Dental handpiece for treating hard material in a patient's mouth

Abstract

The present invention relates to a dental handpiece (1) for processing hard materials in a patient's oral cavity, the dental handpiece comprising: an outer sleeve (2) having a handle portion (2A) extending along a longitudinal axis (3) and a head portion (2B) extending along a rotation axis (4); clamping forceps (5) for holding the processing tool for processing hard materials, wherein the clamping forceps (5) is rotatably supported in the head portion (2B) about the rotation axis (4) by first and second rolling bearings (6, 7); and a coupling device (8) on the handle portion (2A) for connecting the dental handpiece (1) to a power supply and / or control device, wherein the rotation speed-transmission ratio of the dental handpiece (1) is 1:4±3%, and the clamping forceps (5) has a pull-out force greater than 35N according to ISO 14457:2017.

Description

Technical Field

[0001] This utility model relates to a dental handpiece designed for handling hard materials in a patient's oral cavity. Background Technology

[0002] Artificial crowns and tooth replacements (such as bridges) are made of various materials. In recent years, zirconium has been the preferred and therefore most commonly used material. This is because zirconium is hypoallergenic, its color closely resembles the natural color of teeth, and it has high hardness, which is particularly advantageous for dentures (which can replace multiple teeth). However, it is precisely this high hardness—especially when dealing with (e.g., removing) zirconium crowns or tooth replacements present in a patient's mouth—that presents a challenge for dentists. Currently, this is done using traditional bending handpieces, but these handpieces are used for softer materials, such as natural tooth structure or cavities. If such handpieces are used to treat hard materials (especially zirconium, but also other ceramics or particularly hard metal alloys) in a patient's mouth, the treatment needs to be sustained for a long time, and / or the components of the handpiece (which are subjected to special loads due to the treatment of hard materials) wear out or break quickly. Utility Model Content

[0003] Therefore, the objective of this invention is to design a curved dental handpiece, which is particularly suitable for handling hard materials in a patient's oral cavity. Specifically, the curved dental handpiece is designed to better withstand greater forces exerted by the hard materials themselves and by the user of the handpiece when handling them in the patient's oral cavity.

[0004] According to this invention, the task is solved by a dental handpiece having the features described herein, used for handling hard materials in a patient's oral cavity. Particularly advantageous embodiments are given in the dependent claims.

[0005] According to the present invention, a dental handpiece for handling hard materials in a patient's oral cavity includes an outer sleeve that isolates the handpiece from the surrounding environment, and the outer sleeve has a handle portion extending along a longitudinal axis and a head portion extending along a rotation axis. The longitudinal axis and the rotation axis are arranged at an angle not equal to 0° relative to each other, such that the handling tool for handling hard materials extends from the dental handpiece at an angle to the handle portion or the longitudinal axis.

[0006] The dental handpiece also includes: a spannzange holding a processing tool for handling hard materials, wherein the spannzange is rotatably supported in the head portion by first and second rolling bearings about a rotation axis; and a coupling device on the handle portion for connecting the dental handpiece to a power supply and / or control device and / or motor drive.

[0007] The dental handpiece of this invention has a speed-to-transmission ratio of 1:4 ± 3%. For example, the maximum input speed (which obviously depends on the drive motor mounted on the dental handpiece) is 40,000 U / min and the maximum output speed is correspondingly 160,000 U / min. Therefore, compared to other handpieces used for restoration and repair, the speed-to-transmission ratio of 1:4 ± 3% provides a lower maximum speed, thereby reducing wear on the rotating parts of the dental handpiece. This lower wear offsets the higher load on the rotating parts of the dental handpiece when handling hard materials in the oral cavity, thus enabling an increased service life of the dental handpiece despite the higher load when handling hard materials.

[0008] According to ISO 14457:2017, the clamping forceps of the dental handpiece according to this invention have a pull-out force (Auszugskraft) greater than 35 N, preferably greater than 36 N. Therefore, the pull-out force is increased compared to other handpieces used for restoration and repair. The increased pull-out force means that the clamping force holds the treatment tool (rotating instrument) with a higher force; that is, the clamping force of the clamping force is increased. The pull-out force or clamping force is preferably about 20% higher than other handpieces used for restoration and repair. This higher pull-out force or clamping force is achieved, for example, through: an increased wall thickness in at least a portion of the clamping forceps; and / or, an increase in the size of the clamping forceps, for example, an increase in length compared to other handpieces used for restoration and repair; and / or, specific geometric features of at least a portion of the clamping forceps. The increased pull-out force or clamping force has the advantage that the clamping forceps can reliably hold the treatment tool despite the higher mechanical load when handling hard materials in the patient's oral cavity.

[0009] According to this invention, the first and second rolling bearings of the dental handpiece are preferably supported on first and second bearing seats, respectively, wherein the first and second bearing seats are disposed on the same bearing body in the head portion. In particular, this feature improves the mechanical stability of the dental handpiece, thereby better maintaining the load generated when handling hard materials in the patient's oral cavity compared to other handpieces used for restorations and repairs. The bearing body is preferably constructed as a single piece, for example, formed as a bearing sleeve inside the head portion or through an outer sleeve inside the head portion. However, the bearing body can also be composed of multiple components interconnected to form a single integral component and / or function as a single-piece component.

[0010] Therefore, each of the features mentioned above advantageously improves the applicability of the dental handpiece according to the present invention for processing hard materials (particularly zirconium) in a patient's oral cavity. However, it is particularly advantageous to combine several or all of these features, especially through synergistic effects, to further improve the applicability of the dental handpiece according to the present invention for processing hard materials. Thus, for example, a speed-to-transmission ratio of 1:4 ± 3% not only reduces the load on the transmission system itself but also reduces the stress on the clamps, in addition to the aforementioned adjusted geometry or altered dimensions of the clamps. Therefore, providing first and second bearing seats on the same bearing housing is also advantageous for the clamps, because the contact pressure applied by the user to the hard material to be processed can be transmitted from the clamps to the rolling bearings and bearing housing, and absorbed by them, thereby reducing the load on the clamps. Attached Figure Description

[0011] The present invention will now be explained with reference to preferred embodiments and accompanying drawings. The drawings show:

[0012] Figure 1 This is a side view of a dental handpiece used to handle hard materials in a patient's mouth.

[0013] Figure 2 yes Figure 1 A top view of a dental handpiece;

[0014] Figure 3 This is a partial cross-sectional view of a dental handpiece used to handle hard materials in a patient's mouth. Detailed Implementation

[0015] exist Figures 1 to 3The dental handpiece 1 shown, used for processing hard materials (particularly zirconium) in a patient's oral cavity, includes an outer sleeve 2 that isolates the handpiece 1 from its surroundings. The outer sleeve 2 has a handle portion 2A extending along a longitudinal axis 3 and a head portion 2B extending along a rotation axis 4. The longitudinal axis 3 and the rotation axis 4 are arranged at an angle not equal to 0° relative to each other, such that a processing tool (not shown) for processing hard materials extends from the dental handpiece 1 at an angle to either the handle portion 2A or the longitudinal axis 3.

[0016] A clamping clamp 5 is provided in the head portion 2B, which holds the treatment tool used for handling hard materials. The clamping clamp 5 is rotatably supported in the head portion 2B about the rotation axis 4 by first and second rolling bearings 6, 7, and in particular by ball bearings. According to ISO 14457:2017, the clamping clamp 5 has a pull-out force or clamping force for the treatment tool greater than 35 N, thereby ensuring reliable fixation of the treatment tool when handling hard materials in the patient's oral cavity.

[0017] The clamping forceps 5 is preferably configured as a force-operated or friction-operated clamping forceps, having multiple spring arms 17 that are configured to be resilient relative to the rotation axis 4. The force-operated clamping forceps 5 are adapted to provide sufficient clamping force in an advantageous manner to hold the treatment tool when handling hard materials in the patient's oral cavity.

[0018] The clamping forceps 5 also has a tool receiving opening 18 and a tool guide portion 5A. Through the tool receiving opening 18, a treatment tool can be introduced into and removed from the clamping forceps 5 and the dental handpiece 1. In the tool guide portion 5A, the axis of the treatment tool is radially supported relative to the axis of rotation 4, particularly when a radial force (relative to the axis of rotation 4) is applied to the treatment tool during the treatment of hard materials in the patient's oral cavity. Preferably, the tool guide portion 5A has an inner diameter of 1.6 mm, such that the axis of the treatment tool (when introduced into the clamping forceps 5) contacts the inner wall, or is at least spaced from the inner wall by only a minimal air gap. The tool guide portion 5A extends from the tool receiving opening 18 in the direction of the spring arm 17 of the clamping forceps 5 by at least 4.5 mm (preferably at least 5.0 mm). Compared to other handpieces used for restoration and repair, the length of the tool guide portion 5A is at least [insert length here].

[0019] With a diameter of 4.5 mm and an inner diameter increased by 1.6 mm, the tool can be reliably supported on a longer tool spindle section when machining hard materials, thereby achieving higher mechanical stability, which is necessary for machining hard materials.

[0020] The tool guide portion 5A extends from the tool receiving opening 18 by at least 4.5 mm, and in particular extends to the portion 5B of the clamping pliers 5 adjacent to the tool guide portion 5A, the inner diameter of which is not equal to

[0021] 1.6 mm. The adjacent portion 5B of the clamping pliers 5 includes, for example, the clamping portion of the clamping pliers 5 and / or the spring arm 17 of the clamping pliers 5 and / or the portion of the clamping pliers 5 having an inner diameter greater than 1.6 mm and / or the portion of the clamping pliers 5 having an inner diameter less than 1.6 mm. The tool guide portion 5A is specifically arranged between the tool receiving opening 18 and the spring arm 17 of the clamping pliers 5. The tool guide portion 5A is specifically positioned in the region near the second rolling bearing 7 arranged in the tool receiving opening 18, so that forces acting advantageously on the processing tool can be directly transmitted via the second rolling bearing to the head portion 2B of the dental handpiece 1.

[0022] Preferably, the clamping clamp 5, including the wedge sleeve 19 (which is used to release the processing tool from the clamping clamp 5), has a length or total length of at least 12 mm. Compared to other bent tools used for repair and compensation, the increased total length of the clamping clamp 5, at least 12 mm, allows for reliable support of the processing tool on the larger tool shank portion when processing hard materials, thereby advantageously achieving the higher mechanical stability necessary for processing hard materials.

[0023] First and second rolling bearings or ball bearings 6, 7 (which rotatably support the clamping clamp 5 in the head portion 2B) are respectively supported on first and second bearing seats 10, 11, wherein the first and second bearing seats 10, 11 are disposed on the same bearing body 9 in the head portion 2B. By disposing the two bearing seats 10, 11 and, in particular, the two rolling bearings 6, 7 on the same bearing body 9, the dental handpiece 1 (compared to other handpieces used for restoration and repair, wherein the bearing seats are disposed on two different bearing bodies) has the high mechanical stability necessary for handling hard materials in the patient's oral cavity space.

[0024] The first and second bearing housings 10, 11 are formed via a surface 20 of the bearing body 9, which is substantially parallel to the axis of rotation 4. Preferably, the bearing body 9 is formed via a head portion 2B and / or the surface 20 is formed via the inner side of the head portion 2B of the outer sleeve 2. Advantageously, this eliminates the need for additional bearing bodies to form the bearing housings 10, 11 and / or support the rolling bearings 6, 7. Alternatively, the bearing body 9 and bearing housings 10, 11 may be configured as a separate component arranged in the head portion 2B, for example, in the form of a bearing sleeve.

[0025] Preferably, each of the rolling bearings 6 and 7 includes a generally cylindrical outer raceway having an outer surface or circumferential surface 21, 22. Preferably, the circumferential surfaces 21, 22 of the outer raceways of the first and second rolling bearings 6 and 7 are anti-rotationally supported on the first and second bearing housings 10, 11.

[0026] Preferably, at least the first and / or second rolling bearings 6, 7 have ceramic components. In particular, the rolling elements of the first and / or second rolling bearings 6, 7 are made of ceramic material.

[0027] Preferably, at least the first and / or second rolling bearings 6, 7 have at least nine rolling elements. This is a greater number of rolling elements compared to other handpieces used for restoration and repair. Consequently, the forces acting on the treatment tool and the dental handpiece 1 during the treatment of hard materials in the patient's oral cavity are advantageously distributed across the more rolling elements, making the rolling bearings 6, 7 and the dental handpiece 1 more robust and better suited for treating hard materials in the patient's oral cavity. Preferably, the diameter of the rolling elements is approximately 1 mm.

[0028] Preferably, at least the first and / or second rolling bearings 6, 7 are configured as shoulder bearings. Rolling bearings 6, 7 configured as shoulder bearings are particularly suitable for advantageously absorbing forces acting on the treatment tool and dental handpiece 1 when handling hard materials in the patient's oral cavity.

[0029] A coupling device 8 is provided on the end of the handle portion 2A away from the head portion 2B to connect the dental handpiece 1 to a power supply and / or control device, and / or to a drive device (particularly an electric motor). The drive device can be integrated into the outer sleeve 2 of the dental handpiece 1, or it can be detachably connected to the dental handpiece 1 via the coupling device 8 as a separate component.

[0030] An equal-diameter bevel gear 12 is provided in the handle portion 2A (particularly in the curved area of ​​the handle portion 2A). The driven shaft 26 has a first gear or pawl 13, and the drive shaft 27 has a second gear 16. The first and second gears 13 and 16 mesh with each other and form the equal-diameter bevel gear 12, which is configured as a first transmission mechanism. Another equal-diameter bevel gear 28 is provided in or at the head portion 2B. It includes a third gear 29 located on the driven shaft 26 and a gear ring 30 anti-rotationally connected to the clamping jaw 5, which mesh and form the equal-diameter bevel gear 28 configured as a second transmission mechanism. Therefore, the equal-diameter bevel gear 28 is configured to transmit drive motion and torque to the clamping jaw 5. The design and interaction of the two equal-diameter bevel gears 12 and 28 (e.g., by the number of their teeth) result in a speed-to-gear ratio of 1:4 ± 3% for the dental handpiece 1. The 1:4 ± 3% speed-to-gear ratio has proven particularly suitable for handling hard materials in the patient’s oral cavity, whether from the perspective of the torque used to handle hard materials, the duration of handling hard materials, or the wear of the components that bear particular loads in the dental handpiece 1.

[0031] Two shafts 26 and 27 are rotatably supported in bearing sleeves 15 and 31 by rolling bearings. Bearing sleeves 15 and 31 also advantageously protect the transmission devices 12 and 28 and the rolling bearings from particles of the hard material being processed. To allow the driven first gear 13 and the driving second gear 16 to mesh with each other when surrounded by bearing sleeves 15 and 31, an opening 14 is provided in bearing sleeve 15 (which houses the second gear 16), through which the first gear 13 extends. For sealing purposes, the opening 14 is surrounded by a sealing element (e.g., an O-ring).

[0032] Preferably, a button 23 is provided on the head portion 2B to release the processing tool from the clamping pliers 5. This button 23 is specifically positioned at the end of the head portion 2B opposite to the tool receiving opening 18. The button 23 is configured to be movable relative to the outer sleeve 2 (particularly relative to the head portion 2B). Specifically, the button 23 can be moved in a known manner along the direction of the tool receiving opening 18, thereby pushing the wedge sleeve 19 also along the direction of the tool receiving opening 18, and engaging the wedge-shaped extension of the wedge sleeve 19 with the spring arm 17 of the clamping sleeve 5, and moving them radially apart, thereby allowing the processing tool to be introduced into or removed from the clamping sleeve 5.

[0033] Button 23 preferably has an outer diameter of at least 9.0 mm. This advantageously improves the operability of button 23, particularly in improving the pull-out or clamping force of the aforementioned increased clamping sleeve 5.

[0034] Preferably, button 23 has markings to distinguish the dental handpiece 1 from other dental handpieces, particularly those used for restoration and repair. Preferably, the markings on button 23 include colored and / or alphanumeric markings or symbols. Particularly preferably, a circular colored marking or circular area, for example, set in black, is provided on button 23. Figure 2 Dental handpieces typically have a colored plastic ring at one end near the coupling device 8 for identification. Marking the button 23 makes it easier and safer to identify and differentiate the dental handpiece 1 used for handling hard materials in the patient's mouth, thereby advantageously further reducing the possibility of misuse of dental handpieces used for handling hard materials.

[0035] Preferably, the dental handpiece 1 includes up to three output openings 24 (arranged around the tool receiving opening 18) for discharging coolant, particularly an air-water spray. Furthermore, this feature advantageously improves the robustness of the dental handpiece 1 compared to other handpieces used for repair and restoration that have more than three coolant output openings 24.

[0036] Preferably, a light-emitting device 25 is provided on or near the dental handpiece 1, particularly on or near the head portion 2B, for illuminating the processing tool and / or the processing area. This allows the user to better observe the hard material being processed in an advantageous manner. The light-emitting device 25 includes, for example, a light conductor and / or a light source made of glass or plastic, particularly a light-emitting diode (LED).

[0037] The described or illustrated embodiments are specifically for illustrating the present invention. Therefore, the features disclosed in one embodiment are not limited to that embodiment, but can be used alone or in combination with one or more features of other embodiments.

Claims

1. A dental handpiece (1) for handling hard materials in a patient's oral cavity, said dental handpiece (1) comprising: The outer sleeve (2) isolates the dental handpiece (1) from its surroundings. The outer sleeve (2) has a handle portion (2A) extending along a longitudinal axis (3) and a head portion (2B) extending along a rotation axis (4), wherein the longitudinal axis (3) and the rotation axis (4) are arranged at an angle not equal to 0° relative to each other. A clamping pliers (5) holding a processing tool for handling hard materials, wherein the clamping pliers (5) are rotatably supported in the head portion (2B) about the rotating shaft (4) by first and second rolling bearings (6, 7), and The coupling device (8) on the handle portion (2A), which connects the dental handpiece (1) to a power supply and / or control device, is characterized in that... The rotational speed-transmission ratio of the dental handpiece (1) is 1:4 ± 3%, and According to ISO 14457:2017, the clamping pliers (5) have a pull-out force greater than 35 N.

2. The dental handpiece (1) according to claim 1, characterized in that, The first and second rolling bearings (6, 7) are respectively supported on the first and second bearing housings (10, 11), wherein the first and second bearing housings (10, 11) are disposed on the same bearing body (9) of the head portion (2B).

3. The dental handpiece (1) according to claim 1, characterized in that, An equal-diameter bevel gear (12) is arranged in the handle portion (2A).

4. The dental handpiece (1) according to claim 2, characterized in that, An equal-diameter bevel gear (12) is arranged in the handle portion (2A).

5. The dental handpiece (1) according to claim 3 or 4, characterized in that, The first gear (13) of the equal diameter bevel gear (12) extends into the opening (14) of the bearing sleeve (15), and the second gear (16) of the equal diameter bevel gear (12) is arranged in the bearing sleeve (15), wherein the first gear (13) and the second gear (16) mesh with each other.

6. The dental handpiece (1) according to any one of claims 1 to 4, characterized in that, The clamp (5) is configured as a force-operated clamp with a plurality of spring arms (17) which are configured to be elastic relative to the rotation axis (4).

7. The dental handpiece (1) according to claim 6, characterized in that, The clamping forceps (5) also has a tool receiving opening (18) and a tool guide portion (5A), wherein the processing tool can be introduced into and removed from the dental handpiece (1) through the tool receiving opening (18), and the axis of the processing tool is radially supported relative to the rotation axis (4) in the tool guide portion (5A), wherein the tool guide portion (5A) has an inner diameter of 1.6 mm and extends from the tool receiving opening (18) at least... The 4.5 mm length extends in the direction of the spring arm (17) of the clamping clamp (5).

8. The dental handpiece (1) according to claim 7, characterized in that, The tool guide portion (5A) extends into the portion (5B) of the clamping pliers (5) adjacent to the tool guide portion (5A), and its inner diameter is not equal to 1.6 mm.

9. The dental handpiece (1) according to any one of claims 1 to 4, characterized in that, The clamping pliers (5), including the wedge sleeve (19), have a length of at least 12 mm, and the wedge sleeve (19) is used to release the processing tool from the clamping pliers (5).

10. The dental handpiece (1) according to claim 2 or 4, characterized in that, The first and second bearing housings (10, 11) are formed by the surface (20) of the bearing body (9) which is substantially parallel to the axis of rotation (4).

11. The dental handpiece (1) according to claim 2 or 4, characterized in that, The bearing body (9) is formed through the inside of the head portion (2B).

12. The dental handpiece (1) according to any one of claims 2 to 4, characterized in that, The circumferential surfaces (21, 22) of the outer raceways of the first and second rolling bearings (6, 7) are supported on the first and second bearing housings (10, 11).

13. The dental handpiece (1) according to any one of claims 2 to 4, characterized in that, At least the first or second rolling bearing (6, 7) has at least nine rolling elements.

14. The dental handpiece (1) according to any one of claims 2 to 4, characterized in that, At least the first or second rolling bearing (6, 7) is constructed as a shoulder bearing.

15. The dental handpiece (1) according to any one of claims 1 to 4, characterized in that, A button (23) is provided on the head portion (2B) for releasing the processing tool from the clamp (5), wherein the button (23) has an outer diameter of at least 9.0 mm.

16. The dental handpiece (1) according to claim 15, characterized in that, The button (23) has a marking for distinguishing the dental handpiece (1).

17. The dental handpiece (1) according to any one of claims 1 to 4, characterized in that, It includes up to three output openings (24) arranged around the tool receiving opening (18) of the clamping clamp (5) for discharging coolant.

18. The dental handpiece (1) according to any one of claims 1 to 4, characterized in that, The device includes a light-emitting device (25) disposed on or near the head portion (2B) for emitting light to the processing tool and / or the processing area.

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