Dental tapping drill

Abstract

The utility model provides a kind of tapping drill for stomatology, including mutually connected tapping head and shank, cutting tooth has the rake face adjacent to chip flute and towards the tapping drill rotation direction, the rake face has the outermost end portion away from the central axis, the outermost end portion and the central axis jointly define base surface, the included angle between the base surface and the rake face defines positive rake angle, and the positive rake angle is acute angle;Setting positive rake angle can make the cutting edge of cutting tooth more "sharp", so that cutting tooth can quickly cut into bone tissue, avoid due to excessive force and lead to implantation nest deviation or bone microcrack, improve the success rate of operation;The tapping drill provided by the utility model can reduce the cutting contact area with bone tissue, reduce the friction area in tapping process, improve cutting performance, reduce heat generation, avoid bone burning, so as to ensure the structure rigidity of tapping drill while meeting the chip removal demand.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a tapping drill for dental use. Background Technology

[0002] Since the 1950s (when Professor Brånemark proposed the "osseointegration" theory), the core goal of dental implant technology has been to achieve long-term stable integration between the implant and the alveolar bone. Early implants were mostly placed by "indentation" (relying on the mechanical friction between the implant and the bone wall), but this method has extremely poor initial stability in cases of low bone density or osteoporosis, which can easily lead to implant loosening and dislodgement.

[0003] With technological advancements, threaded implants have become mainstream—the threaded structure on their surface significantly improves initial stability through "threaded engagement" with bone tissue and provides a more stable mechanical environment for osseointegration. However, the prerequisite for implanting threaded implants is the pre-machining of matching internal threads on the inner wall of the implant socket, a task accomplished by a tapping drill.

[0004] It can be said that the emergence of tapping drills is a "supporting technology" for the popularization of threaded implants, directly promoting the technological upgrade of implants from "passive adaptation" to "active engagement".

[0005] However, existing tapping drills used in dentistry still have the following drawbacks: First, the existing tapping drill structure, through longitudinal cutting, has systemic defects in terms of cutting mechanism and machining accuracy, directly restricting the precision and safety of implantation surgery. Second, using a five-axis machining center to manufacture tapping drills inevitably leads to high costs and long processing cycles. Finally, the machined tapping drill must be protected from damage to the cutting edge in subsequent processing steps, which could result in loss of function. Utility Model Content

[0006] In order to solve at least one of the above problems, this utility model provides a tapping drill for dental use.

[0007] This utility model is achieved using the following solution: This utility model proposes a dental tapping drill, comprising a tapping head and a shank connected to each other, the tapping drill being rotatable about a central axis; cutting teeth are spirally distributed on the outer periphery of the tapping head, and multiple chip removal grooves are also distributed on the outer periphery of the tapping head, the chip removal grooves extending along the axial direction of the tapping head; the cutting teeth have a rake face adjacent to the chip removal grooves and facing the rotation direction of the tapping drill, the rake face having an outermost end away from the central axis, the outermost end and the central axis jointly defining a base surface, the angle between the base surface and the rake face defining a positive rake angle, the positive rake angle being an acute angle.

[0008] In one embodiment, the positive front angle is 3° to 15°.

[0009] In one embodiment, the cutting tooth further has a flank face facing the outer periphery of the tapping head, the flank face being adjacent to the front face at the outermost end, the flank face having a first tangent at the outermost end, the cutting tooth rotating to cut and machine a bone wall surface, the bone wall surface having a second tangent at the outermost end, the included angle between the first tangent and the second tangent defining a back angle, the back angle being an acute angle.

[0010] In one embodiment, the rear angle is 5° to 12°.

[0011] In one embodiment, the tapping head has a maximum outer diameter D, and the cutting teeth disposed between two adjacent chip removal grooves have a cutting width W, wherein the cutting width W is set to 0.3D to 0.7D.

[0012] In one embodiment, the end of the tapping head away from the shank is defined as the front end of the tapping head, and the end of the tapping head near the shank is defined as the rear end of the tapping head. The cutting teeth include a cutting edge front end facing the front end direction, and the cutting edge front end retracts backward in a helical direction to form an avoidance angle, which is 1° to 10°.

[0013] In one embodiment, the end of the tapping head away from the shank is defined as the front end of the tapping head, and the groove depth of the cutting teeth increases in the direction towards the front end.

[0014] In one embodiment, the end of the tapping head away from the shank is defined as the front end of the tapping head, and at least some of the cutting teeth have an outer diameter that gradually decreases in the direction toward the front end.

[0015] In one embodiment, the tapping head has four chip removal grooves distributed on its outer periphery; the shank has a tool interface at the end away from the tapping head, the tool interface being used to connect a drive tool to drive the tapping drill to rotate.

[0016] In one embodiment, the tapping drill is longitudinally machined to create chip removal grooves and a tapping drill outline, and then subjected to vacuum heat treatment to temper it to a hardness of 52°. Furthermore, it undergoes straightening treatment to ensure that the coaxiality between the tapping head and the shank is within 0.05 mm. The tapping drill is then machined with cutting teeth using a five-axis grinding machine, and residual burrs are removed by abrasive jet polishing. The technical solution provided by this utility model has the following technical effects: 1. This utility model provides a dental tapping drill, including a tapping head and a shank connected to each other. Cutting teeth are spirally distributed on the outer periphery of the tapping head. Each cutting tooth has a rake face adjacent to the chip removal groove and facing the rotation direction of the tapping drill. The rake face has an outermost end far from the central axis. The outermost end and the central axis together define a base surface. The angle between the base surface and the rake face defines a positive rake angle, which is an acute angle. Setting a positive rake angle can make the cutting edge of the cutting teeth "sharper", enabling the cutting teeth to quickly cut into the bone tissue, avoiding implant displacement or bone microfracture due to excessive force, and improving the success rate of surgery.

[0017] 2. The cutting tooth also has a flank face facing the outer periphery of the tapping head. The flank face has a first tangent at the outermost end. The cutting tooth rotates to cut and machine the bone wall surface. The bone wall surface has a second tangent at the outermost end. The angle between the first tangent and the second tangent defines a clearance angle, which is an acute angle. Setting a clearance angle can reduce the contact area between the cutting tooth and the bone wall, reduce the friction area during tapping, improve cutting performance, reduce the heat generated by the friction between the tapping drill and the bone wall, and protect the activity of bone cells.

[0018] 3. The cutting teeth include a cutting edge front end facing the front end direction. The cutting edge front end retracts backward and inward along the helical direction to form an avoidance angle, which is 1° to 10°. When performing cutting and tapping, setting an avoidance angle further reduces the friction area during the tapping process and improves cutting performance. Attached Figure Description

[0019] Figure 1 This is a perspective view of a dental tapping drill according to an embodiment of the present invention; Figure 2 This is a front view of the tapping head according to an embodiment of the present utility model; Figure 3 This is a left view of a dental tapping drill according to an embodiment of the present invention; Figure 4 This is a left view showing the cutting width of a dental tapping drill according to an embodiment of this utility model. Detailed Implementation

[0020] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0021] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0022] Reference Figures 1-4 As shown, this embodiment provides a dental tapping drill 1, including a tapping head 10 and a shank 20 connected to each other. The shank 20 has a tool interface 21 at the end away from the tapping head 10. The tool interface 21 is used to connect a drive tool to drive the tapping drill 1 to rotate. (Refer to...) Figure 3 The tapping drill 1 rotates along the M direction and has a rotation center axis C.

[0023] Cutting teeth 11 are distributed around the outer periphery of the tapping head 10. The cutting teeth 11 are spirally arranged around the outer periphery of the tapping head 10. Multiple chip removal grooves 12 are also distributed around the outer periphery of the tapping head 10. In this embodiment, four chip removal grooves 12 are shown. The chip removal grooves 12 extend along the axial direction of the tapping head 10. The cutting teeth 11 are located between two adjacent chip removal grooves 12. The cutting teeth 11 have a rake face 13 adjacent to the chip removal groove 12 and facing the rotation direction of the tapping drill 1. The rake face 13 has an outermost end 131 away from the central axis C. The outermost end 131 and the central axis C together define a base plane E. The angle between the base plane E and the rake face 13 defines a positive rake angle β, which is an acute angle and is typically 3° to 15°. Setting a positive rake angle β makes the cutting edge of the cutting tooth 11 "sharper," allowing the cutting tooth 11 to quickly cut into the bone tissue, avoiding implant misalignment or bone microfracture due to excessive force, and improving the success rate of the surgery.

[0024] The cutting tooth 11 also has a flank face 14 facing the outer periphery of the tapping head 10, which is adjacent to the rake face 13 at the outermost end 131. When the cutting tooth 11 rotates and cuts in the M direction, it can machine the machined bone wall surface S. The flank face 14 has a first cutting surface G1 at the outermost end 131, and the bone wall surface S has a second cutting surface G2 at the outermost end 131. The included angle between the first cutting surface G1 and the second cutting surface G2 defines the clearance angle α, which is an acute angle and is usually 5° to 12°. Setting the clearance angle α can reduce the contact area between the cutting tooth 11 and the bone wall, reduce the friction area during tapping, improve cutting performance, reduce the heat generated by the friction between the tapping drill 1 and the bone wall, and protect the activity of bone cells.

[0025] Reference Figure 3 The tapping head 10 has a maximum outer diameter D. The cutting teeth 11, positioned between two adjacent chip removal grooves 12, have a cutting edge width W, defined by the two adjacent chip removal grooves 12. In this embodiment, the cutting edge width W is typically set to 0.3D to 0.7D. If the cutting edge width is too narrow, the edge sharpness increases, but the edge's impact resistance is weak, easily leading to chipping during the cutting of dense cortical bone. Conversely, if the cutting edge width is too wide, the edge strength increases, and the overall rigidity is strengthened, but this compresses the chip removal groove space, resulting in decreased chip removal efficiency, and may even cause the drill bit to get stuck in the implantation hole during cutting.

[0026] Reference Figure 2 The end of the tapping head 10 furthest from the shank 20 is defined as the front end of the tapping head 10, and the end of the tapping head 10 closest to the shank 20 is defined as the rear end of the tapping head 10. The cutting teeth 11 include a cutting edge front end 14 facing the front end direction. The cutting edge front end 14 retracts rearward and inward along the helical direction, thereby forming an avoidance angle γ, which is typically 1° to 10°. During tapping, setting the avoidance angle γ further reduces the friction area during the tapping process and improves cutting performance.

[0027] The groove depth of the cutting teeth 11 increases towards the front end, which is beneficial for forming a deeper thread structure in the implantation socket; and at least some of the cutting teeth 11 have an outer diameter that gradually decreases towards the front end, which is beneficial for the cutting teeth 11 of the tapping head 10 to gradually cut into the bone tissue, reduce cutting resistance to avoid bone microcracks, and improve the success rate of the operation.

[0028] After the tapping drill 1 is longitudinally machined to form the chip removal groove 12 and the outer contour structure of the tapping drill 1, it is subjected to vacuum heat treatment to temper to a hardness of 52°, and then the coaxiality between the tapping head 10 and the shank 20 is adjusted to within 0.05mm. Then, the cutting teeth 11 are machined by a five-axis grinding machine, thereby shortening the processing cycle and improving the cutting edge quality.

[0029] The tapping drill 1 removes residual burrs from grinding through abrasive blasting polishing. The cutting edge structure of the tapping drill 1 retains fine burrs after machining. Compared to traditional polishing methods, which remove burrs but damage the cutting edge, abrasive blasting polishing effectively removes burrs without damaging the cutting edge.

[0030] The tapping drill 1 provided in this embodiment can reduce the cutting contact area with bone tissue, reduce the friction area during the tapping process, improve cutting performance, reduce heat generation, and avoid bone burning, thereby ensuring the structural rigidity of the tapping drill 1 while meeting the chip removal requirements.

[0031] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A dental tapping drill, comprising a tapping head and a shank connected to each other, the tapping drill being rotatable about a central axis; cutting teeth are helically distributed on the outer periphery of the tapping head, and a plurality of chip removal grooves are also distributed on the outer periphery of the tapping head, the chip removal grooves extending along the axial direction of the tapping head; characterized in that, The cutting tooth has a rake face adjacent to the chip removal groove and facing the rotation direction of the tapping drill. The rake face has an outermost end away from the central axis. The outermost end and the central axis together define a base surface. The angle between the base surface and the rake face defines a positive rake angle, which is an acute angle.

2. The dental tapping drill according to claim 1, characterized in that: The positive front angle is 3° to 15°.

3. The dental tapping drill according to claim 1, characterized in that: The cutting tooth also has a back face facing the outer periphery of the tapping head. The back face is adjacent to the front face at the outermost end. The back face has a first cutting surface at the outermost end. The cutting tooth rotates and cuts to form a bone wall surface. The bone wall surface has a second cutting surface at the outermost end. The included angle between the first cutting surface and the second cutting surface defines a back angle, which is an acute angle.

4. The dental tapping drill according to claim 3, characterized in that: The rear angle is 5° to 12°.

5. The dental tapping drill according to claim 3, characterized in that: The tapping head has a maximum outer diameter D, and the cutting teeth disposed between two adjacent chip removal grooves have a cutting width W, wherein the cutting width W is set to 0.3D to 0.7D.

6. The dental tapping drill according to claim 1, characterized in that: The end of the tapping head away from the shank is defined as the front end of the tapping head, and the end of the tapping head near the shank is defined as the rear end of the tapping head. The cutting teeth include a cutting edge front end facing the front end direction. The cutting edge front end retracts backward in the helical direction to form an avoidance angle, which is 1° to 10°.

7. The dental tapping drill according to claim 1, characterized in that: The end of the tapping head away from the shank is defined as the front end of the tapping head, and the tooth groove depth of the cutting teeth increases in the direction towards the front end.

8. The dental tapping drill according to claim 1, characterized in that: The end of the tapping head away from the shank is defined as the front end of the tapping head, and at least some of the cutting teeth have an outer diameter that gradually decreases in the direction toward the front end.

9. The dental tapping drill according to claim 1, characterized in that: The tapping head has four chip removal grooves distributed on its outer periphery; the shank has a tool interface at the end away from the tapping head, the tool interface being used to connect a drive tool to drive the tapping drill to rotate.

10. The dental tapping drill according to claim 1, characterized in that: The tapping drill is longitudinally machined to create chip removal grooves and a tapping drill outline structure. It is then subjected to vacuum heat treatment to temper it to a hardness of 52° and straightened to ensure that the coaxiality between the tapping head and the shank is within 0.05 mm. The tapping drill is machined to create cutting teeth using a five-axis grinding machine, and grinding residue burrs are removed by abrasive jet polishing.

Images