ANNULAR RESILIENT RETENTION MEMBER

Abstract

A dental tool, such as an insertion tool for a dental implant, including a shaft extending along a longitudinal axis and having a distal end and a proximal end, the tool further including an annular resilient retention member formed of a metal material and connected to the shaft such that at least a section of the member protrudes from a surface of the shaft.

Claims

1. A dental tool comprising: a shaft extending along a longitudinal axis and including a distal end and a proximal end, and a distal end region of the tool comprising a functional element, the functional element comprising a metal annular resilient retention member for axially retaining a cooperating component, wherein the annular resilient retention member is a band.

2. The dental tool according to claim 1, wherein the band is discontinuous.

3. The dental tool according to claim 1, wherein the annular resilient retention member is formed from titanium, a titanium alloy, or stainless steel.

4. The dental tool according to claim 1, wherein the annular resilient retention member is formed of the same material as the shaft of the dental tool at a location at which the annular resilient retention member is connected.

5. The dental tool according to claim 1, wherein the band has at least one protrusion on its outer surface.

6. The dental tool according to claim 5, wherein the band comprises at least one kink.

7. The dental tool according to claim 1, wherein the band comprises a ring.

8. The dental tool according to claim 1, wherein a proximal end region of the tool comprises a connection means for connection to a manipulating device, the connection means comprising a further metal annular resilient retention member.

9. The dental tool according to claim 8, wherein the connection means further comprises a torque receiving section for receiving torque from a manipulating device.

10. The dental tool according to claim 1, wherein the shaft comprises an annular groove dimensioned to accommodate the annular resilient retention member.

11. The dental tool according to claim 10, wherein a depth of the annular groove is less than a cross-sectional diameter of the band such that the band protrudes beyond the annular groove.

12. The dental tool according to claim 1, wherein the annular resilient retention member is connected to an external surface of the shaft.

13. The dental tool according to claim 1, wherein the functional element further comprises a torque applying means suitable for transmitting torque to a dental implant, and the annular resilient retention member is configured to axially connect the dental implant to the tool.

14. The dental tool according to claim 1, wherein the band comprises a circumferential gap.

15. The dental tool according to claim 1, further comprising a shoulder on a proximal end side of the annular resilient retention member along the longitudinal axis of the tool.

16. The dental tool according to claim 1, further comprising a break zone located between the distal end and the proximal end, the break zone being adapted to break above a predetermined amount of torque, wherein the annular resilient retention member is positioned distally of the break zone.

17. A combination comprising: a dental tool; and a dental implant; the dental tool comprising a shaft extending along a longitudinal axis and including a distal end and a proximal end, a distal end region of the tool comprising a functional element, the functional element comprising a metal annular resilient retention member for axially retaining the dental implant, wherein the annular resilient retention member is a band.

Description

[0075] FIG. 1 shows a perspective view of a first embodiment of the present invention;

[0076] FIG. 2 shows a side view of the embodiment shown in FIG. 1;

[0077] FIG. 3 shows a longitudinal cross-section of the insertion tool of FIG. 1 in combination with an implant and drive tool;

[0078] FIG. 4 shows a cross-section along the plane A-A shown in FIG. 3;

[0079] FIG. 5 shows detail X of FIG. 4;

[0080] FIG. 6 shows a perspective view of a second embodiment of the present invention;

[0081] FIG. 7 shows a side view of the embodiment shown in FIG. 6;

[0082] FIG. 8 shows a longitudinal cross-section of the insertion tool of FIG. 6 in combination with an implant and a drive tool;

[0083] FIG. 9 shows a longitudinal cross-section of a third embodiment of an insertion tool in accordance with the present invention in combination with an implant;

[0084] FIG. 10 shows a resilient retention ring according to the present invention in isolation;

[0085] FIG. 10A shows a cross-section along line E-E of FIG. 10; and

[0086] FIG. 11 shows a perspective view of a fourth embodiment of the present invention.

[0087] As shown in FIGS. 1 and 2, an insertion tool 2 according to the present invention comprises a tool shaft 4 extending along a longitudinal axis L from a proximal end 6 to a distal end 8.

[0088] In the region of the proximal end 6, a connection means 10 is formed, which comprises a torque receiving means 12 adapted for receiving torque from a manipulating tool.

[0089] In the embodiment shown, the torque receiving means 12 has the form of a polygonal cylinder, more specifically of an octagonal cylinder. The torque receiving means 12 thus has an external lateral surface having eight flat areas angularly spaced about the longitudinal axis L, each of them forming a torque receiving surface 14. As can be seen, the corners of the octagon are rounded off to prevent sharp edges.

[0090] The connection means 10 of the insertion tool 2 further comprises a resilient C-ring 15 made of TAN. In order to hold the ring 15 in place, the tool shaft comprises an annular groove 56 on its external surface. The TAN ring 15 is positioned in the annular groove 56 and is thus sandwiched between and held in place by clamping sections 54a, 54b.

[0091] At least a section of the outer diameter of ring 15 protrudes from the outer diameter of the clamping sections 54a, 54b. The surface of the protruding section of the ring allows a friction-fit or snap fit to be established with the internal surface of the sleeve of a manipulating device.

[0092] At the distal end 8 of insertion tool 2, a functional element 18 is formed which comprises a torque applying means 20 adapted for applying torque—received by the insertion tool at the torque receiving means 12—to the dental implant.

[0093] In the embodiment shown, the torque applying means 20 is a non-circular cylindrical section, the lateral surface 22 of which having four longitudinal grooves 24 angularly spaced around the longitudinal axis L by 90°. Each groove 24 is curved over a radius, such that the cross-section of the grooves in the direction perpendicular to the longitudinal axis L is arc-shaped. The curved surface of each groove 24 forms a torque applying surface.

[0094] Between the connection means 10 and the functional element 18, the tool shaft 4 comprises a break zone 32, which is designed to break above a predetermined amount of torque T.sub.break. In the embodiment shown, the break zone 32 is a narrow section of reduced diameter arranged between two cylindrical sections 34a, 34b of a larger diameter. Break zone 32 forms the narrowest part of the insertion tool 2.

[0095] Between the torque applying means 20 and the break zone 32, the tool shaft 4 comprises an auxiliary torque receiving means 36 which is also adapted for receiving torque from a manipulating device. In the embodiment shown, the cross-sectional contour of the auxiliary torque receiving means 36 is substantially identical to the primary torque receiving means 12 as both torque receiving means 12, 36 have the basic form of a regular polygonal cylinder and have an identical octagonal basic area shape. The external lateral surface of the auxiliary torque receiving means 36 therefore provides eight flat areas angularly spaced about the longitudinal axis L, each of them forming a torque receiving surface 37.

[0096] The orientation holes 33 which are located on every second auxiliary torque receiving surface 37 indicate to the user the orientation of the anti-rotation surfaces of the attached implant. Thus, the surgeon can insert the implant into the bone at a desired angular orientation.

[0097] Directly apically adjacent to the torque applying means 20, an extension section 38 in the form of a circular cylinder of reduced diameter is formed. From this, axial retention means 39, comprising two identically formed longitudinal dental implant retention arms 40a, 40b, extends. The dental implant retention arms 40a, 40b are separated from each other by a longitudinal slit 42 having an axis coinciding with the longitudinal axis L of the insertion tool 2; they are thus arranged symmetrically about the longitudinal axis L of the insertion tool 2.

[0098] In the longitudinal direction, a first portion 44a, 44b of both dental implant retention arms 40a, 40b, which are directly adjacent to the extension section 38, form stems. Due to the thinness of the first portions 44a, 44b, they are resiliently deflectable towards the longitudinal axis L of the insertion tool.

[0099] Apical of the first portions 44a, 44b the outer diameter of the dental implant retention arms 40a, 40b, increases and forms a bulge 48a, 48b.

[0100] In use, the insertion tool 2 is brought into engagement with a dental implant 100 by inserting the functional element 18 into the implant bore 101, as shown in FIG. 3. The resilient dental implant retention arms 40a, 40b are thereby compressed inwardly and thus deflected towards the longitudinal axis L. Since the outer radius of the bulges 48a, b is greater than the radius of the implant bore 101 at the axial location at which the bulges 48a, b are located, the dental implant retention arms 40a, 40b try to return to their rest position and thereby contact and press outwardly against the internal wall of the implant bore 101, which creates a press or interference fit between the dental implant 100 and the insertion tool 2. Thus, the dental implant 100 is releasably axially held by the insertion tool 2 and accidental disconnection of the two components is prevented.

[0101] In the present embodiment the insertion tool 2 is prevented from being inserted too deeply into the implant bore 101 by shoulder 31, which in use abuts against the coronal end 104 of the implant 100.

[0102] When the insertion tool 2 is inserted into the implant bore 101, the two components are fixed anti-rotationally, which ultimately allows torque to be transmitted to the dental implant. To this end, the implant bore 101 comprises an anti-rotation means 102 having four radially inwardly protruding projections 103, each providing anti-rotation surfaces complementary to the respective torque applying surfaces of the torque applying means 20.

[0103] This can be seen most clearly in FIG. 4, which shows a cross-section through the aligned anti-rotation means 102 and torque applying means 20. Each of the projections 103 contacts a groove 24 of the torque applying means 20. When the insertion tool 2 is rotated in the direction indicated in FIG. 4 the surface of the grooves 24 is brought into contact with the protrusions 103 as shown in detail in FIG. 5. This contact occurs in the same area of each groove and protrusion, thus providing an evenly distributed transmission of torque. As can be seen in FIG. 5, minimal surface contact is achieved between the groove 24 and protrusion 103, thus reducing the possibility for jamming.

[0104] For applying torque to the insertion tool 2, the primary torque receiving means 12 is brought into engagement with a manipulating device 200.

[0105] The manipulating device 200 has at its distal end a hollow sleeve 201 into which the connection means 10 of the insertion tool 2 can be inserted. Flat surface areas on the interior surface of sleeve 201 form torque transmitting surfaces 202. In the present embodiment these surfaces form an octagonal cross-section matching the torque receiving surfaces 14 of the insertion tool 2. When engaged, the torque transmitting surfaces 202 of the manipulating device 200 and the torque receiving surfaces 14 of the insertion tool 2 are in non-rotational alignment with each other, thus providing for torque transmission between the components.

[0106] Distal of the torque transmitting surfaces 202, sleeve 201 comprises an annular groove 205. This recess is dimensioned to have a diameter greater than the diameter of TAN ring 15. Distal of the groove 205, at the distal end of the sleeve 201, the walls form a constriction 206. The diameter of the sleeve at this constriction 206 is approximately equal to the diameter of clamping sections 54a, b of shaft 4. As the ring 15 has at least one section which protrudes beyond clamping sections 54a, b this must distort as it passes through constriction 206. Once the ring 15 is moved into alignment with the groove 205 this can return to its rest position. This “springing” or “snapping” back into its original shape informs the user that connection to the manipulating device 200 has been achieved. Furthermore, in order to move ring 15 back through constriction 206 force is required to again compress the ring 15. Therefore, until this force is supplied, ring 15 holds the insertion tool 2 in axial engagement with the manipulating device 200.

[0107] For inserting the dental implant into the implantation site, torque is applied from the manipulating device 200 to the insertion tool 2 which transmits torque to the dental implant 100. Torque can be applied to the manipulating device 200 via the human hand gripping handle 203. Handle 203 comprises angularly spaced longitudinal grooves 204, which can alternatively be engaged by a suitably shaped wrench or ratchet.

[0108] FIGS. 6 and 7 show an alternative insertion tool 3 according to the present invention which differs from the embodiment shown in FIG. 1 mainly in the design of the functional element 18. Where appropriate the same reference numerals are used for each embodiment.

[0109] The connection means 10 is substantially identical to that of the first embodiment, in particular in the provision of a TAN resilient retention C-ring 15 located within an annular groove 56 on the exterior of the tool shaft 4.

[0110] At the distal end 8 of the tool 3, the axial retention means 39 of the first embodiment has been replaced by axial retention means 49, which consists of a circular cylindrical section 43 having an annular groove 46 on its exterior surface. The groove 46 is sized to accommodate resilient TAN C-ring 45. The depth of groove 46 is less than the cross-sectional diameter of ring 45, such that this protrudes beyond the groove 46 and the surface of the cylinder 43.

[0111] Torque applying means 20 is formed by a section having a generally octagonal cross-section, thus it comprises eight angularly spaced torque applying surfaces 25. Each surface 25 is curved over a radius, such that the cross-section of the each surface in the direction perpendicular to the longitudinal axis L is arc-shaped. In other embodiments however the surfaces 25 may be planar.

[0112] The difference in the shape of the toque applying means 20 enables the insertion tool 3 to be used with a different implant.

[0113] FIG. 8 shows the insertion tool 3 of FIG. 6 in combination with a dental implant 300 and the same manipulating device 200 as shown in FIG. 3.

[0114] Dental implant 300 is similar to dental implant 100 except that the anti-rotation means 302 has an octagonal cross-section. The torque applying means 20 can thus engage with this in a non-rotational manner to transmit torque to the implant 300.

[0115] Cylindrical section 43 has a diameter substantially equal to distal end 305 of implant bore 301, which may or may not be threaded. As discussed above, ring 45 protrudes beyond the outer surface of cylindrical section 43 and so, upon insertion into distal end 305, ring 45 is compressed. The force exerted by ring 45 on the walls of distal section 305, as the ring 45 attempts to revert to its rest shape, creates a press fit, otherwise known as a friction or interference fit, thus axially retaining the insertion tool 3 within the implant 300.

[0116] In the present embodiment the insertion tool 3 is prevented from being inserted too deeply into the implant bore 301 by shoulder 31, which in use abuts against the coronal end 304 of the implant 300, although such an abutment surface is not necessary.

[0117] At the opposing end of insertion tool 3, resilient ring 15 operates as described above in relation to FIG. 3 in order to create a snap-fit connection to the manipulating device 200. Resilient ring 15 is designed to have a greater pull off force than ring 45, such that after the implant has been inserted into the jawbone and force is applied to the insertion tool in a direction away from the implant, the insertion tool disengages first from the implant. This eases the handling of the system as both the insertion tool 3 and manipulating device 200 can be removed from the implantation site in one action.

[0118] In an alternative to the embodiment shown in FIG. 8, a resilient metal retention ring can be positioned and dimensioned to fit within an undercut within implant 300, thus creating a snap fit between the insertion tool 3 and implant 300.

[0119] This is shown in FIG. 9, in which the same reference numerals are used where appropriate.

[0120] Insertion tool 4 is identical to insertion tool 3 of FIGS. 6-8 with the exception that cylindrical section 43 does not comprise a groove. Instead, an annular groove 47 is located directly apical of the torque applying means 20. A resilient metal C-ring 48 is accommodated within this groove 47 such that at least a section of the ring 48 protrudes beyond the groove 47.

[0121] Implant 300 comprises, directly apical of the anti-rotation means 302, an undercut 307 having a greater diameter than the anti-rotation means 302. As the functional end of the insertion tool is inserted into the implant bore 301, ring 48 is compressed until it is brought into alignment with the undercut 307. At this point the ring is able to return to its rest position, causing a “snap” sensation which is felt by the user. This informs the user that the correct axial alignment between the insertion tool 4 and the implant 300 has been achieved and further the positioning of the ring 48 in the undercut 307 axially holds the implant 300 on the insertion tool 4.

[0122] FIG. 10 shows a plan view of a resilient retention ring 70 of the present invention in isolation. Such a ring could be used in any of the above discussed embodiments at either the distal or proximal end of the tool.

[0123] Ring 70 is a C-ring and has a circumferential gap G. This enables the ring 70 to compress and provides a spring force to bias this towards its rest shape (which is shown in FIG. 10). Gap G extends over an angle of approximately 90°.

[0124] As can be seen in FIG. 10, ring 70 does not follow a circular path about central axis A but instead comprises a kink 71. This kink is formed by a section of ring 70 which is bent around an axis B remote from the central axis A at a smaller radius of curvature than the remaining ring section. As a result the kink 71 forms a protrusion, that is, it extends further from the central axis A than the remainder of the ring. In addition, the kink 71 acts as a lever arm which increases the retentive force provided by the ring 70.

[0125] If desired further kinks could be added to the ring 70, although in general, in situations in which the ring is intended for cooperation with a circular recess or wall, a single kink is preferred for simplicity.

[0126] The cross-section of ring 70 in a plane perpendicular to longitudinal axis L of the ring 70 is shown in FIG. 10A. The ring has a circular cross-section, although other cross-sections are possible. The diameter D of the ring 70 is equal to its longitudinal length L. When the longitudinal length L is more than twice as large as the diameter D the annular resilient member is considered to be a sleeve. Such sleeves may also comprise kinks of the type shown in FIG. 10, however they may also comprise protrusions located only at a certain longitudinal location of the sleeve, e.g. a circumferential bulge may run about the middle of the sleeve.

[0127] Returning to FIG. 10A, the diameter D of ring 70 can be larger than the groove 56, 46, 47 in which, in use, the ring 70 is housed. This enables the ring 70 to form a press or snap fit with a cooperating component. Alternatively only the kink 71 or kinks, where present, may be shaped to protrude from the groove 56, 46, 47, such that there is only a predetermined number of points of contact. For example, when a single kink is used there will be only one point of contact between the ring 70 and the co-operating device, e.g. manipulating tool, implant etc.

[0128] The previous three embodiments show examples of dental tools in which the resilient rings of the present invention are attached to the exterior of the shaft. FIG. 11 shows a basic representation of a tool in which the ring is located on the interior of the tool.

[0129] Dental tool 80 comprises a shaft 84 extending along a longitudinal axis L from a proximal end 86 to a distal end 88. The tool is hollow at its distal end 88, creating a sleeve 82. The interior wall of sleeve 82 comprises an annular groove 83, which is dimensioned to house a resilient metal ring, such as that shown in FIG. 10. The groove 83 has a depth dimensioned such that the at least a portion of the ring protrudes from the interior surface of the sleeve 82. In this way, the ring can form a press or snap fit with the external surface of a device or component over which the sleeve 82 is placed. For example, the sleeve may be dimensioned to fit over the coronal end of implant 300 such that a ring housed within groove 83 can form a snap-fit connection to the external undercut 308 formed by the flared neck portion of the implant.

[0130] The proximal end 86 of the tool 80 comprises a torque receiving means 12 and groove 56 of the type described in detail in relation to FIGS. 1 and 2. A resilient metal ring housed in groove 56 can thus be used to axially attach the tool 80 to a manipulating device. Of course, it is also possible that the proximal end 86 of the tool 80 comprises a hollow sleeve with an internal resilient ring. The shape and positioning of the ring at either end will depend on the type and shape of the device to which it is intended to fasten the tool 80.

[0131] The above described embodiments are for illustrative purposes only and the skilled man will realize that many alternative arrangements are possible which fall within the scope of the claims. In particular, the resilient ring could be replaced by another form of resilient annular member such as a sleeve or integral section of the tool shaft. The ring could be made from any suitable flexible, biocompatible metal, such as titanium or steel. The dental tool can be any known dental tool which currently comprises an elastomeric retention ring, such as a dental drill or other surgical tool.

[0132] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.