KR102304075B1 - Pixture for dental implant - Google Patents

Abstract

The present invention provides a dental implant fixture structure capable of preventing a lateral fracture caused by stress concentration in the vicinity of a polygonal structure part inside a fixture by improving an outer screw thread structure of the fixture. To this end, according to the present invention, in a dental implant fixture which is inserted into alveolar bone tissue to form an artificial tooth root according to a rotational movement about a central axis, a screw thread of a single pitch is formed on the outer circumferential surface of the fixture. From the lower end of the fixture upward to a certain section, an outer lower screw thread section in which a deep screw thread is formed is formed. Above the outer lower screw thread section, an outer upper end screw thread section in which a screw thread having a low valley depth is formed is formed. An inner groove to which an abutment for supporting a prosthesis can be coupled is formed inside the upper end of the fixture. The inner groove comprises: an upper inclined part positioned at an upper end inlet of the fixture and having a circular cross-section and a shape in which the inner diameter is gradually narrowed toward the bottom; a polygonal part formed under the upper inclined part and having a polygonal cross-sectional shape; and an abutment-coupling screw part formed under the polygonal part and having a smaller diameter than a circle which is inscribed in the polygon of the polygonal part. When viewed with respect to the upper end surface of the fixture, the outer upper end screw thread section is positioned from the lower end of the polygonal part to the lower section as much as 2 to 4 screw threads.

Description

Dental implant fixture {Pixture for dental implant}

The present invention relates to a dental implant fixture, and more particularly, to a dental implant fixture capable of preventing transverse fracture caused by stress concentration in the vicinity of a polygonal structure inside the fixture by improving the external thread structure of the fixture. .

Osseo-integration, in which titanium is combined with bone, was discovered by Professor Branemark of Sweden, and a titanium artificial tooth fixed to the jawbone was introduced in 1965 by applying this theory. Dental implants are artificial teeth that can permanently replace missing teeth, and are widely used to restore chewing function in partially or completely edentulous areas.

Dental implants (hereinafter, simply referred to as 'implants') must not only be functionally capable of acting as actual teeth, but also must be made to be used for as long as a real tooth by properly distributing the load applied to the teeth.

The implant fixture (fixture) to be placed in the alveolar bone is roughly divided into an external connection method and an internal connection method depending on the form in which the abutment and the fixture are combined. The external connection method with a regular hexagonal structure protruding from the bone has the advantage that the fixture inserted into the bone is relatively robust, but the gap between the fixture platform and the abutment is wide in the initial stage after implantation, so there is a high probability of bacteria inhabiting the boundary area. The disadvantage is that bone resorption occurs.

For this reason, recently, the internal connection method is mainly used. The internal connection method was first applied to the product introduced by Astra Tech. A regular hexagonal groove (generally called a hexa part) is formed inside the fixture, The part where the abutment meets the fixture is formed in a cone shape to exclude a space for bacteria to inhabit, thereby minimizing initial bone resorption, which has the advantage of high implantation success rate. However, there is a disadvantage in that the fracture possibility of the fixture inserted into the bone is relatively high due to the structural limitation due to the abutment going into the fixture.

As the number of users who have used it for more than 10 years after implantation has increased, fracture cases of fixtures or abutment screws are relatively rare, but the frequency of occurrence is gradually increasing recently, the case in FIG. 1 (https://blog.naver. com/anatole0613/2 22004874696) is a representative example.

1 a) is a periapical radiograph PA (Periapical) photograph of an implant used for 15 years after implantation in a patient. The state in which the implant is split into several along the corner of the hexa part can be confirmed with the photograph taken with the abutment removed, and FIG. 1 c) is a photograph showing the abutment and the fixture that have been placed, and the slope where the abutment and the fixture meet It can be seen that the negative inclination angle is large, and the thickness of the top of the fixture has a structure having an edge surface close to zero.

As in the case of FIG. 1, fractures occurring along the axis of the fixture are usually referred to as longitudinal fractures, and as shown in the PA picture of FIG. It is a form mainly found in clinical practice with transverse fractures occurring in the horizontal direction at the tangent boundary.

Such fracture is caused by a fatigue phenomenon. Fatigue refers to a phenomenon in which the strength of a material or structure is lowered and ultimately fracture occurs due to an increase in the number of repetitions of the stress when a cyclic stress occurs in a material or structure. As a dental implant is a structure to replace a lost tooth, it is repeatedly subjected to stress due to mastication, so the possibility of fatigue fracture (referred to as fatigue fracture in the industry hereinafter as fatigue fracture) is excluded. can't

In particular, as shown in Fig. 2c), not only the vertical masticating force in the axial direction acts on the fixture, but also the horizontal masticating force perpendicular to the axial direction complexly acts on the abutment during the actual masticating motion, so the moment as shown is applied. In addition, the lower end of the abutment can touch the hexa part and repeatedly apply a force, which causes a tensile stress to be periodically applied to the geometrically discontinuous edge of the hexa part, which may result in fatigue fracture in the form of longitudinal or transverse fracture.

According to the study, the magnitude of the masticatory force exerted when food in the oral cavity is crushed by the teeth does not exceed 66 N (newton). 400-890 N. For this reason, in the ISO 14801:2016 regulation, which sets the fatigue test to determine the durability limit of dental implants by repetition of stress in the range of stress that dental implants can receive in the oral cavity, the fatigue limit load (210 N or more) It is stipulated that it shall not cause destruction for 5 million repetitions.

The minimum force of 400 N, which is the minimum of the maximum occlusal force, is equivalent to the amount of force required to lift a woman weighing 40 kg. It is made at a rate of 2Hz, and it is the number of times assuming that it can be used for about 5 to 10 years or more based on 3 meals a day and 3 to 15 minutes of food intake per serving.

Although the standard of the fatigue test assumes that the durability of the implant fixture is 5 to 10 years, the patient or operator who has undergone the procedure has no choice but to want to use it stably for a long time.

If the implanted fixture is damaged due to fatigue fracture, the fractured area causes necrosis of the gums and damage to the alveolar bone. will give In addition, from the viewpoint of implant manufacturers, if the fracture rate is high, the reliability of their products may be lowered, which may act as a factor that greatly affects product sales.

However, as a way to overcome the problem of fatigue fracture, using an alloy of titanium and zirconium instead of pure titanium to improve the tensile strength characteristics, increasing durability against fatigue fracture, or surface treatment is known. The domestic patent literature that is searched for "implant" and "fatigue fracture" or "fatigue destruction" is also registered utility model No. 20-0386621 (change the combination method of abutment and fixture) and registered patent No. 10-1668889 ( There are only two cases of coating the surface of the fixture), and the reality is that it is difficult to find a patent designed to overcome the problem of fatigue fracture.

On the other hand, a recent study confirmed that the mechanical properties of the hexa part connection area were defective as one of the causes of fracture of the internally connected pure titanium material fixture. to form crack nucleation, and as a result, as shown in FIG. 3, it was confirmed that cracks start and propagate at the interface with the horizontal plane at the bottom of the hexa part where crack nuclei are mainly located.

Through FIG. 3, the longitudinal fracture occurring in the implant fixture as shown in FIG. 1 is initiated and propagated in the crack nucleation at the bottom of the hexa part indicated by the white arrow in FIG. 3 b). I can tell.

3 c) SEM picture is a picture taken by magnifying a) the square part of the picture, d) picture is a picture taken by magnifying the square part of the picture c) again. It showed crack propagation.

However, through research, it has only been confirmed that the cause of fatigue fracture is a defect during plastic machining, and there is still no solution to the specific cause of fatigue fracture or the manufacturing process to solve the cause. No solution has been sought.

Registered Utility Model Publication No. 20-0386621 (Announcement on June 16, 2005) Registered Patent Publication No. 10-1668889 (Notice on October 24, 2016)

The technical problem to be solved in the present invention is to extend to a certain position below the polygonal structure inside the fixture by extending the external upper thread section of the fixture, where the valley depth of the screw thread is processed low, to a polygonal structure inside the fixture caused by stress concentration in the vicinity An object of the present invention is to provide a dental implant fixture capable of preventing transverse fracture.

The present invention for solving the above technical problem, in the dental implant fixture that is inserted into the alveolar bone tissue according to the rotational behavior about the central axis to form an artificial tooth root, a single pitch thread on the outer circumferential surface of the fixture Is formed, from the lower end of the fixture upwards to a certain section, an external lower thread section in which a thread having a deep valley depth is formed is formed, and an external upper thread section in which a thread having a low valley depth is formed above the external lower thread section is formed. An inner groove to which an abutment for supporting a prosthesis can be coupled is formed inside the upper end of the fixture, and the inner groove is located at the upper inlet of the fixture and has a circular cross-section and has an inner diameter toward the bottom. An upper inclined portion having a gradually narrower shape, a polygonal portion formed below the upper inclined portion and having a polygonal cross-sectional shape, and a thread formed below the polygonal portion and having a smaller diameter than a circle inscribed in the polygonal portion of the polygonal portion It comprises a formed abutment coupling thread portion, wherein the external upper thread section is characterized in that it is positioned from the lower end of the polygonal part to the lower section by 2 to 4 threads when viewed based on the top surface of the fixture.

In this case, the depth of the thread valley of the external upper thread section may be formed to gradually decrease from the lower part to the upper part.

The inner groove may further include a circular vertical portion having a circular cross-section and connected to a lower portion of the polygonal portion.

In addition, the inner groove is formed to be connected between the circular vertical portion and the abutment coupling screw portion, and the upper end forms the same diameter as the circular vertical portion and the lower end forms the same diameter as the abutment coupling screw portion and may further include a lower inclined portion having a shape in which the inner diameter is gradually narrowed toward the bottom.

On the other hand, in the external upper thread section, a thread non-processing section in which the thread is not machined over a predetermined section downward from the top end of the fixture may be formed.

In this case, the non-threading section may be formed to a position of 0.2 to 0.3 mm downward from the top end of the fixture.

In addition, an ending point, which is a point at which the inclination of the external upper thread processing trajectory changes, is set at the bottom of the non-threading section, and the ending point is formed to be located at a point 0.6 to 0.8 mm from the uppermost end of the fixture can be

At this time, the movement trajectory in which the bite performing the thread processing of the external upper threaded section moves away from the ending point after the thread processing is completed is inclined at an angle of 23.5 to 26.5 degrees with respect to the axis of the fixture. It can be formed.

According to the structure of the dental implant fixture of the present invention having the above configuration, an external upper thread section in which the thread bone depth is processed is formed in the fixture, and the lower end of the hexagonal part is based on the external upper thread section by the upper surface of the fixture By forming 2 to 4 threads extending from the bottom to the lower section, it is possible to secure the thickness of the fixture in the vicinity of the hexagonal part, and the structural rigidity of this part can be increased. It has the effect of preventing transverse fracture.

In addition, by changing the escape position and escape angle of the bite when machining the external upper end screw of the fixture using a bite to form a Closed Thread structure on the outer upper part of the fixture, the thickness of the upper part of the fixture can be increased to increase the structural rigidity of the upper part of the fixture, , it is possible to prevent longitudinal fracture due to fatigue fracture at the upper end of the fixture.

1 is a photograph showing a case of longitudinal fracture of the implant fixture.
Figure 2 is a photograph showing a case of transverse fracture of the implant fixture.
3 is a photograph showing that the longitudinal fracture of the implant fixture is initiated at the lower edge of the hexa part.
Figure 4 is a perspective view and a plan view showing a dental implant fixture structure according to the present invention.
Fig. 5 is a front view of Fig. 4;
Figure 6 is a cross-sectional view showing the external thread structure of the implant fixture according to the present invention.
7 is a cross-sectional view specifically showing the internal structure of the implant fixture according to the present invention.
8 is an exemplary view showing the movement trajectory of the bite when machining the external upper thread of the fixture.
9 is a front view specifically showing the position where the non-threaded section and the Closed Thread structure are formed on the top of the fixture.
Figure 10 is an exemplary view showing a comparison of the thread width in the case of machining an external thread using a bite of the same shape and when processing an external thread using a bite of a different shape.
11 is a view specifically showing the external upper thread forming section with a low valley depth in the fixture of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains can easily implement them.

However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. In addition, it should be noted that parts denoted by the same reference numerals throughout the detailed description mean the same components.

Hereinafter, one embodiment of a dental implant fixture according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a perspective view and a plan view showing a dental implant fixture structure according to the present invention, and FIG. 5 is a front view of FIG. 4 . And, Figure 6 is a cross-sectional view showing the external thread structure of the implant fixture according to the present invention, Figure 7 is a cross-sectional view specifically showing the internal structure of the implant fixture according to the present invention.

4 to 7, the dental implant fixture 300 according to the present invention is a structure that is inserted into the alveolar bone tissue according to the rotational behavior about the central axis (CL) to form an artificial tooth root, the fixture of the present invention ( 300) A plurality of threads 212 and 222 having the same (single) pitch in the vertical direction are formed on the outer circumferential surface.

In this case, for machining the threads 212 and 222 having the same pitch (P) on the outer peripheral surface of the fixture 300, two bites having different machining surface shapes on the processing target surface of the fixture base material in the state before the screw thread is processed ) is sequentially introduced and then the processing is performed while moving from the lower end to the upper end of the fixture, thereby forming two thread sections 210 and 220 having different valley depths on the outer circumferential surface of the fixture 300 .

That is, when two thread sections 210 and 220 having different thread trough depths are formed on the outer circumferential surface of the fixture 300, the first bite 230 is shown in FIG. By processing the thread 222 having a deep valley depth (or high mountain height) through the outer lower thread section 220, the second bite 240 is above the outer lower thread section 220. Through processing the thread 212 having a shallow valley depth (or a low mountain height), the external upper thread section 210 can be formed.

In this case, as shown in FIG. 6 , the valley depths D2 and D3 of the thread 212 formed in the external upper thread section 210 are the valley depths D1 of the thread 222 formed in the external lower thread section 220 . ), and in particular, in the external upper thread section 210, the valley depth (or mountain height; D2, D3) of the thread 212 may be formed in a structure that is gradually lowered from the bottom to the top. That is, in the outer top screw thread section 210 , the bone depth of the screw thread is gradually lowered from the bone depth D2 of the lowermost thread to the upper part, so that the valley depth D3 of the uppermost thread can be formed to be the lowest.

For example, in the external upper thread section 210, the lowest thread 212 with the highest height is formed to a height of 0.22 mm, and the top thread 212 may be formed to a height of 0.12 mm, and the height is the highest. High (0.22 mm) from the bottom of the screw thread to the top, the height of the screw is gradually lowered toward the upper end of the last uppermost screw thread can be configured to form the lowest (0.12 mm) thread 212 in height.

In this way, when the height (depth) of the screw thread 212 formed in the external upper thread section 210 of the fixture 300 is formed in a structure that gradually decreases toward the top, the fixture 300 is more in the dense bone region of the alveolar bone surface. In addition to being able to be firmly fixed, the wall thickness of the upper part of the fixture 300 is increased to secure the rigidity of the upper part of the fixture 300, so it is possible to prevent longitudinal fractures occurring in the upper part of the fixture.

On the other hand, inside the upper end of the fixture 300, an abutment (Abutment) for supporting the prosthesis can be coupled, an inner groove 100 having a specific shape dug a certain depth from the upper end of the fixture 300 is formed. At this time, the inner groove 100 has an upper inclined portion 110 , a hexagonal portion 120 , a circular vertical portion 130 , a lower inclined portion 140 , and a screw portion 150 for coupling an abutment to the fixture ( 300) to form a structure arranged sequentially downward from the upper inlet.

Specifically, the upper inclined portion 110 is a portion located at the upper inlet portion of the fixture 300, and has a shape structure in which the cross-sectional shape is made in a circular shape and the inner diameter width is gradually narrowed downward.

And, the hexagonal part 120 is a part connected to the lower side of the upper inclined part 110, and the cross-sectional shape is a hexagonal shape. At this time, the hexagonal part 120 is presented as one embodiment shape, and in addition to the hexagonal shape, it may be formed to have various regular polygonal shapes, such as octagonal and 12 sided.

The circular vertical part 130 is a portion having a circular cross-sectional shape connected to the lower side of the hexagonal part 120 , and the lower inclined part 140 is between the circular vertical part 130 and the abutment coupling screw part 150 . As a connecting part, the upper end forms the same diameter as the circular vertical part 130 and the lower end forms the same diameter as the abutment coupling screw part 150 . The lower inclined portion 140 is also formed in a structure in which the inner diameter is gradually narrowed toward the bottom.

The abutment coupling thread 150 is connected to the lower side of the lower inclined part 140, and the abutment coupling thread 152 having a smaller diameter than a circle inscribed in the hexagonal part of the hexagonal part 120. This is the formed part.

On the other hand, in the fixture 300 of the present invention, a non-threading section (H) in which thread processing is not performed over a certain section from the top of the fixture 300 to the upper side is provided on the upper side in the external upper thread section 210. . At this time, such a non-threading section (H) is preferably formed from the top of the fixture 300 in the downward direction to 0.2 ~ 0.3mm position (see Fig. 9). In addition, the peripheral portion of the upper surface of the non-threading section (H) may be accompanied by a chamfering process of about 0.12mm.

This non-threaded section (H) is a section provided to secure the robustness of the upper part of the fixture 300 that can cause longitudinal fracture, and since the thread is not formed in the non-threaded section (H) portion, the fixture When the 300 is implanted in the alveolar bone, the non-threaded section (H) is partially exposed outside the upper surface of the alveolar bone without being inserted into the alveolar bone.

However, since the non-threaded section (H) formed at the top of the fixture 300 is a section formed with a very small length (0.2-0.3mm) compared to the entire length of the fixture 300, such a non-threaded section ( Even if it is not implanted into the alveolar bone until H), the support rigidity of the fixture 300 in the alveolar bone is not significantly reduced.

If the non-threaded non-threading section (H) is formed at the upper end of the fixture 300 as described above, when the fixture 300 is implanted in the alveolar bone, the bearing capacity of the fixture 300 in the alveolar bone is not significantly reduced. Since it is possible to secure a certain level of thickness for the upper part of the fixture 300 , it is possible to increase the structural rigidity of the upper part of the fixture 300 .

On the other hand, the fixture 300 of the present invention has two bites 230 and 240 having different machining surface shapes to form two thread sections 210 and 220 having different thread valley depths (or thread thread heights) on the outer peripheral surface thereof. ) to perform thread processing on the processing target surface of the fixture base material.

A typical fixture thread processing operation is to perform thread processing while rotating the fixture base material while moving the bite into the lower part of the processing target surface of the fixture and moving it upward along a predetermined moving trajectory. The thread height can be adjusted by adjusting the entry depth of the bite.

In the fixture 300 of the present invention, when the external lower thread section 220 is formed, the first bite 230 is entered into the fixture base material to process the thread 222 with a deep (or high mountain height) thread trough depth. At the time when the processing of the thread 222 by the first byte 230 is completed, the thread 212 processing of the external upper thread section 210 is performed by replacing the first byte 230 with the second byte 240 . will do

In this case, as mentioned above, from the top of the fixture 300 downward to a certain depth (0.2 to 0.3 mm), since a non-threading section (H) is formed, the second bite (240) The external upper thread processing of the fixture 300 by By enlarging the thread processing is completed, the external upper end of the fixture 300 may be formed in a closed thread structure as shown in FIGS. 4 and 5 .

Figure 8 shows the movement trajectory of the bite when machining the outer top thread of the fixture 300, and Figure 9 shows the location where the non-threading section (H) and the Closed Thread structure are formed on the top of the fixture 300. .

As shown in FIGS. 8 and 9 , in order to form a Closed Thread structure on the outer upper end of the fixture 300 , it moves along the first movement trajectory P1 when processing the outer upper end thread by the second bite 240 . (212) It is enough to set a specific point at which the second byte 240 performing the machining operation moves to the second movement trajectory P2 out of the first movement trajectory P1.

That is, the ending is the point at which the second bite 240 moves along the first movement trajectory P1 and performs the processing of the thread 212 deviate from the first movement trajectory P1 (or the starting point of the second movement trajectory). When an Ending Point (EP) is set at the lower side of the non-threading section (H), a Closed Thread structure can be made at the top of the exterior of the fixture 300 .

To explain this in more detail, as shown in FIG. 8 , when the external upper end thread of the fixture 300 is machined, the second byte 240 enters the lower end of the processing target surface of the fixture 300 and then the first movement trajectory P1 ) while moving upward, the thread 212 processing operation is performed, and at the time when the thread 212 processing is all completed, the second bite 240 is separated from the first movement trajectory P1 and then the second It moves along the movement trajectory P2.

At this time, the first movement trajectory P1 on which the second bite 240 is moved for the external upper thread processing operation does not form parallel to the axis line CL of the fixture 300, and the first movement trajectory P1 with respect to the axis line CL. It has a shape inclined by one angle (θ1). Due to this, the fixture 300 has a shape in which the diameter gradually decreases as it goes downward.

In addition, the second byte 240 moves along the first moving trajectory (P1) and while processing the thread, the second moving trajectory (P2) that moves after deviating from the ending point (EP) at the top of the fixture 300 is formed to be inclined by a second angle θ2 with respect to the axis CL of the fixture 300 .

At this time, the second angle θ2 between the second movement trajectory P2 and the axis line CL forms an angle sufficiently larger than the first angle θ1 between the first movement trace P1 and the axis line CL. Since the second byte 240 performs the thread processing operation along the first moving trajectory P1, it departs from the ending point EP and moves along the second moving trajectory P2 again after a specific point. Since no further thread processing is performed from, the thread located at the uppermost end in the external upper thread section 210 of the fixture 300 does not pass through the top surface of the fixture 300 and is blocked from the bottom of the non-threading section (H). It can be formed with a closed thread structure in the form of

In this case, it is preferable to set the ending point EP where the processing of the thread 212 by the second bite 240 is completed to be located at a point 0.6 to 0.8 mm from the uppermost end of the fixture 300 . In this case, the ending point EP refers to a central location point of the second byte 240 at the point when the second byte 240 deviates from the first movement trajectory P2 .

In addition, it is preferable to set the second movement trajectory P2 to which the second bite 240 moves after completing the thread processing to be inclined at an angle of 23.5 to 26.5 degrees with respect to the axis of the fixture 300 .

In this way, during the external upper thread machining operation of the fixture 300, the second byte 240 moves along the first movement trajectory P1 after the initial entry into the fixture 300 and performs thread processing. When the second bite 240 is set to move along the second movement trajectory (P2) away from the processing target surface at an angle of 23.5 to 26.5 degrees at a position of 0.6 to 0.8 mm below the uppermost section, the upper part of the fixture 300 A Closed Thread structure can be formed in

As described above, in processing the external upper thread of the fixture 300 using the second bite 240, the upper end of the fixture 300 through changing the escape position and the escape angle of the second bite 240 Since it is possible to form a Closed Thread structure of a closed screw thread structure in the fixture 300, it is possible to increase the structural rigidity of the upper part of the fixture 300 through the reinforcement of the thickness of the upper part, and through this, it is frequently used in the upper part of the fixture 300 Longitudinal fractures that have occurred can be prevented.

On the other hand, in order to process the threads 212 and 222 having the same pitch (P) on the outer surface of the fixture 300, the first bite 230 for performing the external lower thread processing of the fixture 300 and the external upper thread processing are performed. The difference in shape for the machining surface of each end of the second bite 240 must be accompanied.

FIG. 10 shows the thread valley depth and thread width in the case of machining an external thread on the fixture using a bite of the same shape and when processing an external thread using a bite of a different shape.

First, (a) of FIG. 10 is a case in which the external lower thread 222 and the external upper thread 212 are processed using the same bite, and when a bite having the same shape of the end processing surface is used, the outer upper end with a low trough depth Since the peak width of the screw thread 212 is widened, when the fixture 300 is implanted in the alveolar bone, a relatively large torque is required, which makes it difficult to install the fixture 300 and may also cause damage to the alveolar bone.

On the other hand, in the present invention, as shown in FIG. 10 (b), the shape and width of the end processing surface of the first bite 230 and the second bite 240 for processing the external bottom thread 222 and the external top thread 212 are By performing the thread processing operation differently, the valley depth of each thread 212 , 222 formed in the external upper and lower thread sections 210 , 220 of the fixture 300 is different, but the pitch P of each thread is the same, and the It is possible to form a thread structure having the same peak width. If the peak width of the screw thread is narrowed as described above, the area of the screw thread valley is increased compared to the prior art, thereby obtaining advantageous effects even during blasting or coating treatment.

On the other hand, Figure 11 shows in detail the formation position of the outer top screw thread section 210 in the fixture 300 of the present invention.

11, in the fixture 300 of the present invention, the lower end of the external upper thread section 210 in forming the outer upper thread section 210 having a low height (or valley depth) of the screw thread 212 is the fixture (300) It may be formed so as to descend to a lower position by 2 to 4 threads 212 from the bottom surface of the lower end of the inner hexagonal part 120 as a starting point.

In this way, when the lower end of the external upper thread section 210 is disposed to be located below 2 to 4 threads 212 from the bottom bottom surface of the inner hexagonal part 120 of the fixture 300, the fixture 300 of When the punching process is performed to create the hexagonal part 120 structure in the inner groove 100, a geometric non-uniformity point is generated at the lower edge of the hexagonal structure, so that the hexagonal part 120 vicinity is the starting point of fatigue fracture cracking. Since it is possible to indirectly reinforce the thickness of the corresponding part by forming the screw thread 212 to have a low depth, it is possible to prevent the transverse fracture phenomenon occurring in the vicinity of the hexagonal part as in the existing technology.

In the above, preferred embodiments of the present invention have been described, but the scope of the present invention is not limited to these specific embodiments, and those skilled in the art may appropriately change within the scope described in the claims of the present invention. this will be possible

100: inner groove 110: upper inclined portion
120: hexagonal part 130: circular vertical part
140: lower inclined portion 150: threaded portion for abutment coupling
210: external upper thread section 212,222: thread
220: external lower thread section 230,240: second, second byte
CL: Axis EP: Ending Point
H : non-threading section P : Pitch

Claims (8)

In the dental implant fixture for forming an artificial tooth root by being inserted into the alveolar bone tissue according to the rotational behavior about the central axis,
An inner groove to which an abutment for supporting a prosthesis can be coupled is formed inside the upper end of the fixture, and the inner groove is located at the upper inlet of the fixture and has a circular cross-section and the inner diameter gradually decreases toward the bottom. A narrow upper inclined portion, a polygonal portion formed under the upper inclined portion and having a polygonal cross-sectional shape, and a thread formed below the polygonal portion and having a smaller diameter than a circle inscribed in the polygonal portion of the polygonal portion. Includes a thread for butt coupling,
From the lower end of the outer circumferential surface of the fixture upward to a certain section, an external lower threaded section is formed, which is processed to form a high thread by the first bite, and the upper side of the outer lower threaded section is different from the first bite An external upper thread section is formed that is processed to form a low-height thread by a second bite having a face shape and a width,
The pitch and the peak width of the threads of each thread section processed through the first and second bytes are formed to be the same,
The external upper threaded section is dental implant fixture, characterized in that it is positioned from the lower end of the polygonal part to the lower section by 2 to 4 threads when viewed with respect to the upper surface of the fixture.
The dental implant fixture according to claim 1, wherein the thread bone depth of the external upper thread section gradually decreases from the lower part to the upper part.
The dental implant fixture according to claim 1, further comprising a circular vertical portion having a circular cross-section and connected to a lower portion of the polygonal portion.
According to claim 3, wherein a connection is formed between the circular vertical portion and the abutment coupling thread, the upper end forms the same diameter as the circular vertical portion and the lower end forms the same diameter as the abutment coupling screw portion, , Dental implant fixture, characterized in that it further comprises a lower inclined portion made of a shape in which the inner diameter is gradually narrowed toward the bottom.
The dental implant fixture according to claim 1, wherein the external upper thread section has a non-threaded thread processing section in which the thread is not machined over a predetermined section downward from the top end of the fixture.
[Claim 6] The dental implant fixture according to claim 5, wherein the non-threading section is formed to a position of 0.2 to 0.3 mm downward from the top end of the fixture.
According to claim 5, wherein an ending point (Ending Point) is set at a point where the inclination of the external upper thread processing trajectory changes at the bottom of the non-threading section, and the ending point is 0.6 to 0.8 mm from the top end of the fixture. Dental implant fixture, characterized in that located in.
The method according to claim 7, wherein the movement trajectory in which the bite performing the thread processing of the external upper thread section moves away from the ending point after the thread processing is completed is inclined at an angle of 23.5 to 26.5 degrees with respect to the axis of the fixture. Characterized by dental implant fixtures.

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