Root canal cleaning device

Abstract

A root canal cleaning device according to one embodiment of the present invention comprises: a sound pressure generating device that operates by turning on power; a handle housing for accommodating the sound pressure generating device; a cooling water channel formed inside the handle housing; a cooling water injection port communicating with the cooling water channel formed in the handle housing; and the cleaning liquid nozzle is arranged on the handle shell. The ultrasonic sound pressure applied to the cooling water by the sound pressure generating device is transmitted to the cleaning liquid, a vapor bubble is generated in the cleaning liquid by the transmitted ultrasonic sound pressure, and the vapor bubble and the cleaning liquid act on the tooth to be treated together to remove dirt inside the tooth including the root canal. And the cleaning liquid is a degassing liquid (degassing liquid).

Description

Technical Field

[0001] The invention relates to a root canal cleaning device. Background Art

[0002] After Kakeyash et al. first proved that the main cause of pulpitis was bacteria in germ-free mice in 1967, it was clarified that biofilm and necrotic tissue, which are bacteria that form colonies inside the root canal, are the main causes of inflammatory reactions. In order to successfully achieve nerve treatment, the above bacteria and necrotic tissue present in the root canal must be completely removed.

[0003] The root canal treatment process is roughly divided into three steps: root canal formation, root canal cleaning, and root canal filling. The present invention relates to a device for root canal cleaning, which is the second step.

[0004] Root canal cleaning is formed by removing the decayed nerve with an endo file. It is a necessary step to remove infected microorganisms and an important step that has a great impact on the successful implementation of nerve treatment.

[0005] Among the root canal cleaning devices in the prior art, there is a well-known device that fills the root canal of the tooth with a cleaning liquid and inserts a tip that generates ultrasonic waves to clean the root canal, i.e., passive ultrasonic irrigation (PUI). For this device, if the tip is to be inserted into the root canal, the root canal needs to be expanded, but for a severely curved root canal, there is a problem that it is difficult to insert the tip.

[0006] In addition to the root canal cleaning devices of the prior art as described above, the inventors studied many patents and papers of many representative researchers in the field of root canal cleaning devices during the process of completing the present invention. Among them, the U.S. authorized patent No. 8,753,121B2 (hereinafter referred to as the "'121 patent") and US10,420,630B2 (hereinafter referred to as the "'630 patent") of Sonendo, Inc. are representatively introduced. Unlike the above-mentioned passive ultrasonic irrigation device, the above-mentioned U.S. authorized patent technology of Sonendo, Inc. is characterized in that there is no need to directly insert the cleaning device into the root canal when cleaning the root canal. Therefore, problems such as tip breakage will not occur, and there is an advantage that multiple root canals can be cleaned simultaneously through a single treatment. This effect that is superior to the existing passive ultrasonic irrigation device is not only achieved by the above-mentioned U.S. authorized patent technology of Sonendo, Inc., but can also be achieved by the present invention.

[0007] First, in this manual, Figure 1The representative diagram of the "'121 patent" is shown. The first feature of this US patent is that in the process of cleaning the root canal, a cleaning liquid is sprayed at a very high speed and high pressure, that is, a liquid jet. According to the description in this specification, the liquid jet refers to a high-speed, high-pressure fluid sprayed by a high-pressure pump system. Figure 1 In the figure, the liquid jet is represented by the reference numeral 60 and is shown in a straight line to rinse the inner surface of the tooth. According to the description in the specification, the conditions of a pressure of 7000 psi (about 48263 kPa) or more and a speed of 50 m / s or more should be met. There are roughly two reasons for using this high-speed, high-pressure jet liquid. The first is to generate vapor bubbles. The second is to generate acoustic waves in the process of causing the liquid jet to collide with the dentin, which is the hard tissue inside the tooth. Vapor bubbles and acoustic waves are helpful in removing biofilms and / or necrotic tissues that are the objects of root canal cleaning. However, this prior art using liquid jets will cause problems due to the high speed and high pressure of the liquid jet. Since the liquid jet is in a high-speed, high-pressure state, it will cause safety problems when it is directed directly to the inside of the root canal. Although safety problems will arise when the liquid jet is directed directly to the inside of the root canal, if it contacts other soft tissues in the oral cavity, it may cause greater safety problems. Therefore, if Figure 1 As shown, in this technology, a cleaning liquid is guided into the root canal after the liquid jet is reflected by the hard tissue of the tooth wall. In the process of root canal cleaning by this technology, it is difficult to aim the liquid jet, which causes a heavy burden on doctors with poor skills. Therefore, in order to use the liquid jet disclosed in the "'121 patent" of Sonendo Company of the United States for scaling, a separate structure is required to solve the safety problem. Let's take a look at the "'630 patent" as a patent related to this structure, which is also an improved version of the "'121 patent". Figure 2 A representative diagram of the '630 patent is shown.

[0008] like Figure 2 As shown, in the '630 Patent, the liquid jet 60 is guided along the guide tube indicated by reference numeral 100, and finally a water column is guided into the root canal after the liquid jet 60 collides with an impingement member, that is, finally a water column is guided into the root canal after the liquid jet 60 collides with a structural element (indicated by reference numeral 110) at the distal end of the impingement member. The reason for adopting such a measure is described in the '630 Patent as follows.

[0009] "Embodiments of the guide tube 100 which include an impingement member 110 may reduce or prevent possible damage that may be caused by the jet during certain dental treatments. For example, use of the impingement member 110 may reduce the likelihood that the jet may undesirably cut tissue or propagate into the root canal spaces 30 which may undesirably pressurize the canal spaces in some cases. (Embodiments of the guide tube 100 which include an impingement member 110 may reduce or prevent possible damage that may be caused by the jet during certain dental treatments. For example, the use of the impingement member 110 may reduce the likelihood that the jet may undesirably cut tissue or propagate into the root canal spaces 30 which may undesirably pressurize the canal spaces in some cases.)"

[0010] The cited portion of the specification of the '630 patent describes the problems caused by the use of a liquid jet, namely, the damage to the patient, and explains the function of the impact member 110 as a structural element to solve the problem of cutting tissue or increasing the pressure inside the root canal to a level that may cause safety problems. The core of the '630 patent is the impact member 110.

[0011] The present inventor has the following understanding of the problems of the cleaning device of the prior art mentioned in the patent of Sonendo Corporation of the United States as mentioned above. First, in order to generate high-speed, high-pressure fluids at the levels mentioned in the above-mentioned U.S. patents, it is necessary to use a special high-pressure pump. Moreover, the durability of high-pressure generating units such as pumps and fluid channels such as fluid pipes for the flow of such high-pressure fluids needs to be managed at a special level. In addition, additional structural elements such as the impact components introduced in the "'630 patent" are required. This will ultimately lead to the complexity of the structure of the device for cleaning and increase the production cost of the equipment. Moreover, as long as a high-speed, high-pressure liquid jet is used, the above-mentioned safety problems cannot be fundamentally solved, that is, the problem of cutting the patient's oral tissue or causing excessive pressure increase inside the root canal cannot be fundamentally solved.

[0012] Based on the understanding of the problem as described above, the inventors felt the necessity of developing a device that uses a relatively low-speed, low-pressure cleaning fluid and can maximize cleaning efficiency, compared to the high-speed, high-pressure cleaning fluid used in the U.S. patent, and after continuous efforts in research and development, the present invention was finally completed. Summary of the invention

[0013] Technical issues

[0014] The object of the present invention is to provide a cleaning device that does not need to expand the root canal during cleaning, and can easily clean the root canal even if it is severely curved. Cleaning can be performed without directly inserting the cleaning device into the root canal, so that the problem of tip breakage does not occur, and multiple root canals can be cleaned simultaneously in a single treatment.

[0015] Furthermore, an object of the present invention is to provide a cleaning device that can spray cleaning liquid at a low speed and low pressure and maximize the cleaning effect, compared to the prior art that uses a high-speed and high-pressure liquid jet to clean the root canal.

[0016] Furthermore, an object of the present invention is to provide a cleaning device that sprays cleaning liquid at a low speed and low pressure, and structurally includes an ultrasonic vibration structure that can effectively generate steam bubbles even in an environment where degassed liquid (degassed liquid, in this field, the term "degassed liquid" is commonly used, and in the following content, the English term "degassed liquid" and Chinese will be used in parallel or alone) is used as a cleaning liquid.

[0017] Furthermore, an object of the present invention is to provide a cleaning device that is structurally capable of easily transmitting ultrasonic vibrations to the inside of teeth.

[0018] Another object of the present invention is to provide a cleaning device that can prevent the root canal passage from being clogged by gas bubbles that cannot be completely blocked even with a degassed liquid.

[0019] Means of solving the problem

[0020] A root canal cleaning device according to an embodiment of the present invention comprises: a sound pressure generating device, which is operated by connecting electricity; a handle housing for accommodating the sound pressure generating device; a cooling water channel formed inside the handle housing; a cooling water inlet connected to the cooling water channel formed in the handle housing; and a cleaning liquid nozzle disposed on the handle housing. The ultrasonic sound pressure applied to the cooling water by the sound pressure generating device is transmitted to the cleaning liquid, and vapor bubbles are generated in the cleaning liquid by the transmitted ultrasonic sound pressure. The vapor bubbles and the cleaning liquid act together on the tooth to be treated to remove dirt inside the tooth including the root canal. The cleaning liquid is a degassed liquid.

[0021] The cooling water may be used to cool the sound pressure generating device, and the cooling water may be a degassed liquid.

[0022] The sound pressure generating device includes: a vibrator that vibrates when power is supplied; and a vibration speaker that is connected to the vibrator and vibrates, and has a shape extending along a straight line.

[0023] The jet flow formed in the root canal by the cleaning liquid nozzle discharges bubbles blocking the root canal passage and / or pollutants separated from the root canal to the outside of the root canal.

[0024] The handle housing is formed in a shape with a bent end portion, and an acoustic reflector is provided at the bent portion, so that the ultrasonic wave applied to the cooling water by the vibration horn is reflected by the acoustic reflector.

[0025] The acoustic reflector is tilted at a specified angle based on the cross section of the vibration horn.

[0026] A bubble trapping space is formed on the upper surface of the handle housing, and a plurality of bubbles gathered near the acoustic reflector rise due to buoyancy and are trapped in the bubble trapping space.

[0027] The length of the cleaning liquid nozzle may be set to spray the cleaning liquid into the root canal cavity (access cavity) of the tooth during root canal cleaning.

[0028] In addition to this, the cleaning device of the present invention may further include other structures.

[0029] Effects of the Invention

[0030] According to the present invention, the following cleaning device is provided, that is, during the process of cleaning the root canal, there is no need to expand the root canal, and even if the root canal is severely curved, cleaning can be easily performed. Cleaning can be performed without directly inserting the cleaning device into the root canal, so the problem of tip breakage does not occur, and multiple root canals can be cleaned simultaneously through a single treatment.

[0031] Furthermore, according to the present invention, a cleaning device is provided, which sprays cleaning liquid at a low speed and low pressure and maximizes the cleaning effect, compared with the prior art that uses a high-speed and high-pressure liquid jet to clean the root canal.

[0032] Furthermore, according to the present invention, there is provided a cleaning device that sprays cleaning liquid at a low speed and low pressure and that structurally includes an ultrasonic vibration structure that can effectively generate vapor bubbles even in an environment where a degassed liquid is used as the cleaning liquid.

[0033] Furthermore, according to the present invention, a cleaning device is provided, which has a structure that can easily transmit ultrasonic vibrations to the inside of teeth.

[0034] Furthermore, according to the present invention, a cleaning device is provided that can prevent the root canal passage from being blocked by bubbles that cannot be completely blocked even with a degassed liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A representative diagram of the prior art U.S. issued patent (the '121 patent) described in the Background section.

[0036] Figure 2 A representative diagram of the prior art US issued patent (the '630 patent) described in the Background section.

[0037] Figure 3 This is a table that summarizes the differences in characteristics between bubbles and steam bubbles obtained by the inventors through research.

[0038] Figure 4 The following is a photo of an existing dental cleaning device.

[0039] Figure 5 This is a photograph of the vibrator and the vibration horn of a cleaning device prototype according to an embodiment of the present invention combined.

[0040] Figure 6 A diagram for briefly explaining the function of an acoustic reflector used in a cleaning device according to an embodiment of the present invention.

[0041] Figure 7 A diagram for explaining the ultrasonic wave transmission principle of an acoustic reflector.

[0042] Figure 8 This figure shows the shape of the vibration after being converted by the acoustic reflector and transmitted to the teeth.

[0043] Fig. 9 Graphs related to an experiment for examining the performance of an acoustic reflector based on ultrasonic power measurement.

[0044] Fig.10FIG. 1 is a diagram showing the overall structure of a cleaning device 10 according to an embodiment of the present invention.

[0045] Fig.11 A diagram illustrating the function of steam bubbles and nozzles in root canal cleaning.

[0046] Fig.12 This is a photo of the model root canal being blocked by bubbles, which hinders cleaning.

[0047] Fig.13 1 is a diagram showing an experiment for evaluating the stability of root apex outflow from the nozzle 7 of the cleaning device according to an embodiment of the present invention.

[0048] Fig.14 The figure shows a state where bubbles are trapped in a space provided in the handle housing of the cleaning device according to one embodiment of the present invention.

[0049] Fig.15 The photographs are taken of the results of cleaning a model root canal using a prototype cleaning device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] Hereinafter, in the detailed description of the present invention, reference will be made to the accompanying drawings in which specific embodiments of the present invention are shown as examples. Such embodiments will be described in detail so that those skilled in the art can fully implement the present invention. The various embodiments of the present invention should be understood to be different from each other but not mutually exclusive. For example, the specific shapes, structures and characteristics recorded in this specification can be changed from one embodiment to other embodiments without departing from the idea and scope of the present invention. Furthermore, it should be understood that the position or arrangement of individual structural elements in each embodiment can also be changed without departing from the idea and scope of the present invention. Therefore, the following detailed description is not restrictive and should be interpreted as the scope of the present invention including the scope requested by the claims in the scope of the invention and all scopes equivalent thereto.

[0051] Hereinafter, in order to enable those skilled in the art to easily implement the present invention, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0052] <Bubbles and Steam Bubbles>

[0053] Figure 3 This is a table that summarizes the differences in the characteristics of bubbles and steam bubbles obtained by the inventor through research. Figure 3As shown in the table, bubbles and steam bubbles differ in characteristics. The residence time of bubbles is long and they are generated at multiple locations at the same time. A single bubble shows the characteristic of moving along the surface and cleaning particles with a weaker force in a narrow area near the bubble. On the other hand, although the residence time of steam bubbles is relatively short, the movement intensity during the residence time is large, thus showing the characteristic of cleaning a wider area with a stronger force at one position. Although bubbles showing two different characteristics both have the effect of helping to clean, the inventor is committed to only producing steam bubbles in both. One of the reasons is that the fatal shortcomings of bubbles in the root canal cleaning process are recognized. Bubbles can cause bubble blockage in the narrow and long root canal. If this bubble blockage phenomenon is not solved, the end of the narrow and long root canal cannot be well cleaned, which is confirmed by the inventor's research. The second reason is that since the movement intensity of steam bubbles is relatively higher than that of bubbles, the cleaning performance is better.

[0054] As the goal is to generate only steam bubbles in the cleaning liquid, a degassed liquid must be used as the cleaning liquid. If a liquid from which the gas is not removed is used as the cleaning liquid, bubbles cannot be prevented. Even if a degassed liquid is used as the cleaning liquid, the generation of bubbles cannot be completely prevented, so the problem of bubbles intermittently generated clogging the root canal needs to be solved, which will be explained later. If you want to use a degassed liquid as a cleaning liquid to generate steam bubbles, as in Figure 3 The contents in the table in need to apply a high sound pressure above a specific critical value to the cleaning liquid. The structure derived by the inventors for applying a high sound pressure to the cleaning liquid will be described in the following content sections.

[0055] <Necessity of strong ultrasonic wave applying device>

[0056] In order to generate steam bubbles, the ultrasonic wave applicator should have high power (or ultrasonic sound pressure). In order to realize high-power ultrasonic waves, the cross-sectional area of ​​the ultrasonic vibrator and the vibration applicator component (scaling tip, file, vibration horn, etc.) combined with the vibrator should reach a specified area or more, preferably forming a straight line shape. In order to be used in the oral cavity, the existing dental cleaning device uses thin and curved components (scaling tip or file, etc.), so it is difficult to effectively apply high-power ultrasonic waves.

[0057] The inventors have developed a solution to select a BLT type vibrator as a vibrator and use it in combination with a linear vibration horn. BLT is the abbreviation of Bolt-clamped Langevin Transducer. The BLT type vibrator is one of the various types of vibrators that were commercially available at the time of completing the present invention, including nickel vibrators, ferrite vibrators, piezoelectric ceramic vibrators, BLT vibrators, crystal vibrators, etc. The purpose of using the BLT type vibrator is to achieve high-power ultrasonic waves. In order to achieve high power, the BLT vibrator is determined to be relatively large at the level of about 30mm. The inventors selected the BLT type from a variety of types of vibrators for use, but the vibrators used in the present invention should not be limited to the BLT type. It must be understood that as long as ultrasonic power that can generate steam bubbles well in the cleaning liquid as a degassed liquid can be provided, the use of any type of vibrator falls within the scope of the present invention.

[0058] In addition to the vibrator, another important structural element is a vibration transmission element combined with the vibrator and used to transmit the vibration generated by the vibrator to the medium (cooling water and cleaning liquid) as a fluid. In this embodiment, a vibration horn will be used as a vibration transmission element for transmitting the ultrasonic wave generated by the BLT vibrator to the oral cavity through a fluid medium. In this embodiment, a vibration horn is used as a vibration transmission element. It should be understood that in addition to the vibration horn, other structures or shapes of vibration transmission elements can also be used. In order to minimize the power loss of the ultrasonic wave applied from the BLT vibrator, it is more advantageous to use a linear vibration horn. Since the cleaning device of the present invention has the characteristic of being inserted into the patient's mouth, the volume of the vibration horn can only be limited, but if the volume of the vibration horn is too small, it will cause ultrasonic power loss and cannot effectively generate steam bubbles in the degassed liquid, so the inventor has developed a linear vibration horn. The inventor finally chose to combine a linear vibration horn with a cross-sectional diameter of approximately 8 mm with a BLT type vibrator, and manufactured a trial product, and verified the cleaning performance by actually applying this trial product.

[0059] As for dental cleaning devices, ultrasonic wave emitting devices have also been used before the present invention. Figure 4 This is a photo of an existing dental cleaning device. Figure 5 This is a photo of the vibrator and the vibration horn of a cleaning device prototype according to an embodiment of the present invention combined. Figure 4 and Figure 5 There is a clear difference between the vibration applying part (tip or file) of the existing dental cleaning device using ultrasonic waves and the vibration applying part vibrating horn of the device of the present invention. Figure 4As shown, the existing dental cleaning devices are almost unable to generate ultrasonic power capable of generating steam bubbles in the degassed liquid. The inventors of the two prior arts cited in the background technology section of this specification, namely the "'121 patent" and the "'630 patent" of the U.S. Sonendo Company, recognized the fact that it is difficult to use an ultrasonic vibration generating device to generate steam bubbles in the degassed liquid due to the physical limitations of the size of the dental treatment device inserted into the patient's mouth, and used a circuitous method of generating steam bubbles by using a high-speed, high-pressure liquid jet.

[0060] <Acoustic reflector for guiding powerful ultrasonic waves into the oral cavity>

[0061] Figure 6 FIG. 2 is a diagram for briefly explaining the function of an acoustic reflector used in a cleaning device according to an embodiment of the present invention. Figure 5 The ultrasonic vibrator and the vibration horn connected thereto may cause problems in inserting into the patient's mouth. The use of a linear vibration horn will result in a longer length of the cleaning device. Therefore, it is necessary to add another structural element to transmit the ultrasonic vibration generated by the vibration horn to the teeth. The inventors of the present invention have made the cleaning device of one embodiment of the present invention include the following in terms of structure: Figure 6 The acoustic reflector shown solves this problem. The acoustic reflector is used to facilitate the cleaning device including a linear ultrasonic wave applicator to be located in the oral cavity. By using the acoustic reflector, high-power ultrasonic waves can be directly applied to the tooth root canal cavity and the root canal. Ultrasonic waves have the characteristic of linear movement, and the acoustic reflector will perform the function of changing the forward direction of the linearly moving ultrasonic waves.

[0062] Figure 7 This is a diagram for explaining the ultrasonic transmission principle of an acoustic reflector. The ultrasonic wave applied from the vibration horn will generate a pressure wave in the process of being transmitted to the medium (cooling water in the present invention). In this case, the ultrasonic wave will propagate in a direction perpendicular to the cross section of the vibration horn (linear mobility of ultrasonic wave). Ultrasonic waves have the characteristic of being reflected when encountering a medium with significantly different acoustic impedance (the product of density and sound wave transmission speed in each medium). In this case, the direction of travel of the reflected ultrasonic wave follows the principle of the incident angle and reflection angle of the wave.

[0063] Figure 8 This is a diagram showing the shape of the vibration direction after being converted by the acoustic reflector and transmitted to the teeth. Figure 8As shown, the acoustic reflector included in the cleaning device of one embodiment of the present invention is preferably tilted at an angle of 45 degrees based on the cross-section of the ultrasonic vibration horn. Ordinary solid materials can be used as materials for acoustic reflectors. However, the greater the difference in acoustic impedance between the material and the liquid, the better its reflection efficiency will be. From this perspective, it is better to use glass or metal materials rather than plastic materials. Figure 8 In the figure, the acoustic reflector is shown as a flat plate, but in fact, it can take any shape that can reflect ultrasonic waves.

[0064] Fig. 9 FIG. 1 is a graph related to an experiment for testing the performance of an acoustic reflector based on ultrasonic power measurement. In order to test the performance of the acoustic reflector, the present inventors performed the following Fig. 9 The present inventors conducted experiments shown in FIG. 1 . The present inventors used a hydrophone to measure the sound pressure of ultrasonic waves applied by a vibrating horn under conditions with and without an acoustic reflector and compared the results. As a result of this experiment, it was confirmed that ultrasonic waves can be transmitted well even in the presence of an acoustic reflector. However, it was confirmed that some loss in output sound pressure occurs due to reflection by the acoustic reflector. According to Fig. 9 The results in the table on the right show that the power of the reflected ultrasonic wave is approximately between 150 kPa and 220 kPa, which is sufficient to generate steam bubbles in the degassed liquid.

[0065] <Overall structure of a cleaning device according to an embodiment of the present invention>

[0066] Reference Fig.10 , the overall structure of the cleaning device 10 of one embodiment of the present invention is described. The cleaning device 10 is a sound pressure generating device that vibrates by connecting electricity, and includes a vibrator 1 and a linear vibration horn 2 connected to the vibrator 1. Among them, "connection" means direct connection or indirect connection achieved through other vibration transmission media. Among them, "straight line" means forming a straight line shape as a whole. Even if there are partial bends or slightly twisted parts, as long as the whole forms a straight line shape, that is, a shape extending along the length direction, it can be regarded as a straight line shape. The vibrator 1 and the vibration horn 2 are both housed in a handle shell 3. The handle shell for housing the vibrator 1 and the handle shell for housing the vibration horn 2 can be of a separate type or an integrated type. When the handle shell 3 for housing the vibrator 1 can be separated from other parts, additional advantages can be achieved. After cleaning, it is preferable to remove the part that is indirectly in contact with the patient's mouth and replace it with a new handle device during the next cleaning process in terms of hygiene. When replacing the part including the vibrator 1 and the vibration horn 2, a lot of expenses need to be borne. As Fig.10As shown, the vibrator 1 does not contact the cooling water A and the cleaning liquid B used in the patient's mouth, and is located at the farthest position from the patient's mouth in the entire handle device that contacts the patient's mouth. In the case where the handle housing 3 is manufactured in a separate manner so that the handle housing 3 for storing the vibrator 1 can be separated from other parts, the handle housing 3 for storing the vibrator 1 does not need to be replaced and only other parts combined with it can be replaced, which is conducive to reducing costs.

[0067] The handle housing 3 is formed into a shape in which the outlet portion is bent at 90 degrees. The acoustic reflector 4 is to be set at this bent portion. A good setting angle is an angle of 45 degrees with the cross section of the vibration horn as a standard. The ultrasonic wave can be reflected by the acoustic reflector 4 set in this way and transmitted to the tooth to be treated. The function, principle and ultrasonic wave reflection effect of the acoustic reflector 4 have been described in detail in the first half of this specification.

[0068] Cooling water A is formed inside the handle housing 3 (at Fig.11 A channel (indicated by blue in the figure). A cooling water injection port 5 is formed in the handle housing 3, and the cooling water injection port 5 is connected to the internal space of the handle housing, that is, it is connected to the cooling water channel. The cooling water injection port 5 can be connected to a cooling water injection pump (not shown) to apply pressure to the cooling water stored in the cooling water storage and inject cooling water A into the cooling water channel inside the handle housing 3 through the injection port 5. The cooling water A injected into the cooling water channel through the cooling water injection port 5 with the pressure applied by the injection pump will surround the vibration horn 2 and move toward the open outlet of the handle housing 3. In this embodiment, the use of a cooling water injection pump is illustrated, and the cooling water A does not have to flow at a specific pressure or speed, and the use of the cooling water injection pump can also be excluded. The cooling water A performs the function of cooling the vibration horn 2 whose temperature rises due to the vibration of the ultrasonic wave. Another important function of the cooling water A is to add pressure to the cleaning liquid B (in Fig.10 In yellow) transmits ultrasonic waves. Fig.10 In the figure, as indicated by an arrow near the outlet of the handle housing 3, the cooling water A that cools the vibration horn 2 and transmits ultrasonic waves to the cleaning liquid B can overflow from the gap between the cleaning device and the teeth and be discharged. As another embodiment, the following method can also be adopted, that is, instead of allowing the cooling water A to overflow from the gap between the cleaning device and the teeth and be discharged, a separate suction unit is added to suck and recover the cooling water A.

[0069] A cleaning liquid nozzle 7 for injecting cleaning liquid B into the inside of the teeth is provided at the outlet of the handle housing 3. The cleaning liquid nozzle 7 is connected to the cleaning liquid channel 6, and the cleaning liquid channel 6 is connected to a cleaning liquid injection pump (not shown) for providing pressure. In this embodiment, although the use of a cleaning liquid injection pump is illustrated, in addition to a pump, any device can be used for the cleaning device of the present invention as long as it is a unit that can apply a spray pressure to the cleaning liquid B discharged through the cleaning liquid channel 6 and the nozzle 7.

[0070] Next, the function of the cleaning liquid nozzle 7 will be described. Fig.11 FIG. 7 is a diagram showing the function of the steam bubbles and the nozzle 7 in root canal cleaning. Fig.11 As shown in FIG. 1 , the contaminants attached to the root canal wall will be separated from the wall due to the cleaning power of the steam bubbles. Even if they are separated from the wall, the contaminants may continue to remain in the root canal, but in order to discharge the contaminants to the outside of the root canal, a nozzle 7 is necessary. Fig.11 In the figure, the red curved arrow schematically indicates "exhausting contaminants by jet flow". The cleaning liquid injected into the root canal cavity of the tooth through the nozzle 7 and guided into the root canal generates a jet flow in the root canal, thereby exhausting contaminants detached from the wall surface due to the cleaning force of the steam bubbles to the outside of the root canal. The jet flow generated by the nozzle 7 will also solve the problem of bubbles blocking the root canal, ensuring smooth cleaning.

[0071] Fig.12 This is a photograph of the cleaning condition being hindered by bubbles blocking the root canal of the model. One of the features of the present invention is the use of cooling water A and degassed liquid as cleaning liquid B. This feature can minimize the generation of bubbles in the root canal during the cleaning process. Even with degassed liquid, a 100% degassed state cannot be guaranteed. Therefore, bubbles will also be intermittently generated by the strong ultrasonic sound pressure used to generate steam bubbles in the degassed liquid. As described in the part related to the characteristics of bubbles and steam bubbles in this specification, since the retention time of bubbles is longer than that of steam bubbles, if bubbles block the root canal, the part blocked by bubbles cannot be cleaned for a long time, so external force must be applied to remove the bubbles blocked in the root canal. The inventor confirmed that the bubbles blocked in the root canal can be easily discharged to the outside of the root canal by applying external force to the bubbles blocked in the root canal through the jet generated by the nozzle 7. On the contrary, if the nozzle 7 is not used, the bubbles will not be discharged. The following describes the stability of the root apex outflow of the cleaning liquid nozzle 7.

[0072] Fig.13The figure shows an experiment to evaluate the stability of the outflow from the nozzle 7 of the cleaning device of one embodiment of the present invention. The inventors compared the stability of the jet nozzle of the cleaning device of one embodiment of the present invention and needle irrigation (a method used for tooth cleaning in the past) by measuring the pressure at the root apex. The greater the pressure at the root apex, the greater the risk of outflow in actual clinical practice. Both the method currently used for root canal cleaning in dentistry and the method of one embodiment of the present invention are shown in FIG. Fig.13 The left side of the figure. The diameter of the needle that performs the function of the jet nozzle is 30 gauge (150 μm). However, compared with the ordinary needle used in the cleaning device of the present invention, the needle used in the existing syringe cleaning device as a control group is a side-vented needle. In the prior art, if an ordinary needle is used, a side-vented needle is used to solve the problem of excessive pressure applied to the root apex. Comparing the two, the biggest difference lies in the injection position of the needle. In the prior art, in order to inject cleaning liquid into the root canal, the cleaning liquid is injected at the root canal entrance. On the contrary, in one embodiment of the present invention, the cleaning liquid is injected into the root canal cavity (access cavity) which is a position separated from the root canal by a specified distance. For the cleaning device of one embodiment of the present invention, it is measured that the root apex pressure is significantly lower than the existing method when the cleaning liquid injection flow rate is set to 15m / s and when it is set to 20m / s. Therefore, it can be evaluated that the use of the cleaning device of one embodiment of the present invention will significantly increase stability compared with the prior art in terms of root apex outflow stability.

[0073] Next, refer to Fig.10 and Fig.14 The bubble trapping space provided in the handle housing 3, which is one of the inherent features of the present invention, will be described. Fig.10 In the figure, the bubble trapping space is shown by reference numeral 8. The bubble trapping space 8 is designed so that the plurality of bubbles C that have grown larger are trapped in one place. If the plurality of bubbles C that are unnecessary bubbles are gathered near the acoustic reflector 4, the ultrasonic transmission efficiency will drop sharply. The inventors set the bubble trapping space 8 in the handle housing 3 in such a way that the plurality of bubbles C that have grown larger after merging rise due to buoyancy and are trapped in a specific space. Fig.10 and Fig.14 As shown in FIG. 1 , the bubble trapping space 8 may be formed in a dome shape, but its shape is not limited as long as it can trap multiple bubbles C. The bubble trapping space 8 is used to trap multiple bubbles C gathered near the acoustic reflector 4, and the location where the space is formed is preferably near the acoustic reflector 4 in the handle housing 3. Fig.10 and Fig.14As shown, if a bubble trapping space 8 is provided at the end portion of the upper surface of the handle housing 3 connected to the acoustic reflector 4 inclined at an angle of 45 degrees, it is beneficial to trap a plurality of bubbles C that reduce the ultrasonic transmission efficiency due to gathering near the acoustic reflector 4. Fig.14 Among the three states shown in FIG. 1 , the state on the left is a state in which the cleaning device of an embodiment of the present invention is used correctly, that is, a state in which the handle of the cleaning device is used horizontally. As described above, in order to place the handle of the cleaning device horizontally, a bubble trapping space 8 is required. Fig.14 As shown in the state in the center and right side of the handle, when the handle is tilted, bubbles will not gather near the acoustic reflector 4. In the cleaning device of the present invention used in the horizontal state of the handle, it should be understood that maintaining the ultrasonic transmission efficiency well by capturing multiple bubbles C in the bubble capture space 8 is one of the important features of the present invention.

[0074] The present inventors verified the cleaning effect by using the cleaning device having the above structure. The cleaning conditions are summarized in [Table 1].

[0075] [Table 1]

[0076]

[0077] In order to artificially create an environment that is difficult to clean, the inventors adopted the condition of the root tip being blocked as shown in the table. The condition of the root tip being unblocked is a relatively easy condition to clean. If effective cleaning can be achieved under the condition of the root tip being blocked, the cleaning effect can also be fully guaranteed under the condition of the root tip being unblocked. The results of this cleaning effect verification experiment are shown in Fig.15 The inventors used Fig.15 The experiment was conducted on the transparent model root canal shown in the photo in , and the process of cleaning the root canal was observed. First, when the model root canal was cleaned using the cleaning device of an embodiment of the present invention, it was confirmed that a plurality of root canals were cleaned simultaneously at the same level as the root canal before being contaminated. Second, it was confirmed that steam bubbles were generated in the root canal and cleaning was performed by using the effect of steam bubbles when both the cleaning liquid B and the cooling water A were used as deaerated liquids. Finally, it was confirmed that although bubbles were intermittently generated and blocked the narrow and long root canal, the bubbles could be discharged from the root canal by the jet of the nozzle 7.

[0078] Finally, the ultrasonic sound pressure and the spray pressure conditions of the cleaning liquid in the cleaning device according to one embodiment of the present invention are described.

[0079] The inventor repeatedly implemented the result of the experiment for generating steam bubbles in the cleaning liquid as the degassed liquid, and grasped that the critical value of the ultrasonic sound pressure reached about 80kPa. In order to generate steam bubbles in the degassed liquid by generating the ultrasonic sound pressure exceeding the above critical value, the ultrasonic sound pressure generated by the inventor in the sound pressure generating device of the prototype of the cleaning device is 150kPa to 220kPa. On the other hand, the inventor sprayed the cleaning liquid B from the nozzle 7 installed in the cleaning device prototype according to the spray pressure of about 6bar to 12bar. When this spray pressure is adopted, the spray speed of the cleaning liquid B sprayed from the nozzle 7 is recorded as about 15m / s to 20m / s. The above-mentioned ultrasonic sound pressure, spray pressure and spray speed are exemplary and do not limit the structure of the cleaning device of the present invention. The above-mentioned numerical value can realize the ultrasonic sound pressure, spray pressure and spray speed in the scope of this degree roughly in the case of using the cleaning device of the present invention, and should be used for the reference purpose of being able to clean in this way.

[0080] The injection pressure of the liquid jet used in the U.S. patent of Sonendo Corporation described in the background technology section of this specification is at least 7000psi (about 483bar), and the injection speed is at least 50m / s. If these data are compared with the injection pressure and injection speed achieved in the cleaning device of the present invention for cleaning the root canal, compared with the prior art that uses high-speed and high-pressure liquid jets for cleaning the root canal, it is possible to inject the cleaning liquid at a low speed and low pressure and maximize the cleaning effect. Therefore, it is possible to provide a root canal cleaning device that reduces the production cost of the equipment and significantly improves the stability level. This representative efficiency of the present invention will be clearly understood.

[0081] The present invention has been described above through specific matters such as specific structural elements and limiting embodiments and drawings, but this is only used to help a more comprehensive understanding of the present invention. The present invention is not limited to the above-mentioned embodiments. As long as one is of ordinary skill in the technical field to which the present invention belongs, various modifications and variations can be implemented according to these descriptions.

[0082] Therefore, the concept of the present invention is not limited to the embodiments described above, and all contents modified in a manner equivalent to or equivalent to the scope of the appended claims for protection belong to the scope of the concept of the present invention.

Claims

1. A root canal cleaning device, characterized in that: include: A sound pressure generating device, which is operated by connecting to electric power; A handle housing, used to accommodate the sound pressure generating device; A cooling water channel is formed inside the handle housing; a cooling water injection port, connected to the cooling water channel formed in the handle housing; and A cleaning liquid nozzle is arranged on the handle housing. The ultrasonic sound pressure applied to the cooling water by the sound pressure generating device is transmitted to the cleaning liquid, and steam bubbles are generated in the cleaning liquid by the transmitted ultrasonic sound pressure. The steam bubbles and the cleaning liquid act together on the teeth to be treated to remove dirt inside the teeth including the root canal. The above cleaning liquid is a degassed liquid.

2. The root canal cleaning device according to claim 1, characterized in that: The cooling water is used to cool the sound pressure generating device. The above cooling water is a degassed liquid.

3. The root canal cleaning device according to claim 2, characterized in that: The above-mentioned sound pressure generating device comprises: a vibrator that vibrates by being supplied with electricity; and The vibration speaker is connected to the vibrator to vibrate and has a shape extending along a straight line.

4. The root canal cleaning device according to claim 3, characterized in that: The jet flow formed in the root canal by the cleaning liquid nozzle discharges bubbles blocking the root canal passage and / or pollutants separated from the root canal to the outside of the root canal.

5. The root canal cleaning device according to claim 4, characterized in that: The handle housing is formed in a shape with a bent end portion, and an acoustic reflector is provided at the bent portion, so that the ultrasonic wave applied to the cooling water by the vibration horn is reflected by the acoustic reflector.

6. The root canal cleaning device according to claim 5, characterized in that: The acoustic reflector is tilted at a specified angle based on the cross section of the vibration horn.

7. The root canal cleaning device according to claim 6, characterized in that: A bubble trapping space is formed on the upper surface of the handle housing. A plurality of bubbles gathered near the acoustic reflector rise by buoyancy and are trapped in the bubble trapping space.

8. The root canal cleaning device according to claim 7, characterized in that: The length of the cleaning liquid nozzle is set to enable the cleaning liquid to be sprayed toward the root canal cavity of the tooth during root canal cleaning.

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