JP2008245994A - Dental implant fixture - Google Patents

Abstract

In an implant fixture that can be widely used for dental implant treatment, an implant fixture having a strong resistance to a rotational force applied to the implant fixture after being inserted into the bone of the jaw. To provide.
A main body 2 having a cylindrical shape with a predetermined diameter is provided, and a screw thread 4 formed in a spiral shape on an outer peripheral surface 3 of the main body and a groove 5 formed along the screw thread 4 are provided. In the implant fixture 1, a concave portion 6 that is recessed in the radial direction is formed on the outer peripheral surface 3, and the depth of the concave portion 6 is 0.05 to 3 mm.
[Selection] Figure 1

Description

  The present invention relates to a dental implant fixture.

Conventionally, in the field of dental treatment, an artificial dental root (implant fixture) is embedded in the jawbone of a missing part of a tooth, and an abutment and an artificial crown (superstructure) are attached to the upper part of the artificial root. Dental implant treatment as a substitute for teeth is widely performed. By performing such dental implant treatment, it is possible to prolong the life of the remaining tooth without damaging the tooth adjacent to the defect, and to firmly fix the artificial tooth without covering the oral mucosa. A feeling of use similar to natural teeth can be obtained without causing a sense of incongruity or dullness in taste when wearing an object.
Dental implant treatment is usually performed by two operations of a primary operation and a secondary operation. For dental implant treatment, an implant fixture having a cylindrical main body and a platform connected to the upper end of the main body, and having a helical thread formed on the outer peripheral surface of the main body is used.

In dental implant treatment, an implant fixture is placed in the jawbone in the primary operation. In the primary operation, after incising the gingiva at the site where the tooth is missing, an embedding cavity of a predetermined size is formed in the jawbone using a drill or the like. Next, an implant fixture having an appropriate thickness is inserted into the formed embedding cavity. After insertion, a protective cover (cover screw) is attached to the head (platform) of the implant fixture, and the incised gingiva is sutured. The protective cover is attached to prevent the head of the implant fixture and the screw hole for the abutment from being covered with the regenerated bone and soft tissue during the holding period described below. A thread groove for mounting an abutment and an upper structure, which will be described later, is formed on the platform of the implant fixture, and the protective cover has a thread portion corresponding to the thread groove. The protective cover is attached by screwing the threaded portion into a thread groove formed in the platform of the implant fixture.
After the primary surgery, the implant fixture implanted in the jawbone is held under the gingiva for a period of time. During this holding period, bone tissue damaged by primary surgery is regenerated, and the surface of the implant fixture and the bone in contact with the surface are combined at a micro level (osseointegration / bone connection). It is firmly fixed in the jawbone.

After a certain period of time, secondary surgery is performed. In secondary surgery, the superstructure is attached directly or via an abutment to an implant fixture embedded in the jawbone.
Specifically, first, the protective cover (cover screw) attached in the primary operation is removed. Thereafter, the superstructure is installed directly or via an abutment in a thread groove formed in the platform of the implant fixture. In some cases, temporary teeth may be temporarily attached before the final prosthesis (abutment and superstructure) is attached. In this way, dental implant treatment is performed.

  By the way, when attaching the protective cover, temporary teeth, abutment, and superstructure, a force is applied in the normal rotation direction similar to the direction in which the implant fixture is screwed in. The power to is added. Thus, when removing and attaching the protective cover, the temporary teeth, the abutment, and the superstructure, a large force is applied to the implant fixture in the forward rotation direction and the reverse rotation direction. This force sometimes reaches 30-40 Ncm. Therefore, when attaching or removing the attachment to or from these implant fixtures, the force in the forward rotation direction and the reverse rotation direction applied to the implant fixture causes the bone bond between the surface of the implant fixture and the bone. When destroyed, the implant fixture could spin around in the bone. In such a case, a further holding period was required to obtain the bone connection again.

As a method for strengthening the above-described bone bonding, an outer surface of the implant fixture is roughened to increase a contact area between the implant fixture and the bone. An implant fixture having a self-tap function for facilitating the implantation of the implant fixture at the tip of the implant fixture is also known. If a self-tapping type implant structure is used, since a thread groove corresponding to the shape of the thread of the implant fixture is formed in the bone at the same time as the implantation, the implantation becomes easy.
However, the resistance to the force in the rotational direction of the implant fixture is limited only by the micro level bone connection.
Therefore, there is a demand for an implant fixture that has a strong resistance to the force in the rotational direction applied to the implant fixture after implantation, not only at the micro level, but also at the macro level.

On the other hand, Patent Document 1 proposes an implant fixture having a cylindrical main body and having a plurality of substantially U-shaped bulges on the outer peripheral surface of the main body.
JP 11-33039 A

  However, the implant fixture described in Patent Document 1 is to form a bulging portion in an arbitrary shape in order to stably implant the implant fixture in an indeterminate portion such as an extraction fossa, It cannot be applied to normal tooth defects. In addition, the plurality of bulging portions in the implant fixture described in Patent Document 1 are for securing a holding force when the implant fixture is embedded in an irregular extraction fossa, and the rotation of the implant fixture It is not intended to improve resistance to directional forces.

  Therefore, an object of the present invention is to provide an implant fixture that can be widely used for dental implant treatment, and has a strong resistance to the rotational force applied to the implant fixture after being inserted into the bone of the jaw. It is to provide an implant fixture.

  The present inventors have found that the above problem can be solved by forming a recess having a predetermined depth on the outer peripheral surface of an implant fixture having a cylindrical main body, and have completed the present invention. Specifically, the present invention provides the following.

  (1) Implant fixture having a cylindrical body with a predetermined diameter and provided with a screw thread formed in a spiral shape on the outer peripheral surface of the main body and a groove formed along the screw thread And the recessed part hollow in the said radial direction is formed in the said outer peripheral surface, The said recessed part is an implant fixture whose depth is 0.05-3 mm.

  (2) The concave portion has a first surface facing a forward rotation direction that is a direction in which the main body is screwed, and a second surface facing a reverse rotation direction that is a direction opposite to the forward rotation direction, The concave portion includes the first concave portion having an angle α1 formed by the first surface and the outer peripheral surface of 30 to 150 degrees.

  (3) The implant fixture according to (2), wherein the recess includes a second recess in which an angle α2 formed by the first recess and the second surface and the outer peripheral surface is 30 to 150 degrees.

  (4) The implant fixture according to any one of (1) to (3), wherein the recess is formed in the screw thread.

  (5) The implant fixture according to any one of (1) to (4), wherein the recess is formed in the groove.

  (6) The outer peripheral surface on one end side of the main body is formed with a cutting blade portion having a self-tapping function and a vertical groove continuous to the cutting blade portion. The described implant fixture.

  ADVANTAGE OF THE INVENTION According to this invention, the implant fixture provided with the strong resistance with respect to the force of the rotation direction added to this implant fixture after implantation to the jawbone of an implant fixture can be provided.

  Hereinafter, an implant fixture of the present invention will be described based on preferred embodiments with reference to the drawings.

  The implant fixture 1 of 1st Embodiment has the main body 2 which is the cylindrical shape of a predetermined diameter, as shown in FIGS. 1-3, and the screw thread 4 formed in the outer peripheral surface 3 of the main body 2 in the shape of a spiral. And a groove 5 formed along the thread 4. A platform 7 is provided at one end of the main body 2 so as to be connected to the main body 2. The platform 7 is a portion that is connected to a temporary tooth, an abutment, a superstructure (none of which are shown), etc., after the implant fixture 1 is embedded in the bone. As shown in FIG. 1, a cavity 9 having a predetermined depth is formed on the upper surface of the platform 7 in the direction of the tip 8 (downward), which is the other end of the main body 2. A thread groove 10 is formed on the inner peripheral surface of the cavity portion 9 to fix the temporary teeth, the abutments, and the superstructure. The implant fixture 1 according to the first embodiment is used by being screwed into the jawbone from the distal end portion 8 side.

  As shown in FIGS. 1 to 3, a recess 6 is formed in the outer peripheral surface 3 of the main body 2. In the first embodiment, a plurality of recesses 6 are formed on the outer peripheral surface 3. In the implant fixture 1 of the first embodiment, each of the plurality of recesses 6 has a depth of 0.05 to 3 mm, preferably 0.1 to 1 mm, and more preferably 0.1 to 0.8 mm. As shown in FIG. 3, the depth of the recess 6 includes a length from the center P 1 of the main body 2 to the outer peripheral surface P 2 of the recess 6 and a length from the center P 1 of the main body 2 to the most depressed point P 3 in the recess 6. Expressed as a difference. When the depth of each of the plurality of recesses 6 is less than 0.05 mm, the resistance force to the force in the rotational direction of the implant fixture 1 caused by the regeneration of the bone tissue in the plurality of recesses 6 described later does not become strong. . In addition, when the depth of each of the plurality of recesses 6 exceeds 3 mm, the space formed in the recesses 6 becomes large, and it takes time to regenerate the bone tissue. Will be weak.

  In the first embodiment, each of the plurality of recesses 6 is formed in the screw thread 4 as shown in FIG. 1, and is formed so as to be recessed in the radial direction of the main body 2 from the top of the screw thread 4. . The plurality of recesses 6 are formed from the thread 4 on the tip 8 side to the thread 4 on the platform 7 side. Here, the plurality of recesses 6 may be formed so that the depth thereof is deeper than the height of the thread 4.

  As shown in FIG. 2, each of the plurality of recesses 6 has a first surface 61 facing the forward rotation direction D1 that is the direction in which the main body 2 is screwed in, and a reverse rotation direction D2 that is opposite to the forward rotation direction D1. It has the 2nd surface 62 which faces.

  As shown in FIG. 3, the plurality of recesses 6 have an angle α1 formed by the first surface 61 and the outer peripheral surface 3 of preferably 30 to 150 degrees, more preferably 45 to 135 degrees, and most preferably 60 to 120. 1st recessed part 6a which is a degree is included. In addition, as shown in FIG. 3, in the plurality of recesses 6, the angle α2 formed between the second surface 62 and the outer peripheral surface 3 is preferably 30 to 150 degrees, more preferably 45 to 135 degrees, and most preferably 60. The second concave portion 6b which is ˜120 degrees is included. Here, the angle formed between the first surface 61 and the outer peripheral surface 3 refers to an angle formed between the first surface 61 and a surface including a tangent line at the start point P2 of the first surface 61. Similarly, the angle formed between the second surface 62 and the outer peripheral surface 3 refers to an angle formed between the second surface 62 and a surface including a tangent line at the start point P2 of the second surface 62.

In the first embodiment, as shown in FIG. 3, the angle α1 formed between the first surface 61 and the outer peripheral surface 3 of the first recess 6a is 90 degrees. Further, an angle α2 formed between the second surface 62 and the outer peripheral surface 3 in the second recess 6b is 90 degrees. In addition, each of the first recess 6a and the second recess 6b has a cross-sectional shape of a substantially right triangle in which the angle formed by the first surface 61 and the second surface 62 is 90 degrees.
In the first embodiment, as shown in FIG. 2, the plurality of recesses 6 are formed with first recesses 6a and second recesses 6b alternately. Further, a total of six first recesses 6 a and two second recesses 6 b are formed in one circumference of the screw thread 4.
The cross-sectional shapes of the first recess 6a and the second recess 6b are not limited to a substantially right triangle, but may be a substantially obtuse triangle or a substantially acute triangle, or may be a substantially square or semicircular shape.

  The ratio of the length L2 (see FIG. 2) of the arc portion cut by one recess 6 to the length L1 (see FIG. 2) of the outer periphery of the main body 2 is preferably 1 to 50%, more preferably 5 to 5. 25%. By setting the ratio of the length L2 of the outer peripheral portion cut out by one recess 6 to the length L1 of the outer periphery of the main body 2 within the above range, the resistance force to the rotation direction of the implant fixture 1 by the recess 6 is reduced. More improved.

  In the implant fixture 1 of the first embodiment, a cutting blade portion 11 having a self-tapping function and a vertical groove 12 continuous to the cutting blade portion 11 are formed on the outer peripheral surface 3 of the distal end portion 8 of the main body 2. . The cutting blade portion 11 is formed so as to continuously extend in the vertical direction from the distal end portion 8 toward the platform 7. Similarly to the cutting edge portion 11, the vertical groove 12 is also formed so as to continuously extend in the vertical direction from the tip portion 8 toward the platform 7. The cutting blade portion 11 is a portion for cutting out bone when the implant fixture 1 is inserted, and is formed on the boundary between the outer peripheral surface 3 and the vertical groove 12 as shown in FIG. The cutting blade portion 11 forms a screw groove having a shape corresponding to the shape of the screw thread 4 while cutting the bone when the implant fixture 1 is embedded in the jawbone. In addition, the vertical groove 12 accumulates bone fragments cut by the cutting blade portion 11, and excess bone fragments are accumulated in the vertical groove 12. The depth of the vertical groove 12 is considerably deeper than that of the plurality of recesses 6 described above. However, when implanting the implant fixture 1, the bone fragments cut by the cutting blade 11 are filled in the space between the vertical groove 12 and the formed embedding cavity, so that the jaw bone and the implant fixture 1 No excessive space is formed between the surface. Since the bone fragment filled in the space between the vertical groove 12 and the jawbone is used for regeneration of the bone tissue, the strength of the bone tissue regenerated in the vertical groove 12 does not decrease.

The length of the implant fixture 1 can be appropriately selected depending on the site in which the implant fixture 1 is implanted in the oral cavity, but is preferably 5 to 20 mm, and more preferably 5 to 15 mm. Further, the outer diameter of the main body 2 can be appropriately selected similarly to the length of the implant fixture 1, but is preferably 2 to 8 mm, and more preferably 3 to 7 mm.
The height of the thread 4 is preferably 0.01 to 2 mm, more preferably 0.1 to 1.5 mm, from the viewpoint of stably fixing the implant fixture 1 in the jawbone. The distance between the adjacent screw threads 4 and 4 is preferably 0.05 to 3 mm, more preferably 0.1 to 2 mm.

  As a material of the implant fixture 1, a metal material having high biocompatibility such as titanium is preferably used. The surface of the main body 2 is preferably subjected to a treatment for enhancing the affinity between the surface and bone, such as anodic oxidation, hydroxyapatite spraying, hydroxyapatite coating, sandblasting, and titanium spraying.

  The implant fixture 1 of 1st Embodiment which has the above structures is first embedded in a jawbone by primary surgery similarly to the conventional implant fixture. In the implanted implant fixture 1, minute spaces are formed in a plurality of recesses 6 provided in the main body 2. Then, during the holding period after the primary surgery, the bone tissue damaged at the time of implantation is regenerated, and at that time, the space formed in the recess 6 is filled with the regenerated bone tissue. Due to the bone tissue filled in the space of the recess 6, the implant fixture 1 is improved in resistance to the force in the rotational direction. Here, since each of the plurality of recesses 6 has a depth of 0.01 to 1 mm, the bone tissue in the space formed in the recess 6 is rapidly regenerated and the regenerated bone tissue is strong. It will be a thing. Thus, by rapidly and firmly regenerating the bone tissue in the recess 6, the implant fixture 1 of the first embodiment has a strong resistance to the forces in the forward and reverse rotation directions applied after the implantation. Have.

  When the depth of each of the plurality of recesses 6 is less than 0.05 mm, it is not possible to sufficiently generate resistance to the force in the rotation direction of the implant fixture 1 due to the regeneration of bone tissue in the plurality of recesses 6. In addition, when the depth of each of the plurality of recesses 6 exceeds 3 mm, the space formed in the recesses 6 becomes large, and it takes time to regenerate the bone tissue. Will be weak.

  Further, as shown in FIG. 2, the plurality of recesses 6 are provided in a first surface 61 that faces the forward rotation direction D1 that is the direction in which the main body 2 is screwed, and in a reverse rotation direction D2 that is opposite to the forward rotation direction D1. It has the 2nd surface 62 which faces, and includes the 1st recessed part 6a whose angle (alpha) 1 which the 1st surface 61 and the outer peripheral surface 3 make is 30-150 degree | times. Thus, by having the 1st recessed part 6a whose angle (alpha) 1 which the 1st surface 61 and the outer peripheral surface 3 make is 30-150 degree | times, especially the resistance force with respect to the reverse rotation direction shown in FIG. 2 improves.

  In the secondary operation, a protective cover (not shown) attached to the platform 7 of the implant fixture 1 is removed during the primary operation. In this case, the implant fixture 1 is subjected to a force in the reverse rotation direction. Is added. Even when a force in the reverse rotation direction is applied in this way, the presence of the first recess 6 described above has a strong resistance at the macro level and can prevent the bone bond from being broken.

  In addition to the first recess 6a, the plurality of recesses 6 also have a second recess 6b in which the angle between the second surface 62 and the outer peripheral surface 3 is 30 to 150 degrees. Resistance to the direction of rotation is also improved. At the time of mounting the abutment and the superstructure in the secondary operation, a force in the forward rotation direction is applied to the implant fixture 1. By having the second recess 6b, a force in the forward rotation direction is applied. At the same time, bone fracture can be prevented.

  Further, since the plurality of recesses 6 are distributed in the height direction and the circumferential direction of the main body 2, the resistance force to the rotation direction of the implant fixture 1 is further improved.

  Moreover, the several recessed part 6 is formed in the screw thread 4, and is formed along with linear form also in the height direction. Therefore, the implant fixture 1 of 1st Embodiment also has the advantage that it can manufacture easily by giving a simple process to the screw thread of the conventional implant fixture.

  Next, 2nd Embodiment of the implant fixture 1 of this invention is described with reference to FIGS. About 2nd Embodiment, a different point from 1st Embodiment is demonstrated, about the same point, the same code | symbol is attached | subjected and description is abbreviate | omitted. For the points that are not particularly described, the above description of the implant fixture 1 is applied as appropriate.

The implant fixture 1 according to the second embodiment is different from the first embodiment in that a plurality of recesses 6 are formed in the groove 5.
In the second embodiment, as shown in FIGS. 5 and 6, the plurality of recesses 6 are formed in one circumference of the groove 5, and each of the plurality of recesses 6 includes the first surface 61 and the outer periphery. It is comprised from the 1st recessed part 6a whose angle (alpha) 1 with a surface is 90 degree | times. Moreover, the 2nd surface 62 in each of the some recessed part 6 is comprised from the curved surface which bulged outside.
According to the implant fixture 1 of the second embodiment having such a configuration, the plurality of recesses 6 are formed in the grooves 5 and are not formed in the threads 4. That is, when the implant fixture 1 is inserted, a space due to the recess 6 is not formed in the screw thread 4. Therefore, the fixation of the implant fixture 1 after the primary operation is particularly excellent.

  The implant fixture 1 of the present invention is not limited to the first embodiment and the second embodiment described above, and can be appropriately changed without departing from the spirit of the present invention.

In the first embodiment and the second embodiment, the first surface 61 and the second surface 62 in the plurality of recesses 6 are configured from a flat surface, but some or all of them are formed from a curved surface. It may be configured.
In the first embodiment and the second embodiment, the plurality of recesses 6 are formed so as to be dispersed in the height direction and the circumferential direction of the outer peripheral surface 3. It may be formed only on the side.
In the first embodiment and the second embodiment, the plurality of recesses 6 are formed, but the number of the recesses 6 may be one.
The plurality of recesses 6 may be formed in both the screw thread 4 and the groove 5.
Moreover, in 2nd Embodiment, although the some recessed part 6 was comprised from the 1st recessed part 6a, you may be comprised from the 1st recessed part 6a and the 2nd recessed part 6b.

In 1st Embodiment and 2nd Embodiment, although the front-end | tip part 8 side of the main body 2 was provided with the cutting blade part 11 and the vertical groove 12 which have a self-tap function, these do not need to be provided. .
The shape of the implant fixture 1 is a so-called straight type in which the shape of the main body 2 is substantially cylindrical in the first and second embodiments, but the outer diameter of the main body 2 gradually increases toward the distal end portion 8. It may be a so-called root-type (taper-type) implant fixture that decreases.
In the first and second embodiments, the platform 7 of the implant fixture 1 is the external type, but the platform 7 may be of other shapes such as an internal type.

FIG. 1 is a side view showing a first embodiment of the implant fixture of the present invention. 2 is a cross-sectional view taken along line XX in FIG. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is a side view showing a second embodiment of the implant fixture of the present invention. FIG. 5 is an enlarged perspective view showing grooves in the second embodiment of the implant fixture of the present invention. 6 is a cross-sectional view taken along line YY in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Implant fixture 2 Main body 3 Outer peripheral surface 4 Thread 5 Groove 6 Groove 6 Recess 61 First surface 62 2nd surface 7 Platform 8 Tip part 9 Cavity part 10 Thread groove 11 Cutting edge part 12 Vertical groove

Claims (6)

An implant fixture having a cylindrical body having a predetermined diameter, provided with a screw thread formed in a spiral shape on the outer peripheral surface of the main body, and a groove formed along the screw thread. ,
The outer peripheral surface is formed with a recess recessed in the radial direction,
The concave portion is an implant fixture having a depth of 0.05 to 3 mm.   The recess has a first surface facing a forward rotation direction that is a direction in which the main body is screwed and a second surface facing a reverse rotation direction that is opposite to the forward rotation direction, and the recess is The implant fixture according to claim 1, further comprising a first concave portion having an angle α1 formed by the first surface and the outer peripheral surface of 30 to 150 degrees.   The implant fixture according to claim 2, wherein the concave portion includes a second concave portion having an angle α <b> 2 formed by the second surface and the outer peripheral surface of 30 to 150 degrees.   The implant fixture according to claim 1, wherein the recess is formed in the thread.   The implant fixture according to claim 1, wherein the recess is formed in the groove.   The implant fixture according to any one of claims 1 to 5, wherein a cutting blade portion having a self-tapping function and a vertical groove continuous to the cutting blade portion are formed on the outer peripheral surface on one end side of the main body. .

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