WO2009075459A1

WO2009075459A1 - Dental implant fixture

Info

Publication number: WO2009075459A1
Application number: PCT/KR2008/005306
Authority: WO
Inventors: Kwang Bum Park; Kyoung Ho Ryoo; Seok Kyu Choi
Original assignee: Megagen Implant Co., Ltd.
Priority date: 2007-12-11
Filing date: 2008-09-09
Publication date: 2009-06-18
Also published as: KR20090005848U

Abstract

Provided is a dental implant fixture including a body portion having a screw thread on an outer surface thereof to be implanted in an alveolar bone and a bevel section provided on an upper region of the body portion and having a diameter gradually reduced upwardly, in which at least one groove is provided along a circumferential direction of the bevel section. According to the present invention, an area contacting the alveolar bone is broadened compared with that in conventional techniques to efficiently distribute load generated by mastication or the like, thereby preventing a phenomenon in which the alveolar bone collapses downward, i.e., an alveolar bone loss and thus improving reliability of an implant surgical operation through firm osseointegration of the dental implant fixture to the alveolar bone.

Description

Description DENTAL IMPLANT FIXTURE

Technical Field

[1] The present invention generally relates to a dental implant fixture, and more particularly, to a dental implant fixture in which an area contacting an alveolar bone is broadened compared with that in conventional techniques to efficiently distribute load generated by mastication or the like, thereby preventing a phenomenon in which the alveolar bone collapses downward, i.e., an alveolar bone loss. Background Art

[2] An implant originally means a substitute for restoring a missed tissue of a human body, but in dentistry, it means a process of implanting an artificial tooth root. The implant is a surgical method which implants an artificial tooth root made of titanium having no rejection by human body into an alveolar bone from which a tooth has been extracted in order to replace a root of the missed tooth and then fixes an artificial tooth into the tooth root in order to restore the function of the missed tooth.

[3] A general prosthesis or denture damages neighboring teeth and bones over time, whereas an implant does not damage neighboring teeth tissues and has the same function or shape as a natural tooth while preventing teeth from decaying. For this reason, the implant may be semi-permanently used.

[4] Also, an implant improves not only the restoration of a single missed tooth but also the function of the artificial teeth of partially toothless or completely toothless patients and enhances the aesthetic feature in the restoration of dental prosthesis. Furthermore, the implant can distribute excessive stress applied to the tissues of the surrounding support bone so as to help the stabilization of a row of teeth.

[5] A fixture of such a dental implant is embedded in upper and lower alveolar bones.

More specifically, an artificial tooth root, called a fixture, is osseointegrated to be completely fixed to a bone like a root of a natural tooth, an abutment is coupled to the osseointegrated fixture, and an artificial crown is mounted on the abutment, thereby completing the implant. The fixture of the dental implant, or the dental implant fixture, is embedded in a cancellous bone having low bone density through a compact bone having high bone density.

[6] The fixture embedded in the alveolar bone is osseointegrated directly to the bone tissues unlike the root of the natural tooth which is coupled to the bone tissues through a periodontal ligament, thus having no physiological motion with respect to the alveolar bone. As a result, load applied from outside is directly delivered to the alveolar bone and thus large stress is generated in the alveolar bone directly receiving the external load.

[7] In particular, in a conventional fixture, as illustrated in FIG. 1, a side portion 130a of an upper region of a fixture 110 contacting an upper region of an alveolar bone 103 is provided almost vertical, and thus load generated by mastication or the like is more well delivered to the alveolar bone 103, resulting in a phenomenon in which the alveolar bone 103 collapses in an arrow direction A as in an enlarged portion of FIG. 1, i.e., an alveolar bone loss. If this phenomenon occurs, foreign substances are likely to be introduced to the collapsed portion, degrading the tooth state. Moreover, if large load is generated because the fixture 110 is not firmly osseointegrated to the alveolar bone 103, the alveolar bone 103 may be damaged.

[8] Therefore, to solve those problems, there is a need for a fixture capable of efficiently distributing load generated by oral activities like mastication. Disclosure of Invention Technical Problem

[9] The object of the present invention is to provide a dental implant fixture in which an area contacting an alveolar bone is broadened compared with that in conventional techniques to efficiently distribute load generated by mastication or the like, thereby preventing a phenomenon in which the alveolar bone collapses downward, i.e., an alveolar bone loss, and thus improving reliability of an implant surgical operation through firm osseointegration of the dental implant fixture to the alveolar bone.

Advantageous Effects

[10] According to the present invention, an area contacting an alveolar bone is broadened compared with that in conventional techniques to efficiently distribute load generated by mastication or the like, thereby preventing a phenomenon in which the alveolar bone collapses downward, i.e., an alveolar bone loss, and thus improving reliability of an implant surgical operation through firm osseointegration of the dental implant fixture to the alveolar bone. Brief Description of Drawings

[11] FIG. 1 is a front view of a dental implant fixture according to the prior art;

[12] FIG. 2 is a perspective view of a dental implant fixture according to an embodiment of the present invention;

[13] FIG. 3 is a cross-sectional view of FIG. 2; and

[14] FIG. 4 is an enlarged view of a portion IV of FIG. 3.

Best Mode for Carrying out the Invention

[15] The foregoing object of the present invention is achieved by a dental implant fixture including a body portion having a screw thread on an outer surface thereof to be implanted in an alveolar bone and a bevel section provided on an upper region of the body portion and having a diameter gradually reduced upwardly, in which at least one groove is provided along a circumferential direction of the bevel section.

[16] The at least one groove may be a plurality of grooves formed depressed in parallel to the circumferential direction of the bevel section to broaden an area contacting the alveolar bone.

[17] An inclination angle of the bevel section with respect to a central axis of the body portion may be one selected from a range of 10° - 80°.

[18] An inner angle of the groove may be one selected from a range of 30° - 90°.

[19] The groove may be rounded.

[20] The screw thread formed in the body portion may be at least one of a single-screw thread, a double-screw thread, and a triple-screw thread.

[21] An inner angle of the screw thread formed in the body portion may be one selected from a range of 5° - 80°.

[22] The foregoing object of the present invention is also achieved by a dental implant fixture including a body portion having a screw thread on an outer surface thereof to be implanted in an alveolar bone and a bevel section provided on an upper region of the body portion and having a diameter gradually reduced upwardly, in which a screw thread is provided along a circumferential direction of the bevel section. Mode for the Invention

[23] To fully understand the present invention, the operational advantages of the present invention, and objects achieved by the working of the present invention, reference should be made to the drawings and descriptions on the drawings.

[24] Hereinafter, the present invention will be described in detail by describing a preferred embodiment of the present invention with reference to the accompanying drawings. Like reference numerals refer to like elements throughout the drawings.

[25] FIG. 2 is a perspective view of a dental implant fixture according to an embodiment of the present invention, FIG. 3 is a cross-sectional view of FIG. 2, and FIG. 4 is an enlarged view of a portion IV of FIG. 3.

[26] As illustrated in FIGS. 2 to 4, a dental implant fixture 10 according to an embodiment of the present invention includes a body portion 20 having screw threads 21 formed on its outer surface in order to be implanted in an alveolar bone 3 and a bevel section 30 on an upper region of the body portion 20, which has a diameter gradually reduced upwardly and is provided with a plurality of grooves 32 for broadening an area contacting the alveolar bone 3 in a circumferential direction thereof.

[27] The screw threads 21 formed on the outer surface of the body portion 20 may be any one of single-screw threads, double-screw threads, and triple-screw threads. However, in the body portion 20 according to an embodiment of the preset invention, as illustrated in FIGS. 2 and 3, the single-screw threads 21 are formed. More specifically, the screw threads 21 having substantially the same depth are regularly formed on the outer surface of the body portion 20, and thus an operator can easily implant the dental implant fixture 10 in the alveolar bone 3 and a manufacturer can easily form the screw threads 21 on the outer surface of the body portion 20.

[28] As illustrated in FIG. 3, each of the screw threads 21 includes a small-width vertical section 21a with a small width formed in parallel to the longitudinal direction of the body portion 20, a lower inclined section 21b formed inclined to the outer surface of the body portion 20 under the small- width vertical section 21a, and an upper inclined section 21c with a larger inclination angle than the lower inclined section 21b, which is formed inclined to the outer surface of the body portion 20 above the small- width vertical section 21a.

[29] Because of the small width of the small- width vertical section 21a, a sharp edge is provided like a V screw, thereby facilitating implantation.

[30] The lower inclined section 21b, which is intended to compensate for a compression force in the longitudinal direction of the body portion 20, has an inclination angle θ 1 of 5° - 20° with respect to the outer surface of the body portion 20. This lower inclined section 21b is a portion using advantages of a square screw.

[31] On the other hand, the upper inclined section 21c, which is intended to guarantee an engagement force preventing arbitrary separation after engagement while providing easy implantation, has an inclination angle Θ2 of 30° - 45° with respect to the outer surface of the body portion 20. This upper inclined section 21c is a portion using advantages of a V screw.

[32] Based on the foregoing structure, each of the screw threads 21 according to an embodiment of the present invention takes only the advantages of a V screw and a square screw. Areas where the lower and upper inclined sections 21b and 21c and the outer surface of the body portion 20 are rounded with the same radius of curvature, respectively, but the scope of the present invention is not limited thereto.

[33] The screw threads 21 may have various depths as necessary, but each of the screw threads 21 of the body portion 20 according to the current embodiment of the present invention has a depth H of approximately 0.3 mm.

[34] In a lower portion of the body portion 20, a lower inclined portion 23 inclined to have a diameter gradually reduced downwardly is formed, thus allowing the dental implant fixture 10 according to the current embodiment of the present invention to be easily implanted in the alveolar bone 3.

[35] As illustrated in FIG. 3, an inner coupling groove 25 to which a lower portion of an abutment (not shown) for supporting an artificial crown (not shown) is insertion- coupled is formed in an upper portion of the body portion 20. In an inner circumferential wall of the inner coupling groove 25, a coupling reinforcing groove 26 depressed to a predetermined depth from the surface of the inner circumferential wall is provided. The coupling reinforcing groove 26 is a portion to which a protrusion portion of a hand piece connector (not shown) is gear-coupled. The coupling reinforcing groove 26 not only prevents rotation of the hand piece connector with respect to the dental implant fixture 10 but also enables firm coupling of the hand piece connector to the dental implant fixture 10.

[36] In a lower portion adjacent to the inner coupling groove 25, a screw groove 27 screw-coupled to a male screw of the abutment is formed. This structure allows the abutment to be removably engaged with the dental implant fixture 10.

[37] As illustrated in FIGS. 2 and 3, the bevel section 30 on an outer circumferential surface of the upper region of the body portion 20 has a diameter gradually reduced upwardly in order to directly contact an upper region of the alveolar bone 3. The bevel section 30 is provided with the plurality of grooves 32 in its circumferential direction in order to broaden an area contacting the alveolar bone 3.

[38] As is mentioned previously, an upper region of a conventional fixture (110 of FIG. 1) is provided vertical or has no groove, though provided as a bevel section, for which if stress is generated in the alveolar bone 3 due to mastication or the like, the stress is concentrated rather than being distributed, resulting in collapse of the upper region of the alveolar bone 3, i.e., an alveolar bone loss.

[39] However, the bevel section 30 according to the current embodiment of the present invention to be described below is inclined at a predetermined angle with respect to a central axis of the body portion 20 and has the plurality of grooves 32 formed depressed along its circumferential direction, whereby stress possible in the alveolar bone 3 can be efficiently distributed by broadening the area contacting the alveolar bone 3 and thus the alveolar bone 3 can be firmly osseointegrated in the bevel section 30.

[40] The bevel section 30 according to the current embodiment of the present invention may be manufactured to be inclined at various angles with respect to the central axis of the body portion 20, but may be provided inclined at any angle selected from a range of 10° - 80° which can efficiently distribute stress likely to be generated in the alveolar bone 3. Therefore, as illustrated in FIG. 4, the bevel section 30 according to the current embodiment of the present invention is provided inclined at an inclination angle Θ3 of approximately 33° with respect to the central axis of the body portion 20, thereby preventing the above-described alveolar bone loss to some extent. The inclination angle Θ3 of the bevel section 30 means an angle between a virtual line connecting a uppermost portion and a lowermost portion of the bevel section 30 and the central axis of the body portion 20.

[41] The grooves 32 formed in the bevel section 30, as described above, are portions for broadening an area contacting the upper region of the alveolar bone 3, and are formed depressed along the circumferential direction of the bevel section 30. An inner angle of each of the grooves 32 may be various, but each of the grooves 32 according to the current embodiment of the present invention may have an inner angle Θ4 selected from a range of 30° - 90° as illustrated in FIG. 4. The alveolar bone 3 is settled in the depressed portion of each of the grooves 32, thereby improving coupling force between the alveolar bone 3 and the bevel section 30 of the body portion 20 when compared to coupling force in a fixture having only the bevel section 30.

[42] In addition, since the alveolar bone 3 is fixed to the inner side of each of the grooves

32, it is possible to more reliably prevent an alveolar bone loss occurring in conventional techniques (see FIG. 1), i.e., a phenomenon where an alveolar bone collapses downwardly. Moreover, stress generated by mastication or the like can be distributed to the depressed portion, i.e., the rounded inner side, of each of the grooves 32, thereby largely reducing stress concentration when compared to conventional techniques.

[43] If the alveolar bone loss excessively occurs due to stress concentration, metal may be seen from outside through a gap between the dental implant fixture 10 and a gum (not shown) and foreign substances introduced to the gap may damage the gum or neighboring teeth. However, as described above, the alveolar bone 3 is firmly os- seointegrated in the dental implant fixture 10 by means of the bevel section 30 provided with the grooves 32 according to the current embodiment of the present invention, thereby preventing such problems.

[44] A description will now be made regarding a surgical operation process of the dental implant fixture 10 having the foregoing structure.

[45] First, a groove fitting to the size of the dental implant fixture 10 is formed in the desired alveolar bone 3 in the mouth through drilling and tapping. The dental implant fixture 10 is then implanted in the groove formed in the alveolar bone 3. During the implantation of the dental implant fixture 10 in the alveolar bone 3, the bevel section 30 provided in the upper region of the dental implant fixture 10 and the upper region of the alveolar bone 3 can be osseointegrated closely to each other by means of the inclined structure of the bevel section 30 and the grooves 32 formed along the circumferential direction of the bevel section 30.

[46] For aesthetic gum formation, a healing abutment (not shown) is engaged with the inner coupling groove 25 of the dental implant fixture 10. Next, after aesthetic gum formation is confirmed, the healing abutment is removed and an impression coping (not shown) is engaged with the upper portion of the dental implant fixture 10 for manufacturing of a prosthesis. A preliminary impression is taken in the mouth by using an impression material, and then the impression coping is removed, after which a tooth model is manufactured and an artificial crown (not shown) is constructed.

[47] Thereafter, an abutment is engaged with the dental implant fixture 10 and the constructed artificial crown is engaged on the abutment, thereby completing the surgical operation of the dental implant.

[48] As such, according to the present invention, the bevel section 30 contacting the upper region of the alveolar bone 3 is provided inclined and the plurality of grooves 32 are formed depressed along the circumferential direction of the bevel section 30, whereby the contact area between the dental implant fixture 10 and the alveolar bone 3 is br oadened, and thus stress likely to be generated by mastication or the like can be prevented from being concentrated, thereby preventing an alveolar bone loss occurring due to stress concentration.

[49] Furthermore, with the above-described structure, the alveolar bone 3 is firmly os- seointegrated in the dental implant fixture 10, thus preventing the upper region of the dental implant fixture 10, i.e., a metal portion from being seen from outside over time and preventing side effects such as decay of neighboring teeth due to introduction of foreign substances through a gap.

[50] Although a plurality of grooves are formed in a bevel section of a dental implant fixture in the foregoing embodiment, a screw thread, instead of the grooves, may also be formed in the bevel section as long as it is easy to manufacture.

[51] It is obvious to one of ordinary skill in the art that the present invention is not limited to the disclosed embodiment and various modifications and variations may be made therein without departing from the spirit and scope of the present invention. Accordingly, such modification examples or variation examples are included in the scope of the present invention. Industrial Applicability

[52] According to the present invention, an area contacting an alveolar bone is broadened compared with that in conventional techniques to efficiently distribute load generated by mastication or the like, thereby preventing a phenomenon in which the alveolar bone collapses downward, i.e., an alveolar bone loss, and thus improving reliability of an implant surgical operation through firm osseointegration of the fixture to the alveolar bone.

Claims

[1] A dental implant fixture comprising: a body portion having a screw thread on an outer surface thereof to be implanted in an alveolar bone; and a bevel section provided on an upper region of the body portion and having a diameter gradually reduced upwardly, in which at least one groove is provided along a circumferential direction of the bevel section.

[2] The dental implant fixture of claim 1, wherein the at least one groove is a plurality of grooves formed depressed in parallel to the circumferential direction of the bevel section to broaden an area contacting the alveolar bone.

[3] The dental implant fixture of claim 1, wherein an inclination angle of the bevel section with respect to a central axis of the body portion is one selected from a range of 10° - 80°.

[4] The dental implant fixture of claim 1, wherein an inner angle of the groove is one selected from a range of 30° - 90°.

[5] The dental implant fixture of claim 1, wherein the groove is rounded.

[6] The dental implant fixture of claim 1, wherein the screw thread formed in the body portion is at least one of a single-screw thread, a double-screw thread, and a triple-screw thread. [7] The dental implant fixture of claim 1, wherein an inner angle of the screw thread formed in the body portion is one selected from a range of 5° - 80°. [8] A dental implant fixture comprising: a body portion having a screw thread on an outer surface thereof to be implanted in an alveolar bone; and a bevel section provided on an upper region of the body portion and having a diameter gradually reduced upwardly, in which a screw thread is provided along a circumferential direction of the bevel section.