display unit 41a, a power supply mark 41b, a tooth display unit 42 to be examined, a root canal display unit 43, a distance display scale unit 44, and a horizontal stripe. A display unit 45, a side branch display unit 46 (LC), a side branch height display unit 47, a side branch distance display unit 48, and a side branch angle display unit 49 are displayed.

The notification display unit 41 a is an icon indicating the notification unit 40.
The power mark 41 b is an icon indicating the operating state of the power source 7.
The inspected tooth display unit 42 is an icon schematically depicting the inspected tooth a to be inspected. A scale representing a distance display scale unit 44 for displaying the distance from the apex position is drawn on the inspected tooth display unit 42.

  The root canal display unit 43 is an icon that schematically displays the shape of a general root canal b. A horizontal stripe display 45 is drawn in the root canal b. As the cutting tool 3 (measurement electrode) is inserted toward the apex i, the lowermost portion 45a of the horizontal stripe display portion 45 is lowered to display the tip position of the cutting tool 3. As an example, the display unit 41 illustrated in FIG. 1 displays a case where the tip of the cutting tool 3 is positioned 3 mm before the apex position. Thus, the root canal length measuring instrument 4 includes a mechanism for measuring the position of the tip of the cutting tool 3 when the cutting tool 3 is inserted into the root canal b.

The distance display scale 44 for indicating the distance from the position of the root apex i is a scale for expressing the measured distance from the position of the root apex i in millimeters (mm).
The horizontal stripe display unit 45 is an icon that displays the distance from the measured position of the apex i of the measured root canal b at a predetermined interval.

The side branch display unit 46 is an icon indicating that the side branch e is present. The side branch presence display unit 46 displays, for example, that there is a side branch e by the letters “LC”.
The side branch height display section 47 is an icon that schematically indicates the vertical length of the side branch e. The side branch height display unit 47 displays the height of the side branch e by a circle on the right side of the display unit 41 (six in FIG. 1). The side branch height display unit 47 can display the position of the side branch e by a circle (six in FIG. 1) when the side branch e is 3 mm before the apex.

The side branch distance display unit 48 is an icon that digitally displays the distance from the root apex i to the side branch e. The distance display of the side branch distance display unit 48 displays, for example, 300 when the side branch e is 3 mm before the root apex i.
The distance display by the side branch height display unit 47 and the side branch distance display unit 48 corresponds to the numerical value (3.0) in the display center. Therefore, the cutting tool 3 is inserted into the root canal b, and the cutting tool 3 is inserted to a position where the horizontal stripe display portion 45 indicates the value 3.0, whereby the tip of the cutting tool 3 is set to the side branch position. Can be arranged.

  For this reason, the surgeon rotates the cutting tool 3 arranged at the position of the side branch e at a low speed by the driving body 25, and the measurement current In flowing between the cutting tool 3 and the electrode terminal 5 becomes the largest. The direction of the detected member 34 can be confirmed as the direction of the side branch e.

  The side branch angle display unit 49 is an icon that displays the angle of the side branch e extending from the root canal b toward the periodontal ligament space h (the detected opening direction of the side branch e). The side branch angle display unit 49 can set the resolution to, for example, 10 degrees. The side branch angle display unit 49 displays an approximate angle by 10 bars forming a circle at the top of the display unit 41.

  As described above, the mechanism for measuring the position of the cutting tool 3 of the root canal length measuring device 4 is configured to measure and display not only the presence or absence of the side branch e but also the position of the side branch e. .

The data processing unit (not shown) of the control device 8 creates display data to be transmitted to the display unit 41 with respect to the DC voltage Vdc.
For example, when a measurement signal Pn of each frequency of 500 Hz or 2 KHz is applied from the power source 7 to the cutting tool 3 that is a measurement electrode, two types of measurement data (for each frequency) between the cutting tool 3 and the electrode terminal 5 ( In _{500 Hz} and In 2 _KHz ) are measured. These two kinds of measurement data (In _{500 Hz} , In 2 _KHz ) are sequentially measured in the process of inserting the cutting tool 3 into the root canal c in the root canal b.

  The waveform of the transition of the measurement data In obtained when the cutting tool 3 (measurement electrode) is inserted from the open end of the root canal b toward the apex i does not have the case where the tooth to be inspected a has the side branch e. In some cases, it was confirmed to show a specific change. That is, the measurement data (In, Vn, Vdc) can be sent to the display unit 41 of the root canal length measuring instrument 4 and displayed as display data indicating the presence or absence of the side branch e.

The horizontal axis of the graphs of FIGS. 3 and 4 indicates the position of the tip of the cutting tool 3. This distance is the distance from the tip of the cutting tool 3 to the position of the apex i. The vertical axis represents the values of measurement data (DC voltages Vdc _{500 Hz} and Vdc 2 _KHz ) at frequencies such as 500 Hz and 2 KHz.

  3, 4, and 5, when the cutting tool 3 is moved toward the apex i, and measurement signals having frequencies of 500 Hz, 1 KHz, 2 KHz, 4 KHz, and 8 KHz are applied to the cutting tool 3. The transition of measured data (waveform of transition) is shown.

  FIG. 3 shows a waveform of transition of measurement data of each frequency when the tooth to be inspected a has no side branch e and has a apical hole c. Similarly, FIG. 4 shows a waveform of transition of each measurement data for each measurement frequency when the side branch e is in the vicinity of 3 mm from the apex i and the apex c is present on the inspected tooth a.

  FIG. 5 shows a waveform of transition of measurement data at each frequency when the tooth a to be inspected has a side branch e and no apex crest c. When the tooth to be inspected a has no side branch e and no apex crest c, it is difficult to obtain a measurement data because a current does not easily flow between the cutting tool 3 serving as a measurement electrode and the electrode terminal 5.

  In FIG. 4, the measurement data (DC voltage Vdc) of each measurement frequency has a relatively flat transition from a linear increase transition waveform, although there is a difference in the degree of frequency near the position of the side branch e (3 mm). It is confirmed that the waveform changes. Such a change is not seen in the measurement data of FIG. 3 in which the tooth to be inspected a has no side branch e.

  FIG. 5 shows measurement data of the tooth to be inspected a having the side branch e but not the apex crest c. The measurement data (DC voltage Vdc) changes from increasing to a substantially flat transition waveform near the position (3 mm) of the side branch e. In this way, when the side branch e is present, the DC voltage Vdc does not increase and becomes constant.

  The reason for the change in the measurement data shown in these figures is that in FIG. 1, when the cutting tool 3 is inserted into the root canal b toward the apex i, the cutting tool 3 and the electrode terminal 5 The measurement current In flowing between them flows from the cutting tool 3 through the root apex i and the side branch e up to the position where the side branch e is present. That is, a current corresponding to the distance between the opening 32a of the cutting tool 3 and the side branch e flows. However, when the opening 32a of the cutting tool 3 passes the position of the side branch e, the distance between the main body surface of the cutting tool 3 and the side branch e becomes constant, and the current passing through the side branch e is substantially equal to the distance. It becomes a constant value.

The root canal length measuring device 4 may generate display data indicating the presence or absence of the side branch e by performing predetermined processing on a plurality of measurement data In _{500 Hz} and In 2 _KHz corresponding to each measurement frequency.
Similarly to the above, the root canal length measuring instrument 4 inserts the cutting tool 3 as a measurement electrode into the root canal b of the tooth to be examined a and moves it toward the apical crest c. At this time, the measurement signal Pn having a plurality of frequencies (for example, 500 Hz and 2 kHz) is switched from the power source 7 to _{500 Hz} and Pn _{2 kHz} and sequentially applied to the cutting tool 3. As a result, measurement data In _{500 Hz} and In _{2 kHz} corresponding to measurement signals Pn _{500 Hz} and Pn _{2 kHz} of _{500 Hz} and _{2 kHz} are sequentially output from the electrode terminal 5 in the process in which the tip of the cutting tool 3 descends. The transition (waveform of transition) of the data of In _{500 Hz} and In _{2 kHz} is shown in FIGS. A data processing unit (not shown) of the control device 8 obtains a relative value between the DC voltages Vdc _{2 kHz} and Vdc _{500 Hz} converted based on the measurement data In _{2 kHz} and In _{500 Hz} corresponding to the measurement signals Pn _{500 Hz} and Pn _{2 kHz.} . As the relative value, a difference “Vdc _{2 kHz−} Vdc _{500 Hz} ” between the two measurement signals, a ratio “Vdc _{2 kHz} / Vdc _{500 Hz} ”, or the like can be used. As the relative value, it is sufficient that the measured data Vdc _{2 kHz} and Vdc _{500 Hz} are compared with each other as long as the change point is clear, and any calculated value can be adopted.

The horizontal axis in FIG. 6 indicates the distance from the tip of the cutting tool 3 to the apex position, and the vertical axis indicates the relative value of Vdc _{2 kHz} and Vdc _{500 Hz} . FIG. 7 also shows the “difference” between Vdc _{2 kHz} and Vdc _{500 Hz} . These measurement data, among the data shown in FIGS. 3 to 5, 500 Hz and 2kHz measurement data _{an In 2kHz} and _{an In 500 Hz} corresponding to the measurement signal _{Pn 500 Hz} and _{Pn 2 KHz,} or those in DC voltage value The converted Vdc _{2 kHz} and Vdc _{500 Hz} are used. The transition waveforms in FIGS. 6 and 7 can be obtained by using a display means for displaying a data trace such as an oscilloscope.

  The ratio data (...,...,...,...) Of the inspected tooth a having the side branch e at a position 3 mm away from the root apex i shown in FIG. ing. However, the ratio data (... x ...) of the tooth a to be inspected without the side branch e shows a monotonous increase curve.

  Therefore, the side branch e can be detected by observing the transition waveform of the ratio data of the tooth a to be inspected and detecting the convex transition waveform. By this detection, the presence of the side branch e can be confirmed more clearly than the waveform of the transition of the measurement current In with respect to the measurement signal Pn having any one of the frequencies shown in FIGS. .

  The difference data shown in FIG. 7 is the ratio data (...,...,...,...) Of the inspected tooth a having the side branch e at a distance of 3 mm at the apical hole c. A convex shape is shown. However, the ratio data (... x ...) of the inspected tooth a without the side branch e shows a monotonically increasing curve.

  Accordingly, the side branch e can be detected by observing the transition waveform of the difference data of the tooth a to be inspected and detecting the convex transition waveform. By this detection, the presence of the side branch e can be more clearly confirmed as compared with the waveform of the transition of the measurement current In with respect to the measurement signal Pn having any one of the frequencies shown in FIGS. .

Here, it has been explained that “difference” or “ratio” can be adopted as a relative value of the measurement currents In _{500 Hz} and In _{2 kHz} corresponding to each measurement signal Pn of a plurality of frequencies (for example, 500 Hz and 2 kHz). The value is not limited to these. In short, any relative value may be used as long as it is a relative value that can more clearly detect the change in the measurement current In due to the presence of the side branch e.

≪Action≫
Next, operations of the cutting tool 3 for the root canal enlargement device and the root canal enlargement device 1 according to the present embodiment, which can detect the side branch, will be described with reference to FIGS.

  When the presence or absence of the side branch e is detected by the root canal enlargement device 1, first, as shown in FIG. 1, the electrode terminal 5 is attached so as to be hooked on the oral mucosa (lip) of the subject. Alternatively, the electrode terminal 5 is brought into contact with a part of the body of the subject. A connection tool 6 connected to the root canal length measuring instrument 4 via a lead wire 91 is attached to the electrode terminal 5. The connecting tool 6 and the electrode terminal 5 may be integrated without being separated.

  Next, a power switch (not shown) and a switch (not shown) of the root canal length measuring instrument 4 are operated to turn on the power supply 7 and the root canal length measuring instrument 4. As a result, the power supply 7 is turned on, and electricity is supplied to the electrode terminal 5 via the lead wires 92 and 91 and the connector 6, and the drive body 25 of the handpiece 2 can be driven to rotate. Further, it becomes possible to measure the root canal length from the insertion depth of the cutting tool 3 inserted into the root canal b and to detect the side branch e based on the insertion position of the opening 32a (see FIG. 2A).

  The cutting tool 3 (side branch direction detection electrode) has a stopper 35 for fixing to the tooth a to be inspected as shown in FIG. The distance from the tip of 3 to the stopper 35 is measured, and the side branch position is detected. Then, after setting the position of the stopper 35 of the cutting tool 3 based on the detected side branch position, the cutting tool 3 is inserted into the root canal b and cutting is performed at a position where the stopper 35 contacts the upper portion of the tooth to be inspected a. The tool 3 is arranged. By this procedure, the tip of the cutting tool 3 can be disposed at the side branch position. Thereby, the root canal enlargement apparatus 1 can detect the opening direction of the side branch e with higher accuracy. Here, the upper part of the inspected tooth a is the measurement reference point g of the inspected tooth a.

  Then, the cutting tool 3 is inserted into the root canal b of the tooth to be inspected a. When the cutting tool 3 is inserted into the root canal b of the tooth a to be inspected, the lowermost portion 45a of the horizontal stripe display portion 45 of the display portion 41 is also lowered toward the apex position. At the position where e is present, the lowermost portion 45a reverses upward. The root canal enlargement device 1 can detect the presence of the side branch e by confirming this inversion. Further, this inversion position can be detected as the position where the side branch e exists.

  The opening 32a for detecting the side branch direction of the cutting tool 3 shown in FIG. 1 or FIG. 2 is arranged at the side branch position by the above procedure. At this position, the power source 7 sequentially switches and applies a plurality of types of measurement signals Pn to one of the cutting tool 3 and the electrode terminal 5, and the cutting tool 3 is applied to the root canal b by the driver 25. Rotate at low speed. The detection unit (not shown) performs each measurement corresponding to each measurement signal Pn between the opening 32a and the electrode terminal 5 in the process of rotating the cutting tool 3 in the major axis rotation direction at the detected side branch position. The detected current is sequentially detected. When the cutting tool 3 is rotated at this position, the measurement current In flowing between the cutting tool 3 and the electrode terminal 5 increases when the opening 32a of the insulating film 32 coincides with the opening of the side branch e.

  On the other hand, when the cutting tool 3 is rotated at a low speed and the opening 32a of the insulating film 32 is removed from the opening of the side branch e, the measurement current In flowing between the cutting tool 3 and the electrode terminal 5 is small. This is because the measurement current In flows through the apical hole c and the side branch e, so that when the opening 32a of the cutting tool 3 is disengaged from the opening of the side branch e, there is a gap between the opening 32a and the opening of the side branch e. This is because the current flowing through the side branch e decreases.

  As described above, the side branch direction detection mechanism (not shown) of the root canal length measuring device 4 is configured to detect each measured current corresponding to each measurement signal that changes as the cutting tool 3 is rotated at the detected side branch position. The direction of the opening 32a of the cutting tool 3 when the value becomes maximum can be detected as the opening direction of the side branch e.

As shown in FIGS. 1 and 2, a cutting tool 3 for a root canal enlargement device capable of detecting a side branch according to an embodiment of the present invention is a root canal enlargement device that enlarges a root canal b of a tooth to be inspected (tooth). The cutting tool 3 includes a conductive metal 31 that forms the cutting tool 3 and an insulating film 32 that covers the conductive metal 31, and a side branch is formed on a part of the insulating film 32. An opening 32a for direction detection is provided.
Thereby, the cutting tool 3 for root canal enlargement apparatus has the opening part 32a for a side branch direction detection in part of the insulating film 32 which covers the electroconductive metal 31 which forms the cutting tool 3, Therefore It can also be used as a detector for detecting the side branch e. As described above, the detector for detecting the side branch e is the cutting tool 3 for the root canal enlargement apparatus 1, so that the cutting tool 3 is driven at a desired rotational speed by the driving body 25 such as a motor of the root canal enlargement apparatus 1. Thus, it can be appropriately rotated. For this reason, the cutting tool 3 for the root canal enlargement device of the present invention can detect the side branch e with higher accuracy than the conventional hand cutting tool.

The insulating film 32 is formed of an insulating material (insulating thin film) having a cutting hardness capable of expanding the root canal b.
Thereby, the insulating film 32 can make the outer periphery of the cutting tool 3 the outer peripheral surface which has the cutting hardness which cuts and expands the root canal b. Further, the insulating film 32 can coat the outer periphery of the cutting tool 3 made of the conductive metal 31 other than the opening 32a in an insulating state.

The insulating material is diamond-like carbon (DLC).
Thus, the insulating film 32 is made of hard, non-conductive diamond-like carbon (artificial diamond) so that the outer periphery of the cutting tool 3 is covered with a thin film, and the outer periphery other than the opening 32a of the cutting tool 3 is hard insulating. Can be a thing.

The insulating material is a material made of a ceramic coating.
Thereby, the insulating film 32 covering the cutting tool 3 can be ceramic coated (titanium coating) with, for example, titanium nitride (TiN) made of an insulating material.

Further, the cutting tool 3 has a marker at a circumferential position corresponding to the opening 32 a provided in the cutting tool 3 or a circumferential position corresponding to the opening 32 a of the holding member 33 fixed to the cutting tool 3. (Detected member 34) is provided.
Thereby, the surgeon can visually recognize the position of the opening 32a of the cutting tool 3 in the root canal axis radial direction by visually observing the marker.

Further, the root canal enlargement device 1 according to the embodiment of the present invention arranges the electrode terminal 5 on a part of the body of the subject, and extends from the root canal b of the tooth to be examined a (tooth) to the periodontal cavity h. A root canal enlarging apparatus 1 that expands the root canal b by attaching a side branch detecting cutting tool 3 for detecting the side branch e, and the cutting tool 3 includes a conductive metal 31 that forms the cutting tool 3, and An insulating film 32 that covers the conductive metal 31, an opening 32 a for detecting the side branch direction is provided in a part of the insulating film 32, and the axial direction of the cutting tool 3 of the opening 32 a provided in the cutting tool 3 Side branch opening position confirmation means 26 that can confirm the relationship between the position of the handpiece head portion 22 that holds the driving body 25 having the chuck 24 on which the cutting tool 3 is mounted. Here, “the axial direction of the cutting tool 3” refers to the radial direction from the central axis of the cutting tool 3.
As a result, the root canal enlargement apparatus 1 holds the position of the opening 32a in the axial direction of the cutting tool 3 and the driving body 25 having the chuck 24 by the operator visually observing the side branch opening position confirmation means 26. The positional relationship with the position of the handpiece head unit 22 can be confirmed. Further, the root canal enlargement apparatus 1 can display the direction of 360 degrees of the outer peripheral surface of the cutting tool 3 with the opening 32a of the cutting tool 3 by the side branch opening position confirmation means 26.

Further, the side branch opening position confirming means 26 is configured to detect the position of the opening 32 a and the detected member 34 and the handpiece head 22 on the holding tool 33 fixed to the cutting tool 3 or the cutting tool 3. And a detection member 27 that detects the detected member 34, and is a means capable of automatically recognizing the position of the side branch direction detection opening 32a.
Thereby, the side branch opening position confirmation means 26 includes the detected member 34 and the detection member 27, so that the position of the detected member 34 can be detected by the detection member 27. For this reason, it is possible to automatically recognize the position in the opening direction where the side branch direction detection opening 32a is present.

Moreover, the notification means 40 which alert | reports the position (position of the root canal axis radial direction of the side branch e) of the opening part 32a for a side branch direction detection is provided. Here, the “root canal axis radial direction” refers to a radial direction from the central axis of the root canal b.
Thus, when the root canal enlargement apparatus 1 inserts the cutting tool 3 into the root canal b and detects the side branch e, the position of the side branch e direction detection opening 32a (the position of the side branch e in the root canal axis radial direction) is detected. ) Can be notified to the operator by display, sound, voice, etc. by the notification means 40.

Further, the value of the current flowing through the opening 32a for detecting the side branch direction is detected, so that the rotational speed of the motor (driving body 25) can be controlled.
Thereby, in the root canal enlargement apparatus 1, the control device 8 detects the value of the current flowing through the opening 32a for detecting the side branch direction and decelerates the rotational speed of the motor, whereby the position of the side branch e in the root canal axis radial direction is detected. Can be easily detected.

In addition, the cutting tool 3 is an ultrasonic vibrator (driving body 25) that enlarges the root canal b by ultrasonically vibrating the cutting tool 3, or a motor that rotates the cutting tool 3 to enlarge the root canal b. Attached to (Driver 25) and driven.
As a result, the root canal enlargement apparatus 1 vibrates the cutting tool 3 with an ultrasonic vibrator to cut and enlarge the root canal b, or rotationally drives the motor to cut and enlarge the root canal b. You can make it.

Further, the position of the side branch e extending in the periodontal cavity h in the root canal axis diameter direction can be detected from the position of the opening 32a when the peak of the current value flowing through the side branch direction detection opening 32a is detected. Yes.
Thereby, the root canal enlarging apparatus 1 uses the driving body 25 that drives the cutting tool 3, thereby detecting the position of the side branch e in the root canal axis radial direction and cutting and expanding the root canal b. Both enlargement work can be performed.

  As described above, the cutting tool 3 for the root canal enlargement device and the root canal enlargement device 1 capable of detecting the side branch according to the present invention simply insert the cutting tool 3 for side branch detection shown in FIG. The situation of a plurality of side branches e corresponding to the position of the opening 32a can be detected. Thereby, the cutting tool 3 and the root canal enlargement apparatus 1 insert the cutting tool 3 for root canal enlargement rotated by a driving body 25 such as a motor provided in the handpiece 2 into the root canal b, and the side branch e. It can be used as a measurement terminal for detecting a side branch for detecting the situation. For this reason, the present invention can detect the side branch e with higher accuracy as compared with the conventional one using a manual cutting tool made of a reamer or a file as a measurement electrode.

Moreover, the cutting tool 3 used as a measurement electrode at the time of side branch detection and root canal length measurement is a root canal cutting tool attached to the root canal enlargement device 1 that cuts and enlarges the root canal b of the tooth a to be inspected. Can be used. For this reason, the cutting tool 3 can be used for removing infected dentin, removing root canal contents, improving drug permeability, and forming a drainage tract.
In addition, since the cutting tool 3 is driven by a driving body 25 including a motor, an ultrasonic vibrator, and the like, compared with a manual reamer or file, the reachability of the medicine, the root canal shape, and In terms of the ability to remove bacterial nutrients, it is superior to the manual method.

[Modification]
The present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the technical idea. The present invention extends to these modifications and changes. Of course.

≪Automated confirmation of side branch direction≫
For example, the procedure for confirming the direction of the side branch e is not limited to being performed manually, and can be automated. In this automation, for example, a rotation mechanism (not shown) that rotates the cutting tool 3 in the holding member 33 of the cutting tool 3 that is a measurement electrode, a detection mechanism for the measurement current, and a rotation angle at which the measurement current exhibits the largest value. This can be realized by providing a detection mechanism for detecting the above.

  When an automatic insertion device that automatically inserts the cutting tool 3 is employed, as a mechanism for measuring the position of the tip of the cutting tool 3 in the root canal b, the cutting tool 3 is automatically inserted into the automatic insertion device. A mechanism for detecting the distance can be incorporated.

≪Stopper modification≫
The stopper 35 shown in FIG. 1 only needs to be large enough to fix the cutting tool 3 to the tooth to be inspected a, and may be smaller than the tooth to be inspected a. Further, in order to set the position of the stopper 35 of the cutting tool 3, the cutting tool 3 may be provided with a scale, or the cutting tool 3 may be color-coded instead of the scale.
Further, the data processing unit (not shown) of the control device 8 can include a setting mechanism that automatically moves the stopper 35 and sets the position of the stopper 35 of the cutting tool 3 based on the detected side branch position. is there. The data processing unit (not shown) further automatically moves the cutting tool 3 for detecting the side branch direction, inserts the cutting tool 3 into the root canal b, and the position where the stopper 35 contacts the upper part of the tooth a to be inspected. It is also possible to provide an arrangement mechanism for arranging the cutting tool 3 on the surface.

≪Deformation example of cutting tool≫
In addition, as an example of the cutting tool 3, as illustrated in FIG. 2, the case where the opening 32 a is formed only at one position of the distal end portion of the conductive metal 31 has been described. However, the opening 32 a is interposed via the opening 32 a. As long as it can be electrically connected to the external environment of the insulating film 32, a plurality of them may be provided. For example, a plurality of openings 32 a may be provided along the axial direction of the cutting tool 3.

  The shape of the opening 32a is not limited to a circle as long as it can be detected with high sensitivity, and may be a non-circle. The cutting tool 3 needs to be insulated at the tip in order to obtain a plurality of measured current waveforms. For example, 1 mm to 5 mm (2 mm is more preferable) is coated from the tip, and the insulating coating The upper 2 mm to 5 mm (3 mm is more preferable) can be the opening. Moreover, you may make it open above 3 mm. Further, the cutting tool 3 can be used in which an opening 32 a is formed by cutting a part after coating with the insulating film 32. The insulating film 32 may be formed by oxidizing the surface of the conductive metal 31 to form an oxide film.

  In addition, the opening 32a can be easily aligned with the position of the side branch without reducing the detection sensitivity in the opening direction of the side branch e by reducing the width of the opening 32a to a rectangular shape that is long vertically. Further, the opening 32a is flattened on the outer surface and has a surface with no irregularities, so that the opening 32a is caught on the inner wall of the root canal b when the cutting tool 3 is inserted into the root canal b and rotated. Can be difficult.

≪Modification of root canal length measuring instrument with side branch detection function≫
The display unit 41 of the root canal length measuring instrument 4 shown in FIG. 1 may be displayed like an oscilloscope to display a waveform of transition of measurement data. In that case, the transition waveform of the measurement data (DC voltage Vdc) output from the data processing unit of the control device 8 is processed so as to display the change in the vertical axis direction (change in height) in an enlarged manner. With this enlarged display, in particular, in the case where the side branch e shown in FIG. 6 is present or in the case of the inspected tooth a without the apex c, the operator can change the measured value shown in the display unit 41. The presence of the side branch e can be grasped more clearly from the waveform. Such processing for enlarged display can also be performed by the display unit 41.

  The root canal length measuring device 4 automatically monitors changes in measurement data, automatically detects the presence of the side branch e, and notifies the notification means 40 of it. The notification means 40 may notify the surgeon that the side branch e has been detected by sound, vibration, character display on the display unit 41, color display, or the like.

  As a mechanism for automatically monitoring the change in the waveform of the measured value, the waveform of the measured data during the measurement was monitored, and the rate of increase in the waveform of the change decreased or became almost flat. When this is detected, a mechanism for displaying the fact on the display unit 41 may be used.

≪Modified examples of driving body≫
The drive body 25 formed of a motor that rotates the cutting tool 3 to cut the tooth to be inspected a is not limited to a general electric motor, and may be a vibration motor. Similarly, the ultrasonic vibrator that cuts the inspected tooth a by ultrasonically vibrating the cutting tool 3 may be a vibration motor.

1 Root canal enlargement device 3 Cutting tool 4 Root canal length measuring device with side branch detection function (root canal length measuring device)
5 Electrode terminal 22 Handpiece head 25 Drive body (motor, ultrasonic transducer)
26 Side branch opening position confirmation means (detection member)
31 Conductive Metal 32 Insulating Film 32a Opening 33 Holding Member 34 Detected Member (Marker)
40 Notification means a Tooth (inspected tooth)
b root canal c apical hole e side branch h periodontal cavity i root apex

Claims (11)

A cutting tool for a root canal enlargement device for enlarging a tooth root canal,
The cutting tool includes a conductive metal that forms the cutting tool, and an insulating film that covers the conductive metal,
A cutting tool for a root canal enlargement device capable of detecting a side branch, wherein an opening for detecting a side branch direction is provided in a part of the insulating film. The cutting tool for a root canal enlargement device capable of detecting a side branch according to claim 1, wherein the insulating film is made of an insulating material having a cutting hardness capable of enlarging the root canal. The cutting tool for a root canal enlargement device capable of detecting a side branch according to claim 2, wherein the insulating material is diamond-like carbon. The cutting tool for a root canal enlargement device capable of detecting a side branch according to claim 2, wherein the insulating material is a material made of a ceramic coating. The cutting tool is provided with a marker at a circumferential position corresponding to the opening provided in the cutting tool or a circumferential position corresponding to the opening of the holding member fixed to the cutting tool. The cutting tool for a root canal enlargement device capable of detecting a side branch according to any one of claims 1 to 4. Place electrode terminals on a part of the subject's body,
A root canal enlargement device that expands the root canal by attaching a cutting tool for side branch detection that detects a side branch extending from the root canal of the tooth to the periodontal ligament cavity,
The cutting tool includes a conductive metal that forms the cutting tool, and an insulating film that covers the conductive metal,
An opening for detecting the side branch direction is provided in a part of the insulating film,
It is possible to confirm the relationship between the position of the opening provided in the cutting tool in the axial direction of the cutting tool and the position of the handpiece head part holding the driving body having a chuck for mounting the cutting tool. A root canal enlargement device comprising side branch opening position confirmation means. In order to enable the side branch opening position confirmation means to confirm the position of the opening,
A member to be detected on the cutting tool or a holding member fixed to the cutting tool, and a detection member that is provided on the handpiece head part and detects the member to be detected,
7. The root canal enlargement device according to claim 6, wherein the root canal enlarging device is means capable of automatically recognizing a position of the opening for detecting a side branch direction. The root canal enlargement device according to claim 6 or 7, further comprising an informing means for informing a position of the opening for detecting a side branch direction. The root canal according to any one of claims 6 to 8, wherein the rotational speed of the motor can be controlled by detecting a value of a current flowing through the opening for detecting a side branch direction. Enlarging device. The cutting tool is driven by being attached to an ultrasonic vibrator that oscillates the cutting tool to enlarge the root canal, or a motor that rotates the cutting tool to enlarge the root canal. The root canal enlargement device according to any one of claims 6 to 8, wherein the root canal enlargement device is characterized. The position in the radial direction of the root canal axis of the side branch extending to the periodontal cavity can be detected from the position of the opening when the peak of the current value flowing through the opening for detecting the side branch direction is detected. The root canal enlargement device according to any one of claims 6 to 8, wherein the root canal enlargement device is characterized.

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