JP3253874B2 - Root canal length measurement and apical foramen position detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a root canal length measuring and apical foramen position detecting device, and more particularly, a single device for measuring a root canal length and apical foramen (or apical stenosis position). : The position of the apical foramen and the position of the apical stenosis are actually slightly different, but here,
(For simplicity of explanation, it is described as apical foramen position)
The present invention relates to a root canal length measurement and apical foramen position detecting device capable of detecting the position of a root canal in real time.

[0002]

2. Description of the Related Art The difficulty of endodontic treatment in endodontics is
The point is to expand and clean the root canal to the apical hole position without injuring the periapical tissue and to fill it tightly. It is not preferable to stimulate the periapical tissue with a reamer, a file, a broach, a root canal filling material (hereinafter, represented by a file), etc. beyond the apical hole position during the treatment.
Insufficient instrument insertion or leaving apical root canals uncleaned and disinfected due to fear of apical periodontal tissue may lead to poor prognosis. Therefore, in order to perform root canal treatment correctly, it is necessary to know the exact length of the root canal in advance.

Heretofore, as a method of knowing the length of a root canal in clinical practice, there has been known a method of inserting a file into the root canal and finding the position of the apical hole by the sense of the operator's finger. But,
According to this method, a simple and thick root canal such as an upper incisor, a canine tooth, a lower premolar, etc., and a complete apex can be almost palpated in cases where the apical hole can be clearly palpated. However, there is a problem that it is difficult for even a skilled person to confirm a thin, incomplete apical tooth or a curved root canal. Therefore, as described in Japanese Patent Publication No. 62-2187, a file is inserted into the root canal and electrically connected to one electrode in contact with the oral mucosa, as described in Japanese Patent Publication No. 62-2187. For example, 1
There has been proposed a method in which an AC voltage having two frequencies of KHz and 5 KHz is applied to detect a root canal length.

FIG. 3 is a view for explaining an example of electrically measuring the root canal length using a hand file.
0 is a file holder, 30 is a file, 40 is a tooth,
41 is a root canal and 42 is a gingiva.
0 has a rubber stopper 31, a gripper 32, and the like. When the root canal length is measured using the file for hand, a file holder 2 is provided between the rubber stopper 31 and the gripper 32.
The electrode section 21 is used as one of the electrical signal extraction sections when measuring the electrical root canal length.
The electrode 22 on the side is, for example, hooked on the lip 42 to be the other electrode, and these electrodes 21 and 22 are connected to the lead wires 23 and 24.
Through which the apex hole position (root canal length) is measured by the well-known method described in the above-mentioned Japanese Patent Publication No. 62-2187, and the root canal is measured by the electrical root canal length measurement. When the length of the canal comes out, the rubber stopper 31 is moved in accordance with the length of the root canal.

[0005] In the above-mentioned conventional operation of the root canal, the measurement of the root canal length and the enlargement of the root canal are performed by using a hand file. As described above, the rubber stopper is moved. Even if the root canal length is transferred to the file, there is not much problem in workability. However, when the above-mentioned file is driven using the power of an ultrasonic transducer, a micro engine, or the like, the root canal length must be measured with the file attached to these heads. Moving the position is very inconvenient and inefficient.

Accordingly, the present applicant has previously proposed a method of extracting an electric signal when a file mounted on a head portion of an ultrasonic vibrator, a micro engine or the like is used as a root canal length measuring needle.

FIG. 4 shows an example of use of an electrode for measuring a root canal length previously proposed by the present applicant. In the figure, reference numeral 50 denotes a handpiece such as an ultrasonic vibrator or a micro engine (FIG. , A micro engine), 51 is a grip portion, 52 is a head portion, 30 is a cutting tool such as a file and a root canal length measuring needle. As is well known, the file 30 is attached to the head portion. 52, the ultrasonic transducer or the micro engine is driven to enlarge and clean the root canal. Before that, the length of the root canal is accurately measured as described above.

FIG. 5 is a view for explaining an example of the case of performing a root canal treatment using an ultrasonic transducer, a micro engine, or the like as described above. As described above, the file 30 is placed in the root canal. As it is inserted, the electrical resistance between the electrodes 21 and 22 shown in FIG. 3 changes, and the change is guided to the root canal length detector 60 through the lead wire 23 and displayed on the display unit of the detector. Is done. FIG. 5A is a diagram showing a relationship between the insertion depth of the file 30 and the output voltage, and FIG. 5B is a diagram showing a display unit of the detector. When the position of the perforation is reached, the current flowing through the file 30 becomes a predetermined constant value, and the pointer 61 of the detector moves to the AP.
The EX position is indicated, and it can be seen that the tip of the file 30 has reached the apical hole position. Therefore, the surgeon stops driving the ultrasonic transducer or the micro engine here, returns the file from the apical hole position, drives the file again, and continues the treatment.

[0009]

In the above-mentioned prior art, the surgeon uses a tweezers-like rubber stopper to electrically detect the position of the apical hole and mark the position at that time. They were moved until they hit the teeth, and then a scaler was applied outside the mouth to measure the position from the tip of the file to the rubber stopper. Further, even when trying to detect the apical foramen position in conjunction with the root canal enlargement device, it was not possible to perform the detection while injecting physiological saline due to the problem of leakage.

[0010] The present invention has been made in view of the above situation, and when the apex hole position detecting device is used,
The purpose is to enable real-time notification that the file has reached the apical hole position. Another object of the present invention is to make it possible to grasp in real time the length of a file inserted into a root canal or the position of the tip of the file. Further, the distance to the apical hole detected by the apical hole position detecting device is measured for the purpose of enabling measurement without a trouble of outputting a file outside the oral cavity, and without requiring the operator to move the rubber stopper. It is a thing.

[0011]

According to a first aspect of the present invention, there is provided a file holder for detachably holding a file at a predetermined position of the file, a stopper movable along the file, and a file holder provided for the file holder. A sensor line extending toward the distal end of the distance file and fixed to the stopper, a displacement amount measuring means for detecting a displacement amount of the sensor line, and a sensor with the file holder fixed at the predetermined position of the file. Apical hole position detecting means for electrically detecting that the leading end of the file has reached the apical hole position when the file is inserted into the root, and the apical hole position detecting means root canals position is to measure the root canal length than the displacement amount of the sensor line when sensed
In the length measurement and apical position detection device, the file
Is to determine the position to fix the file holder
And the position of the mark from the file tip is the apical foramen
Longer than the length L ₃ to the position, and the stopper
Position of shorter than the length L ₃ to the apical foramen location
The file is inserted into the root and the stopper is
Stopped by a tooth, and then further transferred the file to the root
And that the file has reached the apical position
Detected by the apex position measuring means via a sensor line
And then the stopper from the tip of the file
Characterized by measuring distance,
Measure root canal length and file tip position in real time
It is something that can be done.

[0012]

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a file leading end position display means for displaying a file leading end position signal detected by the displacement amount measuring means. The pipe length and the position of the tip of the file can be measured.

According to a third aspect of the present invention, in the second aspect of the present invention, there is provided storage means for storing the apical hole position measured by the displacement amount measuring means, and the apical hole position stored in the storage means is stored. The value is compared with a file tip position signal detected by the displacement amount measuring means, and the distance from the file tip to the apical hole position is displayed, whereby the apex hole from the file tip is displayed. It is possible to detect the distance to the real time.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing an essential part of an embodiment of a root canal length measurement and apical foramen position detecting apparatus according to the present invention. Or root canal length) measurement file, 2 is the tooth whose apical hole position (or root canal length) is to be measured, 3 is the root canal, 4 is the stopper, 5 is the probe, 6 is the file holder, and 7 is the sensor wire. The sensor wire 7 is somewhat hard, for example, like a piano wire.
Further, it is composed of a rigid body having a bendable shape, the tip of which is connected to the stopper 4, and the other end of which is a file holder 6.
Together with the probe 5. The sensor wire 7 is movable in the direction of the arrow, and a detector for electrically detecting the movement amount of the sensor wire 7, for example, a differential transformer is incorporated in the probe 5. Reference numeral 8 denotes a code (corresponding to the code 23 in FIG. 3) including a lead wire communicating with the file holder 6 and a lead wire for detecting a displacement amount of the sensor wire 7, and 9 denotes a tip terminal hooked on a lip or the like. A cord (corresponding to cord 24 in FIG. 3), 10 is a measuring instrument to which these cords 8 and 9 are connected, 11 is an apical hole position detection display section, and 12 is a measurement needle insertion length display section.
When the measuring needle 1 is inserted into the root canal 3 with the file holder 6 installed on the measuring needle (file) 1, the tip of the measuring needle 1 is determined from the pointer position of the apical hole position detection display unit 11. Is reached at the apical foramen position, and by reading the value of the measuring needle insertion length display section 12 at this time, the root canal length can be known.

FIG. 2 is an enlarged view of a main part (probe 5) of the apparatus with root canal length measurement and apical position detection according to the present invention. The probe 5 has a file holder 6 and a sensor wire 7, The file 1 is held by the holder 6, the file holder 6 is electrically connected to the file 1, the position of the apical hole is detected as described above, and the root canal is displayed on the display of the measuring needle insertion length display at that time. Measure the length. The stopper 4 is integrally connected to the sensor wire 7, and the stopper 4 is movable in the axial direction with respect to the file 1.

Here, the position of the apical hole is P ₁ , and the distance from the tip of the file 1 to the file holder 6 is L ₁ (a plurality of files having different lengths are usually prepared. a predetermined distance from the tip corresponding to the length, mark indicating a position of attaching the file holder has been strained facilities, mounting the holder in that position. Therefore, the distance L ₁ is known in advance), the file 1 The distance from the tip of the sensor wire to the stopper 4 is L ₂ (the stopper 4 is connected to a sensor wire 7 which is somewhat hard like a piano wire and can be bent.
It pushed in the direction A by a spring or the like, but apart from the file holder 6 by a predetermined distance L _0, pressing the stopper 4 in the direction of arrow B, moving the B direction against the force of the spring. The probe 5 is provided with, for example, a differential transformer for detecting the movement of the sensor wire 7 as described above, so that the amount of movement of the stopper 4 in the B direction can be known. . In addition, root canal length L ₃
(The root canal length L ₃ is not exactly known, but is roughly determined by the size of the person, and therefore, as described above,
If different lengths are to be have) been prepared two or three, _{these, L 1> L 3, L} 2 ≦ L 3 ( i.e., L _0> L ₃
−L ₂ ), and when the file 1 is inserted into the root canal 3, the tip of the file 1 is moved to the apical hole position P _1.
Before the stopper 4 reaches the root canal opening P of the tooth 2
₂ hits (insertion depth of file 1 at this time is L _2).

In this state, when the file 1 is further inserted, the stopper 4 moves against the arrow B against the force of the spring.
And the sensor wire 7 is also displaced in the direction of arrow B. As described above, the displacement is converted into an electric signal using a displacement measuring device provided in the probe 5, for example, a well-known differential transformer, and measured. In practice, it is necessary to add the aforementioned L ₂ (known) to the amount of displacement measured by the differential transformer, but this value depends on the length of the selected file. entered or read in automatically, by inputting, displaying added to the measured values obtained by measuring the value L ₂ and as described above.

Therefore, after the stopper 4 hits the tooth, the leading end of the file 1 (that is, the insertion depth of the file 1) is displayed on the file leading end position display section 12. Further inserting the file 1, the tip of the file 1 reaches the apical foramen location P _1, in well-known fashion, guidelines apical foramen position display unit 11, the tip of the file 1 is in the apical foramen location Since the reaching is displayed, the root canal length can be measured by reading the display value of the measuring needle tip position display section 12 at this time.

[0020]

As apparent from the above description, according to the present invention, when the position of the apical hole is detected, when the tip of the file reaches the apical hole, the root canal length is determined in real time. You can know. In addition, the length of the file inserted into the root canal and the position of the tip of the file can be grasped in real time. In addition, the detected distance to the apical hole can be known without putting a file out of the oral cavity, and the operator can save the trouble of moving the stopper. In addition, when the approximate length of the root canal is predicted in advance by X-rays, information from the present apparatus, such as a position in the root canal where a leak is found, can be used for diagnosis. In addition, after detecting the apical foramen position by the root canal length measurement function, the position is memorized, and it may be affected by the saline when linked with a magnifying device under injection of physiological saline etc. Instead, the position of the file can be recognized and the apical foramen position signal can be sent to the root canal enlargement device.

According to the first aspect of the present invention, a file holder for detachably holding a file at a predetermined position of the file, a stopper movable along the file, and a predetermined distance from the file holder toward the tip of the file. A sensor line extended and fixed to the stopper, a displacement amount measuring means for detecting a displacement amount of the sensor line,
Apical hole position detecting means for electrically detecting that the tip of the file has reached the apical hole position when the file is inserted into the root with the file holder fixed to the predetermined position of the file. Since the root canal length is measured using the amount of displacement of the sensor line when the apical hole position is detected by the apical hole position detecting means, the stopper is moved in real time. It is possible to measure the root canal length without performing such operations. In addition,
File determines the position to fix the file holder
And the position of the mark from the file tip is
Longer than the length at the position of the apical foramen and the stopper
The position is set shorter than the length to the apical hole position,
Insert the file into the root, and the stopper
And then insert the file further into the root
And the stopper when the file reaches the apical position
Position by the displacement measuring means via the sensor line.
And the file destination of the stopper at that time
Since the distance from the end was measured, the end of the file
When the end reaches the apical hole (apical position) and the root at that time
Tube length can be detected in real time.

[0022]

According to a second aspect of the present invention, in the first aspect of the present invention, since there is provided a file leading end position display means for displaying a file leading end position signal detected by the displacement amount measuring means, the leading end position of the file can be determined in real time. Can be detected.

According to a third aspect of the present invention, in the second aspect of the present invention, there is provided storage means for storing the apical hole position measured by the displacement amount measuring means, and the apical hole stored in the storage means. Since the position value and the file tip position signal detected by the displacement amount measuring means are compared and the distance from the file tip to the apical hole position is displayed,
The distance to the apical foramen can be known in real time, and the root canal treatment can be performed safely.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a main part for explaining an embodiment of a root canal length measurement and apical foramen position detecting device according to the present invention.

FIG. 2 is a main part enlarged configuration diagram for explaining the operation principle of the present invention.

FIG. 3 is a diagram for explaining an example of a conventional manual root canal length measuring method.

FIG. 4 is a diagram for explaining an example of a root canal length measurement method previously proposed by the present applicant.

5 is a diagram for explaining an example of a case where root canal treatment is performed using the root canal length measuring device shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Apical hole position measuring needle (file), 2 ... Teeth, 3 ... Root canal, 4 ... Stopper, 5 ... Probe, 6 ... File holder, 7 ... Sensor wire, 8, 9 ... Cord, 10 ... Measuring instrument,
11: apical hole position detection display unit; 12: measurement needle tip position display unit.

Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61C 19/04

Claims (3)

(57) [Claims] 1. A file holder for detachably holding a file at a predetermined position of the file, a stopper movable along the file, and a stopper extending from the file holder toward a tip of the file by a predetermined distance. A sensor line fixed to the file, displacement amount measuring means for detecting a displacement amount of the sensor line, and when the file is inserted into the root while the file holder is fixed at the predetermined position of the file, the file is Apical hole position detecting means for electrically detecting that the tip of the apical hole has reached the apical hole position, the sensor line when the apical hole position is detected by the apical hole position detecting means Contact the root canal length measuring was to measure the root canal length than the displacement amount and apical foramen position detector
The file has a mark for determining a position for fixing the file holder, the position of the mark from the file tip is longer than the length to the apical hole position, and the position of the stopper is the shorter than the length of up to apical foramen position
The file is inserted into the tooth root,
The upper is stopped by the teeth, and then the
When the file reaches the apex position
The position of the stopper is changed via the sensor line.
The position of the stopper is detected by the position measuring means.
The feature is to measure the distance from the file tip
Root canal length measurement and apical foramen position detecting device according to. 2. The root canal length measurement and apical hole position detection device according to claim 1, further comprising a file tip position display means for displaying a file tip position signal detected by the displacement amount measurement means. . 3. A storage device for storing an apical hole position measured by the displacement measuring device, wherein the apical hole position value stored in the storing device and the apical hole position value detected by the displacement measuring device are stored. 3. The root canal length measurement and apical hole position detecting device according to claim 2 , wherein a distance from the file front end to the apical hole position is displayed by comparing with a file front end position signal.