Abutment screw removal instruments and auxiliary devices

Abstract

The present invention comprises an engagement portion which is provided on a distal end side and engages with an end portion of a fractured abutment screw on a fractured surface side from the radially outside of the abutment screw and a shaft which is provided on a base end side with respect to the engagement portion and extends from the engagement portion in the axial direction. The engagement portion is formed into a tubular shape and an inner surface of the engagement portion engages with the end portion of the abutment screw on the fractured surface side. Moreover, a slit which extends from the distal end of the engagement portion toward the base end side in the axial direction and passes through the engagement portion in the radial direction is formed in the engagement portion.

Description

[Technical Field]

[0001] SUMMARY The present disclosure relates to abutment screw removal instruments and auxiliary instruments. [Background technology]

[0002] Patent Document 1 discloses an instrument used to remove a screw base that has been screwed into a dental implant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-137052 Summary of the Invention [Problem to be solved by the invention]

[0004] In the device disclosed in Patent Document 1, a barbed spike is pressed against the upper end surface of the screw device, and torque is simultaneously applied to the device, thereby rotating the screw device. However, in reality, the diameter of the screw device is very small, so it is difficult to apply sufficient torque to the screw device, and the screw base cannot be easily removed.

[0005] Therefore, in one aspect, an object of the present disclosure is to provide an abutment screw removal instrument that can easily remove an abutment screw by applying an appropriate torque to the abutment screw. [Means for solving the problem]

[0006] In one embodiment, an engaging portion provided on the distal end side and adapted to engage with the end portion of the broken abutment screw on the fractured surface side from the radially outer side of the abutment screw; a shaft provided on the base end side of the engaging portion and extending in the axial direction from the engaging portion; An abutment screw removal instrument is provided, comprising: [Effects of the Invention]

[0007] In one aspect, the present disclosure allows the abutment screw to be easily removed by applying an appropriate torque to the abutment screw. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are diagrams showing the configuration of an abutment screw removal instrument according to the present embodiment. [Figure 1A] 2 is a diagram showing the abutment screw removal instrument of the present embodiment as viewed from below in FIG. 1. FIG. [Figure 1B] FIG. 10 shows the abutment screw removal tool attached to a low-speed dental engine. [Figure 1C] FIG. 10 is a diagram showing an example in which the shape of the base end side of the shaft is adapted to a low-speed dental engine. [Figure 2] FIG. 1 is a cross-sectional view showing the configuration of a dental implant. [Figure 2A] FIG. 10 is a cross-sectional view showing a state in which the abutment screw has fractured. [Figure 2B] 10A to 10C are cross-sectional views showing a method of using the abutment screw removal instrument of the present embodiment. [Figure 2C] 10A to 10C are cross-sectional views showing a method of using the abutment screw removal instrument of the present embodiment. [Figure 2D] 10A to 10C are cross-sectional views showing a method of using the abutment screw removal instrument of the present embodiment. [Figure 2E] 10A to 10C are cross-sectional views showing a method of using the abutment screw removal instrument of the present embodiment. [Figure 3] 10A and 10B are diagrams showing other forms of the engagement portion. [Figure 4] 10A and 10B are diagrams showing other forms of the engagement portion. [Figure 4A] 10A and 10B are diagrams showing other forms of the engagement portion. [Figure 5]10A and 10B are diagrams showing the configuration of an auxiliary instrument that can be used in combination with the abutment screw removal instrument. [Figure 5A] 6 is a diagram showing the auxiliary device as seen from below in FIG. 5. FIG. [Figure 5B] FIG. 10 is a diagram showing a state in which an adhesive member is attached to the auxiliary device. [Figure 5C] 5C is a diagram showing the auxiliary tool and adhesive member as viewed from below in FIG. 5B. FIG. [Figure 6] 10A and 10B are cross-sectional views showing how to use the assistive device. [Figure 6A] 10A and 10B are cross-sectional views showing how to use the assistive device. [Figure 6B] 10A and 10B are cross-sectional views showing how to use the assistive device. [Figure 6C] 10A and 10B are cross-sectional views showing how to use the assistive device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Figure 1 is a diagram showing the configuration of the abutment screw removal instrument of this embodiment, Figure 1A is a diagram showing the abutment screw removal instrument of this embodiment as viewed from below (line IA-IA direction) in Figure 1, Figure 2 is a cross-sectional view showing the configuration of a dental implant, Figure 2A is a cross-sectional view showing a state in which the abutment screw has broken, and Figures 2B to 2E are cross-sectional views showing how to use the abutment screw removal instrument of this embodiment.

[0010] As shown in FIG. 1, the abutment screw removal instrument 10 of this embodiment includes an engagement portion 11 and a shaft 12.

[0011] As shown in FIG. 1, the engagement portion 11 is provided on the distal end side (lower end side in FIG. 1) of the abutment screw removal instrument 10 in the axial direction (up and down direction in FIG. 1). The engagement portion 11 engages with the end of the fractured surface side of the fractured abutment screw 20 (FIGS. 2 to 2D) from the radial outside of the abutment screw 20. The shaft 12 is provided on the proximal end side (upper end side in FIG. 1) of the abutment screw removal instrument 10 in the axial direction relative to the engagement portion 11, and extends in the axial direction from the engagement portion 11. The abutment screw removal instrument 10 may be made of any material; however, for example, a metal that is not harmful to the living body and has appropriate elasticity, strength, and frictional force is suitable as the material for the abutment screw removal instrument 10.

[0012] As shown in Figures 1 and 1A, the engaging portion 11 is formed in a cylindrical shape having an inner surface 11b. The engaging portion 11 also has a pair of slits 11a formed therein, which extend axially from the tip (the lower end in Figure 1) of the engaging portion 11 toward the base end and penetrate the cylindrical engaging portion 11 in the radial direction. As shown in Figures 1 and 1A, the pair of slits 11a are provided at positions symmetrical to each other with respect to the axis of the abutment screw removal instrument 10. The pair of slits 11a function to easily open the tips of the engaging portion 11 by elastic deformation when the abutment screw removal instrument 10 is in use.

[0013] The number of slits 11a is optional, and three or four or more slits 11a may be provided in the circumferential direction of the engaging portion 11. In this case, it is desirable to provide the multiple slits 11a at equal intervals in the circumferential direction of the engaging portion 11.

[0014] An operating part 12a is provided on the base end side of the shaft 12. As shown in Fig. 1, the surface of the operating part 12a is formed with a non-slip texture that facilitates rotational operation using a dental low-speed engine or fingers.

[0015] 1B is a diagram showing the abutment screw removal tool attached to the low-speed dental engine. As shown in FIG. 1B, the abutment screw removal tool 10 is attached to the low-speed dental engine 40 by inserting the operating part 12a into the mounting part 41 of the low-speed dental engine 40 and tightening the mounting part 41. Furthermore, when using the low-speed dental engine 40, the base end side of the shaft 12 may have a shape different from that of the operating part 12a so as to be compatible with mounting to the mounting part 41 of the low-speed dental engine 40.

[0016] 1C is a diagram showing an example in which the shape of the base end side of the shaft is adapted to a low-speed dental engine. In the example of FIG. 1C, a small-diameter portion 12b, which is smaller in diameter than the other portions, is formed on the base end side of the shaft 12. The abutment screw removal tool 10 is then attached to the low-speed dental engine 40 with the small-diameter portion 12b engaged with the attachment portion 41 of the low-speed dental engine 40.

[0017] Next, a method of using the abutment screw removal tool 10 will be described.

[0018] 2, the dental implant includes an implant body 31 that is screwed into a bone-flesh portion 30 (bone portion 30A) consisting of a bone portion 30A and a flesh portion 30B, and a cylindrical abutment 32 to which an artificial tooth 33 is attached. A female thread 31a (FIG. 2E) is formed in the implant body 31, and an abutment screw 20 that passes through the abutment 32 is screwed into the female thread 31a, thereby fixing the abutment 32 to the implant body 31.

[0019] 2A shows a state in which the abutment screw 20 has fractured. The abutment screw 20 may fracture if an excessive mechanical load is applied to the abutment 32. Generally, as shown in FIG. 2A, the fractured surface 20a of the abutment screw 20 is located inside the implant body 31, making it difficult to remove the fractured abutment screw 20, which has traditionally often caused clinical problems.

[0020] A specific factor that causes clinical problems is that, because the implant is located submucosally, it is often difficult to visually check the broken abutment screw 20. Another problem is that the diameter of the broken abutment screw 20 is small (for example, about 1 mm), and there is no effective way to apply counterclockwise rotational torque. Furthermore, if mechanical damage is caused to the inside of the implant when removing the broken abutment screw 20, it becomes impossible to replace it with a new abutment screw 20, and thereafter the implant body 31 becomes unusable. These problems can be solved by using the abutment screw removal tool 10 of this embodiment.

[0021] 2B to 2E show the procedure for removing a fractured abutment screw 20 using the abutment screw removal tool 10. When removing the abutment screw 20, first, as shown in FIG. 2B, the abutment screw removal tool 10 is moved axially (downward in FIG. 2B). Next, as shown in FIG. 2C, the end of the abutment screw 20 on the fracture surface 20a side is inserted into the tip of the engagement part 11 (the lower end in FIG. 2B). At this time, the tip of the engagement part 11 is elastically deformed in the opening direction, and the inner surface 11b of the engagement part 11 abuts against the side surface 20b of the abutment screw 20 (FIGS. 2A and 2B). Therefore, due to the elastic force of the engagement part 11, the side surface 20b of the abutment screw 20 is pressed down by the engagement part 11 from the radially outer side. The abutment screw 20 is pressed by the engaging portion 11 from the radially outer side via the side surface 20b, and is held by the abutment screw removal tool 10 by the frictional force between the side surface 20b and the inner surface 11b (FIGS. 1 and 1A). In this way, the abutment screw removal tool 10 holds the abutment screw 20 by elastic force and frictional force.

[0022] Next, as shown in FIGS. 2C to 2E, when the abutment screw removal tool 10 is rotated around its axis in a predetermined direction (for example, counterclockwise when viewed from the base end) using a low-speed dental engine 40 (FIG. 1B) or by hand (FIG. 2C), the abutment screw 20 also rotates in the same direction. As a result, the abutment screw 20 moves axially toward the base end together with the abutment screw removal tool 10. When the engagement between the abutment screw 20 and the implant body 31 is completely released, the abutment screw 20 is removed from the implant body 31 (FIGS. 2D to 2E).

[0023] As described above, in this embodiment, the abutment screw 20 is pressed by the engaging portion 11 from the radially outer side via the side surface 20b due to the elastic force of the engaging portion 11, and is held in place by the frictional force between the side surface 20b and the inner surface 11b (FIGS. 1 and 1A). Therefore, a torque sufficient to rotate the abutment screw 20 can be applied by operating the abutment screw removal tool 10. Therefore, the abutment screw 20 can be easily removed from the implant body 31.

[0024] On the other hand, the instrument disclosed in Patent Document 1 (JP 2010-137052 A) attempts to rotate the screw instrument by pressing a barbed spike against the upper end surface of the screw instrument and simultaneously applying torque to the instrument. However, the diameter of the abutment screw 20 is very small, and the abutment screw 20 is typically formed of a hard material such as a titanium alloy. Therefore, it is difficult to insert the barbed spike into the fracture surface 20a, making it difficult to apply sufficient torque to rotate the abutment screw 20. Furthermore, by strongly pressing the barbed spike, the frictional force at the fracture surface 20a can be increased, thereby increasing the torque that can be applied to the abutment screw 20. However, this also results in the abutment screw 20 being pressed axially against the implant body 31 with a large force, which increases the friction between them. In other words, as the friction between the abutment screw 20 and the implant body 31 increases, the torque required to rotate the abutment screw 20 also increases. Therefore, even if the barbed spike is pressed hard to rotate it, a torque in the opposite direction due to the frictional force between it and the implant body 31 is applied to the abutment screw 20, which ultimately makes it difficult to rotate the abutment screw 20. Furthermore, pressing the barbed spike hard against the abutment screw 20 may damage the implant body 31.

[0025] In contrast, with the abutment screw removal tool 10 of this embodiment, the engagement portion 11 engages with the side surface 20b of the abutment screw 20. Therefore, a strong axial force is not applied to the abutment screw 20, and the frictional force between the abutment screw 20 and the implant body 31 is maintained at a low level. As a result, even if a small torque is applied to the abutment screw 20, the abutment screw 20 can be rotated and removed. In other words, with the abutment screw removal tool 10, the torque required for removal can be easily applied to the abutment screw 20. Therefore, the above-mentioned problems can be avoided.

[0026] 3, 4 and 4A are diagrams showing other forms of the engagement portion.

[0027] In the example of FIG. 3, an example is shown in which, instead of the engaging portion 11, an engaging portion 11A having a tip portion with a tapered cross section is formed.

[0028] As shown in FIG. 3, the engagement portion 11A has a tapered surface 11c formed continuously from the inner surface 11b. This tapered surface 11c is shaped so that the inner diameter of the engagement portion 11A increases toward the tip (the lower end in FIG. 3). In this case, during the process of inserting the abutment screw 20 into the engagement portion 11A (FIGS. 2B to 2C), the tapered surface 11c serves as a guide to guide the abutment screw 20, allowing the engagement portion 11A to easily engage with the abutment screw 20. This also increases the tolerance for differences in the diameter of the abutment screw 20. That is, the diameter of the abutment screw 20 varies slightly depending on the manufacturer and type of dental implant. To accommodate multiple diameters, it is necessary to prepare multiple abutment screw removal tools 10 with different inner diameters of the engagement portion 11 (engagement portion 11A). However, by forming the tapered surface 11c on the engagement portion 11A, it becomes possible to accommodate differences in the diameter of the abutment screw 20 to some extent by adjusting the insertion depth into the engagement portion 11A. This improves the workability when inserting the abutment screw 20 into the engagement portion 11A. It also reduces the number of abutment screw removal instruments 10 with different inner diameters. For example, it is possible to increase the interval between the inner diameters of the abutment screw removal instruments 10 that need to be prepared.

[0029] The example in FIG. 4 shows an engaging portion 11B in which, in a cross section perpendicular to the axial direction, instead of the circular tapered surface 11c (FIG. 3), an uneven surface 11d having radially unevenness is formed. By forming such an uneven surface 11d, the frictional force between the abutment screw 20 and the engaging portion 11B can be increased. That is, the fracture surface 20a does not usually have a clean flat shape, and unevenness is generated at the edge of the fracture surface 20a. Therefore, when such unevenness and the uneven surface 11d interlock with each other, the frictional force between the abutment screw 20 and the engaging portion 11B is increased, making it easier to apply torque to the abutment screw 20. Note that, similar to the tapered surface 11c (FIG. 3), the uneven surface 11d can also be given a shape in which the inner diameter as a whole increases toward the tip (the lower end of FIG. 3) to achieve the same effect as the tapered surface 11c.

[0030] The example in FIG. 4A shows an engaging portion 11C having a wavy tip with multiple spikes 11e arranged in the circumferential direction. In the example in FIG. 4A, a tapered surface similar to the tapered surface 11c (FIG. 3) is formed at the tip of the engaging portion 11C, and spikes 11e are formed in the area where this tapered surface is formed. In this case, the tips of the spikes 11e can be pressed against the fractured end (fracture surface 20a) of the abutment screw 20 to gradually rotate the abutment screw 20. Then, after slightly moving the fractured end upward, the stump of the abutment screw 20 can be embraced from the side and torque can be applied to remove the abutment screw 20. Therefore, as with the case of using the auxiliary tool 50 described below, this can also be used when the side surface 20b of the abutment screw 20 is not sufficiently exposed.

[0031] The abutment screw removal instrument 10 having the engaging portions 11A to 11C shown in Figures 3, 4, and 4A can also be rotated by a low-speed dental engine. In this case, the shape of the base end side of the shaft 12 may be adapted to fit the low-speed dental engine, as shown in Figure 1C.

[0032] Furthermore, the inner surface 11b of the engaging portion 11, the tapered surface 11c of the engaging portion 11A, or the uneven surface 11d of the engaging portion 11B may be roughened by sandblasting or the like. By roughening these surfaces, the frictional force between the abutment screw 20 and the engaging portions 11A, 11B, and 11C can be further increased.

[0033] Next, an auxiliary tool 50 that can be used in combination with the abutment screw removal tool 10 will be described.

[0034] Figure 5 is a diagram showing the configuration of an auxiliary instrument that can be used in combination with an abutment screw removal instrument, Figure 5A is a diagram showing the auxiliary instrument as viewed from below (in the direction of line VA-VA) in Figure 5, Figure 5B is a diagram showing the auxiliary instrument with an adhesive member attached, and Figure 5C is a diagram showing the auxiliary instrument and adhesive member as viewed from below (in the direction of line VC-VC) in Figure 5B.

[0035] 5 and 5A, auxiliary instrument 50 is provided with an attachment part 51 on the distal end side (lower end side in FIG. 5) to which an adhesive member 6 (FIG. 5A) that is adhesively fixed to fracture surface 20a of abutment screw 20 can be attached, and a shaft 52 that is provided on the proximal end side (upper end side in FIG. 5) of attachment part 51 and extends in the axial direction (up and down direction in FIG. 5) from attachment part 51. The material of auxiliary instrument 50 is arbitrary, but for example, a metal material or the like that has no harmful effect on the living body and has the required strength can be used as the material of auxiliary instrument 50.

[0036] As shown in Figures 5 and 5A, the attachment part 51 has a cylindrical shape that is recessed from the tip to the base end of the auxiliary device 50. As shown in Figures 5B and 5C, a columnar adhesive member 6 is attached to this cylindrical recess. The adhesive member 6 can be replaced each time the auxiliary device 50 is used.

[0037] The adhesive member 6 is, for example, similar to double-sided tape, composed of a base sheet and adhesive layers disposed on both sides of the base sheet. Alternatively, the adhesive member 6 is composed of an adhesive substance formed into a cylindrical shape. The adhesive member 6 is fixed to the attachment portion 51 by its own adhesiveness.

[0038] 5, an operating portion 52a is provided on the base end side of the shaft 52. The surface of the operating portion 52a is formed with an uneven shape to prevent slipping and to facilitate operations such as rotation with fingers.

[0039] Next, a method for using the assistive device 50 will be described.

[0040] 6 to 6C are cross-sectional views showing how to use the assistive device.

[0041] 6 shows an example in which the abutment screw 20 breaks near the female thread 31a (FIG. 2E) of the implant body 31, and the fracture surface 20a remains near the area where the female thread 31a is formed. In such a case, the side surface 20b (FIGS. 2A, 2B, and 6C) of the abutment screw 20 is not exposed, and therefore the abutment screw 20 cannot be held by the abutment screw removal tool 10.

[0042] In such a case, as shown in Figures 6A to 6B, an auxiliary device 50 having an adhesive member 6 attached to an attachment portion 51 is inserted into the inside of the implant body 31, and the adhesive member 6 is pressed against the fracture surface 20a, thereby fixing the auxiliary device 50 to the abutment screw 20 via the adhesive member 6.

[0043] Next, as shown in FIG. 6B, when the auxiliary instrument 50 is rotated around its axis in a predetermined direction (for example, counterclockwise when viewed from the base end), the abutment screw 20 also rotates in the same direction, and the abutment screw 20 moves axially toward the base end together with the abutment screw removal instrument 10. When the abutment screw 20 is rotated to a certain extent, the side surface 20b of the abutment screw 20 becomes exposed and separated from the region where the female thread 31a is formed, as shown in FIG. 6C. In this state, the side surface 20b of the abutment screw 20 can be clamped by the engaging portion 11 of the abutment screw removal instrument 10. Therefore, the fractured abutment screw 20 can then be removed from the implant body 31 by the procedure shown in FIGS. 2B to 2E.

[0044] As described above, in this embodiment, torque is transmitted from the auxiliary tool 50 to the abutment screw 20 via the adhesive member 6. In this case, when fixing the adhesive member 6 to the fractured surface 20a, it is necessary to press the auxiliary tool 50 against the abutment screw 20 with a certain amount of force. However, once the adhesive member 6 is fixed to the fractured surface 20a, only axial torque can be applied to the abutment screw 20 without applying axial force. This suppresses the frictional force generated between the abutment screw 20 and the implant body 31, allowing the abutment screw 20 to be rotated with a small torque. In other words, the adhesive force (adhesion) of the adhesive member 6 allows sufficient torque to be applied to rotate the abutment screw 20.

[0045] As described above, with the abutment screw removal tool 10 of this embodiment, an appropriate torque (torque required for rotation) can be applied to the abutment screw 20 via the side surface 20b of the abutment screw 20, thereby easily removing the abutment screw 20. Furthermore, if the side surface 20b of the abutment screw 20 is not exposed, the side surface 20b of the abutment screw 20 can be exposed by rotating the abutment screw 20 using the auxiliary tool 50. Therefore, in this case as well, the abutment screw 20 can be easily removed with the abutment screw removal tool 10 of this embodiment.

[0046] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments. [Explanation of symbols]

[0047] 10 Abutment screw removal instrument 11, 11A, 11B, 11C Engagement part 11a Slit 11b Inside 11c Tapered surface (inner surface) 11d Uneven surface (inner surface) 11e Spike 12 shafts 12a Operation section 20 abutment screw 20a Fracture surface 20b side 50 Assistive Devices

Claims

1. an engaging portion provided on the distal end side and adapted to engage with the end portion of the broken abutment screw on the fractured surface side from the radially outer side of the abutment screw; a shaft provided on the base end side of the engaging portion and extending in the axial direction from the engaging portion, the engaging portion is formed in a cylindrical shape, and an inner surface of the engaging portion engages with the end portion of the abutment screw on the fracture surface side, The engaging portion has a slit formed therein, the slit extending in the axial direction from the tip end of the engaging portion toward the base end side and penetrating the engaging portion in a radial direction, An abutment screw removal instrument, wherein the outer surface of the engagement portion extends parallel to the axial direction.

2. The abutment screw removal tool according to claim 1 , wherein the engaging portion has a tapered shape in which the inner diameter of the inner surface increases from the base end side toward the tip end side.

3. The abutment screw removal instrument according to claim 1 , wherein the inner surface of the engagement portion is formed with an uneven surface having unevenness in the radial direction in a cross section perpendicular to the axial direction.

4. The abutment screw removal instrument according to claim 1 , wherein the inner surface of the engagement portion is roughened.

5. An auxiliary instrument that can be used in combination with the abutment screw removal instrument according to any one of claims 1 to 4, an attachment portion provided on the distal end side, capable of attaching an adhesive member that is fixed to the fracture surface of the abutment screw by adhesion; a shaft provided on a base end side of the mounting portion and extending in an axial direction from the mounting portion; An assistive device comprising:

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