Method for preventing sucking back of a dental handpiece by bypass injection of driving air and dental handpiece system having a bypass injection structure

Abstract

The present invention relates to a method for preventing suck-back in a dental handpiece and a dental handpiece system equipped with a bypass injection structure, which is intended to effectively prevent the suck-back phenomenon that occurs the moment a rotating impeller stops. The suck-back prevention method of the present invention is characterized in that, the moment the impeller stops rotating inside the head casing, the suck-back phenomenon is prevented by blocking the flow path of the air supply pipe and injecting air pumped from the air pump into the inside of the head casing through the air exhaust pipe while bypassing the air supply pipe.

Description

Technical Field

[0001] The present invention relates to a dental handpiece, and more particularly to a method for preventing backflow in a dental handpiece and a dental handpiece system having a bypass injection structure that can effectively block the backflow phenomenon that occurs at the moment when the rotating impeller stops.

Background Art

[0002] Generally, a dental handpiece used during medical procedures such as dentistry is a device that sprays pressured water or driving air to clean the necessary parts, and is configured in various shapes for each use, and is connected to an air tube or a cooling water tube via a connection hose.

[0003] However, in such a handpiece, even after the supply of driving air is stopped, the impeller maintains rotation due to inertia. At this time, since the supply of driving air is stopped, the driving air that rotates together with the impeller is sent to the air discharge hose. Therefore, part or all of the inside of the head becomes a vacuum state. As a result, foreign substances from the outside, such as burrs adhering to or existing around the tool, for example, the patient's saliva, blood, and cutting powder of teeth, may be sucked into and accumulated in the head through the gaps in the head. This causes a fatal problem of cross-infection with other patients.

[0004] FIG. 1 is a reference diagram for explaining a dental handpiece having a backflow prevention function according to the prior art.

[0005] As shown in the figure, a dental handpiece according to the prior art includes a head 11, an impeller 12 rotatably accommodated in a chamber 11a formed inside the head 11 and providing a rotational force to a tool such as a burr 13, an air supply port 61 for supplying driving air toward the impeller 12, an air discharge port 62 for discharging the driving air supplied to the impeller 12 to the outside, a cooling water supply port 63, and a cooling water injection port 64 for supplying air to inject the cooling water to the outside.

[0006] In the handpiece according to the prior art configured as described above, at the moment of operation stop when the driving air is supplied to the chamber 11a inside the head 11 and then interrupted, a part of the driving air supplied to the chamber 11a due to the rotational inertia of the impeller 12 is discharged through the air supply port 61 and the air discharge port 62. As a result, negative pressure or vacuum pressure is applied to the chamber 11a, and after the patient's saliva, blood, and cutting powder such as teeth are sucked into and accumulated in the head 11 through the gap of the head 11, cross-infection with other patients occurs.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the present invention is proposed to solve the above-mentioned various conventional problems, and the object of the present invention is to provide a method for preventing suck-back of a dental handpiece and a dental handpiece system equipped with a bypass injection structure that can effectively block the suck-back phenomenon occurring at the moment when the rotating impeller stops.

Means for Solving the Problems

[0008] In order to achieve the above object, as a method for preventing suck-back of a dental handpiece according to the technical idea of the present invention, at the moment when the impeller stops rotating inside the head casing, the air pumped from the air pump is bypassed in a state where the flow path of the air supply pipe is blocked and injected into the inside of the head casing through the air discharge pipe to prevent the suck-back phenomenon, which is a feature of its technical configuration.

[0009] Here, in order to bypass the air pumped from the air pump, an air supply pipe connected to supply the driving air pumped from the air pump to the inside of the head casing, and an air discharge pipe connected to the head casing to discharge the air supplied to the inside of the head casing to the outside are connected by a bypass pipe. When the impeller stops rotating and comes to a halt, the outlet-side flow path of the air discharge pipe may also be blocked together with the flow path of the air supply pipe, which is a feature.

[0010] On the other hand, a dental handpiece system for preventing the suck-back phenomenon by a suck-back prevention method of a dental handpiece includes an air supply pipe connected to the head casing to supply the driving air pumped from an air pump to the inside of the head casing in order to rotate an impeller provided inside the head casing of the handpiece, and an air discharge pipe connected to the head casing to discharge the air supplied to the inside of the head casing to the outside. The air supply pipe and the air discharge pipe are connected in a state of bypassing the head casing, and when the impeller stops rotating and comes to a halt, the air pumped from the air pump is guided to be injected into the inside of the head casing through the air discharge pipe after bypassing, and further includes a bypass pipe for guiding this, which is a technical configuration feature.

[0011] Here, a first solenoid valve is provided in the air supply pipe, a second solenoid valve is provided in the air discharge pipe, and a third solenoid valve is provided in the bypass pipe. The first solenoid valve is provided on the front side of the bypass pipe connection point in the air supply pipe, and the second solenoid valve is provided on the rear side of the bypass pipe connection point in the air discharge pipe. When the impeller stops rotating and comes to a halt, the first solenoid valve and the second solenoid valve are in a closed state to block the flow path, and the third solenoid valve is in an open state, and the air pumped from the air pump is guided to be injected into the inside of the head casing through the air discharge pipe after bypassing, which may be a feature.

[0012] Further, the nozzle for injecting the driving air supplied from the air pump in the head casing toward the blades of the impeller is divided into a first nozzle and a second nozzle independent of each other, and the first nozzle and the second nozzle are supplied with air from the air pump through independent flow paths, and the rotational force of the impeller may be increased by simultaneously injecting air to the adjacent blades respectively.

[0013] Further, the air supply pipe is composed of a first air supply pipe and a second air supply pipe that are respectively connected to the first nozzle and the second nozzle of the head casing and independently supply driving air from an air pump. The air discharge pipe is composed of a first air discharge pipe connected to a first discharge port mainly responsible for discharging the air injected into the inside of the head casing from the first nozzle, and a second air discharge pipe connected to a second discharge port mainly responsible for discharging the air injected into the inside of the head casing from the first nozzle separately from the first air discharge pipe. The bypass pipe includes a first bypass pipe that bypasses the head casing and connects the first air supply pipe and the first air discharge pipe, and guides the air pumped from the air pump to be injected into the inside of the head casing through the first air discharge pipe instead of the first air supply pipe at the moment when the impeller stops rotating; and a second bypass pipe that bypasses the head casing and connects the first air supply pipe and the second air discharge pipe, and guides the air pumped from the air pump to be injected into the inside of the head casing through the second air discharge pipe instead of the second air supply pipe at the moment when the impeller stops. A first solenoid valve is provided in the first air supply pipe, a second solenoid valve is provided in the first air discharge pipe, a third solenoid valve is provided in the first bypass pipe, a fourth solenoid valve is provided in the second air supply pipe, a fifth solenoid valve is provided in the second air discharge pipe, and a sixth solenoid valve is provided in the second bypass pipe. The first solenoid valve is provided on the front side of the connection point of the first bypass pipe in the first air supply pipe, the second solenoid valve is provided on the rear side of the connection point of the first bypass pipe in the first air discharge pipe, the fourth solenoid valve is provided on the front side of the connection point of the second bypass pipe in the second air supply pipe, and the fifth solenoid valve is provided on the rear side of the connection point of the second bypass pipe in the second air discharge pipe. At the moment when the impeller stops rotating, the first solenoid valve, the second solenoid valve, the fourth solenoid valve, and the fifth solenoid valve are in a closed state to block the flow path, and the third solenoid valve and the sixth solenoid valve are in an open state.It may be characterized in that the air pumped from the air pump is guided so as to be injected into the inside of the head casing through the first air discharge pipe and the second air discharge pipe, thereby preventing the suck-back phenomenon.

Advantages of the Invention

[0014] In the dental handpiece system according to the present invention, at the moment when the impeller stops rotating, the driving air of the air pump is bypassed using the bypass pipe so that air is injected from the discharge port side, thereby almost completely preventing the suck-back phenomenon, which has been a chronic problem until now.

[0015] Further, in the present invention, after the driving air is supplied through mutually independent flow paths, the rotational force of the impeller can be significantly improved by a dual structure including two nozzles that simultaneously inject air into a plurality of blades, thereby enabling miniaturization of the product.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0017] With reference to the accompanying drawings, a dental handpiece system according to an embodiment of the present invention will be described in detail. Since the present invention can be modified in various ways and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed forms, and it should be understood to include all modifications, equivalents, and alternatives included in the spirit and technical scope of the present invention. Similar reference numerals are used for similar components in the description of each drawing. In the accompanying drawings, the dimensions of the structures are shown enlarged from the actual size for the clarity of the present invention or reduced from the actual size for understanding the schematic configuration.

[0018] Also, terms such as first and second can be used to describe various components, but the above components should not be limited by the above terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the rights of the present invention, the first component can be named the second component, and similarly, the second component can also be named the first component. On the other hand, unless otherwise defined, all terms used in this specification, including technical or scientific terms, have the same meaning as generally understood by those having ordinary knowledge in the technical field to which the present invention belongs. Terms defined as in a generally used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted as an ideal or overly formal meaning unless clearly defined in the present application.

[0019] <Embodiment> FIG. 2 is an overall configuration diagram of a dental handpiece system according to an embodiment of the present invention, FIG. 3 is a rear perspective view of the handpiece in the dental handpiece system according to an embodiment of the present invention, and FIG. 4 is a perspective view of a partially cut-away state for explaining the configuration of the handpiece in the dental handpiece system according to an embodiment of the present invention.

[0020] As shown in the drawings, the dental handpiece system according to the embodiment of the present invention is configured such that, at the moment when the impeller 120 stops rotating, the driving air of the air pump 161 is bypassed using the bypass pipe 143 so that air is jetted from the discharge port side, thereby making it possible to almost completely prevent the sucking-back phenomenon, which has been a chronic problem heretofore.

[0021] For this purpose, the present invention includes an air supply pipe 141 connected to the head casing 110 so as to supply the driving air pumped from the air pump 161 to the inside of the head casing 110 in order to rotate the impeller 120 provided inside the head casing of the handpiece 100, and an air discharge pipe 142 connected to the head casing 110 for discharging the air supplied to the inside of the head casing 110 to the outside, and further includes a bypass pipe 143 that connects the air supply pipe 141 and the air discharge pipe 142 in a state of bypassing the head casing 110.

[0022] As a result, at the moment when the impeller 120 stops rotating and comes to a halt, after bypassing the driving air pumped from the air pump 161, it can be guided to be injected into the inside of the head casing 110 through the air discharge pipe 142. In this way, if air can be injected into the inside of the head casing 110 through the air discharge pipe 142 at the moment when the impeller 120 stops, a part of the driving air supplied to the chamber 110a of the head casing 110 due to the rotational inertia of the impeller 120 is discharged through the air supply port 111 and the air discharge port 112, so that it is possible to completely prevent the suck-back phenomenon in which a negative pressure or a vacuum pressure is applied to the chamber.

[0023] Here, a first solenoid valve 151 is provided in the air supply pipe 141, a second solenoid valve 152 is provided in the air discharge pipe 142, and a third solenoid valve 153 is provided in the bypass pipe 143, respectively. However, it is important that the first solenoid valve 151 is provided on the front side of the connection point of the bypass pipe 143 in the air supply pipe 141, and the second solenoid valve 152 is provided on the rear side of the connection point of the bypass pipe 143 in the air discharge pipe 142. As a result, at the moment when the impeller 120 stops rotating and comes to a halt, the first solenoid valve 151 and the second solenoid valve 152 are in a closed state to block the flow path, and the third solenoid valve 153 is in an open state, so that the air pumped from the air pump 161 can be bypassed through the bypass pipe 143 and then guided to be injected into the inside of the head casing 110 through the air discharge pipe 142.

[0024] Table 1 below summarizes the opening and closing states of the solenoid valves according to the driving state of the impeller 120 of the handpiece, and in particular, attention can be paid to the opening and closing states of the respective solenoid valves for preventing the suck-back phenomenon at the moment when the impeller 120 stops.

[0025]

Table 1

Embodiment

[0026] On the other hand, in the dental handpiece system according to the modified embodiment of the present invention, the handpiece has a dual structure with two nozzles that supply driving air through mutually independent flow paths and then inject it simultaneously into a plurality of blades, which can significantly improve the rotational force of the impeller, and thus the product can be configured to be miniaturized. This will be described below.

[0027] FIG. 5 is a rear perspective view of the handpiece in the dental handpiece system according to the modified embodiment of the present invention, FIG. 6 is a perspective view of the handpiece in a partially cut state for explaining the configuration of the handpiece in the dental handpiece system according to the modified embodiment of the present invention, and FIG. 7 is a plan view of the impeller inside the handpiece in the dental handpiece system according to the modified embodiment of the present invention.

[0028] As shown, in the dental handpiece in the modified embodiment of the present invention, the handpiece includes a head casing 110 having a chamber 110a therein, an impeller 120 rotatably provided inside the head casing 110 and having a plurality of blades 121 on its outer peripheral surface, and a vane 130 coupled to and rotating with the impeller 120. In the head casing 110, nozzles for injecting the driving air supplied from an air pump 161 toward the blades 121 of the impeller 120 are divided into a first nozzle 115a and a second nozzle 115b that are independent of each other, and air is supplied from the air pump 161 through independent flow paths, and is configured to inject air simultaneously to a plurality of adjacent blades 121.

[0029] The handpiece has a unique dual structure in which driving air is injected into two blades 121 by two nozzles different from each other, which can increase the rotational force on the impeller 120 of the same size, and thereby it becomes possible to realize a dental handpiece having a smaller size for the same output.

[0030] For this purpose, the head casing 110 includes a chamber 110a provided so that the impeller 120 can rotate. On the rear body portion of the head casing 110, as described above, nozzles for injecting the driving air supplied from the air pump 161 toward the blades 121 of the impeller 120 are divided into a first nozzle 115a and a second nozzle 115b that are independent of each other and have a dual structure. The first nozzle 115a and the second nozzle 115b are supplied with air from the air pump 161 through independent flow paths, and air is simultaneously injected into different blades 121 from each other to increase the rotational force of the impeller 120.

[0031] Here, the blades 121 of the impeller 120, which are the targets for the first nozzle 115a and the second nozzle 115b to inject driving air, are preferably adjacent to each other. Then, two propulsive forces generated by the air injected from the first nozzle 115a and the second nozzle 115b can be made to act in the same direction without being dispersed from each other, thereby enhancing efficiency. Accordingly, the angle between the first nozzle 115a and the second nozzle 115b is formed to match the angle between the air contact surfaces 121a of the blades 121 adjacent to each other in the impeller 120. Specifically considered, as shown in FIG. 6, the first nozzle 115a is formed forwardly on one of the left and right sides of the head casing 110 (the left side in the drawing), and the second nozzle 115b is formed in a diagonal direction extending from the other side of the head casing 110 to near the tip of the first nozzle 115a. However, for the sake of manufacturing convenience, the second nozzle 115b is formed in a form that linearly reaches near the tip of the first nozzle 115a through the other side surface of the head casing 110, and the through hole on the other side surface is filled with the cap 116.

[0032] In this way, if the first nozzle 115a and the second nozzle 115b, which are separately formed independently in the head casing 110, inject driving air, as shown in FIG. 7, two propulsive forces F1 and F2 act simultaneously on the air contacting the air contact surfaces 121a of two different blades 121, and the rotational force of the impeller 120 can be dramatically improved.

[0033] In the head casing 110, a first supply port 111a communicating with the first nozzle 115a and a second supply port 111b communicating with the second nozzle 115b are formed. The first supply port 111a is formed in a shape that extends linearly from the first nozzle 115a, and the second supply port 111b is formed in a shape that intersects the second nozzle 115b in an oblique direction. These first supply port 111a and second supply port 111b are independently connected to the air pump 161 by the first air supply pipe 141a and the second air supply pipe 141b, respectively. The important point in such a configuration is that the flow paths from the air pump 161 to the first nozzle 115a and the second nozzle 115b are independently divided and formed from the beginning to the end. If the two flow paths have a structure in which they are integrated into one at first and branched in the middle, the cross-sectional area of the flow path becomes narrow at the integrated point, frictional loss occurs, and a loss equivalent to the propulsive force on the impeller 120 is incurred.

[0034] On the other hand, as shown in FIG. 5, in the head casing 110, a first discharge port 112a mainly responsible for discharging the air injected into the head casing 110 from the first nozzle 115a is formed near the first nozzle 115a, and is formed with an inner diameter wider than that of the first nozzle 115a. Similarly, separately from the first nozzle 115a, a second discharge port 112b mainly responsible for discharging the air injected into the head casing 110 from the second nozzle 115b is formed near the second nozzle 115b, and is formed with an inner diameter wider than that of the second nozzle 115b. Thereby, the discharge of the air injected into the head casing 110 to the outside can be performed smoothly.

[0035] Also, as shown in FIG. 5, in the head casing 110, a cooling water supply port 113 for supplying cooling water into the head casing 110 and a cooling water air supply port 114 for supplying air used for injecting the cooling water are formed. These cooling water supply ports 113 are connected to the cooling water supply pipe 144, and the cooling water air supply ports 114 are connected to the cooling water air supply pipe 145.

[0036] Next, the experimental results obtained to confirm the performance of the dual nozzle type handpiece having the above configuration will be described below.

[0037] In this experiment, the rotational force (stopping torque value (gf·cm)) of the impeller 120 was compared by comparing the dual nozzle type handpiece according to the present invention with the conventional product of the applicant having only one nozzle, the product of Kavo in Germany, and the product of NSK in Japan, respectively. As a result of the experiment, as confirmed from Table 2 below, in the normal use pressure range of 0.35 to 0.40 Mpa, it was confirmed that there was an improvement of 33 to 40% compared to the conventional product of the applicant, 10 to 30% compared to the product of Kavo (Germany), and 10 to 27% compared to the product of NSK (Japan).

[0038]

Table 2

[0039] As shown in the figure, the dental handpiece system according to the modified embodiment of the present invention is connected to the first nozzle 115a by using the dual nozzle type handpiece, and includes a first air supply pipe 141a for supplying driving air from the air pump 161, a second air supply pipe 141b that is connected to the second nozzle 115b separately from the first air supply pipe 141a and supplies driving air from the air pump 161, a first air discharge pipe 142a that is connected to the first discharge port 112a and discharges the air inside the head casing 110 to the outside, and a second air discharge pipe 142b that is connected to the second discharge port 112b and discharges the air inside the head casing 110 to the outside.

[0040] In addition to this, a first bypass pipe 143a is further provided for connecting the first air supply pipe 141a and the first air discharge pipe 142a in a state where the head casing 110 is bypassed. The first bypass pipe 143a serves to guide the air pumped from the air pump 161 to be injected into the head casing 110 through the first air discharge pipe 142a instead of the first air supply pipe 141a at the moment when the impeller 120 stops rotating and halts. Also, a second bypass pipe 143b is further provided for connecting the first air supply pipe 141a and the second air discharge pipe 142b in a state where the head casing 110 is bypassed. The second bypass pipe 143b serves to guide the air pumped from the air pump 161 to be injected into the head casing 110 through the second air discharge pipe 142b instead of the second air supply pipe 141b at the moment when the impeller 120 stops.

[0041] On the other hand, a first solenoid valve 151a is provided in the first air supply pipe 141a, a second solenoid valve 152a is provided in the first air discharge pipe 142a, a third solenoid valve 153a is provided in the first bypass pipe 143a, a fourth solenoid valve 151b is provided in the second air supply pipe 141b, a fifth solenoid valve 152b is provided in the second air discharge pipe 142b, and a sixth solenoid valve 153b is provided in the second bypass pipe 143b, respectively.

[0042] Here, the points to be noted are that the first solenoid valve 151a is provided on the front side of the connection point of the first bypass pipe 143a in the first air supply pipe 141a, the second solenoid valve 152a is provided on the rear side of the connection point of the first bypass pipe 143a in the first air discharge pipe 142a, the fourth solenoid valve 151b is provided on the front side of the connection point of the second bypass pipe 143b in the second air supply pipe 141b, and the fifth solenoid valve 152b is provided on the rear side of the connection point of the second bypass pipe 143b in the second air discharge pipe 142b.

[0043] ​With such a configuration, at the moment when the impeller 120 stops rotating, the first solenoid valve 151a, the second solenoid valve 152a, the fourth solenoid valve 151b, and the fifth solenoid valve 152b are in a closed state to block the flow path, and the third solenoid valve 153a and the sixth solenoid valve 153b are in an open state. By guiding the air pumped from the air pump 161 to be injected into the inside of the head casing 110 through the first air discharge pipe 142a and the second air discharge pipe 142b, the sucking-back phenomenon, which has been a chronic problem, can be clearly prevented.

[0044] The opening and closing states of the solenoid valves according to the driving state of the impeller 120 of the handpiece are summarized as follows. In particular, attention can be paid to the opening and closing states of the solenoid valves for preventing the sucking-back phenomenon at the moment when the impeller 120 stops.

[0045]

Table 3

[0046] Although the preferred embodiments of the present invention have been described above, the present invention can use various changes, modifications, and equivalents. It is obvious that the present invention can be similarly applied by appropriately modifying the above embodiments. Therefore, the above description does not limit the scope of the present invention defined by the limits of the following claims.

Explanation of Reference Numerals

[0047] 110: Head casing 110a: Chamber 111a: First supply port 111b: Second supply port 112a: First row outlet 112b: Second row outlet 113: Cooling water supply port 114: Air supply port for cooling water 115a: First nozzle 115b: Second nozzle 120: Impeller 121: Blade 130: Burr 141: Air supply pipe 142: Air discharge pipe 143: Bypass pipe 151: First solenoid valve 152: Second solenoid valve 153: Third solenoid valve

Claims

【Claim 1】 A method for preventing backflow in a dental handpiece, in which an air supply pipe for supplying driving air pumped from an air pump and an air discharge pipe for discharging air to the outside are respectively connected to a head casing. When the impeller stops rotating inside the head casing of the dental handpiece, the flow path of the air supply pipe is blocked so that air is not supplied into the head casing, and the air pumped from the air pump is bypassed and injected into the head casing through the air discharge pipe to prevent the backflow phenomenon. Or, a method for preventing backflow in a dental handpiece, in which a bypass pipe is provided and used to connect an air supply pipe connected to the head casing to supply driving air pumped from the air pump into the head casing and an air discharge pipe connected to the head casing to discharge the air supplied into the head casing to the outside for bypassing the air pumped from the air pump. When the impeller stops rotating, the outlet-side flow path of the air discharge pipe is blocked together with the flow path of the air supply pipe. A dental handpiece system for preventing the backflow phenomenon by the method for preventing backflow in a dental handpiece, An air supply pipe connected to the head casing to supply driving air pumped from an air pump into the head casing to rotate an impeller provided inside the head casing of the handpiece, and an air discharge pipe connected to the head casing to discharge the air supplied into the head casing to the outside are provided, In a state where the head casing is bypassed, the air supply pipe and the air discharge pipe are connected, and when the impeller stops rotating, a bypass pipe is further provided to guide the air pumped from the air pump to be injected into the head casing through the air discharge pipe after bypassing, In the head casing, the nozzles that inject the driving air supplied from the air pump toward the blades of the impeller are divided into a first nozzle and a second nozzle that are independent of each other. The first nozzle and the second nozzle are supplied with air from the air pump through independent flow paths, and by simultaneously injecting air to the adjacent blades respectively, the rotational force of the impeller is increased. The air supply pipe is connected to the first nozzle and the second nozzle of the head casing respectively, and is composed of a first air supply pipe and a second air supply pipe that independently supply the driving air from the air pump. The air discharge pipe is composed of a first air discharge pipe connected to a first discharge port mainly responsible for discharging the air injected into the head casing from the first nozzle, and a second air discharge pipe connected to a second discharge port mainly responsible for discharging the air injected into the head casing from the first nozzle, separately from the first air discharge pipe. The bypass pipe includes a first bypass pipe that connects the first air supply pipe and the first air discharge pipe in a state of bypassing the head casing, and guides the air pumped from the air pump to be injected into the head casing through the first air discharge pipe instead of the first air supply pipe at the moment when the impeller stops rotating; and a second bypass pipe that connects the first air supply pipe and the second air discharge pipe in a state of bypassing the head casing, and guides the air pumped from the air pump to be injected into the head casing through the second air discharge pipe instead of the second air supply pipe at the moment when the impeller stops. A first solenoid valve is provided in the first air supply pipe, a second solenoid valve is provided in the first air discharge pipe, a third solenoid valve is provided in the first bypass pipe, a fourth solenoid valve is provided in the second air supply pipe, a fifth solenoid valve is provided in the second air discharge pipe, and a sixth solenoid valve is provided in the second bypass pipe. The first solenoid valve is provided on the front side of the connection point of the first bypass pipe in the first air supply pipe. The second solenoid valve is provided on the rear side of the connection point of the first bypass pipe in the first air discharge pipe. The fourth solenoid valve is provided on the front side of the connection point of the second bypass pipe in the second air supply pipe. The fifth solenoid valve is provided on the rear side of the connection point of the second bypass pipe in the second air discharge pipe. When the impeller stops rotating, the first solenoid valve, the second solenoid valve, the fourth solenoid valve, and the fifth solenoid valve are in a closed state to block the flow path, the third solenoid valve and the sixth solenoid valve are in an open state, and the air pumped from the air pump is guided to be injected into the inside of the head casing through the first air discharge pipe and the second air discharge pipe, thereby preventing the backflow phenomenon. A dental handpiece system characterized by this.

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