Root canal treatment system

Abstract

A signal supply unit (11) in a root canal treatment system (1) can supply a wetness detection signal for detecting the wetness of a root apex (2a1) to a root canal electrode (31) and a counter electrode (32). The root canal treatment system (1) includes: an operation unit (13) that is operated to switch between a state in which the signal supply unit (11) supplies an apical position detection signal and a state in which the signal supply unit (11) supplies the wetness detection signal; and a display unit (14) and a sound output unit (15) as notification units for notifying the electrical conduction state of the root canal electrode (31) and the counter electrode (32) which have been supplied with the wetness detection signal.

Description

Root canal treatment system

[0001] The present invention relates to a technique for treating a root canal of a subject's tooth.

[0002] Apical lesions are inflammatory diseases that occur at the root apex of a tooth when bacteria enter the root canal, grow, and move to the apex, which is the tip of the root canal. If left untreated, the tooth will need to be extracted. When treating a root canal, the position of the apex, which is the tip of the root canal, is detected (see Patent Document 1).

[0003] Japanese Patent Application Publication No. 4-64354

[0004] In such a method for detecting the position of the root apex, the degree of wetness of the root apex varies depending on the treatment state before detecting the position of the root apex, and this may result in a decrease in the accuracy of detecting the position of the root apex.

[0005] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a root canal treatment system that can suitably notify the surgeon of the moisture level of the root apex.

[0006] In order to solve the above-mentioned problems, the root canal treatment system of the present invention is a root canal treatment system comprising: an intra-root canal electrode to be placed in the root canal of a subject's tooth; a counter electrode to be placed on the body of the subject; a signal supply unit to be placed outside the oral cavity of the subject and to supply an apex position detection signal to the intra-root canal electrode and the counter electrode; and an apex position detection unit to detect the position of the apex, which is the tip of the root canal, when the apex position detection signal is applied to the intra-root canal electrode and the counter electrode, wherein the signal supply unit is capable of supplying a wetness detection signal to the intra-root canal electrode and the counter electrode to detect the wetness of the apex, and the system is characterized by comprising: an operation unit that is operated to switch the signal supply unit between a state in which it supplies the apex position detection signal and a state in which it supplies the wetness detection signal; and a notification unit that notifies the current flow state of the intra-root canal electrode and the counter electrode when the wetness detection signal is supplied.

[0007] According to the present invention, the state of current flow, which correlates with the degree of wetness, is detected and notified to the surgeon, so that the degree of wetness of the apex can be suitably notified.

[0008] 1 is a diagram schematically illustrating a root canal treatment system according to an embodiment of the present invention; FIG. 2 is a graph schematically illustrating the relationship between impedance and current flowing through an intra-root canal electrode and a counter electrode at an arbitrary frequency; FIG. 3 is a diagram schematically illustrating a display unit serving as a notification unit of a root canal treatment system according to an embodiment of the present invention; FIG. 4 is a diagram schematically illustrating the generation of free radicals; FIG. 5 is a diagram schematically illustrating the intra-root canal electrode, stopper, and injectate passage unit of FIG. 1, where (a) is a cross-sectional view taken along line Va in FIG. 1 and (b) is a cross-sectional view taken along line Vb in (a); (a) to (c) are schematic views for explaining a method for manufacturing a catalyst unit.

[0009] An embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same elements are given the same reference numerals, and duplicated explanations will be omitted. Directional expressions in the drawings indicate the corresponding relationships between the drawings.

[0010] As shown in Fig. 1, a root canal diagnosis system 1 according to an embodiment of the present invention is a system for treating a root canal 2a of a tooth 2 serving as a subject's tooth to be examined, and a lateral canal 2b extending from the root canal 2a to a periodontal ligament cavity 3. The root canal diagnosis system 1 detects the position of an apex 2a1, which is the distal end (bottom) of the root canal 2a, and the wetness of the apex 2a1. The root canal diagnosis system 1 also generates free radicals in an injection solution IS injected into the root canal 2a and lateral canal 2b, thereby treating the root canal 2a and lateral canal 2b with the bactericidal, antibacterial, and purifying effects of the free radicals.

[0011] <Injection Liquid> The injection liquid IS is, for example, water or a compound that is the source of free radicals (oxygen (O ２ ), hydrogen peroxide (H ２ O ２) or the like). Here, hydrogen peroxide is an aqueous solution containing hydrogen peroxide at a concentration of 2.5 to 3.5 w / v %. The injection solution IS may also be a neutral aqueous solution with a pH of 4.5 to 8.9. Such injection solution IS can generate free radicals when excitation energy is applied, and can ensure safety when excitation energy is not applied. It is desirable that the injection solution IS be a solution that can be disposed of as general waste without undergoing neutralization treatment or the like.

[0012] The root canal treatment system 1 includes a root canal treatment device 10, a transmission unit 20, an excitation energy application unit 30, a catalyst unit 40, a stopper 50, an injection suction unit 60, and an injection liquid passage unit 70 (see FIG. 5).

[0013] <Root canal diagnosis device (excitation energy supply device)> The root canal diagnosis device 10 supplies an apex position detection signal for detecting the position of the root apex 2a1 to the intra-root canal electrode 31 and the counter electrode 32 described below, and supplies a wetness detection signal for detecting the wetness of the root apex 2a1 to the intra-root canal electrode 31 and the counter electrode 32. The root canal diagnosis device 10 also functions as an excitation energy supply device that supplies excitation energy for causing a catalytic action in the catalyst unit 40 to the excitation energy imparting unit 30 via the transmission unit 20. In this embodiment, the root canal diagnosis device 10 generates electric power as excitation energy and supplies the generated electric power to the excitation energy imparting unit 30.

[0014] The root canal diagnosing device 10 includes a signal supply unit 11, a control unit 12, an operation unit 13, a display unit 14 as a notification unit, and a sound output unit 15.

[0015] <Signal Supply Unit> The signal supply unit 11 generates an apex position detection signal or a wetness detection signal based on a control signal from the control unit 12, and supplies the generated apex position detection signal or wetness detection signal to the intra-root canal electrode 31 and the counter electrode 32 via the transmission unit 20. The signal supply unit 11 also functions as a power supply unit that generates electric power as excitation energy based on a control signal from the control unit 12 and applies the generated electric power to the intra-root canal electrode 31 and the counter electrode 32 via the transmission unit 20. The electric power supplied by the signal supply unit 11 may be AC ​​power (AC signal, such as a sine wave or a square wave) for the apex position detection signal or the like, or DC power (DC signal, which may be positive or negative). In this embodiment, the signal supply unit 11 includes an apex position detection signal generator 11a.

[0016] <<Root Apex Position Detection Signal Generator (Wetness Detection Signal Generator)>> The root apex position detection signal generator 11a generates a root apex position detection signal for detecting the position of the root apex 2a1, which is the tip (bottom) of the root canal 2a, based on a control signal from the controller 12, and transmits the generated root apex position detection signal to the intra-canal electrode 31 via the transmitter 20. The root apex position detection signal generator 11a generates two signals with different frequencies as the root apex position detection signal. The root apex position detection signal generator 11a has a multiplexer and can output the two signals with different frequencies as a single signal that alternates between them, for example, every 100 msec.

[0017] One of the apex position detection signals generated by the apex position detection signal generating unit 11a may be applied to the intra-root canal electrode 31 and the counter electrode 32 as excitation energy.

[0018] In addition, the apex position detection signal generating unit 11a generates one of the two signals with different frequencies (for example, the one with the smaller frequency) as the apex position detection signal based on a control signal from the control unit 12 as a wetness detection signal (a current state detection signal for detecting the current state (impedance) that correlates with the wetness), and also serves as a wetness detection signal generating unit that passes the generated wetness detection signal to the intra-canal electrode 31 via the transmission unit 20.

[0019] The root canal diagnosis device 10 may include a wetness detection signal generating unit separate from the apex position detection signal generating unit 11a, which may generate a wetness detection signal having a frequency different from that of the apex position detection signal. In this case, the root canal diagnosis device 10 may supply the wetness detection signal to the excitation energy applying unit 30 as power for generating free radicals.

[0020] Here, the frequency of the wetness detection signal is preferably 100 Hz to 1000 Hz, whether the frequency is the same as or different from the frequency of the apex position detection signal. With a wetness detection signal set to such a frequency band, there is little change in the electrical conduction state (impedance in this embodiment) due to dentin, soft tissue, etc., and stable measurement of the electrical conduction state is possible, thereby enabling accurate measurement of the wetness of the apex 2a1.

[0021] The apex position detection signal and the wetness detection signal may be a square wave or a sine wave. When the apex position detection signal is a square wave, the root canal diagnosis device 10 can increase the amount of power compared to when the signal is a sine wave, and therefore can efficiently supply excitation energy to the catalyst unit 40.

[0022] <<Control Unit>> The control unit 12 is composed of a CPU (Central Process Unit), ROM (Read Only Memory), RAM (Random Access Memory), an input / output circuit, etc. The control unit 12 controls the signal supply unit 11 (apex position detection signal generating unit 11a) by outputting a control signal to the signal supply unit 11. The control unit 12 includes, as functional units, a power supply amount setting unit 12a, a power supply time setting unit 12b, a signal setting unit 12c, and an apex position detection unit 12d.

[0023] <<Power Supply Amount Setting Unit>> The power supply amount setting unit 12 a sets the amount of power to be supplied per unit time (i.e., the magnitude of the power) as excitation energy (in this embodiment, the apex position detection signal) by changing the current and / or voltage based on the result of an operation by an operator (dentist, dental hygienist, dental assistant, etc.) of the operation unit 13. That is, the power supply amount setting unit 12 a can change the amount of power to be supplied per unit time as excitation energy.

[0024] <Power Supply Time Setting Unit> The power supply time setting unit 12b sets the supply time of power as excitation energy (in this embodiment, the apex position detection signal) based on the result of the operator's operation of the operation unit 13. That is, the power supply time setting unit 12b can change the supply time of power as excitation energy.

[0025] The signal supply unit 11 supplies power to the intra-canal electrode 31 and the counter electrode 32 based on the power supply amount and / or power supply time per unit time set (or default value) by the power supply amount setting unit 12a and / or the power supply time setting unit 12b.

[0026] <Signal Setting Unit> The signal setting unit 12c acquires the operation result of the operation unit 13, sets the type of signal to be generated by the apex position detection signal generating unit 11a based on the acquired operation result, and outputs the setting result to the apex position detection signal generating unit 11a. When the operation unit 13 is operated to perform apex position detection, the signal setting unit 12c outputs a signal to generate an apex position detection signal to the apex position detection signal generating unit 11a. When the operation unit 13 is operated to perform wetness detection, the signal setting unit 12c outputs a signal to generate a wetness detection signal to the apex position detection signal generating unit 11a. When the operation unit 13 is operated to supply power, the signal setting unit 12c outputs a signal to generate one of the apex position detection signals (e.g., the wetness detection signal) as power to the apex position detection signal generating unit 11a.

[0027] <<Root Apex Position Detection Unit>> The root apex position detection unit 12d measures impedances corresponding to the two root apex position detection signals in a circuit including the root canal electrode 31 and the counter electrode 32 when the intra-root canal electrode 31 is inserted into the root canal 2a and two root apex position detection signals with different frequencies are applied between the root canal electrode 31 and the counter electrode 32, and detects the position of the root apex 2a1 based on the measured impedances. The surgeon then inserts the root canal electrode 31 into the root canal 2a. The root apex position detection unit 12d can detect that the tip of the root canal electrode 31 is located at the root apex 2a1 when the relative value of each impedance (e.g., the difference or ratio between the two impedances) reaches a predetermined value. The root apex position detection unit 12d can detect the root apex position when no liquid such as injectate IS is injected into the root canal 2a, and can also detect the root apex position when a liquid such as injectate IS is injected into the root canal 2a.

[0028] The apex position detection unit 12d also determines the presence or absence of a lateral canal 2b by calculation based on the measured impedances, and if a lateral canal 2b is present, detects its position based on the result of the calculation. The surgeon then inserts the intra-root canal electrode 31 into the root canal 2a. When a predetermined change occurs in each impedance, the apex position detection unit 12d can detect that the tip of the intra-root canal electrode 31 is located at the junction of the lateral canal 2b. The apex position detection unit 12d can detect the position of the lateral canal 2b even when no liquid, such as injectate IS, has been injected into the root canal 2a, and can also detect the position of the lateral canal 2b even when a liquid, such as injectate IS, has been injected into the root canal 2a.

[0029] The apex position detection unit 12d detects the position of the tip of the intra-root canal electrode 31 within the root canal 2a based on the measured impedances. The apex position detection unit 12d stores the values ​​of the impedances measured when the intra-root canal electrode 31 is inserted into the root canal 2a to detect the position of the root apex 2a1 and / or the position of the lateral canal 2b. The apex position detection unit 12d can detect the position of the tip of the intra-root canal electrode 31 within the root canal 2a based on the pre-stored impedances and the impedances measured during the current insertion of the intra-root canal electrode 31.

[0030] The apex position detector 12d applies two apex position detection signals, each of which is a weak current and has a different frequency, to the intra-root canal electrode 31 and the counter electrode 32, and detects the relative values ​​of the impedances measured in response to the two applied apex position detection signals. By detecting the relative values ​​of the impedances, the apex position detector 12d can effectively detect the position of the tip of the intra-root canal electrode 31 within the root canal 2a (the position of the apex 2a1 and the position of the lateral canal 2b). That is, the apex position detector 12d can detect the position of the apex 2a1 based on the relative values ​​of the impedances when the tip of the intra-root canal electrode 31 reaches the apex 2a1. The apex position detector 12d can also detect the position of the lateral canal 2b based on the relative values ​​of the impedances when the tip of the intra-root canal electrode 31 reaches the opening of the lateral canal 2b.

[0031] In the present embodiment, the apex position detection unit 12d includes an energization state detection unit 12d1 and an apex position determination unit 12d2.

[0032] The conduction state detector 12 d 1 detects the conduction state (impedance in this embodiment) of the intra-root canal electrode 31 and the counter electrode 32 when signals are applied to the intra-root canal electrode 31 and the counter electrode 32 .

[0033] The apex position determination unit 12d2 calculates the relative value of the conduction states (impedance in this embodiment) of two apex position detection signals with different frequencies while the apex position signals are applied to the intra-root canal electrode 31 and the counter electrode 32. Based on the calculated relative value of the conduction states, the apex position determination unit 12d2 determines whether the position of the tip of the intra-root canal electrode 31 is close to or far from the position of the apex 2a1, and outputs the determination result to the display unit 14 and / or the sound output unit 15 as a notification unit (see FIG. 3 ).

[0034] Specifically, the apex position determination unit 12d2 stores a plurality of model data in advance and calculates the position of the apex 2a1 using the model data. The model data associates the position of the tip of the intracanal electrode 31 with the relative value of the conduction state corresponding to the apex position detection signal at that position.

[0035] The apex position determination unit 12d2 stores three characteristics detected at each position in the root canal 2a during movement of the intracanal electrode 31: the conduction state (impedance in this embodiment) of one of the apex position detection signals (e.g., 500 Hz), the conduction state of the other of the apex position detection signals (e.g., 2 kHz), and the relative value of the two conduction states. From the perspective of determining the position of the root apex 2b1, the apex position determination unit 12d2 may be configured to store only the relative value of the conduction state. The apex position determination unit 12d2 compares the waveform of the detected relative value of the conduction state (detected waveform) with waveforms of relative values ​​of the conduction state (model waveforms) in multiple pre-stored model data, and selects model data of a model waveform having a predetermined relationship with the detected waveform. Furthermore, the apex position determination unit 12d2 determines the presence of a lateral canal 2b when the detected waveform has a lateral canal characteristic (a convex portion). The apex position determination unit 12d2 also calculates the position of the lateral canal 2b (the distance from the apex 2a1) based on a comparison between the model waveform of the selected model data and the detected waveform. In this way, the presence or absence of the lateral canal 2b and the position of the lateral canal 2b are determined and calculated by a calculation based on the relative values ​​of the energization state detected at each position in the root canal 2a when the position of the apex 2a1 is detected.

[0036] In addition, when the tip of the intra-root canal electrode 31 is positioned at the root apex 2a1 and the wetness detection signal is applied to the intra-root canal electrode 31 and the opposing electrode 32, the current flow state detection unit 12d1 detects the impedance of the wetness detection signal and outputs the detection result as wetness to the display unit 14 and / or sound output unit 15 as a notification unit (see Figure 3).

[0037] 2, when a signal of a given frequency is applied to the intracanal electrode 31 and the counter electrode 32, the current value of the signal is inversely proportional to the impedance. Furthermore, when the current value of the wetness detection signal is constant, the impedance increases as the wetness of the root apex 2a1 decreases (as the root apex 2a1 becomes drier), and the impedance decreases as the wetness of the root apex 2a1 increases (as the root apex 2a1 becomes wetter).

[0038] The current flow state detection unit 12d1 may be configured to detect the current value or voltage value when the wetness detection signal of the root canal electrode 31 and the counter electrode 32 is applied, instead of the impedance, as the current flow state of the root canal electrode 31 and the counter electrode 32, and output the detected value to the notification unit.

[0039] <<Operation Unit>> The operation unit 13 is composed of buttons, a keyboard, a touch panel, etc., and outputs a signal corresponding to the result of an operation of the operation unit 13 by the surgeon to the control unit 12. The operation unit 13 is configured so that the surgeon can select either apical position detection or wetness detection (and power generation for generating free radicals). The operation unit 13 may be composed of a sound collection unit (microphone) that can input voice, a camera that can input gestures, etc.

[0040] <Display unit> The display unit 14, which is an example of a notification unit, is composed of a monitor, a touch panel, etc., and displays the position of the tip of the intracanal electrode 31, the position of the root apex 2a1 (i.e., the root canal length, which is the length of the root canal 2a), the position of the lateral branch 2b (the connection point with the root canal 2a), the wetness of the root apex 2a1, etc., based on a control signal from the control unit 12.

[0041] As shown in FIG. 3 , the display unit 14 can display the position of the tip of the intracanal electrode 31 as the length of a bar 14a based on a signal from the apex position determination unit 12d2. The display unit 14 can also display the position of a lateral canal 2b in the root canal 2a as a mark 14b based on a signal from the apex position determination unit 12d2. The display unit 14 can also display the wetness of the apex 2a1 as a multi-level color of the bar 14a extending to the position of the apex 2a1 (e.g., red for a dry state, green for an appropriate range, and blue for a wet state) based on a signal from the energization state detection unit 12d1. The display unit 14 may be configured to highlight (e.g., illuminate) a color corresponding to the wetness of the apex 2a1 from the multi-level colors in a wetness display area 14c other than the bar 14a. The wetness display area 14c can be set at any position on the display unit 14 (e.g., the bottom in the example of FIG. 3 ).

[0042] <Sound Output Unit> As shown in FIG. 1 , the sound output unit 15, which is an example of a notification unit, is composed of a speaker or the like, and notifies the surgeon of the position of the tip of the intracanal electrode 31, the position of the root apex 2 a1 (i.e., the root canal length which is the length of the root canal 2 a), the position of the lateral branch 2 b (the connection part with the root canal 2 a), the wetness of the root apex 2 a1, etc. by sound (warning sound, etc.) or voice based on a control signal from the control unit 12.

[0043] Based on the signal from the power supply state detection unit 12d1, the sound output unit 15 can pronounce the degree of wetness of the root apex 2a1 as a multi-stage sound or voice (for example, "dry state," "in the appropriate range," "wet state," etc.).

[0044] An existing apex position detection device capable of detecting the position of the root apex by generating an apex position detection signal can be used as the root canal diagnosis device 10. In this case, the existing apex position detection device can supply the apex position detection signal as is as power for the excitation energy, or can supply a DC signal (DC power) as power for the excitation energy instead of the apex position detection signal.

[0045] <Transmission Unit> The transmission unit 20 transmits the excitation energy supplied from the root canal diagnosis device 10 to the excitation energy imparting unit 30. In the present embodiment, the transmission unit 20 is an electric wire that transmits electric power as the excitation energy, and forms a series circuit that transmits electric power from the root canal diagnosis device 10 to the excitation energy imparting unit 30.

[0046] <Excitation Energy Applicator> The excitation energy applicator 30 is placed in the oral cavity of the subject, and applies excitation energy supplied from the root canal diagnosis device 10 via the transmitter 20 to the catalyst unit 40. In this embodiment, the excitation energy applicator 30 includes an intra-root canal electrode 31 and a counter electrode 32.

[0047] <Intra-root canal electrode> The intra-root canal electrode 31 is an elongated, generally rod-shaped electrode that is inserted into the root canal 2a of the subject's tooth 2 so as to be electrically conductive to the inner circumferential surface of the root canal 2a (for example, in contact with the pulp of the root canal 2a, or, if the pulp has been removed, the inner circumferential surface other than the pulp). The intra-root canal electrode 31 is made of a conductive material (for example, a conductive metal such as stainless steel, nickel titanium, or tungsten). The diameter of the tip of the intra-root canal electrode 31 is 0.1 mm to 2 mm, preferably 0.2 mm, and is flexible enough to accommodate a curved root canal 2a.

[0048] A blade portion 31 a may be formed on the outer peripheral surface of the intraroot canal electrode 31. The blade portion 31 a is a spiral-shaped blade capable of cutting the inner peripheral surface of the root canal 2 a and functions as a file and / or a reamer. The blade portion 31 a may be formed on the outer peripheral surface of the intraroot canal electrode 31 in a portion where a catalyst portion 40 (described later) is not provided, or in a portion where the catalyst portion 40 is provided, or may be formed over both of these portions.

[0049] The blade portion 31a as a file is formed in a spiral shape and has a cutting edge at the tip of the intra-root canal electrode 31A. The blade portion 31a is used to scrape out and remove necrotic dental tissue, enlarge the root canal 2a, and form the root canal by reciprocating in the axial direction within the root canal 2a. The spiral twist of the blade portion 31a as a file is formed tighter than the spiral twist of the blade portion 31a as a reamer.

[0050] The blade portion 31 a serving as a reamer is formed in a spiral shape and does not have a cutting edge at the tip of the intra-root canal electrode 31 A. The blade portion 31 a is used to cut the inner wall of the root canal 2 a by twisting it to remove the nerve of the tooth or to form the root canal.

[0051] The intra-root canal electrode 31, together with a catalyst section 40 described later, constitutes an intra-root canal electrode unit U. That is, the intra-root canal electrode unit U includes the intra-root canal electrode 31 and the catalyst section 40 arranged on the intra-root canal electrode 31.

[0052] Counter Electrode The counter electrode 32 is a rod- or plate-shaped electrode that can be electrically connected to the subject's body (e.g., the gums 4) (e.g., in contact with the body). The counter electrode 32 is formed of a conductive material (e.g., a conductive metal such as stainless steel, nickel titanium, or tungsten). The counter electrode 32 may be a counter electrode plate attached to the gums 4, an electrical connection terminal such as a lip clip that is attached to the gums 4, a crocodile clip attached to the subject's body, an electrode held by the subject, or a saliva ejector made of a conductive metal that is placed at the corners of the mouth. In other words, the shape of the counter electrode 32 is not limited to a plate shape, but may also be a rod shape, a sphere, or the like. Furthermore, the attachment position of the counter electrode 32 is not limited to the gums 4, which are the intraoral surface, but may be any part of the subject's body, such as the lips, intraoral surface, hand, or skin.

[0053] Here, the intra-canal electrode 31 and the counter electrode 32 on which the catalyst unit 40 is arranged are configured to be detachable (replaceable) with respect to the transmission unit 20. Alternatively, the transmission unit 20 is configured to be detachable (replaceable) with respect to the root canal diagnosis device 10.

[0054] <Catalyst section> The catalyst section 40 is disposed on the outer peripheral surface of the intra-root canal electrode 31 (more preferably, on the outer peripheral surface of the tip). The catalyst section 40 is disposed in the injectate IS injected into the root canal 2a, and is catalytically activated by excitation energy supplied from the root canal diagnosis device 10 to generate free radicals in the injectate IS. In this embodiment, the catalyst section 40 generates free radicals by electric power as excitation energy. The material of the catalyst section 40 is selected from metal oxide semiconductors that are n-type semiconductors (photoactive anatase or rutile titanium oxide (TiO ２ , i.e., titanium dioxide), zinc oxide (ZnO), tungsten oxide (WO ３ ), strontium titanate (SrTiO ３ ), metal sulfides (zinc sulfide (ZnS), etc.), etc. These substances are photocatalysts that exhibit catalytic action when irradiated with light, and also exhibit catalytic action when excitation energy is imparted by electricity or vibrations in addition to light.

[0055] As shown in FIG. 4, when excitation energy is applied to titanium oxide serving as the catalyst portion 40 and is absorbed by the titanium oxide, electrons in the valence band move beyond the band gap to the conduction band due to the excitation energy, and excited electrons (e － ) in the conduction band inside titanium oxide. － ) is generated, and holes (h ＋ The electrons generated in the conduction band react with oxygen contained in the injection liquid IS (reduction action), and superoxide (O ２ － ) occurs. － +O ２ →O ２ － In addition, the holes generated in the valence band react with water, which is the injection liquid IS, to generate hydroxyl radicals (OH) as free radicals (oxidation). ＋ +H ２ O → OH + H ＋Such free radicals, superoxide and hydroxyl radical, exert bactericidal, antibacterial and purifying effects by decomposing organic substances, thereby killing bacteria and the like in the root canal 2a and lateral canal 2b.

[0056] In titanium oxide, when the crystal system is rutile, the excitation energy is 3.0 eV, and when the crystal system is anatase, the excitation energy is 3.2 eV. Therefore, the root canal treatment system 1 can generate free radicals in the injection solution IS by applying excitation energy of this magnitude or more to the catalyst portion 40 formed from titanium oxide. The excitation energy can be applied to the catalyst portion 40 in the form of light or vibration, in addition to electricity.

[0057] Titanium dioxide is chemically stable and is an abundant resource. Furthermore, because titanium dioxide is not harmful to living organisms, it is used as a white pigment in cosmetics and in medical devices such as catheters. It is also used in dentistry, where its antibacterial properties are utilized as a denture cleaner and tooth whitener.

[0058] In addition to the above, titanium oxide has a band gap that does not cause self-dissolution in water, and therefore is suitable from the standpoints of durability and practicality as a material for the catalyst section 40. Here, the self-dissolution phenomenon is a phenomenon in which, when excitation energy is applied to a material with a small band gap (less than 3.0 eV) in water, holes generated in the conduction band oxidize themselves, causing metal ions to dissolve into the water.

[0059] The catalyst portion 40 is formed by a dip coating method. As shown in FIG. 6( a), the tip of the intraroot canal electrode 31 is immersed in a solution Sa containing a catalyst substance (e.g., rutile titanium oxide) 41 at a first predetermined speed (e.g., 10 mm / sec) (first step). The tip of the intraroot canal electrode 31 is then held in the solution Sa for a predetermined time (e.g., 10 sec) (second step). As shown in FIG. 6( b), the tip of the intraroot canal electrode 31 is then withdrawn from the solution Sa at a second predetermined speed (e.g., 10 mm / sec) (third step). As shown in FIG. 6( c), the withdrawn tip of the intraroot canal electrode 31 is then dried (fourth step). Steps 1 to 4 are then repeated a first predetermined number of times (e.g., five times). The tip of the intraroot canal electrode 31 is then heated (e.g., at 200°C for 10 minutes) (fifth step). Subsequently, the first to fourth steps are repeated, and the fifth step is repeated a second predetermined number of times (for example, twice).

[0060] The thickness of the catalyst material 41 forming the catalyst portion 40 increases as the second predetermined speed for lifting the intra-root canal electrode 31 from the solution Sa increases, and decreases as the second predetermined speed decreases.

[0061] 1, the stopper 50 is a plate-like member that is disposed at the occlusal end of the tooth 2 (the tip of the occlusal surface; the lower end of the upper tooth and the upper end of the lower tooth) and fixes the intraroot canal electrode 31 inserted into the root canal 2a at a desired insertion depth. The stopper 50 is formed, for example, from a rubber material. The intraroot canal electrode 31A is press-fitted into a hole 51 in the stopper 50 so as to be movable (slidable) in the axial direction of the intraroot canal electrode 31A.

[0062] The stopper 50, when abutted against the occlusal end of the tooth 2, serves as a reference position for measuring the root canal length, which is the length of the root canal 2a. That is, the surgeon abuts the stopper 50 against the occlusal end of the tooth 2 when the apex position detection unit 16a detects that the tip of the intraroot canal electrode 31 is located at the root apex 2a1. Next, the surgeon removes the intraroot canal electrode 31 and the stopper 50 from the oral cavity of the subject and measures the distance from the stopper 50 to the tip of the intraroot canal electrode 31, thereby measuring the root canal length. In addition, the surgeon can measure the position of the lateral canal 2b (the distance from the occlusal end of the tooth 2 to the connection site of the lateral canal 2b) using a similar technique.

[0063] <Injection and Suction Unit> The injection and suction unit 60 injects the injection liquid IS into the root canal 2 a (and lateral canal 2 b) of the subject's tooth 2, and suctions the injection liquid IS from the root canal 2 a (and lateral canal 2 b). The injection and suction unit 60 includes a storage unit 61 in which the injection liquid IS is stored, a piston unit 62 for pushing the injection liquid IS out of the storage unit 61 and for suctioning the injection liquid IS into the storage unit 61, and a gripping unit 63 that is disposed to cover the storage unit 61 and can be gripped by the surgeon.

[0064] 5, the injectable liquid passage 70 is a passage that is installed inside the root canal 2a and outside the oral cavity of the subject, and connects the reservoir 61 and the root canal 2a so that the injectable liquid IS can pass through. In this embodiment, the injectable liquid passage 70 is a through-hole that passes through the intra-root canal electrode 31 in the axial direction.

[0065] The injectable liquid passage portion 70 may be formed as a separate body from the intraroot canal electrode 31, and the grip portion 63 of the injection suction portion 60 may be formed at the base end of the intraroot canal electrode 31. In this case, the surgeon can use an injection suction tool (e.g., a dropper) as the injection suction portion 60 and the injectable liquid passage portion 70 to inject the injectable liquid IS into the root canal 2a or aspirate the injectable liquid IS from the root canal 2a.

[0066] <Operation Example> First, the surgeon (dentist, dental hygienist, dental assistant, etc.) attaches the counter electrode 32 to the gum 4 and inserts the intra-root canal electrode 31 into the root canal 2a. Next, the surgeon operates the operation unit 13, causing the signal setting unit 12c to cause the apex position detection signal generator 11a to generate an apex position detection signal. The apex position detection unit 12d (apex position determination unit 12d2) detects the position of the apex 2a1 based on the apex position detection signal. Furthermore, while the intra-root canal electrode 31 moves within the root canal 2a to detect the position of the apex 2a1, the apex position detection unit 12d (apex position determination unit 12d2) stores a relative value of the conduction state (impedance) corresponding to the apex position detection signal. After detecting the position of the apex 2a1, the apex position detection unit 12d (apex position determination unit 12d2) performs a calculation based on the stored relative value to determine whether or not a lateral canal 2b exists. If a lateral canal 2b exists, the apex position detection unit 12d detects the position of the lateral canal 2b based on the result of the calculation. In such an operation, an intracanal electrode 31 without a catalyst portion 40 may be used.

[0067] The injectate IS may be injected into the root canal 2a and the lateral branch 2b before the positions of the apex 2a1 and the lateral branch 2b are detected. That is, the positions of the apex 2a1 and the lateral branch 2b can be detected even when the injectate IS has been injected into the root canal 2a and the lateral branch 2b. Note that, when the positions of the apex 2a1 and / or the lateral branch 2b are detected after the injectate IS has been injected into the root canal 2a and the lateral branch 2b, treatment of the apex 2a1 and the lateral branch 2b by generating free radicals is also performed at the same time.

[0068] More specifically, when detecting the position of the root apex 2a1, the surgeon operates the operation unit 13, causing the signal setting unit 12c to generate an apex position detection signal from the root apex position detection signal generator 11a. In this state, the surgeon uses his / her fingertip to slowly move the intra-root canal electrode 31 from the opening of the root canal 2a toward the root apex 2a1. The intra-root canal electrode 31 moves relative to a stopper 50 positioned so as to abut against a measurement reference point g, which is the occlusal end of the tooth 2 being examined. When the movement is stopped, the intra-root canal electrode 31 is fixed relative to the stopper 50. When the intra-root canal electrode 31 approaches the root apex 2a1, the apex position detection unit 12d notifies (warns) the surgeon by displaying a meter on the display unit 14 and emitting a warning sound from the sound output unit 15. The surgeon can measure the dimension L (i.e., root canal length) from the measurement reference point g, where the stopper 50 is positioned, to the tip of the intra-root canal electrode 31.

[0069] To detect the position of the lateral canal 2b, the surgeon operates the operation unit 13, causing the signal setting unit 12c to generate an apex position detection signal (here, a lateral canal position detection signal) from the apex position detection signal generator 11a. In this state, the surgeon uses his fingertip to slowly move the intracanal electrode 31 from the opening of the root canal 2a toward the apex 2a1. During the movement from the opening to the position of the apex 2a1, the apex position detection unit 12d stores the relative values ​​of the conduction state (impedance) corresponding to the apex position detection signal at each position during the movement. After detecting the position of the apex 2a1, the apex position detection unit 12d determines the presence or absence of the lateral canal 2b by calculation based on the stored relative values. If the lateral canal 2b is present, the apex position detection unit 12d detects its position by the calculation. The apex position detection unit 12d then displays the detected position of the lateral canal 2b as a mark 14b on the display unit 14. Thereafter, the surgeon uses his / her fingertip to move the intraroot canal electrode 31 to the position of the lateral canal 2b, referring to the position of the mark 14b displayed on the display unit 14. The intraroot canal electrode 31 moves relative to a stopper 50 arranged so as to abut against a measurement reference point g, which is the occlusal end of the tooth 2 as the examined tooth, and stops moving at the position of the mark 14b, where the electrode is fixed relative to the stopper 50. When the intraroot canal electrode 31 approaches the lateral canal 2b, the apex position detection unit 12d notifies (warns) the surgeon by displaying a meter on the display unit 14 and emitting a warning sound from the sound output unit 15. The surgeon can measure the dimension L from the measurement reference point g, where the stopper 50 is arranged, to the tip of the intraroot canal electrode 31 (i.e., the position length of the lateral canal 2b). In addition, the surgeon may place the tip of the intracanal electrode 31 at the position of the side branch 2b with the stopper 50 spaced away from the measurement reference point g, and then position the stopper 50 so that it abuts the measurement reference point g.

[0070] By measuring and recording the dimension L from the measurement reference point g when the root apex 2a1 and the lateral branch 2b are detected to the tip of the intra-root canal electrode 31, the surgeon can set the position of the tip of the intra-root canal electrode 31 to the position of the root apex 2a1 and the lateral branch 2b even after the intra-root canal electrode 31 is pulled out of the root canal 2a.

[0071] Next, when the surgeon places the tip of the intra-root canal electrode 31 at the root apex 2a1 (when the tip of the intra-root canal electrode 31 has reached the root apex 2a1), the surgeon operates the operation unit 13, which causes the signal setting unit 12c to generate a wetness detection signal in the root apex position detection signal generator 11a. With the wetness detection signal applied to the intra-root canal electrode 31 and the counter electrode 32, the current-carrying state detector 12d1 detects the impedance of the intra-root canal electrode 31 and the counter electrode 32, and outputs the detection result to the display unit 14 and / or the sound output unit 15, which serve as notification units. This allows the root canal diagnosis system 1 to notify the surgeon of the state (wetness) of the root apex 2a1.

[0072] The current-carrying state detecting unit 12d1 can detect the current-carrying state (impedance in this embodiment) corresponding to the wetness detection signal when the injectate IS is injected into the root canal 2a, and can also detect the current-carrying state corresponding to the wetness detection signal when the injectate IS is not injected into the root canal 2a. It is preferable that the current-carrying state detecting unit 12d1 detects the current-carrying state in the same state (whether the injectate IS is injected or not) as when detecting the apex position and / or the position of the lateral canal 2b.

[0073] For example, if the apex 2a1 in the root canal 2a is blocked due to aging, the energization state detection unit 12d1 may detect an impedance corresponding to a dry state as the wetness of the apex 2a1. Furthermore, if a medicinal solution used for treatment remains in the root canal 2a, the energization state detection unit 12d1 may detect an impedance corresponding to a wet state as the wetness of the apex 2a1. The root canal diagnosis system 1 can notify the surgeon of the wetness of the apex 2a1 using the display unit 14 and / or the sound output unit 15, thereby prompting the surgeon to re-treat the root canal 2a and the apex 2a1 or to re-detect the apex 2a1. For example, if the wetness of the apex 2a1 is wet, the surgeon performs a procedure such as removing (wiping off) the moisture in the root canal 2a, and then re-detects the position of the apex and the position of the lateral canal 2b. Also, if the moisture content of the root apex 2a1 is dry, the surgeon performs a procedure such as adding water (e.g., injection liquid IS) into the root canal 2a, and then redetects the position of the root apex and the position of the lateral branch 2b.

[0074] Next, the surgeon injects the injectate IS into the root canal 2a and the lateral branch 2b by operating the injection and suction unit 60. Next, with the injectate IS injected into the root canal 2a and the lateral branch 2b, the surgeon operates the operation unit 13 to input the amount and duration of the apex position detection signal to be supplied as electric power. The power supply amount setting unit 12a sets the amount of power to be supplied per unit time (in this embodiment, one of the apex position detection signals) based on the input value, and the power supply time setting unit 12b sets the duration of the power to be supplied based on the input value. The signal setting unit 12c causes the apex position detection signal generating unit 11a to generate the apex position detection signal (one of two signals with different frequencies, for example, a wetness detection signal) as electric power based on the set amount and duration of the power to be supplied per unit time.

[0075] Here, the surgeon can position the tip of the intracanal electrode 31 at a desired position (for example, the position of the lateral canal 2b) based on the detection result of the position of the tip of the intracanal electrode 31 by the apex position detection unit 12d.

[0076] The catalytic action of the catalyst 40 is caused by the power, generating free radicals in the injectate IS. The free radicals are generated intensively near the catalyst 40 and throughout the injectate IS. The generated free radicals have a bactericidal effect, killing bacteria, viruses, etc. in the root canal 2a and lateral branches 2b, thereby treating the root canal 2a and lateral branches 2b.

[0077] Next, the surgeon aspirates the injectate IS from the root canal 2a and the lateral branch 2b by operating the injector suction unit 60. Subsequently, the surgeon pulls out the intra-root canal electrode 31 from the root canal 2a and removes the counter electrode 32 from the gums 4.

[0078] Next, the surgeon removes the used intraroot canal electrode 31 (and the injection suction unit 60) and the counter electrode 32 from the transmitter 20, and discards (as general waste) the injectate IS that has been sucked and stored in the reservoir 61. When performing root canal treatment on another patient, the surgeon replaces the intraroot canal electrode 31 and the counter electrode 32 with new ones, and fills the reservoir 61 with new injectate IS.

[0079] Therefore, the root canal treatment system 1 has the function of detecting the position of the root apex 2a1, the function of detecting the moisture level of the root apex 2a1, and the function of generating free radicals within the root canal 2a, thereby reducing the number of devices (systems) required to treat the root canal 2a.

[0080] A root canal treatment system 1 according to an embodiment of the present invention is a system including an intra-root canal electrode 31 arranged in a root canal 2a of a tooth 2 of a subject, a counter electrode 32 arranged on the body of the subject, a signal supply unit 11 arranged outside the oral cavity of the subject and supplying an apex position detection signal to the intra-root canal electrode 31 and the counter electrode 32, and an apex position detection unit 12d that detects the position of the apex 2a1, which is the tip of the root canal 2a, in a state in which the apex position detection signal is applied to the intra-root canal electrode 31 and the counter electrode 32. The system includes a signal supply unit (11) capable of supplying a wetness detection signal for detecting the wetness of the root apex (2a1) to the intra-root canal electrode (31) and the counter electrode (32), an operation unit (13) operated to switch the signal supply unit (11) between a state of supplying the apex position detection signal and a state of supplying the wetness detection signal, and a notification unit (a display unit (14) and a sound output unit (15)) that notifies the surgeon of the conduction state of the intra-root canal electrode (31) and the counter electrode (32) when the wetness detection signal is supplied. Therefore, the root canal diagnosis system (1) can appropriately notify the surgeon of the wetness of the root apex (2a1) by detecting the conduction state correlated with the wetness and notifying the surgeon. This allows the root canal diagnosis system (1) to prompt the surgeon to perform appropriate treatment of the root canal (2a) (root apex (2a1)) and to redetect the root apex position after the appropriate treatment.

[0081] In the root canal diagnosis system 1, the signal supply unit 11 supplies two signals with different frequencies as the apex position detection signal, and supplies one of the two signals as the wetness detection signal. Therefore, the root canal diagnosis system 1 can realize the detection of the apex position and the wetness degree with a small number of types of signals.

[0082] In the root canal diagnosis system 1, the signal supply unit 11 supplies a signal having a different frequency from the apex position detection signal as the wetness detection signal. Therefore, the root canal diagnosis system 1 can set a frequency suitable for wetness detection for the wetness detection signal.

[0083] In the root canal diagnosis system 1, the notification unit notifies the energization state when the wetness detection signal is supplied by displaying or sounding in multiple stages according to the energization state. Therefore, the root canal diagnosis system 1 allows the surgeon to intuitively grasp the wetness state.

[0084] The root canal diagnosis system 1 includes a catalyst unit 40 disposed in the intra-root canal electrode 31. The catalyst unit 40 generates free radicals in the injectate IS injected into the root canal 2a by catalyzing the injectate IS with power from the signal supply unit 11. Therefore, the root canal diagnosis system 1 has the functions of detecting the position of the root apex 2a1 and sterilizing the root canal 2a, thereby reducing the number of devices (systems) required for treating the root canal 2a. Furthermore, the root canal diagnosis system 1 continuously generates free radicals in the root canal 2a using power as excitation energy, allowing for optimal treatment of the root canal 2a in a short and simple manner. Furthermore, the root canal diagnosis system 1 can generate free radicals by disposing the intra-root canal electrode 31 near the apex 2a1, which is the narrowed portion of the root canal 2a, thereby effectively reducing the occurrence of apical lesions. Furthermore, the root canal diagnosis system 1 can effectively treat the root canal 2a by disposing a catalyst unit in the intra-root canal electrode of an existing apex position detection system. The root canal diagnosis system 1 can simultaneously detect the position of the root apex 2a1 (measure the root canal length) and treat the root canal 2a (sterilize the root apex 2a1). The root canal diagnosis system 1 can simultaneously detect the wetness and treat the root canal 2a by applying a wetness detection signal to the intra-root canal electrode 31 and the counter electrode 32 as power for generating free radicals.

[0085] In the root canal treatment system 1, the catalyst portion 40 is formed of titanium oxide. Therefore, the root canal treatment system 1 can suitably generate free radicals by catalytic action.

[0086] In the root canal treatment system 1, the injectate IS is water, oxygenated water, hydrogen peroxide, or a neutral aqueous solution with a pH of 4.5 to 8.9. Therefore, the root canal treatment system 1 exhibits bactericidal, antibacterial, and purifying effects due to free radicals when excitation energy is applied, and can return the injectate IS to its original, harmless state by ceasing the application of excitation energy, thereby enabling safe disposal.

[0087] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, the apex position detection signal generator 11a may be configured to generate three or more apex position detection signals with different frequencies. In this case, the apex position detector 12d (apex position determiner 12d2) selects two apex position detection signals with the largest relative impedance values ​​from the three or more apex position detection signals, and detects (determines) the position of the apex 2a1 (and the lateral canal 2b) based on the selected two apex position detection signals, thereby improving the position detection accuracy.

[0088] Furthermore, in the root canal diagnosis system 1, the apex position detection signal generating unit (wetterness detection signal generating unit) 11a can generate a worseness detection signal when the tip of the intra-root canal electrode 31 is positioned at any position in the root canal 2a other than the root apex 2a1. In this case, the energization state detecting unit 12d1 can detect an energization state (e.g., impedance) that correlates with the worseness at the any position in the root canal 2a and output it to the notifying unit.

[0089] REFERENCE SIGNS LIST 1 Root canal treatment system 2 Tooth (tooth to be examined) 2a Root canal 2a1 Root apex 2b Lateral canal 10 Root canal treatment device 11 Signal supply unit 11a Root apex position detection signal generation unit (moisture detection signal generation unit) 12d Root apex position detection unit 20 Transmission unit (electric wire) 30 Excitation energy application unit 31 Intra-root canal electrode 32 Counter electrode 40 Catalyst unit 41 Catalyst substance 50 Stopper 60 Injection and suction unit 70 Injection liquid passage unit

Claims

1. A root canal treatment system comprising: an intra-root canal electrode to be placed inside a root canal of a tooth of a subject; a counter electrode to be placed on the body of the subject; a signal supply unit to be placed outside the oral cavity of the subject and supplying an apex position detection signal to the intra-root canal electrode and the counter electrode; an apex position detection unit to detect the position of the apex, which is the tip of the root canal, when the apex position detection signal is applied to the intra-root canal electrode and the counter electrode, wherein the signal supply unit is capable of supplying a wetness detection signal to the intra-root canal electrode and the counter electrode to detect the wetness of the apex; an operation unit that is operated to switch the signal supply unit between a state in which it supplies the apex position detection signal and a state in which it supplies the wetness detection signal; and a notification unit that notifies the current flow state of the intra-root canal electrode and the counter electrode when the wetness detection signal is supplied.

2. The root canal diagnosis system according to claim 1, characterized in that the signal supply unit supplies two signals with different frequencies as the apex position detection signal, and supplies one of the two signals as the wetness detection signal.

3. The root canal diagnosis system according to claim 1, wherein the signal supply unit supplies, as the wetness detection signal, a signal having a frequency different from that of the root apex position detection signal.

4. The root canal treatment system according to claim 1, characterized in that the notification unit notifies the power supply state when the wetness detection signal is supplied by displaying or sounding in multiple stages according to the power supply state.

5. A root canal treatment system as described in claim 1, characterized in that it comprises a catalyst unit disposed in the intra-root canal electrode, and the catalyst unit generates free radicals in the injectate injected into the root canal by causing a catalytic action in the injectate by electric power from the signal supply unit.

6. The root canal treatment system according to claim 5, wherein the catalyst portion is formed from titanium oxide.

7. A root canal treatment system according to claim 5 or 6, characterized in that the injection liquid is water, oxygenated water, hydrogen peroxide, or a neutral aqueous solution with a pH of 4.5 to 8.9.

Images