JP4896176B2 - Abutment assembly - Google Patents

Description

  The present invention relates to an abutment assembly for use in an implant therapy.

  Conventionally, an implant treatment method in which an artificial dental crown is attached is known as a method for repairing a missing tooth. In this implant treatment method, for example, an implant as an implanted body is implanted in a place where a tooth is missing. The implant includes a fixture which is formed in a bolt shape and is fixed to an alveolar bone in the alveolar cavity of a missing tooth based on screwing. On the fixture, an abutment as a bracket body of the artificial dental crown is coupled. An artificial crown is mounted on the abutment on the gingival margin.

  In realizing this implant treatment method, for example, a dental appliance is proposed. This dental appliance includes a fixture made of metal such as titanium and an abutment formed of a metal material having mechanical strength and biocompatibility in order to achieve both mechanical strength and biocompatibility. . For example, a bolt or the like is used for coupling the abutment to the fixture. Such a dental appliance is described in Patent Document 1, for example.

US Pat. No. 7,104,797

  When an artificial crown is attached to a place where a tooth is missing based on the above-mentioned implant treatment, the same chewing function as a natural tooth can be restored, and the natural appearance and expression can be restored. There are advantages. However, in a metal abutment, the transparency of the teeth is lacking or black lines appear on the teeth, so that the appearance of the artificial crown is inferior. In this respect, for example, a ceramic material is excellent in chemical stability and is resistant to coloring and abrasion, and has recently been used as an abutment material. However, there are some points to be improved.

  Since the space between the missing tooth and the tooth adjacent to the missing tooth is limited, the space that can be used for fixing the fixture is limited. As a result, when the abutment is coupled, a large area is not secured on the coupling surface (platform) of the abutment and the fixture. Moreover, since the abutment is formed thin, the abutment is easily broken. Therefore, even if screw tightening is performed when the abutment is mounted, it is difficult to realize good coupling.

  For example, the hardness of a ceramic abutment is higher than that of a metal fixture. As a result, the fixture is easily worn when the two are joined. Further, when the condition of the coupling is adjusted after the coupling, the fixture may be worn or deformed. If an abutment and a fixture made of different materials are combined with high accuracy, the degree of freedom in design is lost. In addition, since the ceramic abutment is bonded to a metal fixture different from the ceramic material, reliable bonding is not realized.

  An object of the present invention is to provide an abutment assembly that can satisfactorily be coupled to a fixture.

  In order to achieve the above object, the present invention is an abutment assembly that is connected to a fixture as a planted body to be implanted in the alveolar cavity of a missing tooth with a bolt and used for mounting an artificial dental crown. Received by the fixture extending in the major axis direction, a hollow tubular annular mount in the major axis direction, extending upward from the annular mount and extending in the major axis direction, and extending downward from the annular mount A joint member mounted on the fixture and having a hollow tubular bushing in the long axis direction, a coping portion used for mounting the artificial crown, and being received by the annular mount at the lower end while continuing to the lower end of the coping portion And a central hole penetrating the coping part and the lower part in the longitudinal direction, and a hole formed in the central hole for receiving the fitting ring. And a bracket formed in the central hole and continuing to the bore, and having an engagement portion having a smaller diameter than the bore, and is received in the bracket and the joint member and penetrates in the longitudinal direction. Forming a central hole for receiving the bolt, and being sandwiched between the head of the bolt and the engaging portion of the bracket, and tightening toward the engaging portion based on screwing of the bolt into the fixture An abutment assembly comprising a sleeve having a pressing portion that contacts the abutment assembly is provided.

  In this abutment assembly, the sleeve has an abutting portion that is received on the inner peripheral surface of the joint member based on screwing of the bolt into the fixture. The joint member is preferably formed from a metal material. Further, it is preferable that the relative rotation of the bracket and the joint member is restricted based on the spline engagement of the bore hole and the fitting ring. At this time, it is preferable that the cross-sectional outline of the fitting ring and the cross-sectional outline of the bore are formed in a non-circular shape. On the other hand, the fitting ring may be formed in a truncated cone shape that decreases the outer diameter toward the upper end. The bracket defines an end face that is in intimate contact with the annular mount. Thus, the movement of the joint member in the long axis direction is restricted. The sleeve protrudes downward from the pressing portion in the major axis direction at a predetermined interval, and is formed into a plurality of strips that are elastically deformable in a direction orthogonal to the major axis direction, and is formed in the major axis direction. You may provide the engagement step part which protrudes on the outer side in the direction orthogonal to, and has a latching | locking part caught on the lower end edge of a bushing. The lower portion preferably defines an end surface received by an annular seat surface defined at an upper end of the fitting ring of the joint member. Moreover, it is preferable that the bushing of a coupling member has an engagement hole which prescribes | regulates a polygonal cross-sectional external shape.

  According to the abutment assembly of the present invention, the bolt is screwed into the fixture while being inserted into the sleeve. At this time, the head portion of the bolt presses the pressing portion of the sleeve tightly against the engaging portion of the bracket. Thus, the bracket can be held immovably with respect to the joint member based on the sleeve. The bracket can be tightly secured to the gingival margin. As a result, the abutment assembly is fixedly fixed at a predetermined position with respect to the fixture based on the bolt.

  In addition, since the bracket is formed of a ceramic material, it is possible to improve the aesthetic appearance of the artificial crown to be attached to the bracket. Moreover, since the joint member is formed of the same metal material as the fixture, the joint member and the fixture can be coupled with high accuracy. At the same time, the occurrence of wear between the joint member and the fixture can be greatly reduced.

  Furthermore, since the ceramic bracket does not contact the metal fixture based on the joint member, damage to the fixture can be avoided when the abutment assembly is attached or when the attachment position is adjusted. Moreover, for example, even if the joint member is damaged due to contact with the bracket, only the joint member can be easily replaced with a new joint member based on the removal of the bolt. Fixture replacement is not required.

1 is an exploded perspective view schematically showing a structure of an abutment assembly according to a first embodiment of the present invention. FIG. 2 is a vertical sectional view of FIG. 1. 1 is a vertical sectional view schematically showing a structure of an abutment assembly according to a first embodiment of the present invention. It is a partial expanded sectional view of Drawing 3A. FIG. 4 is a horizontal sectional view taken along line 4-4 of FIG. 3A. 1 is a vertical sectional view schematically showing a structure of an implant including an abutment assembly according to a first embodiment of the present invention. It is a principal part horizontal sectional view which shows roughly the structure of the abutment assembly which concerns on 2nd Embodiment of this invention. FIG. 6 is a vertical sectional view schematically showing a structure of an abutment assembly according to a third embodiment of the present invention. It is a partial expanded sectional view of Drawing 7A. It is a vertical sectional view showing roughly the structure of an abutment assembly according to a fourth embodiment of the present invention. It is a disassembled perspective view which shows roughly the structure of the abutment assembly which concerns on 5th Embodiment of this invention. FIG. 10 is an assembled vertical sectional view of FIG. 9. It is a disassembled perspective view which shows roughly the structure of the abutment assembly which concerns on 6th Embodiment of this invention. It is an assembly vertical sectional view of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, about the component which has the same structure and function, the same referential mark is attached | subjected and the description is abbreviate | omitted.

  FIG. 1 is an exploded perspective view schematically showing an abutment assembly according to a first embodiment of the present invention. FIG. 2 is a vertical sectional view of FIG. FIG. 3A is a vertical sectional view of the abutment assembly according to the first embodiment of the present invention. FIG. 3B is a partially enlarged cross-sectional view of FIG. 3A. 4 is a horizontal sectional view taken along line 4-4 of FIG. 3A. FIG. 5 is a vertical sectional view of an implant including an abutment assembly according to the first embodiment of the present invention.

  As shown in FIG. 5, an implant used in a dental implant treatment method includes an abutment assembly according to the present invention, a fixture 4 as an implant to be implanted in an alveolar bone in the alveoli of a missing tooth, The fixture 4 includes a bolt 5 for connecting the abutment assembly. The fixture 4 is screwed in the longitudinal direction into a perforation drilled in the alveolar bone under the gingival margin. The abutment assembly according to the present invention includes a bracket 1, a joint member 2 connected to the fixture 4, and a sleeve 3 that couples the bracket 1 to the joint member 2. An artificial crown (not shown) is mounted on the bracket 1 on the gingival margin.

  The fixture 4 defines a bone side end portion 42 that extends in the major axis direction from the upper end to the lower end, and a gingival end portion 43 that is integrated with the upper end of the bone side end portion 42. A male screw is cut on the outer peripheral surface of the bone side end portion 42. The bone side end portion 42 is fixed to the perforation of the alveolar bone based on screwing. In the fixture 4, a connecting hole is formed in the long axis direction from the gingival side end portion 43 toward the bone side end portion 42. In the bone side end portion 42, a female screw, that is, a screw portion 44 is formed on the inner peripheral surface of the connection hole. At the gingival end portion 43, an engaging portion 41 is formed on the inner peripheral surface of the connecting hole. The engagement portion 41 receives the abutment assembly.

  The bolt 5 includes a shaft portion 52 that extends in the major axis direction from the upper end to the lower end, and a head portion 51 that is integrated with the upper end of the shaft portion 52. The diameter of the head 51 is set larger than the diameter of the shaft portion 52. The head 51 forms an annular shoulder 53 at the lower end. An engagement step portion 521 is defined at the upper end of the shaft portion 52. The diameter of the engaging step portion 521 is set larger than the diameter of the shaft portion 52 and smaller than the diameter of the head portion 51. A male screw is formed on the outer peripheral surface of the connecting step portion 522 defined at the lower end of the shaft portion 52. When the shaft portion 52 is screwed into the screw portion 44 of the fixture 4 at the connecting step portion 522, the shoulder 53 approaches the gingival side end portion 43 of the fixture 4.

  1 to 4, the joint member 2 includes a hollow fitting ring 21 from the upper end to the lower end, and a hollow bushing 22 connected to the lower end of the fitting ring 21 from the upper end to the lower end. The joint member 2 receives the bolt 5. At the lower end of the fitting ring 21, an annular mount 24 that protrudes in a collar shape from the outer peripheral surface of the fitting ring 21 is formed. In the present embodiment, the annular mount 24 defines an upper seat surface 241 defined on the fitting wheel 21 side and a lower seat surface 242 defined on the bushing 22 side. The upper seat surface 241 receives the bracket 1. The lower seating surface 242 is received by the gingival side end portion 43. The fitting ring 21, the bushing 22 and the annular mount 24 are made of a metal material.

  The fitting ring 21 extends upward from the upper seat surface 241. As shown in FIG. 1, FIG. 2, and FIG. 3A, an annular seating surface 212 is defined at the upper end of the fitting ring 21 along a virtual plane orthogonal to the long axis direction. The joint member 2 defines an inner peripheral surface 25 that faces the outer peripheral surface of the shaft portion 52 of the bolt 5. The bushing 22 extends downward from the lower seat surface 242. The bushing 22 is received by the engaging portion 41 of the fixture 4. As is clear from FIG. 1, the cross-sectional outline of the bushing 22 defined along a virtual plane orthogonal to the major axis direction is defined by a polygon, that is, a hexagon. The cross-sectional outline of the engaging portion 41 is defined by a complementary polygon, that is, a hexagon. As a result, the rotation of the bushing 22, that is, the joint member 2 is restricted around the major axis in the engaging portion 41.

  The bracket 1 includes a coping portion 11 that receives the artificial crown, and a lower portion 14 that is integrated with the lower end of the coping portion 11 and is received by the gingival margin. The bracket 1 extends in a hollow tubular shape from the coping portion 11 to the lower portion 14 in the long axis direction. Thus, a central hole is formed in the bracket 1 in the major axis direction. In the center hole, the joint member 2, the sleeve 3 and the bolt 5 are received. The central hole is defined by the inner ring wall 13. The inner ring wall 13 defines an insertion portion 131 formed in the coping portion 11, an engagement portion 132 connected to the lower end of the insertion portion 131, and a bore 143 connected to the lower end of the engagement portion 132. . Such a bracket 1 is formed from a ceramic material.

  As is clear from FIG. 2, the inner diameter of the engaging portion 132 decreases as the distance from the insertion portion 131 increases. The diameter of the bore 143 is set larger than the diameter of the engaging portion 132. As a result, the contact end face 15 is formed at the boundary between the engaging portion 132 and the bore 143 along a virtual plane orthogonal to the long axis direction. The fitting ring 21 of the joint member 2 is received in the bore 143. Thus, as is apparent from FIGS. 3A, 3 </ b> B, and 5, the contact end face 15 faces the annular seating surface 212 of the joint member 2. At this time, the end surface 142 of the lower portion 14 is abutted against the upper seat surface 241 of the annular mount 24 of the joint member 2. Further entry of the joint member 2 into the central hole of the bracket 1 is restricted.

  An inner surface 1431 is formed around the major axis in the bore 143. As shown in FIGS. 1 and 4, the inner surface 1431 is formed with a pair of long grooves 141 and 141. The long groove 141 is formed based on a cut formed in the inner surface 1431 parallel to the long axis direction. The long groove 141 extends from the end surface 142 to the contact end surface 15 along the long axis direction. On the other hand, the fitting ring 21 of the joint member 2 is formed with a pair of ribs 211 and 211 that protrude from the outer peripheral surface of the fitting ring 21 corresponding to the long grooves 141 and 141. The long groove 141 receives the rib 211. As a result, the rotation of the bracket 1 with respect to the joint member 2 is restricted. Thus, the fitting wheel 21 is spline-engaged with the bore 143.

  The sleeve 3 is formed in a hollow tubular shape in the long axis direction. A central hole 33 is formed in the sleeve 3 on the inner peripheral surface 34. The center hole 33 receives the bolt 5. The outer peripheral surface 32 of the sleeve 3 is received by the inner ring wall 13 of the bracket 1 and the inner peripheral surface 25 of the joint member 2. As shown in FIG. 2, the inner peripheral surface 34 defines a locking portion 341 that extends around the head 51 of the bolt 5 and an insertion portion 342 that continues to the locking portion 341 in the long axis direction. The insertion portion 342 receives the shaft portion 52 of the bolt 5. The diameter of the insertion part 342 is set smaller than the diameter of the locking part 341. The sleeve 3 is made of, for example, a metal material.

  An annular shoulder surface 35 is defined on the inner peripheral surface 34 between the locking portion 341 and the insertion portion 342. In the annular shoulder surface 35, the diameter of the inner peripheral surface 34 decreases from the locking portion 341 toward the insertion portion 342. As is apparent from FIG. 5, the annular shoulder surface 35 receives the shoulder 53 of the head 51 of the bolt 5. As a result, further entry of the head 51 of the bolt 5 into the central hole 33 in the major axis direction is restricted. When the connecting step portion 522 of the bolt 5 is screwed into the screw portion 44 of the connecting hole of the fixture 4 through the center hole 33, the shoulder 53 of the bolt 5 is pressed against the annular shoulder surface 35 of the sleeve 3. Thus, the shoulder 53 comes into close contact with the annular shoulder surface 35. At this time, the engaging step portion 521 of the bolt 5 is received by the insertion portion 342 of the sleeve 3.

  The outer peripheral surface 32 of the sleeve 3 is divided into a pressing portion 321 received by the engaging portion 132 of the bracket 1 and a contact portion 322 received by the inner peripheral surface 25 of the joint member 2. The pressing portion 321 is formed at a position corresponding to the annular shoulder surface 35. Similarly to the above, when the connecting step portion 522 of the bolt 5 is screwed into the screw portion 44 of the fixture 4, the shoulder 53 abuts against the annular shoulder surface 35. As a result, the pressing portion 321 is pressed against the engaging portion 132 of the bracket 1. Thus, the bracket 1 can come into close contact with the gingival margin. At the same time, the contact portion 322 is pressed against the inner peripheral surface 25 of the joint member 2. Thus, when the abutment assembly is fixed to the fixture 4 based on the bolt 5, the bracket 1 is held immovably on the joint member 2 based on the sleeve 3.

  Next, a method for assembling the implant will be described. Referring to FIG. 5, when the bushing 22 of the joint member 2 is fitted into the engagement portion 41 of the connection hole of the fixture 4, the lower seating surface 242 of the annular mount 24 is received by the gingival side end portion 43 of the fixture 4. . Thus, the joint member 2 is attached to the fixture 4. Subsequently, the bore 143 of the bracket 1 is fitted into the fitting ring 21 of the joint member 2. The ribs 211 and 211 are inserted into the long grooves 141 and 141. As a result, the rotation of the bracket 1 with respect to the joint member 2 is restricted. At this time, the end surface 142 of the lower portion 14 of the bracket 1 abuts against the upper seat surface 241 of the annular mount 24. Thus, the bracket 1 is attached to the joint member 2.

  Thereafter, the sleeve 3 is inserted into the insertion portion 131 of the center hole of the bracket 1. The pressing portion 321 of the outer peripheral surface 32 is received by the engaging portion 132 of the bracket 1. At the same time, the contact portion 322 of the outer peripheral surface 32 is received by the inner peripheral surface 25 of the joint member 2. Thus, the lower end of the sleeve 3 coincides with the lower end of the joint member 2. Subsequently, the bolt 5 is inserted into the center hole 33 of the sleeve 3. The connecting step portion 522 of the bolt 5 is screwed into the screw portion 44 of the fixture 4. As a result, the bracket 1 is fixed at a predetermined position with respect to the fixture 4. Thus, the implant is assembled. On the other hand, when the bolt 5 is removed from the assembled implant, the abutment assembly is removed from the fixture 4.

  In the implant as described above, since the bracket 1 is formed of a ceramic material, the appearance after the artificial dental crown is mounted is improved. In addition, since the joint member 2 and the fixture 4 are both formed from the same metal material, the joint member 2 and the fixture 4 are connected with high accuracy. Rupture of the joint member 2 and the fixture 4 is avoided at the connection point. In addition, since the ceramic bracket 1 is connected to the metal fixture 4 via the metal joint member 2, contact between the bracket 1 and the fixture 4 is avoided. Wear of the fixture 4 is avoided. For example, the joint member 2 worn due to contact with the bracket 1 can be easily replaced based on the removal of the bolt 5.

  FIG. 6 is a horizontal sectional view of an essential part schematically showing the structure of the abutment assembly according to the second embodiment of the present invention. In the second embodiment, the formation of the rib 211 described above is omitted from the fitting ring 21 of the joint member 2. The cross-sectional outer shape of the fitting wheel 21 defined in a virtual plane orthogonal to the major axis direction is defined as a polygon, that is, a hexagon. On the other hand, the formation of the long groove 141 described above is omitted in the bore 143 of the bracket 1. The cross-sectional outline of the hole 143 defined in a virtual plane orthogonal to the major axis direction is defined as a polygon complementary to the cross-sectional outline of the fitting ring 21, that is, a hexagon. When the fitting ring 21 is fitted in the bore 143 in this way, the rotation of the bracket 1 is restricted with respect to the joint member 2.

  FIG. 7A is a vertical sectional view schematically showing a structure of an abutment assembly according to the third embodiment of the present invention. FIG. 7B is a partially enlarged sectional view of FIG. 7A. In the third embodiment, the contact end surface 15 of the lower portion 14 of the bracket 1 is received by the annular seating surface 212 of the fitting wheel 21 of the joint member 2. In this way, the joint member 2 is restricted from further entering the center hole of the bracket 1 in the long axis direction. At this time, the end surface 142 of the lower portion 14 of the bracket 1 is received by the upper seat surface 241 of the annular mount 24 of the fitting ring 21.

  FIG. 8 is a vertical sectional view schematically showing a structure of an abutment assembly according to the fourth embodiment of the present invention. In this 4th Embodiment, the fitting ring 21 of the coupling member 2 is formed in the truncated cone shape which decreases an outer diameter as it goes to the cyclic | annular seating surface 212. FIG. On the other hand, the hollow 143, that is, the inner surface 1431 of the lower portion 14 of the bracket 1 is defined in a truncated cone shape corresponding to the outer shape of the fitting wheel 21. In this way, the fitting ring 21 is fitted into the bore 143. As a result, the entry of the joint member 2 into the center hole of the bracket 1 in the major axis direction is restricted. As described above, the rib 211 and the long groove 141 are formed.

  FIG. 9 is an exploded perspective view schematically showing a structure of an abutment assembly according to the fifth embodiment of the present invention. FIG. 10 is an assembled vertical sectional view of FIG. In the fifth embodiment, the sleeve 3 defines an engagement step portion 324 that forms a plurality of strips 326, 326... At a predetermined interval 325 from each other. The strip 326 extends from the pressing portion 321 toward the lower end of the sleeve 3. A hook-like locking portion 323 is formed at the end of each strip 326 on the fixture 4 side. The locking portion 323 protrudes from the tip of the strip 326 outward in the radial direction of the sleeve 3. The tip of the strip 326 can be elastically deformed in the radial direction of the sleeve 3.

  As is clear from FIG. 10, when the sleeve 3 is inserted into the center hole of the bracket 1, the locking portion 323 is elastically deformed inward based on the contact between the locking portion 323 and the inner peripheral surface 25 of the joint member 2. As a result, elastic force is accumulated in the strip 326. When the sleeve 3 is completely inserted into the central hole of the joint member 2, the locking portion 323 is elastically deformed outward based on the elastic force of the strip 326. As a result, the locking portion 323 is caught on the lower end edge 221 of the joint member 2. At this time, since the pressing portion 321 of the sleeve 3 is pressed against the engaging portion of the bracket 1, the bracket 1, the joint member 2, and the sleeve 3 are connected. At the same time, the sleeve 3 is held immovably with respect to the bracket 1 and the joint member 2.

  FIG. 11 is an exploded perspective view schematically showing a structure of an abutment assembly according to the sixth embodiment of the present invention. FIG. 12 is an assembled vertical sectional view of FIG. In the sixth embodiment, an engagement hole 222 is formed in the bushing 22 of the joint member 2 in the abutment assembly of the first embodiment. The cross-sectional outer shape of the engagement hole 222 defined in a virtual plane orthogonal to the long axis is defined as a polygon, that is, a hexagon. On the other hand, the cross-sectional outer shape of the gingival side end 43 of the fixture 4 is defined as a polygon complementary to the cross-sectional outer shape of the engagement hole 222, that is, a hexagon. As a result, the gingival end 43 of the fixture 4 is fitted into the engagement hole 222. Thus, relative rotation of the joint member 2 with respect to the fixture 4 is restricted.

  According to the abutment assembly of the present invention, since the bracket 1 is formed of a ceramic material, it is possible to improve the appearance, that is, the aesthetics of the artificial dental crown mounted on the bracket 1. Further, since the joint member 2 and the fixture 4 are formed of the same metal material, the joint member 2 and the fixture 4 are connected with high accuracy. Further, since the bracket 1 made of ceramic does not contact the metal fixture 4 by the function of the joint member 2, damage to the fixture 4 can be avoided when the abutment assembly is attached or when the attachment position is adjusted. In addition, even if the joint member 2 is damaged due to contact with the bracket 1, only the joint member 2 can be easily replaced with a new joint member 2 based on the removal of the bolt 5. Replacement of fixture 4 is not required.

  DESCRIPTION OF SYMBOLS 1 Bracket, 11 Coping part, 13 Inner ring wall, 131 Insertion part, 132 Engagement part, 14 Lower part, 141 Long groove, 142 End surface, 143 Hollow hole, 1431 Inner surface, 15 Contact end surface, 2 Joint member, 21 Fitting ring, 211 rib, 212 annular seat surface, 22 bushing, 221 bottom edge, 24 mount, 241 upper seat surface, 242 lower seat surface, 25 inner peripheral surface, 3 sleeve, 32 outer peripheral surface, 321 pressing portion, 322 abutting portion, 323 Stop part, 324 Engagement step part, 325 interval, 326 strip, 33 Center hole, 34 Inner peripheral surface, 341 Locking part, 342 Insertion part, 35 Shoulder surface, 4 Fixture, 41 Engagement part, 42 Bone side end Part, 43 gingival side end part, 44 screw part, 5 bolt, 51 head part, 52 shaft part, 521 engagement step part, 522 connection step part, 53 shoulder.

Claims (11)

An abutment assembly that is connected to a fixture as a planted body to be implanted in the alveolar cavity of a missing tooth with a bolt and used for mounting an artificial dental crown,
Received by the fixture extending in the major axis direction, a hollow tubular annular mount in the major axis direction, extending upward from the annular mount and extending in the major axis direction, and extending downward from the annular mount A joint member attached to the fixture and having a hollow tubular bushing in the longitudinal direction;
A coping part used for mounting an artificial dental crown, a lower part received by the annular mount at the lower end while continuing to the lower end of the coping part, a central hole penetrating the coping part and the lower part in the longitudinal direction, and A bracket having a hole formed in the center hole for receiving the snap ring, and an engagement portion formed in the center hole and having a smaller diameter than the hole while being continuous with the hole;
A center hole that is received in the bracket and the joint member and receives the bolt while penetrating in the longitudinal direction is formed, and is sandwiched between a head portion of the bolt and the engaging portion of the bracket, and the fixture. An abutment assembly, comprising: a sleeve having a pressing portion that comes into close contact with the engagement portion based on screwing of the bolt into the engagement portion.   2. The abutment assembly according to claim 1, wherein the sleeve has a contact portion that is received on an inner peripheral surface of the joint member based on screwing of the bolt into the fixture. 3.   3. The abutment assembly according to claim 1, wherein the joint member is made of a metal material.   The abutment assembly according to any one of claims 1 to 3, wherein relative rotation of the bracket and the joint member is restricted based on spline engagement between the bore and the fitting ring. Assembly.   The abutment assembly according to claim 4, wherein a cross-sectional outer shape of the fitting ring and a cross-sectional outer shape of the bore are formed in a non-circular shape.   5. The abutment assembly according to claim 4, wherein the fitting ring is formed in a truncated cone shape that decreases in outer diameter toward the upper end.   The abutment assembly according to any one of claims 1 to 6, wherein the bracket defines an end face that is in intimate contact with the annular mount.   The abutment assembly according to claim 1, wherein a cross-sectional outer shape of the bushing of the joint member is formed in a polygonal shape. The abutment assembly according to claim 1, wherein the sleeve comprises:
A plurality of strips that protrude downward in the major axis direction from the pressing portion at a predetermined interval and are elastically deformable in a direction perpendicular to the major axis direction;
An abutment assembly, comprising: an engaging step portion formed on the strip and projecting outward in a direction perpendicular to the major axis direction and having a locking portion hooked to a lower end edge of the bushing.   The abutment assembly according to any one of claims 1 to 9, wherein the lower portion defines an end surface received by an annular seat surface defined at an upper end of the fitting wheel of the joint member. Abutment assembly.   The abutment assembly according to any one of claims 1 to 7, wherein the bushing of the joint member has an engagement hole that defines a polygonal cross-sectional outer shape.

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