Dental handpiece

Abstract

The present invention relates to a dental handpiece including a handle and a housing having a first light emitting diode and a first optical sensor. According to the present invention, the housing includes a second light emitting diode, a second optical sensor, and a shielding window for each optical sensor. The dental handpiece includes means for supplying compressed air to each shielding window. The housing includes an opening for supplying compressed air to each shielding window. A diffuser is disposed at each opening, and the diffuser is adapted to generate an air jet that forms an air curtain. The technical problem is to provide reliable protection of the optical sensor by the implementation of the air curtain during treatment in the oral cavity by the dental handpiece and to obtain a high-quality three-dimensional image of the oral cavity.

Description

Detailed Description of the Invention

[0001] The present invention relates to dental equipment. More specifically, the present invention relates to a dental handpiece including a handle and a housing having a light emission source represented by at least one light emitting diode connected to a power source. The handpiece has an optical sensor adapted to be connected to a visualization device. The handpiece can be used by a dentist for dental procedures.

[0002] As a known example of the prior art, there is a dental handpiece including a handle and a housing having a light emission source represented by at least one light emitting diode connected to a power source, wherein the housing includes an optical sensor adapted to be connected to a visualization device. See the specification of Utility Model RU114603U1.

[0003] This device is the closest prior art to the claimed invention and is regarded as a prototype. Therefore, the claimed invention will be described from the perspective of the differences from this prototype.

[0004] One drawback of this device is that although it has a video camera (optical sensor) that can project an image of the oral cavity onto an external screen, it cannot guarantee that small pieces from the oral cavity will not adhere to its surface during dental procedures. In fact, specific tools such as drills can generate solid pieces that scatter at high speed. These solid pieces can cross the surrounding air and adhere to the video camera.

[0005] Another major drawback of this prototype is that a high-quality three-dimensional image of the oral cavity cannot be obtained while the dental handpiece is operating inside the oral cavity.

[0006] The main object of the present invention is to provide a dental handpiece including a handle and a housing having a light emission source represented by at least one first light emitting diode connected to a power source, the dental handpiece having a first optical sensor adapted to be connected to a visualization device, and capable of ensuring a high-quality and stable three-dimensional image (this is one of the claimed technical problems).

[0007] For this purpose, · The housing has a second light emitting diode connected to a power source, and the housing has a second optical sensor adapted to be connected to a visualization device, · The housing has a first transparent shielding window of the first optical sensor and a second transparent shielding window of the second optical sensor, · The handpiece has means for supplying compressed air to the first transparent shielding window and the second transparent shielding window, · The housing has a first opening for supplying compressed air to the first transparent shielding window and a second opening for supplying compressed air to the second transparent shielding window, and both openings are connected to a device for supplying compressed air, · A diffuser is disposed at each opening, and the diffuser is designed to generate an air jet that forms an air curtain in front of the shielding window.

[0008] In addition to simply blowing the transparent shielding window of the optical sensor to protect it from fogging, these useful configurations protect the shielding window from contamination by solid chips and droplets generated during the pretreatment of the patient's biological tissue, that is, to protect the shielding window so that chips do not adhere to the external optical components. In other words, it is possible to generate a strong air curtain to ensure reliable protection of the optical sensor by the implementation of the air curtain. Also, since the second optical sensor is reliably protected so that chips do not adhere to the external optical components, it is possible to generate a three-dimensional image of the oral cavity.

[0009] Furthermore, a virtual 3D model can be generated using the pre-rendered CT images. The virtual 3D model can be combined with the CT images using an optical sensor. As a result, the hidden cavities of the dental caries can be seen and how the cutting end is positioned with respect to these cavities can be understood.

[0010] An optional embodiment of the present invention is also contemplated where the housing has a third light emitting diode connected to a power source and the housing has a third optical sensor adapted to be connected to a visualization device.

[0011] These useful configurations make it possible to create an embodiment of a dental handpiece where three optical sensors generate a higher quality three-dimensional image.

[0012] An optional embodiment of the present invention is also contemplated where the housing has a fourth light emitting diode connected to a power source and the housing has a fourth optical sensor adapted to be connected to a visualization device.

[0013] These useful configurations make it possible to propose an optional form of a dental handpiece where four optical sensors generate an even higher quality three-dimensional image.

[0014] An optional embodiment of the present invention is also contemplated where each diffuser is arranged from the working end of the housing and is designed to direct the air jet in a direction away from the housing end.

[0015] These useful configurations make it possible to propose an optional form of a dental handpiece where the optical sensor is arranged further away from the housing end than the drill bit. Under such conditions, the air jet is directed tangentially to each shielding window, in a direction away from the working end of the housing, i.e., in a direction away from the patient's oral cavity under operating conditions.

[0016] Also, an alternative embodiment of the present invention is conceivable in which each diffuser is arranged from the handle of the housing and is designed to direct the air jet away from the handle. Under these conditions, the housing has a protrusion arranged from the working end, and the protrusion has a surface shape that turns (rotates) the air jet by 120° to 140°.

[0017] These useful configurations make it possible to propose an alternative optional form of the dental handpiece in which the drill bit is arranged farther from the housing end than the optical sensor. The air jet is directed tangentially to the shielding window and toward the housing end, and then rotated by the protrusion, that is, away from the patient's oral cavity under the use conditions.

[0018] Also, since the housing has a protrusion arranged from the working end and the protrusion has a surface shape that turns the air jet by 120° to 140°, the formed jet consists of two echelons with different directional flows. By expanding the range of its speed and density with such a complex flow of the high-speed jet, it becomes possible to enhance the blocking efficiency of the scattered chips. Thereby, further contamination of the optical element is prevented.

[0019] Another embodiment of the present invention is also conceivable in which each diffuser faces a direction perpendicular to the handle. The diffuser is designed to direct the air jet laterally from the handle. Under these conditions, the housing has a protrusion arranged from the working end, and the protrusion has a surface shape that turns the air jet by 120° to 140°.

[0020] These useful configurations make it possible to propose an optional form of the dental handpiece in which the optical sensor is arranged laterally with respect to the drill bit, the air jet is directed away from the central axis of the housing, and is rotated in the same manner as in the above-described embodiment.

[0021] Finally, an embodiment of the present invention is also contemplated, in which each diffuser is designed to generate an air jet having an outflow velocity of 6 m / s to 50 m / s, and the outflow velocity forms an angle of 0° to 15° with the plane of the transparent shielding window.

[0022] These useful configurations make it possible to propose alternative and optional forms of the diffuser that have the target specifications and maximize the protective effect on the optical sensor.

[0023] Other significant features and advantages of the present invention will become readily apparent from the following description with reference to the accompanying drawings. These include, but are not limited to, the following features for purposes of illustration. In the accompanying drawings: · Figures 1 and 2 represent a design of a dental handpiece according to a first embodiment of the present invention. Two optical sensors according to the present invention are arranged longitudinally (along the axis MN of the handle 5 (Figure 2)). Figure 1 represents a side view of the dental handpiece (a partial cross-section A of the elements of the housing 50 including the axis MN of the handle 5, Figure 2), and Figure 2 represents a plan view of the dental handpiece; · Figure 3 represents a longitudinal vertical cross-section of the dental handpiece according to the first embodiment of the present invention (along the MN axis of the handle 5, plane B - B, see Figure 2), and has two optical sensors arranged longitudinally (along the MN axis of the handle 5 (see Figure 2)); · Figures 4 and 5 represent an enlarged cross-section A of the elements of the housing 50 of the dental handpiece (see Figure 1). The enlarged cross-section A shows a direct air jet and a reverse air jet blowing onto the transparent shielding window according to the present invention; · Figures 6 and 7 represent a dental handpiece according to a second embodiment of the present invention. Two optical sensors are arranged laterally (across the axis MN of the handle 5 (see Figure 7)). Figure 6 represents a side view of the dental handpiece, and Figure 7 represents a plan view of the dental handpiece; · Figures 8 and 9 show a dental handpiece according to the third embodiment of the present invention. The two optical sensors are arranged at an angle of 90° with respect to each other (at an angle of 45° with respect to the longitudinal axis MN of the handle 5 (see Fig. 9)). Fig. 8 shows a side view of the dental handpiece, and Fig. 9 shows a plan view of the dental handpiece; · Figures 10 and 11 show a cross-section of a dental handpiece according to the fourth embodiment of the present invention, in which three optical sensors indicate the "forward" position. The first optical sensor and the second optical sensor are arranged at an angle of 90° with respect to each other (at an angle of 45° with respect to the longitudinal axis MN of the handle 5 (see Fig. 11)), and the third optical sensor is arranged along the longitudinal axis MN from the handle 5. The angle between the first optical sensor and the second optical sensor is equal to the angle between the second optical sensor and the third optical sensor and corresponds to 135° (Fig. 11). Fig. 10 shows a side view of the dental handpiece (Fig. 11, having a partial cross-section of the element of the housing 50 including the axis MN of the handle 5), and Fig. 11 shows a plan view of the dental handpiece; · Figures 12 and 13 show a cross-section of a dental handpiece according to the fourth embodiment of the present invention, in which three optical sensors indicate the "reverse" position. The first optical sensor is arranged along the longitudinal axis MN towards the handle 5 (Fig. 13), the second optical sensor is arranged on one side (the right side in Fig. 13) from the longitudinal axis MN in a direction away from the handle 5 at an angle of 120° with respect to the longitudinal axis MN, and the third optical sensor is arranged on the other side (the left side in Fig. 13) from the longitudinal axis MN in a direction away from the handle 5 at an angle of 120° with respect to the longitudinal axis MN. The angle between the second optical sensor and the third optical sensor is also equal to 120°. Fig. 12 shows a side view of the dental handpiece (Fig. 13, having a partial cross-section of the element of the housing 50 including the axis MN of the handle 5), and Fig. 13 shows a plan view of the dental handpiece; · Figures 14 and 15 show a dental handpiece according to a fifth embodiment of the present invention, in which four optical sensors are in a position that is "symmetrical with respect to the longitudinal axis MN and perpendicular to the cross shape in the longitudinal direction with respect to the longitudinal axis MN" (see Figure 15). The first optical sensor is arranged along the longitudinal axis MN towards the handle 5 (Figure 15), the second optical sensor is arranged perpendicular to the longitudinal axis MN on one side from the longitudinal axis MN (to the right side in Figure 15), the third optical sensor is arranged along the longitudinal axis MN in a direction away from the handle 5 (Figure 15), and the fourth optical sensor is arranged perpendicular to the longitudinal axis MN on the other side from the longitudinal axis MN (in front of the second optical sensor, to the left side in Figure 15) (Figure 15). Figure 14 shows a side view of the dental handpiece (a partial cross-section of the elements of the housing 50 including the axis MN of the handle 5, Figure 15), and Figure 15 shows a plan view of the dental handpiece; · Figures 16 and 17 show a dental handpiece according to a sixth embodiment of the present invention, in which four optical sensors are in a position that is "symmetrical with respect to the longitudinal axis MN and at an angle of 45° with respect to the longitudinal axis MN and perpendicular to the cross shape" (see Figure 17). The first optical sensor is arranged along the longitudinal axis MN towards the handle 5, laterally to the longitudinal axis MN (to the right side in Figure 17) at an angle of 45° with respect to the axis MN (Figure 17), the second optical sensor is arranged along the longitudinal axis MN in a direction away from the handle 5, laterally to the longitudinal axis MN (to the right side in Figure 17) at an angle of 90° with respect to the first optical sensor (Figure 17), the third optical sensor is arranged towards the handle 5, laterally to the longitudinal axis MN (to the left side in Figure 17) at an angle of 45° with respect to the axis MN (Figure 17), and the fourth optical sensor is arranged along the longitudinal axis MN in a direction away from the handle 5 (Figure 17), laterally to the longitudinal axis MN (to the left side in Figure 17) at an angle of 90° with respect to the third optical sensor. Figure 16 shows a side view of the dental handpiece, and Figure 17 shows a plan view of the dental handpiece.

[0024] The following are shown in Figures 1 to 17: S - dental handpiece; Preferred axis of the MN-dental handpiece; 1-Rotor group; 2-Drill; 3-Collet clamp button; 4-Cover of the dental handpiece; 5-Handle of the dental handpiece; 50-Housing of the dental handpiece; 6-Sleeve of the optical sensor; 7-Latch of the optical sensor board; 8-「Midwest 4」adapter; 9-Protective part of the optical sensor board; 10-Optical sensor board; 11-Air supply circuit; 12-First optical sensor; 120-Second optical sensor; 13-First light-emitting diode; 14-Second diffuser; 15-First transparent shielding window; 16-Protrusion; 17-Connector socket 18-Spray supply circuit.

[0025] The compressed air source (dental unit compressor) and the dental unit are not shown.

[0026] According to FIGS. 1 to 17, the dental handpiece includes a handle 5 and a housing 50 having a light emission source represented by at least one first light-emitting diode 13 connected to a power source. The housing 50 includes a first optical sensor 12 adapted to be connected to a visualization device.

[0027] The housing 50 (more precisely, its light source) includes a second light-emitting diode connected to a power source. The housing 50 includes a second optical sensor adapted to be connected to a visualization device. The housing 50 includes a first transparent shielding window 15 (Figs. 4 to 5) of the first optical sensor and a second transparent shielding window of the second optical sensor. The handpiece has means for supplying compressed air to the first shielding window and the second shielding window. The housing 50 includes a first opening for supplying compressed air to the first shielding window and a second opening for supplying compressed air to the second shielding window, and both openings are connected to means for supplying compressed air. Each opening has a diffuser designed to generate an air jet that forms an air curtain in front of the transparent shielding window. See Figs. 1 to 9.

[0028] The housing 50 optionally includes a third light-emitting diode connected to a power source. The housing 50 (more precisely, its light source) includes a third optical sensor adapted to be connected to a visualization device. See Figs. 10 to 13.

[0029] The housing 50 optionally includes a fourth light-emitting diode connected to a power source. The housing 50 (more precisely, its light source) includes a fourth optical sensor adapted to be connected to a visualization device. See Figs. 14 to 17.

[0030] Each diffuser can be arranged on the side of the working end of the housing and can be designed to direct the air jet in a direction away from the working end of the housing. See Fig. 4.

[0031] Each diffuser can be arranged on the handle side of the housing and can be designed to direct the air jet in a direction away from the handle of the housing. Under these conditions, the housing has a protrusion arranged from the working end, and the protrusion has a surface shape that turns the air jet by 120° to 140°. See Fig. 5.

[0032] Each diffuser may be directed in a direction perpendicular to the handle of the housing and can be designed to direct the air jet away from the handle of the housing. Under these conditions, the housing has a protrusion arranged from the working end, and the protrusion has a surface shape that rotates the air jet by 120° to 140°.

[0033] Each diffuser can be designed to generate an air jet having an outflow velocity of 6 m / s to 50 m / s and forming an angle of 0° to 15° with the plane of the transparent shielding window.

[0034] The dental handpiece is designed to have a plurality of air supply options: direct air supply and reverse air supply (with rotation of the air curtain). Also, depending on the number of 2 to 4 optical sensors, there are various arrangements of the optical sensors.

[0035] The dental handpiece operates as follows. The following is the most comprehensive example of an embodiment of the present invention, but this example does not limit other applications of the present invention.

[0036] Compressed air is supplied from the dental unit compressor to the housing 50 as an air jet carried through the flow path (inside the handle 5) through the compressed air supply pipe 11. When the air passes through the housing 50, it goes towards the directional diffuser 14. The directional diffuser 14 forms a uniform jet directed at an angle of up to 15 degrees with respect to the housing surface. At this time, the outflow velocity is 6 m / s to 50 m / s. This high-speed jet prevents foreign objects having typical densities and velocities for dental procedures from passing through its core and keeps them away from each shielding window of each optical sensor.

[0037] The quantitative attributes of the technical parameters (for example, the air jet turning angle, the air jet outflow velocity, the angle between the air jet outflow and the plane of the transparent shielding window in the range of continuously varying variables) can be adjusted by changing the geometric shapes of the protrusion and the diffuser.

[0038] The selection of the specific range of the technical parameter values is made experimentally and depends on the blowing efficiency of the shielding window of the optical sensor (camera). The method for controlling the blowing efficiency is the visual control of the readability of the image contaminated by artifacts due to foreign matters and droplets adhering to the shielding window, which is transferred from the optical sensor. As the criterion for the blowing efficiency, assume the number of four levels of image artifacts: "none" - there are no visible artifacts derived from foreign matters and droplets, "mild" - foreign matters and droplets are not retained on the surface of the transparent shielding window and do not affect the readability of the transferred image, "moderate" - foreign matters and droplets remain on the surface of the shielding window and affect the image transferred from the optical sensor, but sufficient readability is maintained to orient the dental handpiece in the operating environment, "severe" - foreign matters and droplets remain on the surface of the shielding window, making the image from the optical sensor unreadable and unsuitable for accurately orienting the dental handpiece in the operating environment.

[0039] The air jet rotation angle is adjusted within the range of 120° to 140° by adjusting the shape of the protruding portion surface directed towards the diffuser. The value of the protruding portion inclination angle is a geometric parameter related to the air jet turning angle. The protruding portion inclination angle is found between the tangent to the edge of the concave surface and the plane of the transparent shielding window. For the relationship between the air jet turning angle, the image artifact grade, and the above geometric parameters, please refer to Table 1. For an example of an embodiment of the present invention having the boundary values of the above range, please refer to FIG. 1.

[0040] [Table 1]

[0041] The air jet outflow velocity is adjusted within the range of 6 m / s to 50 m / s by adjusting the diffuser outlet cross-sectional area. The geometric parameter characterizing the air jet outflow velocity is the value of the diameter of a circular cross-section having the same area as the diffuser outlet cross-section. Refer to Table 2 for the relationship between the air jet outflow, the image artifact grade, and the above geometric parameter.

[0042]

Table 2

[0043] The angle between the air curtain outflow direction and the shielding window plane is adjusted within the range of 0 degrees to 15 degrees by adjusting the diffuser outlet cross-sectional opening angle. The diffuser outlet cross-sectional opening angle was taken as a characteristic geometric parameter. Refer to Table 3 for the angle between the air curtain outflow direction and the shielding window plane, the image artifact grade, and the dependence on the above geometric parameter.

[0044]

Table 3

[0045] A three-dimensional image of the oral cavity can be obtained by a plurality of optical sensors. In other words, the operator of the dental handpiece according to the present invention can view the three-dimensional image on the screen during any intervention in the oral cavity.

[0046] Furthermore, a virtual three-dimensional (3D) model can be generated using the pre-rendered CT images. The virtual three-dimensional (3D) model can be combined with the CT images using an optical sensor. Under these conditions, the operator of the dental handpiece according to the present invention can view the hidden caries cavities and understand how the cutting end is positioned with respect to these caries cavities.

[0047] The claimed dental handpiece can be actually implemented by those skilled in the art and guarantees that the claimed objectives are satisfied after implementation. Therefore, it reaches the conclusion that the present invention meets the requirement of "industrial applicability".

[0048] To confirm the operability of the proposed dental handpiece, a series of actual machine tests were carried out. As a result, it was shown that there was no contamination of the optical window and all the optical sensors continued to send clear images, enabling three-dimensional imaging of the oral cavity throughout the treatment process.

[0049] Therefore, these novel features enable the achievement of the claimed technical results. That is, by implementing the air curtain, it is possible to guarantee reliable protection of the optical sensor, and it is possible to obtain high-quality three-dimensional images of the oral cavity of the patient to whom the dental handpiece according to the present invention is applied by the operator.

[0050] Therefore (see FIGS. 1 to 17), the present invention is a dental handpiece, · a handle 5 extending along an axis MN, having a first end adapted to be connected to a dental unit and a second free end axially opposite to the first end; · a housing 50 firmly connected to the second free end of the handle 5; including, the housing 50 includes, · a light emission source represented by at least one first light-emitting diode 13 connected to a power supply; · a first optical sensor 12 adapted to be connected to a visualization device; relating to a dental handpiece.

[0051] According to the present invention, the light emission source further includes a second light-emitting diode different from the first light-emitting diode 13. The second light-emitting diode is connected to the power supply. Under these conditions, the housing 50 · A second optical sensor 120 different from the first optical sensor 12, the second optical sensor 120 being adapted to be connected to the visualization device; · A first transparent shielding window 15 adapted to protect the first optical sensor 12; · A second transparent shielding window different from the first transparent shielding window 15 and adapted to protect the second optical sensor 120; It further includes.

[0052] Under these conditions, the dental handpiece S further includes means 11 for supplying compressed air to the first shielding window 15 and the second transparent shielding window. The housing 50 · A first opening adapted to supply compressed air to the first transparent shielding window 15, the first opening being connected to the means 11 for supplying compressed air; · A second opening different from the first opening, the second opening being adapted to supply compressed air to the second transparent shielding window and being connected to the means 11 for supplying compressed air; It further includes.

[0053] Under these conditions, the first diffuser 14 is disposed at the first opening. The first diffuser 14 is adapted to generate an air jet that forms an air curtain in front of the first transparent shielding window 15. A second diffuser different from the first diffuser 14 is disposed at the second opening. The second diffuser is adapted to generate an air jet that forms an air curtain in front of the second transparent shielding window.

[0054] Preferably, the light emission source further includes a third light emitting diode different from the first light emitting diode and the second light emitting diode. The third light emitting diode is connected to a power source. The housing 50 further includes a third optical sensor different from the first optical sensor 12 and the second optical sensor 120. The third optical sensor is adapted to be connected to the visualization device.

[0055] Preferably, the light emission source further includes a fourth light-emitting diode different from the first light-emitting diode, the second light-emitting diode, and the third light-emitting diode. The fourth light-emitting diode is connected to a power source. The housing 50 further includes a fourth optical sensor different from the first optical sensor 12, the second optical sensor 120, and the third optical sensor. The fourth optical sensor is adapted to be connected to a visualization device.

[0056] In the first embodiment (FIG. 4) of the present invention, each of the first diffuser 14 and the second diffuser is disposed from the working end of the housing 50. Each of the diffusers is adapted to direct an air jet in a direction away from the working end of the housing 50 along the axis MN of the handle 5.

[0057] (For the above first embodiment) In the second alternative embodiment (FIG. 5) of the present invention, each of the first diffuser 14 and the second diffuser is disposed from the working end of the housing 50. Each of the diffusers is adapted to direct an air jet in a direction away from the working end of the housing 50 along the axis MN of the handle 5. The housing 50 includes a protrusion 16 disposed from the working end of the housing 50. The protrusion has a surface shape that turns the air jet flowing out of each diffuser at a first angle included in a first interval of 120° to 140°.

[0058] (For the above first embodiment and the above second embodiment) In the third alternative embodiment of the present invention, each of the first diffuser 14 and the second diffuser faces in a direction perpendicular to the handle 5. Each of the first diffuser 14 and the second diffuser is adapted to direct an air jet laterally from the handle 5. The housing 50 includes a protrusion disposed from the working end. The protrusion has a surface shape that turns the air jet flowing out of each diffuser by a first angle included in a first interval of 120° to 140°.

[0059] Preferably, each of the first diffuser 14 and the second diffuser is adapted to generate an air jet having an outflow velocity of 6 m / s to 50 m / s. The outflow velocity of the air jet forms a second angle with the plane of the transparent shielding window corresponding to each diffuser, and the second angle is included in a second interval of 0° to 15°.

[0060] Any of the above first light-emitting diode, second light-emitting diode, third light-emitting diode, and fourth light-emitting diode may have a dot geometric shape. However, preferably, any of the above light-emitting diodes particularly has a ring pattern as shown in the embodiments in FIGS. 4 and 5: According to the applicant's observation, such a ring pattern ensures uniform (hot spot and / or shadow-free) illumination of the oral cavity sufficient to obtain a high-quality three-dimensional image.

Brief Description of the Drawings

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Claims

1. A dental handpiece (S), comprising: A handle (5) extending along an axis (MN), the handle (5) having a first end adapted to be connected to a dental unit and a second free end axially opposite the first end; A housing (50) rigidly connected to the second free end of the handle (5); Including: The housing (50) includes: A light emission source represented by at least one first light emitting diode (13) connected to a power source; A first optical sensor (12) adapted to be connected to a visualization device; Including: The light emission source further includes a second light emitting diode different from the first light emitting diode (13); The second light emitting diode is connected to the power source; The housing (50) further includes: A second optical sensor (120) different from the first optical sensor (12), the second optical sensor (120) being adapted to be connected to the visualization device; A first transparent shielding window (15) adapted to protect the first optical sensor (12); A second transparent shielding window different from the first transparent shielding window (15) and adapted to protect the second optical sensor (120); Further including: The dental handpiece (S) further includes means (11) for supplying compressed air to the first shielding window (15) and the second transparent shielding window; The housing (50) further includes: A first opening adapted to supply compressed air to the first transparent shielding window (15), the first opening being connected to the means (11) for supplying compressed air; A second opening different from the first opening, the second opening being adapted to supply compressed air to the second transparent shielding window and being connected to the means (11) for supplying compressed air; Further including: A first diffuser (14) is disposed in the first opening; The first diffuser (14) is adapted to generate an air jet that forms an air curtain in front of the first transparent shielding window (15); A second diffuser different from the first diffuser (14) is disposed in the second opening; The second diffuser is adapted to generate an air jet that forms an air curtain in front of the second transparent shielding window, the dental handpiece (S).

2. The light emission source further includes a third light emitting diode different from the first light emitting diode and the second light emitting diode, the third light emitting diode is connected to the power supply, the housing (50) further includes a third optical sensor different from the first optical sensor (12) and the second optical sensor (120), the third optical sensor is adapted to be connected to the visualization device, the dental handpiece (S) according to claim 1.

3. The light emission source further includes a fourth light emitting diode different from the first light emitting diode, the second light emitting diode, and the third light emitting diode, the fourth light emitting diode is connected to the power supply, the housing (50) further includes a fourth optical sensor different from the first optical sensor (12), the second optical sensor (120), and the third optical sensor, the fourth optical sensor is adapted to be connected to the visualization device, the dental handpiece (S) according to claim 1.

4. Each of the first diffuser (14) and the second diffuser is disposed from the working end of the housing (50), each of the diffusers is adapted to direct the air jet in a direction away from the working end of the housing (50) along the axis (MN) of the handle (5), the dental handpiece (S) according to any one of claims 1 to 3.

5. Each of the first diffuser (14) and the second diffuser is disposed from the working end of the housing (50), each of the diffusers is adapted to direct the air jet in a direction away from the working end of the housing (50) along the axis (MN) of the handle (5), the housing (50) includes a protrusion (16) disposed from the working end of the housing (50), the protrusion (16) has a surface shape that turns the air jet flowing out from each of the diffusers at a first angle included in a first interval of 120° to 140°, the dental handpiece (S) according to any one of claims 1 to 3.

6. Each of the first diffuser (14) and the second diffuser faces a direction perpendicular to the handle (5), Each of the first diffuser (14) and the second diffuser is adapted to direct the air jet laterally from the handle (5). The housing (50) includes a protrusion disposed from the working end portion. The protrusion has a surface shape that causes the air jet flowing out from each of the diffusers to turn by the first angle included in the first interval of 120° to 140°. The dental handpiece (S) according to any one of claims 1 to 3. **Claim 7** Each of the first diffuser (14) and the second diffuser is adapted to generate the air jet having an outflow velocity of 6 m / s to 50 m / s. The outflow velocity forms a second angle with the plane of the transparent shielding window corresponding to each diffuser. The second angle is included in the second interval of 0° to 15°. The dental handpiece (S) according to any one of claims 1 to 3.

Images