Dental Instrument With a Flexible Tip End and Method of Manufacture

Abstract

Dental instruments, assemblies, and components for a dental instrument are described with a two-piece tip that includes a flexible tip end and a stiff shank. Various methods of assembly are described for securing the flexible tip end to the shank including utilizing a slot in the shank and one or more pins inserted through the tip and shank, a securing material, and forming the shank with a distal portion coupled to a portion of the flexible tip end.

Claims

1. A dental instrument comprising: a handle; a tip attached to the handle, the tip including: a shank including a distal portion extending along a longitudinal axis, the distal portion having an end surface and a slot having an opening along the end surface and extending rearwardly therein along the longitudinal axis; a tip end having a rear portion disposed within the slot and a forward portion extending forwardly away from the distal portion of the shank along the longitudinal axis thereof; and a material disposed within the slot between the rear portion of tip end and the distal portion of the shank to secure the tip end to the shank.

2. The dental instrument of claim 1, wherein the material comprises a filler metal to secure the tip end to the shank with a brazing process.

3. The dental instrument of claim 1, wherein the material comprises an adhesive.

4. The dental instrument of claim 1, wherein the tip end comprises a foil.

5. The dental instrument of claim 4, wherein the foil has superelastic flexibility at room temperature.

6. The dental instrument of claim 4, wherein the foil comprises a Nickel Titanium foil.

7. The dental instrument of claim 1, wherein the tip end comprises a spatula.

8. The dental instrument of claim 7, wherein the forward portion of the tip end has a curved configuration and the rear portion has a rectangular configuration.

9. The dental instrument of claim 1, wherein the shank comprises a steel shank.

10. The dental instrument of claim 1, wherein the material provides the only securing mechanism to secure the tip end to the shank.

11. The dental instrument of claim 1, wherein the slot extends entirely through the shank in a direction perpendicular to the longitudinal axis forming longitudinal openings along an exterior thereof.

12. The dental instrument of claim 1, wherein the end surface extends transverse to the longitudinal axis of the distal portion of the shank.

13. The dental instrument of claim 12, wherein the end surface has a rectangular configuration.

14. The dental instrument of claim 1, wherein the distal portion includes opposed tapering side surfaces extending to the end surface thereof.

15. The dental instrument of claim 14, wherein the shank comprises a cylindrical body, the tapering side surfaces having a parabolic configuration.

16. A method of manufacturing a dental instrument, the method comprising: providing a flexible tip end having a flat body with opposing planar main surfaces, the body including a retaining portion in a proximal end thereof; and forming a shank by at least one of 3D printing or injection molding around the retaining portion of the body, such that a distal portion of the shank is coupled to the retaining portion of the body to secure the flexible tip end to the shank, the shank configured to be coupled to a handle.

17. The method of claim 16, wherein the retaining portion of the body comprises one or more apertures extending therethrough; and forming the shank comprises at least one of 3D printing or injection molding material through the one or more apertures to secure the flexible tip end to the shank.

18. The method of claim 16, wherein the retaining portion of the body comprises one or more protrusions extending outwardly from the body; and forming the shank comprises at least one of 3D printing or injection molding material around the one or more protrusions.

19. The method of claim 16, wherein forming the shank comprises forming a shank in a bent configuration.

20. The method of claim 16, wherein forming the shank further comprises forming a handle with the shank at one end of the handle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above needs are at least partially met through provision of the embodiments described in the following detailed description, particularly when studied in conjunction with the drawings, wherein:

[0020] FIG. 1 is a perspective view of a dental instrument showing a handle with shanks coupled to opposite ends of the handle in accordance with various embodiments;

[0021] FIG. 2 is a perspective view of a shank having a bent configuration and a distal portion in accordance with various embodiments;

[0022] FIG. 3 is a perspective view of a portion of a distal portion of the shank of FIG. 2 with a flexible tip secured thereto and a pin in accordance with various embodiments;

[0023] FIG. 4 is a top plan view of a shank having a flexible tip secured thereto with a pin in accordance with various embodiments;

[0024] FIG. 5 is a perspective view of a flexible tip for a dental instrument with an aperture extending therethrough in accordance with various embodiments;

[0025] FIG. 6 is a side elevational view of the flexible tip of FIG. 5 in accordance with various embodiments;

[0026] FIG. 7 is a top plan view of the flexible tip of FIG. 5 in accordance with various embodiments;

[0027] FIG. 8 is top plan view of a shank having a flexible tip secured thereto with a plurality of pins in accordance with various embodiments;

[0028] FIG. 9 is a perspective view of a flexible tip for a dental instrument with a plurality of apertures extending therethrough in accordance with various embodiments; and

[0029] FIG. 10 is a perspective view of a portion of a distal portion of the shank of FIG. 8 with a flexible tip secured thereto with a material in accordance with various embodiments.

[0030] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Dental instruments, assemblies, and components for a dental instrument are described herein with a flexible tip end and a stiff shank. A two-material dental instrument component achieves these beneficial results by utilizing the preferred properties of the two materials. In embodiments, the shank can be a stiff material, such as stainless steel, and the tip end can be a NiTi foil, also known as Nitinol foil. Nitinol foil advantageously provides a flexible tip that resiliently bends without breaking.

[0032] Example configurations and components for a dental instrument 10 are shown in FIGS. 1-10. As shown in FIG. 1, the dental instrument 10 includes a handle portion 11 having a shaft configuration for a user to grip and manipulate the dental instrument 10. The handle portion 11 has opposite first and second ends 14, 16 that can be configured to have a shank 12 coupled thereto, if desired. In the illustrated form, the first and second ends 14, 16 have a tapered configuration to provide a transition to the relatively smaller diameter of the shank 12.

[0033] An example shank 12 is shown in FIG. 2 that includes a coupling end portion 17 configured to engage one of the ends 14, 16 of the handle 11, a tapering portion 18, first and second bends 20, 22, an intermediate portion 24 extending between the first and second bends 20, 22, and a distal portion 26 extending from the second bend 22 to a distal end 28 of the shank 12. The tapering portion 18 decreases a diameter of the shank 12 from adjacent to the handle 11 to the relatively smaller diameter intermediate and distal portions 24, 26, which can have a generally constant diameter.

[0034] The first bend 20 directs the shank 12 along a horizontal plane away from a longitudinal axis L (FIG. 1) of the handle 11 and the second bend 22 directs the shank 10 along the horizontal plane back towards the longitudinal axis L of the handle 11. In the illustrated form, the second bend 22 is a generally 90 degree bend and the intermediate portion 24 has a longer longitudinal length than the distal portion 26, such that the distal end 28 of the shank 10 is spaced from the longitudinal axis L of the handle 11 along the horizontal plane. Of course, other bend and length configurations are within the scope of this disclosure.

[0035] The distal end 28 of the shank 12 includes opposing planar sides 30 extending inwardly with respect to one another to a rectangular end surface 32. With the distal portion 26 being cylindrical, in the illustrated form, the planar sides 30 have a parabolic shape. A slot 34 with an opening 36 disposed along the end surface 32 extends within the distal portion 26 along a longitudinal axis X (FIG. 2) thereof to a desired depth. In the illustrated form, the slot 34 extends through the width of the distal end 28. In one example, and as depicted in FIG. 3, the slot 34 may further include openings 38 along an exterior 40 of the distal portion 26. The slot 34 can be cut into the distal end 28 of the shank 12 in a hatchet and/or hoe orientation by an electric discharge machining (EDM) wire, micro saw blade, mill, and so forth.

[0036] A tip end 42 is coupled to the distal end 28 of the shank 12 to provide desirable characteristics for a particular dental procedure. By one approach, and referring now to FIGS. 5-7, the tip end 42 is a spatula tip having a thin planar body 44 with a curved forward portion 46 and a rectangular rear portion 48. As discussed above, the shank 12 and tip end 42 are different materials and, as such, are secured together with a suitable method, examples of which are described below with reference to FIGS. 2-10. The tip end 42 also includes an aperture 54 extending through the rear portion 48 and corresponds to an aperture in the distal end 28 of the shank 12, as described more below.

[0037] In each securing example, the tip end 42 is inserted into the slot 34 to mount to the distal end 28 of the shank 12. The orientation of the planar sides 30 with respect to the horizontal plane can provide a hoe orientation for the tip end 42 or a hatchet orientation for the tip end 42, as desired. In addition, in each example, the shank 12 may comprise a stiff material, such as stainless steel, and the tip end 42 may comprise a NiTi foil, also known as Nitinol foil.

[0038] In one form, the dental instrument 10 includes shanks 12 on both sides 14, 16 of the handle 11 with one shank 12 having distal end 28 with a hoe orientation where the tip end 42 is generally orthogonal to the horizontal plane and the other shank 12 having a distal end 28 with a hatchet orientation where the tip end 42 is generally parallel with the horizontal plane to provide a user with both functionalities. Further, if desired, the tip end 42 and slot 34 can be configured so that forward portion 46 of the tip end 42 extends to intersect the longitudinal axis L of the handle 11 so that a user has precise manipulation of the tip end 42.

[0039] In a first embodiment, shown in FIGS. 2-7, the tip end 42 is secured to the distal end 28 of the shank 12 with a pin 50. More specifically, the distal end 28 of the shank 12 has an aperture 52 extending radially through a portion thereof including the slot 34 in a direction generally orthogonal to the longitudinal axis X of the distal portion 26. The aperture 54 of the tip end 42 corresponds to the aperture 52 of the distal end 28 of the shank 12. So configured, with the rear portion 48 inserted into the slot 34, the pin 50 can be inserted through both the aperture 52 and the aperture 54 to secure the tip end 42 to the shank 12. By one approach, the pin 50 can have a cross-section dimension greater than one or both of the apertures 52, 54 so that the insertion of the pin 50 therethrough creates an interference fit. Further, the pin 50 can be permanently joined to the shank 12 by swaging and grinding an outer surface 56 of the pin 50 so that the outer surface 56 is smooth and aligned with adjacent portions of the shank 12. In the illustrated form, the pin 50 and apertures 52, 54 are cylindrical. Of course, other shapes and configurations can alternatively be used. For example, the pin 50 and apertures 52, 54 can have a cross-section shape to aid in resisting rotation of the tip end 42, such as a triangle, square, star, ovular, and so forth.

[0040] In a second embodiment, shown in FIGS. 8 and 9, the shank 12 has a configuration similar to the above embodiment and, as such, only the differences will be described. In this form, the tip end 42 is secured to the distal end 28 of the shank 12 with a second pin 58 in addition to the first pin 50. As such, the distal end 28 of the shank 12 has a second aperture 60 that extends radially through a portion thereof including the slot 34 in a direction generally orthogonal to the longitudinal axis X of the distal portion 26. The second aperture 60 is spaced from the first aperture 52 along a length of the distal portion 26. The tip end 42 includes a corresponding second aperture 62 that extends through the rear portion 48 thereof, as depicted in FIG. 9. So configured, with the rear portion 48 inserted into the slot 34, the second pin 56 can be inserted through the aligned second apertures 60, 62 to further secure the tip end 42 to the shank 12. Using a plurality of pins 50, 58 accommodates a larger tolerance stack when installing the tip end 42 to the shank 12, which advantageously results in more efficiencies during manufacturing. For example, the length of the tip rear portion 48 is on the shorter end of the tolerance and the depth of the shank slot 34 is on the larger end of the tolerance, a gap would exist that would allow for rotation of the tip end 42. Using two or more points to secure the tip end 42 to the shank 12 prevents tip rotation in such a tolerance scenario.

[0041] By one approach, the second pin 58 can have a cross-section dimension greater than one or both of the second apertures 60, 62 so that the insertion of the second pin 58 therethrough creates an interference fit. Further, the second pin 58 can be permanently joined to the shank 12 by swaging and grinding an outer surface 64 of the second pin 58 so that the outer surface 64 is smooth and aligned with adjacent portions of the shank 12. In the illustrated form, the second pin 58 and apertures 60, 62 are cylindrical. Of course, other shapes and configurations can alternatively be used. For example, the pins 50, 58, and apertures 52, 54, 60, 62 can have a cross-section shape to aid in resisting rotation of the tip end 42, such as a triangle, square, star, ovular, and so forth. Further, although only two pins are shown, it will be understood that additional pins can be utilized and configured in a similar manner.

[0042] In a third embodiment, the slot 34 can have a wider configuration relative to the thickness of the tip end 42 as compared to the above embodiments. This allows the tip end 42 to be inserted into the slot 34 with little to no resistance. After the tip end 42 has been inserted into the slot 34 to a desired depth, a user can then pinch the planar sides 30 of or otherwise physically deform the distal end 28 of the shank 12 to clamp down on the tip rear portion 48 to secure the tip end 42 to the shank 12. This clamping action can be achieved by the use of any suitable tools.

[0043] In other embodiments, shown in FIG. 10, the tip rear portion 48 can be inserted into the slot 34 and secured therein using a third material 66. In a first example, the third material 66 is an adhesive disposed within the slot 34 or applied to the tip rear portion 48. In a second example, the third material 66 is a filler metal flowed into the joint between the tip end 42 and shank 12 in a brazing process. Utilizing an adhesive or a brazing process secures the tip end 42 to the shank 12 without the added steps and components of the above embodiments including forming the apertures 52, 54, 60, 62 and inserting the pins 50, 58. Of course, an adhesive or brazing process can alternatively be used in combination with the pin embodiments discussed above to ensure that the tip end 42 is securely coupled to the shank 12.

[0044] A stainless steel shank provides several advantages, including: a stiffness that provides maximum control and manipulation of the tip end for a user, good material formability enabling a two-bend shank configuration that allows a user access and visibility inside a patient's mouth, no reduction in appearance or strength of the shank after being sterilized multiple times, patient bio-compatibility, and a relatively low cost manufacturing to obtain a desired shank geometry.

[0045] A Nitinol foil tip end provides several advantages, including: superelastic flexibility at room temperature, about 10-30 times ordinary metal, for spreading and controlling composite onto a tooth, implant surface, or other application location, very good strain recovery allowing for excellent kink resistance even at very aggressive bend angles, an advantageous shape memory effect allowing the foil to recover an original shape upon heating above a transformation temperature after being deformed at a lower temperature, the Nitinol foil tip can be cut into a variety of tip end shapes allowing for a range of surface access and orientations, ability to sterilize the instrument multiple times with no reduction in appearance, flexibility, or strength, and patient bio-compatibility.

[0046] Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the scope of the invention, and that such modifications, alterations, and combinations are to be viewed as being within the ambit of the inventive concept.

[0047] For example, the shank 12 can alternatively be composed of plastic, coated steel, or other suitable rigid material. Additionally, the shank 12 may be 3D printed into a desired shape, such as the two bend configuration described above, out of a suitable material, including steel, plastic, or other rigid material. Alternatively, the shank 12 can be injection molded into a desired shape. Further, if desired, the shank 12 can be 3D printed or injection molded around a flexible tip end 42 configured as described above. The tip end 42 can include a retaining portion, such as the apertures 54, 60 described above, or other protrusion(s) and fixed in position as the shank 12 is 3D printed or molded therearound. With the retaining portion, the tip end 42 can be fixedly secured to the shank 12. Still further, the tip end 42 may be composed of an alternate material, such as plastic, stainless steel, or a coated steel.