JP7492795B2 - Dental water purification equipment - Google Patents

Description

The present invention relates to a dental water modification device, and more particularly to a device for mixing fine air bubbles into water supplied to dental equipment.

In recent years, it has been reported that by incorporating fine air bubbles into water, the water containing the bubbles exhibits properties and behaviors that are different from those of water alone. For example, water containing air bubbles is used in the fields of cleaning various items and maintaining the freshness of food. In particular, water containing air bubbles with diameters of less than 1 μm, known as ultra-fine bubbles, is known to have a high cleaning effect. Devices for generating water containing ultra-fine bubbles have been proposed (for example, Patent Documents 1, 2, 3, etc.).

However, conventional devices for generating water containing ultra-fine bubbles are often large-scale equipment that generates a large amount of water per unit time, as they are intended for cleaning applications. In addition, because ultra-fine bubbles are mixed into water using high pressure, the equipment itself, including piping, pumps, and bubble mixing parts, is large and heavy due to pressure resistance considerations.

Considering dental treatment, hopes are high for water containing ultra-fine bubbles to be used in the oral cavity. However, for dental treatment, the amount used per session is limited, and there is little need for large equipment. Also, it is desirable for the equipment to be smaller and lighter so that it can be easily connected to existing dental equipment installed in dental clinics.

JP 2020-099862 A JP 2017-094300 A JP 2008-289769 A

The present invention has been developed in consideration of the above points, and provides a small, lightweight dental water modification device that produces water containing ultra-fine bubbles, particularly with consideration for installation in dental clinics.

That is, the dental water reforming device of the embodiment includes a water supply unit, a dental treatment unit, and a water reforming unit installed between the water supply unit and the dental treatment unit, and the water reforming unit includes a water inlet unit connected to the piping unit of the water supply unit, an orifice unit that reduces the pressure of the water supplied from the water inlet unit, an orifice side expansion unit connected to the orifice unit and expanding the flow path cross-sectional area, a first gas supply unit connected to the orifice side expansion unit and supplying gas to the water flowing into the orifice side expansion unit, a diameter expansion unit connected downstream of the orifice side expansion unit and expanding the flow path cross-sectional area, and a diameter reduction unit that reduces the flow path cross-sectional area of the diameter expansion unit, and a bubble mixing unit that mixes the water flowing in from the orifice side expansion unit with the gas supplied from the first gas supply unit to mix bubbles, and the water that has passed through the bubble mixing unit is supplied to the dental treatment unit.

Furthermore, in the bubble mixing section, multiple diameter enlargement sections and diameter reduction sections may be arranged in series and alternately along the water flow path.

Furthermore, a piping section may be provided that connects the air bubble mixing section and the water inlet section and allows the water discharged from the air bubble mixing section to flow into the water inlet section.

Furthermore, a tank section for storing water discharged from the bubble mixing section may be installed in the piping section.

Furthermore, a pressure pump may be provided in the piping section upstream of the water inlet.

Furthermore, the first gas supply unit may store air as the gas, and supply the air from the first gas supply unit to the tank unit.

Furthermore, a second gas supply unit may be provided that stores nitrogen, oxygen, or carbon dioxide as gas, and the gas stored in the second gas supply unit may be supplied from the second gas supply unit to the tank unit.

According to the dental water reforming device of the present invention, the device comprises a water supply unit, a dental treatment unit, and a water reforming unit installed between the water supply unit and the dental treatment unit. The water reforming unit comprises a water inlet unit connected to the piping unit of the water supply unit, an orifice unit that reduces the pressure of the water supplied from the water inlet unit, an orifice side expansion unit connected to the orifice unit and expanding the flow path cross-sectional area, a first gas supply unit connected to the orifice side expansion unit and supplying gas to the water flowing into the orifice side expansion unit, a diameter expansion unit connected downstream of the orifice side expansion unit and expanding the flow path cross-sectional area, and a diameter reduction unit that reduces the flow path cross-sectional area of the diameter expansion unit. The device also comprises an air bubble mixing unit that mixes the water flowing in from the orifice side expansion unit with the gas supplied from the first gas supply unit to mix bubbles. The water that has passed through the air bubble mixing unit is supplied to the dental treatment unit, so that the dental water reforming device can be completed as a small and lightweight dental water reforming device that generates water containing ultra-fine bubbles, taking into consideration installation in a dental clinic.

1 is a schematic diagram of a dental water reforming device according to an embodiment. FIG. FIG. 2 is a schematic diagram of a water reforming section in the dental water reforming device. FIG. 4 is an enlarged schematic cross-sectional view of a gas mixing portion. FIG. 4 is an enlarged schematic cross-sectional view of a bubble mixing section. Photographs of cleaning test results for model soil samples. 1 is a graph showing statistically the cleaning test results.

The dental water reforming device of the embodiment is mainly connected to a dental treatment tool that uses dental water in a dental clinic. The dental water reforming device reforms the water supplied to the treatment tool into water containing ultra-fine bubbles. In general, ultra-fine bubbles are fine bubbles with a diameter of less than 0.001 mm. In the case of water containing ultra-fine bubbles, shock waves called cavitation are generated when the bubbles present in the water burst. This improves the cleaning efficiency of teeth and gums compared to cleaning with water alone. In addition, the cell membrane of the caries bacteria (Streptococcus mutans) is destroyed by cavitation, which is also effective in suppressing tooth decay (dental caries).

In particular, bubbles the size of nanobubbles and ultrafine bubbles remain in the water as bubbles and hardly evaporate from the water surface. Therefore, the dental water modification device of the embodiment is proposed as equipment for generating and supplying water containing ultrafine bubbles for dental use.

Figure 1 is a schematic diagram of a dental water reformer 1 according to an embodiment. The dental water reformer 1 is connected downstream of a water supply unit 2. A tank of clean water such as tap water or sterilized purified water is connected to the water supply unit 2. If necessary, a filter for filtration sterilization or the like may be installed in the water supply unit 2.

The dental water reformer 1 is connected downstream of the water supply unit 2, and the dental treatment unit 3 is connected downstream of the dental water reformer 1. The dental treatment unit 3 is equipped with treatment tools 4 such as a treatment drill and a running water sprayer.

In addition, because this is dental equipment, in addition to the equipment shown in the figure, various other devices such as chairs for patients to sit on, a sink for gargling, and a shadowless lamp are also provided (none of which are shown).

The dental water reforming device 1 is equipped with a water reforming section 10 for generating water containing ultra-fine bubbles. Figure 2 is a schematic diagram of the water reforming section 10. The water reforming section 10 is equipped with a gas mixing section 20 having a water inlet section 21, an orifice section 22, an orifice side expansion section 23, a first gas supply section 25, and a second gas supply section 26, and a bubble mixing section 30 having a diameter expansion section 31 and a diameter reduction section 32. In Figure 2, the connection portion between the water inlet section 21 of the water reforming section 10 and the water supply section 2 (see Figure 1) is omitted from the illustration.

At least one of the first gas supply unit 25 and the second gas supply unit 26 may be installed. The types of gas supplied from the first gas supply unit 25 and the second gas supply unit 26 will be described later.

The dental water modification device 1 is connected to the piping section downstream of the water supply section 2 (see Figure 1), and water supplied from the water supply section 2 is supplied to the water inlet section 21. An orifice section 22 is connected to the water inlet section 21. The orifice section 22 functions as a pressure loss section, reducing the pressure of the water supplied from the water inlet section 21 and increasing the flow rate. The shape of the orifice section 22 may be a tapered pipe configuration in which the cross-sectional diameter gradually decreases as shown, or the structure of the orifice section 22 may be a plate-like member with holes (not shown).

The orifice side expansion section 23 is connected to the downstream side of the orifice section 22. The gas supply pipe 24 is connected to the orifice side expansion section 23, and gas is supplied to the gas supply pipe 24 from either the first gas supply section 25 or the second gas supply section 26, or from both the first gas supply section 25 and the second gas supply section 26. The gas supplied from the first gas supply section 25 is air. The gas stored in the second gas supply section 26 and supplied from the second gas supply section 26 is other than air, and is either nitrogen, oxygen, or carbon dioxide. A mixed gas such as nitrous oxide is also used. In addition, a fine mesh, porous body, etc. is provided at the connection portion between the gas supply pipe 24 and the orifice side expansion section 23, and the gas that passes through the gas supply pipe 24 becomes bubbly in the orifice side expansion section 23.

Figure 3 is an enlarged schematic cross-sectional view of the gas mixing section 20. Water that has passed through the orifice section 22 from the water inlet section 21 flows into the orifice side expansion section 23 with an increased flow rate. As the water passes through the orifice section 22, pressure loss occurs, and the water pressure decreases. In addition, when the water flows into the orifice side expansion section 23 and spreads inside, pressure loss of the water itself occurs. In other words, the water pressure is lower in the orifice side expansion section 23 than in the water inlet section 21. Therefore, the gas supplied from the first gas supply section 25 is more likely to flow into the orifice side expansion section 23 through the gas supply pipe 24. As a result, water and gas bubbles B1 are more likely to mix in the orifice side expansion section 23. The arrows in the figure indicate the flow of water.

As shown in FIG. 2, after the water and the air bubbles B1 are mixed in the orifice side expansion section 23, the water mixed with the air bubbles B1 (hereinafter referred to as "air bubble mixed water") is pumped to the air bubble mixing section 30 downstream of the orifice side expansion section 23. The air bubble mixing section 30 has a diameter enlarged section 31 and a diameter reduced section 32. The diameter enlarged section 31 is connected to the downstream side of the orifice side expansion section 23 and expands the flow path cross-sectional area of the pipe downstream of the orifice side expansion section 23. The diameter enlarged section 31 is provided with a diameter reduced section 32 that reduces the flow path cross-sectional area of the diameter enlarged section 31. In the embodiment, the diameter enlarged section 31 and the diameter reduced section 32 of the air bubble mixing section 30 are arranged in series along the water flow path in multiple pieces (three in the figure).

Because air is supplied from the first gas supply unit 25, the bubbles B1 are air bubbles. Also, because either nitrogen, oxygen or carbon dioxide gas is supplied from the second gas supply unit 26, the bubbles B1 are nitrogen, oxygen or carbon dioxide gas bubbles. Note that when both the first gas supply unit 25 and the second gas supply unit 26 are installed, the bubbles B1 are not only air bubbles but also nitrogen, oxygen or carbon dioxide gas bubbles. The type of gas in the bubbles B2 and B3 described below is the same as that in the bubbles B1.

Figure 4 is an enlarged schematic cross-sectional view of the air bubble mixing section 30. Three combinations of enlarged diameter sections 31 and reduced diameter sections 32 are arranged in series and alternately. Air bubble mixed water (containing air bubbles B1) flows into the enlarged diameter section 31 located most upstream (closest to the orifice side enlarged section 23), and is compressed as it passes through the reduced diameter section 32, at the same time the air bubbles B1 are compressed. Then, when the air bubble mixed water flows into the middle enlarged diameter section 31 of the three in series, the bubble diameter shrinks to air bubbles B2, which are finer than the air bubbles B1.

Furthermore, the air bubble mixed water (containing air bubbles B2) flows from the intermediate diameter expansion section 31 into the most downstream diameter expansion section 31, and as the air bubble mixed water passes through the diameter reduction section 32, the air bubble mixed water is compressed, and at the same time, air bubbles B3 are also compressed. Thus, in the most downstream diameter expansion section 31, the air bubble diameter shrinks to air bubbles B3 that are finer than air bubbles B2. Each time the air bubble mixed water passes through the flow path that combines the diameter expansion section 31 and the diameter reduction section 32, the air bubbles contained in the air bubble mixed water gradually become smaller, resulting in the generation of ultra-fine bubbles with diameters of less than 1 μm.

The number of combinations of the diameter enlargement section 31 and the diameter reduction section 32 in the bubble mixing section 30 is not limited to three as in the illustrated embodiment, and it is also possible to reduce or increase the number. However, if the number of combinations of the diameter enlargement section 31 and the diameter reduction section 32 is increased, the configuration of the pipeline becomes complex and large, and the number of parts also increases. In addition, the influence of pressure loss increases each time the bubble-mixed water passes through the diameter reduction section 32. Therefore, the fluid pressure for pumping the bubble-mixed water must be set high. This tends to result in excessive equipment design such as increasing the pressure resistance of the piping and the output of the pumping pump 50 in FIG. 2, and an increase in the weight of the device. Therefore, the number of combinations of the diameter enlargement section 31 and the diameter reduction section 32 in the bubble mixing section 30 is two to four, preferably three as illustrated. As another embodiment, it is also possible to reduce the flow path cross-sectional area of the diameter reduction section 32 toward the downstream side.

As can be seen from FIG. 2, the dental water reforming device 1 of the embodiment is provided with a piping section 40. The piping section 40 connects the air bubble mixing section 30 and the water inlet section 21 of the gas mixing section 20, and allows the water (air bubble mixed water) discharged from the air bubble mixing section 30 to flow into the water inlet section 21. In the dental water reforming device 1 of the embodiment, the water (air bubble mixed water) discharged from the air bubble mixing section 30 flows again into the gas mixing section 20 and the air bubble mixing section 30, and the water is circulated. When circulating the water, a pressure pump 50 is provided in the piping section 40 upstream of the water inlet section 21, and the water is pressure-fed. When circulating the water, the supply of water from the water supply section 2 to the water inlet section 21 of the gas mixing section 20 is stopped. The supply and stop of water from the water supply section 2 is performed by an appropriate switching valve (solenoid valve) or the like (not shown).

A single pass through the air bubble mixing section 30 is not sufficient to reduce the diameter of the air bubbles contained in the air bubble mixed water in the air bubble mixing section 30 and to generate ultra-fine bubbles. As mentioned above, even if the number of combinations of the diameter enlargement section 31 and diameter reduction section 32 in the air bubble mixing section 30 is increased, the supply pressure of the air bubble mixed water needs to be increased, so the size of the pressure pump 50 cannot be avoided. Therefore, the installation of the piping section 40 is preferable as a simple method of increasing the number of times the air passes through the diameter enlargement section 31 and diameter reduction section 32 in the air bubble mixing section 30.

A tank section 45 is installed midway through the piping section 40. By installing the tank section 45, it is possible to adapt to changes in the amount of water used by the dental treatment section 3, which is connected downstream of the dental water modification device 1. It is possible to store water in which an appropriate amount of ultra-fine bubbles have been generated. As shown in Figure 2, the water in which ultra-fine bubbles have been generated is supplied from the tank section 45 to the dental treatment section 3. The water inlet section 21 of the gas mixing section 20 is connected to the water supply section 2 by a pipeline (not shown).

Furthermore, in the dental water reformer 1 of the embodiment, the gas supplied from either the first gas supply unit 25 or the second gas supply unit 26, or from both the first gas supply unit 25 and the second gas supply unit 26, is also supplied to the tank unit 45. When gas is supplied to the orifice side expansion unit 23 of the gas mixing unit 20, gas bubbles such as air are unlikely to mix with the water. Therefore, by supplying gas in advance to the water being circulated (before heading to the orifice side expansion unit 23) stored in the tank unit 45, in addition to supplying gas to the orifice side expansion unit 23, the amount of bubbles that are the source of ultra-fine bubbles can be increased.

Water containing ultra-fine bubbles generated by the dental water modification device described above is supplied to a dental treatment unit and sprayed into the patient's (recipient's) mouth from a treatment tool such as a dental drill connected to the dental treatment unit. Since there is no difference in substance between water containing ultra-fine bubbles and regular water, it can be used in the same way as conventional water. Furthermore, since there is no need to change the specifications of the dental treatment unit for water containing ultra-fine bubbles, it is sufficient to simply connect it to an existing dental treatment unit. For this reason, it can be said that the barriers to introducing a dental water modification device are low.

Water containing ultra-fine bubbles of nitrogen, oxygen, or carbon dioxide gas through the second gas supply unit 26 is expected to have the following effects compared to water containing ultra-fine bubbles of air. Water containing ultra-fine bubbles of nitrogen has a relatively low amount of oxygen in the water. This makes it possible to form an anaerobic atmosphere for aerobic fungi. Water containing ultra-fine bubbles of oxygen has increased oxidizing power caused by oxygen, improving antibacterial properties due to damage to bacterial cell membranes. Furthermore, water containing ultra-fine bubbles of carbon dioxide gas is more acidic than carbonated water, improving antibacterial properties due to damage to bacterial cell membranes caused by acid.

[the purpose]
It is believed that by adding ultrafine bubbles to water, the ultrafine bubbles present in the water can easily penetrate into tiny gaps between teeth and reach stains. Furthermore, because ultrafine bubbles promote underwater cavitation when irradiated with ultrasound, they are also believed to promote the detachment and removal of stains adhering to the tooth surface. Therefore, the combined use of an ultrasonic scaler in dentistry and water containing ultrafine bubbles is expected to result in advanced removal of stains on the tooth surface.

Therefore, the inventors have verified the effectiveness of water containing ultrafine bubbles in removing stains and biofilms that are difficult to remove by normal dental cleaning. Specifically, a comparative test was conducted on the cleaning and removal effect of pigments applied to a smooth surface by preparing water containing low concentration of ultrafine bubbles (ultrafine bubble number concentration: 39 million/mL, hereinafter referred to as "UFB water L") and water containing high concentration of ultrafine bubbles (ultrafine bubble number concentration: 230 million/mL, hereinafter referred to as "UFB water H"). The concentration of ultrafine bubbles was measured using a laser diffraction/scattering method. UFB water L is general water, and refers to the control of UFB water H.

Materials and Methods
An A4 size OHP film (VF-1100N, manufactured by Kokuyo Co., Ltd.) was prepared, and 100 circles (diameter 9.98 mm) were printed on the OHP film with pink ink (color code R: 255, G: 0, B: 255) using an inkjet printer (TS3330, manufactured by Canon Inc.). After printing, the film was left to stand for 6 hours to dry naturally, and then reprinted with the same ink in the same position to prepare a model stain sample.

A straw measuring 30 mm in length and 5 mm in diameter was connected to the tip of a dental cleaning Airflow Prophylaxis Master (S1 Airflow, manufactured by EMS Japan Co., Ltd.), and cleaning was performed by spraying UFB water L or UFB water H onto the model stain sample for 3 seconds while fixing the distance and angle from the model stain. The color difference ΔE and brightness difference ΔL of the model stain before and after cleaning were measured using a handheld colorimeter (NR-11A, manufactured by Nippon Denshoku Industries Co., Ltd.). Statistical analysis was then performed using Tukey's test.

[Results and Discussion]
The cleaning results for 100 ink-printed circles in the model soil sample were ranked in ascending order of ΔE values for UFB water L and UFB water H, and four samples of each rank were selected. Figure 5 shows photographs of the cleaning results. The upper photograph shows the cleaning results when UFB water H was used, and the lower photograph shows the cleaning results when UFB water L was used. It was observed that the ink was removed and turned white within the circle where the UFB water of 5 mm in diameter collided within the ink-applied circle. A comparison of UFB water L and UFB water H revealed that UFB water H was whiter than UFB water L, and cleaning was promoted more.

Figure 6 is a graph showing the statistical results of the cleaning test. The horizontal axis of the graph is the color difference (ΔE), and the vertical axis is the statistical frequency. The ΔE of the surface to be cleaned before and after cleaning improved as the ultra-fine bubble number concentration increased. A t-test was performed using SPSS (Statistical Package for the Social Science), and a statistically significant difference was shown (p<0.001). ΔE>20 indicates that cleaning is complete because there is no difference between cleaning with UFB water L and UFB water H, and the closer ΔE is to 0 from 20, the more residual dirt there is in the sample. There was a lot of residual dirt in UFB water L, and less residual dirt in UFB water H. This statistically clarified that ultra-fine bubbles contribute to the removal of dirt.

Therefore, it is believed that using water containing a high concentration of ultra-fine bubbles for oral cleaning in clinical dentistry can provide a more effective way of removing plaque and other substances that have adhered to the teeth. Furthermore, it is believed that using a gas other than air can add to the effects caused by the gas.

The dental water modification device of the present invention produces water containing ultra-fine bubbles using a small and simple device configuration. This makes it easier to introduce equipment for use in patients' oral cavities into existing dental treatment facilities.

REFERENCE SIGNS LIST 1 Dental water reforming device 2 Water supply section 3 Dental treatment section 4 Treatment tool 10 Water reforming section 20 Gas mixing section 21 Water inlet section 22 Orifice section 23 Orifice side expansion section 24 Gas supply piping 25 First gas supply section 26 Second gas supply section 30 Air bubble mixing section 31 Diameter expansion section 32 Diameter reduction section 40 Piping section 45 Tank section 50 Pressure pump B1, B2, B3 Air bubbles

Claims (3)

A dental water reforming device comprising a water supply unit, a dental treatment unit, and a water reforming unit installed between the water supply unit and the dental treatment unit,
The water reforming unit includes:
A water inlet portion connected to a piping portion of the water supply portion;
an orifice portion for reducing the pressure of the water supplied from the water inlet portion;
an orifice side expansion portion connected to the orifice portion and expanding a cross-sectional area of a flow path;
a first gas supply unit connected to the orifice side expansion unit and configured to supply air as a gas to the water flowing into the orifice side expansion unit;
a second gas supply unit connected to the orifice side expansion section and configured to supply nitrogen, oxygen, or carbon dioxide gas as a gas to the water flowing into the orifice side expansion section;
a bubble mixing section that includes a diameter enlarged section connected downstream of the orifice side enlarged section and enlarging a flow path cross-sectional area, and a diameter reduced section that reduces the flow path cross-sectional area of the diameter enlarged section, and mixes water flowing in from the orifice side enlarged section with gas supplied from the first gas supply section and the second gas supply section to mix bubbles;
A piping section that connects the air bubble mixing section and the water inlet section and allows the water discharged from the air bubble mixing section to flow into the water inlet section;
A tank section that is installed in the piping section and stores the water discharged from the air bubble mixing section and supplies it to the dental treatment section,
The water that has passed through the air bubble mixing section is supplied from the tank section to the dental treatment section ,
The gas supplied from either the first gas supply unit or the second gas supply unit, or from both the first gas supply unit and the second gas supply unit, is supplied to the tank unit.
A dental water modification device characterized by: The dental water reforming device according to claim 1, wherein the bubble mixing section has a plurality of the enlarged diameter sections and the reduced diameter sections arranged in series and alternately along the water flow path. 2. The dental water modifying device according to claim 1, wherein a pressure pump is provided in the piping section upstream of the water inlet section.

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