Dental implant abutments with occlusal force buffering function

Abstract

The present invention relates to a dental implant abutment that functions to buffer occlusal forces transmitted through a prosthesis and that can be attached to the prosthesis elastically rather than with an adhesive. More specifically, the present invention relates to a dental implant abutment in which a prosthesis fastening protrusion is formed on the upper outer surface of the abutment, to which the prosthesis is attached, and that protrudes outward with an outer diameter larger than that of the portion directly below, and in which incisions that divide the upper portion of the abutment into multiple sections are formed continuously from the upper end surface of the abutment downward for a certain distance, with the certain distance being formed in a spiral or oblique shape.

Description

Technical Field

[0001] The present invention relates to an abutment for a dental implant that functions to buffer the biting force transmitted through a prosthesis, and enables the connection with the prosthesis by elastic connection rather than an adhesive. More specifically, on the upper outer surface of the abutment to which the prosthesis is attached, a prosthesis fastening protrusion is formed so as to protrude outward with an outer diameter larger than that of the directly lower part, and a cut-out portion that divides the upper part of the abutment into a plurality of sections is continuously provided from the upper end surface of the abutment downward for a certain interval. By being formed in a spiral or diagonal line shape for a certain interval, the prosthesis can be easily connected to the upper part of the abutment without an adhesive by a simple operation using the elastic restoring force of the plurality of sections, and a sufficient buffering function can be obtained by the spiral or diagonal cut-out portion structure. Thereby, the biting force continuously applied to the abutment is efficiently buffered, significantly reducing the loosening phenomenon and breakage of the fixing screw. The present invention relates to an abutment for a dental implant that simplifies fastening and disassembly by not using an adhesive for the connection with the prosthesis, and reduces the possibility of gum diseases caused by excess adhesive remaining on the gum side.

Background Art

[0002] Generally, a dental implant is a substitute for a lost natural tooth. After implanting a fixture into the alveolar bone and allowing it to fuse with the alveolar bone over a predetermined period, a prosthesis such as an abutment or an artificial tooth is fixed thereon to restore the original function of the tooth, which is a natural tooth substitute.

[0003] An implant used in artificial tooth surgery consists of a fixture with threads formed on its outer surface and an axial hole formed along its vertical central axis so that it can be embedded in the alveolar bone; an abutment, the lower part of which is inserted into the axial hole of the fixture and to which a prosthesis is attached at the top; and a fixing screw that fastens the fixture and abutment together for secure fixation. The abutment has a screw insertion hole formed along its vertical central axis. In some cases, the abutment and the fixing screw may be formed integrally.

[0004] In other words, the abutment is fastened and fixed to the fixture by a separate fixing screw or a fixing screw integrally formed on the lower part. Conventional separate fixing screws consist of a head portion, a threaded portion, and a body portion that connects the head portion and the threaded portion. A polygonal groove into which a tooth tool is inserted is formed on the upper end surface of the head portion, and a thread is formed on the lower part of the body portion to form the threaded portion.

[0005] Furthermore, the abutment, which has a fixing screw separately formed to fasten to the fixture, has a screw insertion shaft hole that runs from the top end to the bottom end, and the outer surface of the abutment consists of a part that is inserted into the shaft hole of the fixture and a part to which the prosthesis is attached, and a step portion D that prevents downward movement of the fixing screw is formed on the inner surface of the screw insertion shaft hole, which comes into contact with the bottom surface C of the head of the fixing screw.

[0006] When fastening a fixed screw in a type where the abutment and fixing screw are separate, the practitioner inserts the fixing screw through the insertion hole of the abutment until it reaches the axial hole of the fixture, with the abutment seated in the axial hole of the fixture. Then, a dental tool such as a screwdriver is fitted into the polygonal groove formed on the upper end surface of the fixing screw head, and the fixing screw is rotated. The bottom surface C of the fixing screw head comes into contact with a fixing screw downward movement prevention step D formed on the inner surface of the screw insertion axial hole of the abutment, which prevents the fixing screw from moving downward. The fixing screw head presses the abutment toward the fixture, and as a result, the threads formed on the outer surface of the fixing screw are fastened with the threads formed on the inner surface of the axial hole of the fixture, and a strong tensile force is applied between the fixing screw head and the threads. As a result, the abutment is firmly fixed to the fixture by the fixing screw, and the prosthesis is bonded to the firmly fixed abutment using adhesive.

[0007] However, in conventional implants, where a screw is tightened to obtain fastening force between the fixture and the abutment, and the prosthesis is fixed using adhesive, the conventional fixing screw [i.e., a type of male thread] is fastened to the axial hole [i.e., a type of female thread] of the fixture, and then tightened strongly, causing the fixing screw to experience tensile force in the longitudinal direction. As a result, the upper surface of the screw threads of the fixing screw tightly adheres to the lower surface of the screw threads of the axial hole of the fixture, exerting considerable fastening force. However, this has the following fundamental problems or limitations.

[0008] For example, if we consider the tensile force N generated between the head and threads of a conventional fixing screw, which is sufficient to securely fasten the abutment to the fixture when the screw is tightened firmly, then if the tensile force applied by tightening the fixing screw is weaker than N, the expected sufficient tensile force cannot be obtained, resulting in a problem where a firm fastening force cannot be achieved.

[0009] In other words, when a tensile force weaker than N is applied between the head and threads of the fixing screw due to weak tightening, the force with which the upper surface of the fixing screw's threads adheres to the lower surface of the threads on the inner surface of the fixture's axial hole also weakens, reducing the fastening force between the threads. In such a situation, the fixing screw gradually loosens even with small rotational forces such as sustained vibrations and impacts caused by the occlusal force applied to the prosthesis, and the abutment connected to the fixture often becomes loose.

[0010] Furthermore, in order to prevent the aforementioned phenomena from loosening, if the fixing screws are tightened too much so that a tensile force far stronger than N is applied, permanent deformation occurs in the fixing screw material. This can lead to fatigue accumulating in the fixing screw material itself, and if other impacts such as occlusal forces are continuously transmitted to the fixing screw, fracture of the fixing screw may occur more easily.

[0011] Furthermore, conventional abutments have a problem in that when occlusal forces are continuously applied to the abutment from various directions, the applied stress is transmitted to the fixing screw without being buffered, and continues to accumulate between the head and threads of the fixing screw, resulting in loosening and fracture of the fixing screw.

[0012] For example, as shown in Figure 8, when a lateral occlusal force is applied to the abutment, a rotational force is generated in the abutment with respect to the point where the abutment and fixture are in close contact. This rotational force generates an upward force that pushes the fixing screw, which is applying a downward force to firmly adhere the abutment, upward. However, this stress can accumulate and cause the fixing screw to break, which is a problem.

[0013] The lower part of the abutment is inserted into the shaft hole of the fixture and fastened as an internal type. In this type of abutment, after the fixture and abutment are fastened together, the occlusal force is continuously applied without any buffering action, causing the abutment to move downward over time from its initial vertical position within the fixture's axial hole when it was first tightened with the fixing screw. This sinking phenomenon occurs, where the abutment's position moves downward from its initial vertical position within the fixture's axial hole. In this case, a gap is created between the bottom surface C of the fixing screw head and the downward movement prevention step D formed on the inner surface of the screw insertion axial hole of the abutment. As a result, the fixing screw head can no longer press the abutment downward and fix it to the fixture, and no tensile force is generated between the fixing screw head and the threads. Consequently, the upper surface of the threads formed on the fixing screw does not tightly adhere to the lower surface of the threads formed on the inner surface of the fixture's axial hole. In this state, the abutment moves within the fixture's axial hole, and each time occlusal force is applied from various directions, the stress is not evenly distributed but concentrates in one place. This results in alveolar bone destruction and abutment neck damage. There are problems such as neck fracture, fixture fracture, fixing screw fracture, and fixing screw loosening. Generally, to prevent problems caused by such thinking phenomena, conventional abutments have the problem of requiring a cumbersome method of initially tightening the fixing screw, using it for a certain period of time so that occlusal force is applied to the abutment, and then tightening the fixing screw again so that the head of the fixing screw and one surface of the abutment make strong contact. Furthermore, even when the head of the fixing screw is in contact with one surface of the abutment and tightly adheres to the fixture side, if lateral pressure is continuously applied to the prosthesis, tensile and lateral forces are transmitted to the fixing screw via the abutment, which can cause the fixing screw to loosen or fracture.

[0014] Furthermore, as mentioned above, when a fixing screw breaks due to various reasons, conventionally, removing the broken pieces of the fixing screw that remain fastened to the female thread portion on the inner surface of the fixture's shaft hole required a great deal of time and effort. In some cases, there was a problem in that it was not possible to completely remove the broken pieces of the fixing screw.

[0015] Conventional abutments, lacking occlusal force buffering capabilities, have resulted in numerous problems.

[0016] Furthermore, with conventional abutments, even after the abutment was bonded to the fixture, in order to attach the prosthesis to the top of the abutment, additional adhesive had to be applied to the inside of the prosthesis and the top of the abutment, the prosthesis was fitted onto the top of the abutment, and the prosthesis was pressed in the direction of the abutment (i.e., downwards) for a considerable amount of time to attach the prosthesis to the top of the abutment. In this case, the practitioner had to apply additional adhesive to attach the prosthesis, and after the adhesive hardened, the adhesive residue remaining between the prosthesis and the abutment / gum had to be removed one by one, and the patient had to wait while continuously pressing the prosthesis towards the gums while the adhesive hardened, resulting in many troublesome and inconvenient procedures.

[0017] Furthermore, when a prosthesis is fixed to an abutment using adhesive, there is a problem that the adhesive may separate due to sustained occlusal force, often causing the prosthesis to detach from the abutment. In addition, when attempting to remove a prosthesis fixed to an abutment due to certain issues, it is time-consuming and painful. [Overview of the project] [Problems that the invention aims to solve]

[0018] The object of the present invention is to provide a dental implant abutment that includes an incision that divides the upper part of the abutment into multiple sections, extending from the upper end surface of the abutment to the lower part for a certain distance, and in order to improve the elastic force of the sections that affect the occlusal force buffering function, the length of the sections is increased by forming a certain distance of the incision that divides the upper part of the abutment into multiple sections in a spiral or oblique shape, thereby maximizing the elastic restoring force by making the sections helical in shape, and as a result providing a buffering function with a strong elastic force when occlusal force is applied, thereby improving the problems of conventional implants that occurred due to the lack of an occlusal force buffering function, and thereby improving inconvenience and extending the lifespan of the implant.

[0019] Another object of the present invention is to provide a dental implant abutment in which, in the incision portion that divides the upper end of the abutment into a plurality of sections, the width of the lower incision portion is formed to be significantly smaller than the width of the upper incision portion, thereby increasing the volume of the sections and reinforcing their strength, and by forming the incision portion in a spiral or oblique shape, an inclined surface is created, so that when the section deforms due to occlusal force, the significantly reduced width of the lower incision portion and the inclined surface created by the spiral incision portion make quick contact with the adjacent section even with less deformation than the vertically formed incision portion, and the applied occlusal force is well distributed to the adjacent section.

[0020] Generally, in the present invention, after the abutment is fixed to an abutment in which the upper part is separated into multiple sections by an incision, in order for it to exhibit the occlusal force buffering function described above, when occlusal force is applied to the multiple sections separated by the incision formed on the upper part of the abutment, the occlusal force must be buffered by elastic movement and then restored. For this reason, no hardened material should be embedded in the space between the sections even after the prosthesis is fixed to the abutment. For this reason, if an adhesive is used to fill the space between the sections as a method for fixing the prosthesis to the abutment, the adhesive hardens after filling the space between the sections, making the elastic movement of the sections impossible, and as a result the buffering function is substantially lost.

[0021] Another object of the present invention is to provide a dental implant abutment with an occlusal force buffering function, which solves the above problems by providing a prosthesis fastening projection on the upper part of the abutment, which is divided into a plurality of sections for elastic bonding between the prosthesis and the abutment, having a diameter even larger than the diameter of the part directly below it, so that when a prosthesis is fitted onto the upper part of the dental implant abutment, the plurality of sections are inserted into the bonding hole of the prosthesis, elastically deform inward as they are inserted and then return to their original state, and the prosthesis fastening projection on the upper part of the abutment is fitted into the corresponding fastening groove in the bonding hole of the prosthesis, so that the prosthesis fastening projection can be easily and firmly bonded to the corresponding fastening groove of the prosthesis without additional adhesive by the elastic restoring force of the plurality of sections.

[0022] Another object of the present invention is to provide a dental implant abutment with an occlusal force buffering function that prevents the fixing screw from loosening and allows the abutment to recover after elastic deformation when occlusal force is applied. This is achieved by forming spiral, oblique, or vertical slot cutouts with sealed upper and lower ends at regular intervals along the circumference of the lower portion of the abutment inserted into the axial hole of the fixture. The multiple independent surfaces formed along the circumference by the slot cutouts deform within an elastic range as the fixing screw is tightened, and in close contact with the inclined surface on the inner surface of the axial hole of the fixture. At this time, the elastic repulsive force generated by the surfaces that deform and come into contact within an elastic range creates an upward force on the abutment. As a result, a sustained upward force is generated on the fixing screw in contact with the fixing screw downward movement prevention step D of the abutment, causing the upper thread surface 2a of the fixing screw to make strong contact with the lower thread surface 3a formed on the inner surface of the axial hole of the fixture.

[0023] Another object of the present invention is to provide a dental implant abutment that includes a separate fixing screw, which is configured to have sufficient tensile force, elastic restoring force, and cushioning function by having a helical spiral incision portion that horizontally penetrates the vertical central axis of the fixing screw and divides the cross-section perpendicular to the vertical central axis of the body into equal parts, with a fixed length in the upper or lower part of the screw threads of the fixing screw, thereby enabling the fixing screw itself to maintain a firm fastening force for a long period of time, as well as efficiently cushioning occlusal forces that are continuously applied from the side or from various directions, thereby preventing fracture of the fixing screw due to stress accumulation or concentration.

[0024] Another objective of the present invention is to enable the removal of remaining fixed screw fragments in the female thread portion on the inner surface of the axial hole of the fixture by inserting a straight-type screwdriver into the straight-type cut exposed on the fracture surface and rotating it, even when the fixed screw breaks.

[0025] Another objective of the present invention is to ensure that the upper thread surface 12a of the fixing screw and the lower thread surface 3a formed on the inner surface of the shaft hole of the fixture are strongly fastened by the elastic force of the helical cutting portion between the fixing screw head and the thread portion, thus eliminating the cold pressure welding phenomenon and allowing the remaining fixing screw portion to be easily removed when the fixing screw breaks.

[0026] Another object of the present invention is to ensure that the upper cut portion of the threaded part of the fixing screw has a helical spiral shape for a certain section, thereby having a strong elastic restoring force. This allows the helical section to deform within the elastic range during fastening of the abutment and fixture, creating a strong bond. Even if a sinking phenomenon occurs in the case of an internal type abutment where the abutment moves downward due to sustained occlusal force after initial fastening, the helical section will elastically deform, allowing the abutment and fixture to be tightly bound together with a force greater than a certain level without the need to retighten the fixing screw.

Means for Solving the Problem

[0027] In one embodiment of the present invention for achieving the above object, in a dental implant abutment having a bite force buffering function, the outer diameter of the upper end portion of the abutment to which the prosthesis is attached is formed to have a larger outer diameter than that of the immediately lower portion thereof, and includes a prosthesis fastening protrusion protruding outward and an incision portion that divides the upper portion of the abutment into a plurality of sections. The incision portion is continuously provided so as to continue for a certain interval downward from the upper end surface of the abutment, and is characterized in that it consists of a spiral or oblique line in a certain interval.

Effect of the Invention

[0028] According to the present invention, the prosthesis can be coupled to the upper portion of the abutment by a simple operation without an adhesive and maintain a strong fastening force over a long period of time. It can efficiently buffer the bite force continuously applied from the side or various directions, and prevent the loosening phenomenon and breakage of the fixing screw due to stress accumulation or concentration. It can prevent the phenomenon that the abutment is cold pressure welded to the insertion portion of the fixture's shaft hole. Therefore, when it is necessary to separate the abutment from the fixture, it can be easily removed. Even when the fixing screw breaks, by fitting a single-slot driver into the incision portion exposed on the fracture surface and rotating it, the broken piece of the fixing screw remaining on the female screw portion of the inner surface of the fixture's shaft hole can be easily removed.

Brief Description of the Drawings

[0029] [Figure 1a] It is a perspective view of a fixing screw according to an embodiment of the present invention. [Figure 1b] It is a sectional view taken along line A-A of FIG. 1a and a perspective view showing the fractured cross section thereof. [Figure 2a] It is a perspective view of an implant abutment according to an embodiment of the present invention. [Figure 2b]This is a perspective view of an implant abutment according to another embodiment of the present invention. [Figure 3a] This is a cross-sectional view showing the state in which the fixing screw shown in Figure 1a, separately provided by one embodiment of the present invention, is connected to the implant abutment shown in Figure 2a. [Figure 3b] This is a conceptual diagram showing the action of the fixing screw on the implant abutment in the connected state shown in Figure 3a. [Figure 4a] This is a perspective view of an implant abutment according to another embodiment of the present invention. [Figure 4b] This is a perspective view of an implant abutment according to another embodiment of the present invention. [Figure 5] Figure 5(a) is a cross-sectional view of a fixing screw according to another embodiment of the present invention, and Figure 5(b) is a conceptual diagram showing the operation of the fixing screw shown in Figure 5(a). [Figure 6] This is a perspective view of a fixing screw according to another embodiment of the present invention. [Figure 7] This is a perspective view showing the prosthesis X according to the present invention bonded to the upper part of the abutment without adhesive. [Figure 8] This is a cross-sectional view of a modified example in which the inclination of the outer surface of the abutment changes according to another embodiment of the present invention. [Figure 9] This is a perspective view of a modified example of a prosthetic fastening projection according to another embodiment of the present invention. [Figure 10] This is a cross-sectional view of a modified upper part of an abutment according to another embodiment of the present invention. [Figure 11] This is a cross-sectional view of an implant abutment according to another embodiment of the present invention. [Figure 12] This is a cross-sectional view of a modified example of a prosthetic fastening projection according to another embodiment of the present invention. [Figure 13] Figure 12 is a reference diagram illustrating the effects obtained during abutment placement using the modified example shown. [Figure 14]This cross-sectional view shows the upward force exerted on the fixing screw by the rotational force generated when a lateral occlusal force is applied to the abutment in conventional technology. [Modes for carrying out the invention]

[0030] Preferred embodiments of the present invention will be described in more detail below with reference to the drawings.

[0031] Figure 1a is a perspective view of a fixing screw according to one embodiment of the present invention, Figure 1b is a perspective view of the A-A cross-section of Figure 1a and a perspective view showing the fracture surface thereof, Figure 2a is a perspective view of an implant abutment according to one embodiment of the present invention, and Figure 2b is a perspective view of an implant abutment according to another embodiment of the present invention.

[0032] Referring to Figure 2a, in the dental implant abutment 200 of the present invention, the upper outer surface of the abutment to which the prosthesis is attached maintains a taper angle in which the outer diameter decreases as it moves upward from the area where the prosthesis margin is located, and a prosthesis fastening projection 210 is formed that protrudes outward from the tapered surface, with an outer diameter that is even larger than that of the area directly below the upper end surface. Also, as shown in Figures 2a and 2b, incisions 220, 220' that divide the upper part of the abutment into a plurality of sections are provided in a series that extend downward from the upper end surface of the abutment for a certain distance. Preferably, at least two incisions 220, 220' are formed on the upper part of the abutment, so that the upper part of the abutment can be divided into at least two sections. For reference, Figure 2a shows that the upper part of the abutment was divided into four sections by four incisions, and Figure 2b shows that the upper part of the abutment was divided into two sections by two incisions.

[0033] Thus, because the upper part of the abutment is divided into multiple sections by the incision, when a prosthesis is fitted onto the upper part of the dental implant abutment according to the present invention, the multiple sections can be elastically deformed inward as they are inserted into the coupling hole of the prosthesis. Consequently, when the prosthesis fastening projection 210 is fitted into the corresponding fastening groove X1 in the coupling hole of the prosthesis X and fastened, the elastic restoring force of the multiple sections allows the prosthesis fastening projection 210 to be firmly bonded to the corresponding fastening groove X1. According to the present invention, as shown in Figure 7, the prosthesis X can be bonded to the upper part of the abutment 200 by simple operation without the use of adhesive.

[0034] Preferably, a flat portion 250 is formed on a part of the circumferential surface on which the prosthesis fastening projection 210' is formed, as shown in Figure 2b. Such a flat portion 250 has the function of specifying the mounting direction of the prosthesis when the prosthesis is fixed and preventing the prosthesis from rotating after mounting. Preferably, the flat portion can also be formed on an inclined surface having a taper angle equal to or greater than the taper angle of the abutment.

[0035] More preferably, the incisions 220 and 230 are arranged in a continuous manner, extending downward from the upper end surface of the abutment for a certain distance, as shown in Figures 2a and 2b, but may be formed in a spiral or oblique shape for that distance. Such spiral or oblique incisions are intended to further increase the elastic deformation force and elastic restoring force of the upper part of the abutment, and to complement the occlusal force buffering function and fixing screw loosening prevention function of the abutment itself.

[0036] In other words, the incisions 220 and 230, formed by spiral or oblique incisions, allow multiple independent surfaces along the circumference to deform within an elastic range, thereby cushioning the occlusal force. In particular, the sustained occlusal force applied during food chewing can be cushioned by the sustained deformation and restoration of the multiple independent surfaces along the circumference within the elastic deformation limit.

[0037] In particular, it is preferable that the spiral or oblique incision formed in a certain section be formed so that the direction of the incision from the top to the bottom of the incision section is the same as the rotational direction for fastening the fixing screw that fastens to the fixture. The effect of this is that when occlusal force is applied to the abutment through the prosthesis, the occlusal force is transmitted through the helical spiral section formed on the upper part of the abutment, and in the process, a force acts on the lower fixing screw in a direction that fastens the fixing screw, thereby preventing the fixing screw from loosening. In particular, in abutments where the connection portion between the fixing screw and the prosthesis is integrally formed, the effect of preventing the fixing screw from loosening may be even greater.

[0038] Figure 4a is a perspective view of an implant abutment according to another embodiment of the present invention, and Figure 4b is a perspective view of an implant abutment according to another embodiment of the present invention.

[0039] Referring to Figures 4a and 4b, in another embodiment of the present invention, a dental implant abutment 300, in which a prosthesis mounting portion and a threaded portion are integrally provided, is configured to include a threaded portion 360 having a predetermined vertical length and having threads formed on its outer surface, a prosthesis mounting portion 340 integrally formed on the upper part of the threaded portion and to which a prosthesis is fixed, and a body portion 350 connecting the threaded portion and the prosthesis mounting portion, with a helical spiral incision portion 352 formed in the longitudinal direction for a certain length. The spiral incision portion 352 is formed to penetrate horizontally through the vertical central axis of the body portion and to have a certain length in the longitudinal direction of the vertical central axis of the body portion, thereby dividing the cross-section perpendicular to the vertical central axis into equal parts.

[0040] As explained earlier, the upper outer surface of the abutment to which the prosthesis is attached maintains a taper angle, as shown in Figure 4a, where the outer diameter decreases as it moves upward from the area P where the prosthesis margin is located. Prosthesis fastening protrusions 310 and 310' are formed, which protrude outward from the tapered surface, with an outer diameter even larger than that of the area directly below the upper end surface. Also, as shown in Figures 4a and 4b, incisions 320 and 320' that divide the upper part of the abutment into multiple sections are provided in a continuous manner from the upper end surface of the abutment downward for a certain distance, and are formed in a spiral or oblique shape for that distance. Preferably, at least one of the incisions 320 and 320' is formed on the upper part of the abutment, so that the upper part of the abutment can be divided into at least two sections.

[0041] As described above, a section having a projection on the upper outer surface of the abutment with a larger diameter than the portion directly below it deforms toward the vertical central axis during the process of the prosthesis being fitted, then returns to its original shape and connects with a groove formed on the bottom surface of the axial hole in the prosthesis, thereby enabling the abutment and prosthesis to be bonded without adhesive. Furthermore, by having a spiral or oblique incision that provides a certain section of spiral or oblique helical shape that rotates around the vertical central axis of the abutment, the occlusal force applied during food chewing can be buffered.

[0042] Preferably, a flat portion 350 having a taper angle equal to or greater than the taper angle of the abutment is formed on a part of the circumferential surface on which the prosthesis fastening projection 310' is formed. Such a flat portion 370 complementarily performs the function of specifying the mounting direction of the prosthesis and preventing rotation of the prosthesis.

[0043] Referring to Figures 1a and 1b, the fixing screw 100 separately provided to the dental implant abutment of the present invention is configured to include a threaded portion 12 having a predetermined vertical length and having threads 12a and 12b formed on its outer circumference, a head portion 20 formed above the threaded portion and having a polygonal fitting groove 22 on its upper end surface into which a screwdriver is fitted, and a body portion 10 connecting the threaded portion 12 and the head portion 20, with a helical spiral incision portion 14 formed in the longitudinal direction for a certain length.

[0044] Preferably, as shown in Figure 1b, the helical incision portion 14 is formed to horizontally penetrate the vertical central axis of the body portion 10 and to have a constant length in the longitudinal direction of the vertical central axis of the body portion 10, thereby dividing the cross-section perpendicular to the vertical central axis into equal parts. The helical incision portion 14 can be selectively formed in a clockwise or counterclockwise direction. The helical incision portion 14 can also be selectively formed in the threaded portion 12. Furthermore, the body portion 10 can extend below the threaded portion 12, and further helical incisions 16 can be formed in such an extension of the body portion 10.

[0045] Furthermore, it is preferable that the cutting direction of the helical spiral incision formed between the head and thread portion of the fixing screw is formed in the same direction as the thread portion of the fixing screw.

[0046] Referring to Figures 2a and 2b, the dental implant abutment 200 of the present invention has a plurality of slot cuts 240, 240' formed along the circumference of the lower part of the abutment that is inserted into the axial hole of the fixture. Preferably, of the abutment portion, a plurality of slot cuts 240, 240' that penetrate from the outer diameter to the inner diameter, with at least one end closed, are formed at regular intervals along the circumference of the lower part of the abutment that is inserted into the axial hole of the fixture. Preferably, the slot cuts 240, 240' can be formed in the shape of diagonal lines, vertical lines, or horizontal lines.

[0047] The aforementioned slot cuts 240 and 240', when the fixing screw is tightened firmly, cause multiple independent surfaces formed along the circumference by the obliquely shaped slot cuts to deform within the elastic range and come into close contact with the inclined surface on the inner surface of the axial hole of the fixture. At this time, the elastic repulsive force generated by the surfaces that deform and come into contact within the elastic range generates a force that pushes the abutment upward. As a result, a force is generated that continuously pushes upward the head of the fixing screw that is in contact with the step portion D that prevents the fixing screw from moving downward of the abutment. Consequently, the upper surface of the screw threads of the fixing screw come into close contact with the lower surface of the screw threads formed on the inner surface of the axial hole of the fixture, thereby preventing the fixing screw from loosening.

[0048] Furthermore, the sustained biting force applied during food chewing is buffered by multiple independent surfaces formed along the circumference that continuously deform and restore within their elastic deformation limits. This action prevents the cold-pressure welding phenomenon that occurs when the abutment tightly adheres to the insertion shaft hole of the fixture, thus enabling easy separation of the abutment from the fixture whenever desired.

[0049] Figure 3a is a cross-sectional view showing the state in which the fixing screw shown in Figure 1a, separately provided according to one embodiment of the present invention, is connected to the implant abutment shown in Figure 2a, and Figure 3b is a conceptual diagram showing the action of the fixing screw on the implant abutment in the connected state shown in Figure 3a.

[0050] Referring to Figures 3a and 3b, the helical notch 14 formed on the body portion 10 of the fixing screw 100 increases the elastic deformation force and elastic restoring force of the fixing screw itself, thereby allowing the fixing screw of the present invention to fasten the abutment to the fixture more firmly compared to conventional fixing screws. In other words, the fixing screw 100 of the present invention has an increased absolute length that can be elastically deformed by the helical notch 14, and has a stronger elastic restoring force after elastic deformation, allowing it to accept more fastening energy, i.e., a stronger fastening force. As a result, it can have an even stronger fastening force than conventional fixing screws, thus preventing problems such as loosening of the fixing screw.

[0051] The helical incision portion 14 can be formed in at least a certain section between the upper and lower ends of the body portion 10, but preferably the helical incision portion 14 is formed in the part of the body portion 10 that connects the threaded portion 12 and the head portion 10. Referring to Figures 3a and 3b, when the fixing screw 100 is tightened strongly while the threaded portion 12 of the fixing screw 100 is engaged with the threads 3 formed on the inner surface of the shaft hole of the fixture 1, the fixing screw 100 stretches by a certain length within the elastic deformation limit due to the elastic force of the helical incision portion 14, and the elastic restoring force of the helical incision portion 14 pulls the threaded portion 12 of the fixing screw strongly upward, as shown by the arrow in Figure 3a. As a result, as shown in Figure 3b, the upper surface 12a of the screw threads of the fixing screw tightly adheres to the lower surface 3a of the screw threads, which is formed corresponding to the inner surface of the shaft hole of the fixture 1. This ensures an even stronger fastening force between the interlocking screw threads, and consequently, the loosening phenomenon of the fixing screw can be significantly reduced.

[0052] Preferably, the direction in which the helical spiral cutting portion is formed between the head portion and the thread portion of the fixing screw is the same as the direction in which the thread portion of the fixing screw is formed.

[0053] Preferably, as shown in Figure 5, the helical notch 16 can also be formed helically on the lower part of the threaded portion 12 formed on the body portion 10. In this case, if the fixing screw 100 is continued to be tightened strongly even after the end of the fixing screw 100 has contacted the bottom surface of the axial hole of the fixture, the bottom surface of the fixing screw and the bottom surface of the fixing screw will come into contact, compressing the helical helical notch at the lower part of the threaded portion, thereby generating an elastic restoring force. This elastic restoring force strongly pushes the threaded portion of the fixing screw upward. As a result, similar to Figure 3b, the upper surface 12a of the threads of the fixing screw tightly adheres to the lower surface 3a of the threads formed corresponding to the inner surface of the axial hole of the fixture 1, thereby ensuring a more robust fastening force and significantly reducing the loosening phenomenon of the fixing screw. The fixing screw of the present invention is preferably made of a metal with excellent elasticity, such as a Ni-Ti alloy.

[0054] More preferably, the head portion 20 of the fixing screw 10 may further be provided with a screw loosening prevention projection 26 at a certain portion of its outer circumferential surface, as shown in Figure 1a. This allows the screw loosening prevention projection 26 to complementarily prevent the fixing screw from loosening when the implant abutment 200 shown in Figure 2a is fastened to the fixture with the fixing screw 10 shown in Figure 1a, by fitting into a helical or oblique incision portion 230 formed on the upper part of the abutment.

[0055] As described above, when the fixing screw 100 according to the present invention is fastened only within the elastic deformation limit, the helical notches 14 and 16 ensure even greater elastic force and elastic restoring force than conventional fixing screws. As a result, the upper thread surface 12a of the fixing screw can more strongly and sustainably maintain a force that tightly adheres to and presses against the lower thread surface 3a formed on the inner surface of the axial hole of the fixture. Consequently, there is an advantage that the fastening force that fastens the abutment 15 to the fixture 1 does not decrease even after a long period of time.

[0056] Referring to Figures 1a and 5, the helical notches 14 and 16 formed on the body 10 of the fixing screw can perform a stress buffering function due to their own structural characteristics and elastic restoring force. That is, even if lateral pressure in various directions is applied to the abutment due to occlusal force, etc., generating forces that push the fixing screw laterally or push the head of the fixing screw upward, the structure of the helical notches itself can buffer such forces. As a result, stress applied from the side or above does not accumulate in the fixing screw itself, and the possibility of the fixing screw breaking is significantly reduced.

[0057] Furthermore, the conventional problems in internal-type fasteners, where the lower part of the abutment is inserted into the axial hole of the fixture and fastened, can also be solved by the elastic restorative action of the helical incision portion of the present invention. In other words, as mentioned above, even after the fixing screw is initially fastened with a strong fastening force, a sinking phenomenon may occur over time in which the abutment sinks downward. However, even if the abutment moves below its initial fastening position due to such a sinking phenomenon, the elastic restorative action of the helical incision portion pulls the head portion of the upper end of the fixing screw downward together, thereby maintaining the strong fastening force.

[0058] On the other hand, even when the fixing screw breaks due to various reasons, the fracture occurs at the relatively weak point, the spiral incision site. In this case, as shown in Figure 1b, a linear spiral incision penetrating the vertical central axis is exposed on the fracture surface. Therefore, by inserting a straight-ended screwdriver into the linear incision and rotating it, the remaining fixing screw fragments on the inner surface of the fixture's axial hole can be easily removed.

[0059] Figure 6 is a perspective view of a fixing screw according to another embodiment of the present invention. Referring to Figure 6, a helical spiral notch is formed at the lower part of the threaded portion of the fixing screw of the present invention, a straight, cross-shaped, or polygonal projection is formed on the bottom surface of the lowest end of the fixing screw, and a corresponding groove is formed on the bottom surface of the shaft hole of the fixture, thereby allowing the tightening rotation position of the fixing screw to be identified and further providing a function to prevent the fixing screw from loosening.

[0060] In other words, when the fixing screw is tightened, the protrusion on the bottom surface of the fixing screw contacts the upper surface of the lower end of the fixture's axial hole before the lowest end surface where the corresponding groove is formed. If the fixing screw continues to be tightened in this state, the helical spiral notch at the bottom of the screw's threads is compressed as it rotates, and at the point where the protrusion on the bottom surface of the fixing screw coincides with the corresponding groove formed on the lowest end of the fixture's axial hole, the elastic restoring force of the spiral notch at the bottom of the screw's threads engages the protrusion on the bottom surface of the fixing screw with the groove on the lowest end of the fixture's axial hole. In order to release this engagement, a certain amount of horizontal rotational force must be applied directly to the fixing screw, thus providing a loosening prevention function that prevents the fixing screw from loosening due to everyday occlusal forces.

[0061] Figure 8 is a cross-sectional view of a modified example in which the inclination of the outer surface of the abutment changes according to another embodiment of the present invention. Referring to Figure 8, the inclination of the outer surface of the abutment changes at least twice between the upper portion (A) of the maximum diameter of the abutment where the prosthesis margin is located [preferably the upper 1.5 mm portion] and the portion B directly below the prosthesis fastening projection 210'. That is, the outer surface of the abutment can be composed of a first inclined outer surface L1, a first vertical outer surface L2, a second inclined outer surface L3, and a second vertical outer surface L4 sequentially upward from the upper portion A of the maximum diameter of the abutment. By configuring the outer surface of the abutment to have at least two inclination changes in this way, the horizontal thickness of the upper prosthesis fastening projection of the abutment can be additionally secured, and as a result, the bonding strength can be reinforced or increased when the prosthesis is fastened to the upper prosthesis fastening projection of the abutment. For example, if the inclination angle is the same from the upper part A of the abutment's maximum diameter to the lower end of the prosthesis fastening projection, the horizontal thickness of the prosthesis fastening projection at the top of the abutment may be too thin. This can prevent the prosthesis from being securely attached or supported when fastening it, potentially leading to problems such as the prosthesis becoming loose or even breaking.

[0062] Figure 9 is a perspective view of a modified example of the prosthesis fastening projection according to another embodiment of the present invention. Referring to Figure 9, the prosthesis fastening projection 210' is further formed with an inwardly recessed prosthesis fastening position recess 210a', which allows for the identification of the fastening position of the prosthesis during prosthesis placement and prevents rotation of the prosthesis. In other words, the prosthesis fastening position recess 210a' not only allows the practitioner to identify the precise fastening position where the prosthesis should be positioned during prosthesis placement, but also prevents the prosthesis from rotating due to the force applied to it after the prosthesis placement is completed.

[0063] Figure 10 is a cross-sectional view of a modified upper part of an abutment according to another embodiment of the present invention. Referring to Figure 10, the inclination of the outer surface of a certain section directly below the prosthesis fastening projection can be formed with a less inclination than the inclination of the outer surface of the lower 1 / 3 of the section between the maximum diameter portion of the abutment where the prosthesis margin is located and the upper end of the abutment. In some cases, a vertical section with zero inclination that maintains the same diameter as the certain section can also be formed. When a prosthesis is attached to and detached from the prosthesis fastening projection of the abutment multiple times, problems may occur where the sharply protruding portion of the prosthesis (indicated by a circle) on the inside of the prosthesis wears down or cracks. Therefore, by forming an inclined section with a certain less inclination or a vertical section with zero inclination downward from the portion directly below the prosthesis fastening projection, the durability of the prosthesis itself that is coupled in correspondence with the portion directly below the fastening projection of the abutment can be reinforced.

[0064] Figure 11 is a cross-sectional view of an implant abutment according to another embodiment of the present invention. Referring to Figure 11, a through hole extending from the upper end surface to the lower end surface of the abutment can be configured such that the inner diameter D1 on the upper side of the through hole is maintained constant for a certain section, and then has a larger inner diameter D2 below that. With such a through hole structure, the thickness of the fastening portion on the upper side of the abutment where the prosthesis fastening projection 220' is located is increased, further reinforcing the bonding strength when fastening the prosthesis. Preferably, the inner diameter D3 on the lower side of the through hole can be configured to be smaller than the inner diameter D1 on the upper side of the through hole.

[0065] Figure 12 is a cross-sectional view of a modified example of the prosthesis fastening projection according to another embodiment of the present invention, and Figure 13 is a reference diagram for explaining the effects obtained when the abutment is fitted according to the modified example shown in Figure 12. Referring to Figure 12, the prosthesis fastening projection is configured such that its outer diameter gradually increases downward from its upper end, and as a result, when viewed from a vertical cross-section of the prosthesis fastening projection, it is formed asymmetrically with respect to the point of maximum protrusion of the prosthesis fastening projection, so that a part of the outer surface 220c' of the prosthesis fastening projection can have a predetermined angle of inclination. For example, if a part of the outer surface 220c' of the prosthesis fastening projection has an inclined shape, the upper end of the inclined outer surface 220c' can be more easily fitted into and inserted into the corresponding prosthesis fastening hole. This is particularly evident in Figure 13, where the embedding angle of adjacent abutments is too large, making it difficult to fasten the prosthesis due to interference between adjacent prostheses. In such cases, the upper end of the outer surface 220c' of the prosthesis fastening projection can be fitted into the prosthesis's bonding hole with less resistance. When the prosthesis is pressed toward the abutment after being fitted, the prosthesis fastening projection, which has an incision on the inside, deforms inward, reducing resistance, and the prosthesis can slide along the inclined outer surface 220c' of the prosthesis fastening projection, allowing it to enter relatively easily.

[0066] Furthermore, when fixing a prosthesis to the abutment of the present invention, it is preferable to fill the space between the abutment and the prosthesis with an elastic polymer material, such as medical-grade silicone, to prevent foreign matter from entering and to further reinforce the elasticity of the abutment.

[0067] Although the present invention has been described in detail above with reference to the drawings in relation to specific embodiments, the present invention is not limited to such specific structures. Those with ordinary skill in the art can modify or change the present invention in various ways without departing from the technical concept and scope of rights set forth in the following claims. However, it should be made clear beforehand that all such simple design material modifications or structural changes clearly fall within the scope of rights of the present invention.

Claims

1. A dental implant abutment having an occlusal force buffering function, The upper end portion of the abutment to which the prosthesis is attached is formed to have an outer diameter that is even larger than the portion directly below it, and the prosthesis fastening projection protrudes outward, The abutment includes an incision portion that divides the upper part of the abutment into multiple sections, The abutment for a dental implant is characterized in that the incision portion comprises a first incision portion extending downward from the upper end surface of the abutment for a certain distance, and a second incision portion formed spirally and continuously from the first incision portion.

2. The dental implant abutment according to claim 1, characterized in that the width of the lower incision of the second incision is formed to be smaller than the width of the incision at the upper end portion.

3. The dental implant abutment according to claim 1, characterized in that the direction of the incision extending from the upper to the lower part of the second incision is formed to be the same as the rotational direction for fastening the fixing screw that is responsible for fastening the abutment to the fixture.

4. The dental implant abutment according to Claim 1, wherein the abutment is fastened to a fixture by a fixing screw, and the fixing screw comprises a threaded portion having a predetermined vertical length and threads formed on its outer surface, a head portion formed above the threaded portion and having a fitting groove on its upper end surface into which a screwdriver is fitted, and a body portion connecting the threaded portion and the head portion and having a helical spiral incision portion formed for a certain length in the longitudinal direction, wherein the spiral incision portion is formed to divide the cross-section perpendicular to the vertical central axis of the body portion into equal parts by horizontally penetrating the vertical central axis of the body portion and forming a certain length in the longitudinal direction of the vertical central axis of the body portion.

5. The dental implant abutment according to claim 1, characterized in that a plurality of slot cuts extending from the outer diameter to the inner diameter are formed at regular intervals along the circumference of the lower part of the abutment inserted into the axial hole of the fixture, with at least one end of each cut off.

6. The dental implant abutment according to claim 5, characterized in that the slot incision portion consists of diagonal lines, vertical lines, or horizontal lines.

7. The abutment for a dental implant according to Claim 4, wherein the head portion of the fixing screw is further provided with a screw loosening prevention projection at a certain portion of its outer circumferential surface, and when the fixing screw is fastened, the screw loosening prevention projection is fitted into a helical or obliquely shaped incision formed on the upper part of the abutment, thereby preventing the fixing screw from loosening.

8. The dental implant abutment according to claim 1, characterized in that the inclination of the outer surface of the abutment is changed at least twice between the upper part of the maximum diameter portion (A) of the abutment where the prosthesis margin is located and the portion directly below the prosthesis fastening projection.

9. The dental implant abutment according to claim 1, characterized in that the prosthesis fastening projection is further formed with an inwardly recessed prosthesis fastening position recess, thereby specifying the fastening position of the prosthesis when the prosthesis is attached and preventing the prosthesis from rotating.

10. The dental implant abutment according to claim 1, characterized in that a certain section directly below the prosthesis fastening projection is formed with a slope lower than the slope of the outer surface of the lower one-third of the section between the maximum diameter portion of the abutment where the prosthesis margin is located and the upper end of the abutment, or has zero slope.

11. The dental implant abutment according to claim 1, characterized in that the inner diameter of the upper part of the through hole that penetrates from the upper end surface to the lower end surface of the abutment is maintained at the same level for a certain section, and then has a larger inner diameter below that.

12. The dental implant abutment according to claim 1, characterized in that, when viewed from a vertical cross-section of the prosthesis fastening projection, it is formed asymmetrically (220c') vertically with respect to the point of maximum protrusion of the prosthesis fastening projection.

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