JP4698033B2 - Bone repair device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bone repair device for repairing bone tissue, and more particularly, to a bone repair device capable of promoting active new bone formation in an extraction tooth scheduled to be implanted in the future.
[0002]
[Prior art]
An alveolar bone formation method (GBR method: Guided Bone Regeneration) has been used as a bone tissue repair method for extraction wounds based on conventional implant planting. This is because bone defects such as extraction wounds (hereinafter abbreviated as extraction teeth) are sealed with a membrane to prevent soft tissue intrusion into the extraction wound from entering the bone and undifferentiated from the bone marrow side. By storing bone-forming cells such as mesenchymal cells in the extraction wound, it is intended to promote the active formation of new bone. In this GBR method, a bone forming space is secured by using a single membrane, and calcium phosphate-based materials, autologous bone (bone fragments collected from the patient's own iliac bone, etc.) or decalcified freeze-dried bone are extracted under the membrane. A method of filling the inside has been used.
[0003]
As the membrane, a thin plate made of a bioabsorbable polymer such as a bioabsorbable polymer or polylactic acid is used. During the operation, the film is trimmed to an appropriate size and shape using scissors or the like and placed on the extracted tooth. Then, the edge of the membrane and the surrounding living tissue are sutured using a surgical thread and needle. Note that a film having a thickness that can be easily penetrated by a needle is used. After suturing, the extraction wound is continuously sealed with a membrane until a sufficient amount of new bone is formed. When the bone mass reaches an appropriate level for implant implantation, the membrane is removed and the implant is implanted.
[0004]
[Problems to be solved by the invention]
However, in the conventional GBR method, when a membrane is sewn to a surrounding living tissue with a thread, a very high skill is required for an operator in order to obtain a firm fixation. Even if it seems that sufficient fixation has been obtained, in many cases, the membrane may slightly move.In this case, the surrounding biological tissue strongly recognizes the presence of a foreign substance. Soft tissue is formed around it. As a result, a soft tissue is also formed under the membrane, and the space for forming new bone is buried in the soft tissue first, so that there is a possibility that the formation of new bone is inhibited. In addition, the thread may be loosely fixed due to loosening or the like. In this case, the film is displaced and the extracted tooth is exposed to the outside. For this reason, soft tissue may enter the extraction wound and the formation of new bone may be inhibited.
[0005]
In addition, when the extracted tooth is large, the amount of new bone formed is insufficient. In particular, the center upper part of the defect was depressed in a mortar shape, and it was in a bone state where it was impossible to plant the implant, or even when planted, there was a tendency that the supportability of the implant was insufficient.
[0006]
In view of the problems of the prior art, the present invention provides a bone repair device that can promote active new bone formation by applying it to a tooth extraction wound in which implant implantation is planned in the future. With the goal.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the bone repair device of the present invention has a rod-shaped core body having a male screw on the distal end side, and an inclined roof-shaped umbrella member fixed to the rear end portion of the core body. The umbrella member has a through-hole into which the core body is inserted at a central portion, and the core body is substantially columnar and has an outer periphery on the rear end side. It has a circumferential groove formed along the side surface, and the through hole of the umbrella member is engaged with the circumferential groove .
[0008]
According to bone repair device of such a configuration, as well as implantation fixed before the bone distal end side of the extraction wound bottom Kishintai, prior to sequester extraction wound in Kikasa member. At this time, it is not always necessary to sew the umbrella member and the surrounding biological tissue for fixation. Then, before Kikasa member at all times, because it is supported by the front Symbol core body, or worse to stimulate the living tissue and tremor umbrella member, and I Do with the poor state of the extraction wound blockade by the shift of the umbrella member it is possible to prevent to Rukoto chillin. As a result, it is possible to prevent the generation and invasion of soft tissue in the tooth extraction wound and promote the active formation of new bone. Further, since the umbrella member has an inclined roof shape, many new bones can be formed in the axial direction of the core body.
[0009]
Next, it is preferable that a layer made of a surface facing the distal end side of the front Kishintai in bone repair device of the umbrella member above Symbol Configuration calcium phosphate-based material is deposited.
[0010]
Surface facing the distal end side of the front Kikasa member in the used state of the above, located near the upper end of the bone to be exposed to the extraction in the wound. Therefore, according to such a configuration, by a layer made of a calcium phosphate-based material is a material having a new bone forming ability on the surface facing the distal end side of the front Kikasa member is adhered, new bone the calcium phosphate-based material It has the effect | action which accelerates | stimulates the formation of a new bone, especially toward the layer which consists of a calcium-phosphate type material. Thereby, since the depression of the central part of the new bone is less likely to occur, the supportability of the implant to be implanted can be made high.
[0011]
Further, it is preferable that a layer of a calcium phosphate-based material around the front Kishintai are deposited.
[0012]
According to configuration that written, in use of the bone repair device, in particular, bone formation system cells such as undifferentiated mesenchymal cells in the pores, such as porous body carboxymethyl chitin is infiltrated and storage, bone formation by disposing the porous body to provide an environment that is promoted around the core, it is possible to enhance the formation of new bone towards front SL core.
[0013]
Next, it is preferable to pre Kikasa member is made of a transparent material.
[0014]
According to configuration that written can be confirmed after incision gingival epithelium, the formation status of new bone without moving the bone repair device visually.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
In the figure, 1 is a bone repair device, 2 is a core body, 3 is an umbrella member, and 4 is an intraosseous portion. As shown in FIG. 1, the bone repair device 1 has an intraosseous portion 4 on the distal end side of the core body 2, and an umbrella member 3 is fixed to the rear end portion.
[0019]
The core body 2 is formed with a male screw at the distal end portion as the intraosseous embedded portion 4. This male screw is preferably a self-tapping type. Further, a tightening groove 5 for engaging the tip of a tool such as a screwdriver is formed at the rear end. A circumferential groove 6 is formed slightly below the rear end surface for engagement with an umbrella member 3 described later. The diameter of the core body 2 is preferably 1 to 3 mm. If the diameter is 1 mm or less, the strength of the core body 2 may be insufficient. On the other hand, if the diameter exceeds 3 mm, the size may be larger than the diameter of the implant to be implanted, and the implant cannot be planted.
[0020]
As the material of the core body 2, metals or polymer materials that are not harmful to living organisms, for example, titanium, titanium alloys, stainless steel, polyethylene, and the like can be used.
[0021]
As shown in FIG. 1, the umbrella member 3 may have a flat roof shape or an inclined roof shape. A through hole 7 for engagement with the core body 2 is provided in the central portion of the umbrella member 3, and the through hole 7 is formed to be substantially equal to the diameter of the circumferential groove 6 portion of the core body 2. The umbrella member 3 is clamped in the circumferential groove 6 of the core body 2 when the core body 2 is inserted into the through-hole 7 from the tip. Thereby, both are fixed. At this time, particularly in the case of the bone repair device 1 having the inclined roof-shaped umbrella portion 3, the core body 2 for screwing the bone embedding portion 4 of the core body 2 to the bottom portion of the extraction tooth is rotated with respect to the umbrella member 3. It needs to be movable. The height of the rear end portion of the core body 2 protruding from the umbrella member 3 is desirably up to 2 mm. If this height exceeds 2 mm, the gingival tissue is excessively stimulated, which may adversely affect the living body.
[0022]
Examples of the material of the umbrella member 3 include non-bioabsorbable polymers such as polyethylene, silicon, and Teflon that are non-bioabsorbable, and polylactic acid, polyglycolic acid, and a copolymer of polylactic acid and polyglycolic acid. A bioabsorbable polymer free of odor is preferred. Among these, it is more preferable to use a transparent material such as polyethylene and silicon. In the present invention, the transparent material includes a translucent material. It is preferable that the thickness of the umbrella member 3 is set so that it can be trimmed with scissors or the like during the operation, for example, about 5 to 500 μm.
[0023]
FIG. 3 shows a use state of the bone repair device 1. As shown in the figure, the bone embedded portion 4 of the core body 2 is screwed into the bone at the bottom of the extraction tooth B, and the core body 2 is planted in the extraction tooth B. If necessary, the umbrella member 3 is trimmed to adjust the shape. At this time, the umbrella member 3 is placed in contact with the levee portion B1 of the tooth extraction wound B so as to cover the tooth extraction wound B. Thereby, the extraction tooth wound B is sealed from the outside. Since the umbrella member 3 is held in place without moving by the engagement between the core body 2 and the bone, it is not always necessary to sew the surrounding biological tissue for fixation.
[0024]
Moreover, since the said umbrella member 3 is always supported by the said core 2, it can prevent that the umbrella member 3 fluctuates or shift | deviates. As a result, it is possible to prevent the generation of soft tissue in the extracted tooth and promote the active formation of new bone.
[0025]
The embedding depth of the bone embedding portion 4 is up to 3 mm. If the depth is greater than this, the tip of the core body 2 may damage nerve tissue or the like.
[0026]
The core body 2 is arrange | positioned in the embedment planned position of an implant. Originally, since it is not necessary to form new bone at the position where the implant is embedded, the core body 2 is disposed at that position. When the new bone is densely formed, the bone repair device 1 finishes its function and is removed at that time. As described above, according to the bone repair device 1, new bone is formed in the tooth extraction wound B except where the core body 2 is located. Therefore, since the amount of new bone formation may be smaller than in the case where new bone is formed on the entire extraction wound B, the time until implant implantation can be greatly shortened. Moreover, since the required amount of new bone may be small, the healthy formation of new bone is more reliable.
[0027]
Further, by forming the umbrella member 3 in an inclined roof shape, new bone can be grown to a position higher than the bank portion B1 of the tooth extraction wound B. In the present invention, the inclined roof shape includes a dome shape. In addition, any shape that can generate a space for forming new bone above the embankment portion B1 of the tooth extraction wound B, such as a shape in which the central portion is raised from the edge portion of the umbrella member 3, is effective.
[0028]
In addition, in the umbrella member 3 of the bone repair device 1 having the above-described configuration, the layer 9 made of a calcium phosphate material such as hydroxyapatite or TCP (tertiary calcium phosphate) is attached to the surface facing the distal end side of the core body 2. Is preferred. In this case, there are the following advantages. That is, the surface of the umbrella member 3 facing the distal end is located near the upper end of the bone exposed in the extraction tooth B. Therefore, a layer made of a calcium phosphate material that is a material having new bone forming ability is attached to the surface of the umbrella member 3 that faces the distal end side, so that the calcium phosphate material can generate new bone, particularly calcium phosphate. There exists an effect | action which promotes formation of the new bone toward the layer 9 which consists of a system material. Thereby, since it becomes difficult for depression to generate | occur | produce in the center part of the formed new bone, the supportability of the implant to implant can be made into a high level.
[0029]
And it is preferable that the thickness of the layer 9 which consists of said calcium-phosphate type material is the range of 5 micrometers-50 micrometers. When the thickness of the layer 9 is less than 5 μm, the calcium phosphate material disappears very early, so that there is a possibility that the ability to form new bones may not be exhibited. On the other hand, when the thickness exceeds 50 μm, There is a possibility that the adhesive force becomes large and becomes an obstacle when the bone repair device 1 is removed.
[0030]
As a method for depositing the layer 9 made of the calcium phosphate material, the surface of the umbrella member is graft-polymerized by corona discharge treatment or the like to form a hydrophilic polymer surface, and this umbrella member is immersed in a pseudo body fluid to precipitate hydroxyapatite. Any known method can be used.
[0031]
Further, when the umbrella member 3 is made of a transparent material, there is an advantage that the formation status of new bone can be visually confirmed without moving the bone repair device 1 after incising the gingival epithelium.
[0032]
Furthermore, it is preferable that the bone repair device 1 has a layer 12 made of a calcium phosphate material around the core 2. As a result, the formation of new bone in the direction toward the core 2 can be enhanced. In this case, if the bonding force between the layer 12 and the core body 2 is too large, it becomes an obstacle when the core body 2 is removed.
[0033]
The thickness of the layer 12 made of the calcium phosphate-based material is preferably in the range of 5 μm to 50 μm like the layer 9 described above. As the method for forming this layer 12, when the core body 2 is made of a polymer material, the above-described method of graft polymerization and immersion in simulated body fluid can be used. On the other hand, when a metal is used, a known method of depositing hydroxyapatite by heating in a spraying method or an alkaline solution and then dipping in a simulated body fluid can be used.
[0034]
Further, as shown in FIG. 4, the bone repair device 1 infiltrates and retains osteogenic cells such as undifferentiated mesenchymal cells in a pore such as a porous body 11 of carboxymethyl chitin (CM chitin). And can be used in combination with a porous body that provides an environment in which bone formation is promoted. Thereby, the effect | action of new bone formation can be strengthened.
[0035]
Here, since the porous body 11 is made of an elastic sponge-like material, it can be trimmed to a desired shape with a knife, scissors or the like in accordance with the shape of the extraction tooth to be filled. The porous body 11 may be formed with a through hole 13 through which the core body 2 can be inserted. The porous body 11 is filled in the tooth extraction wound B, and the core body 2 is inserted into the through-hole 13 so that the bone embedded portion 4 of the core body 2 can be advanced to the tooth extraction wound B bottom. Then, the core body 2 can be fixed by screwing the bone embedded portion 4 into the bone.
[0036]
Next, specific examples of the present invention will be described.
[0037]
Bone restoration of the extracted tooth was performed using the bone repair device 1 shown in FIG. 1 (a) and the CM chitin porous body 11 in combination. The core body 2 was made of a titanium alloy and had a diameter of 2 mm, and the depth of the circumferential groove 6 was set to 100 μm. Moreover, the umbrella member 3 was formed of a polyethylene plate having a thickness of 500 μm, and the diameter of the central through hole was set to 1.8 mm.
[0038]
The CM chitin porous body 11 was prepared as follows.
[0039]
After preparing a 5 wt% CM chitin aqueous solution, 1/5 of the hydroxyapatite granules are mixed and stirred with respect to the aqueous solution, and poured into a mold having a 2 mm-diameter projection at the center, and the mold (diameter 6 mm, height 5 mm). ) The whole was frozen in an ultra-low temperature cool box (−80 ° C.). Thereafter, the entire mold was placed in a lyophilizer and treated for 24 hours to obtain a lyophilized product. The freeze-dried body was heat-treated at 160 ° C. for 24 hours in a vacuum to obtain a porous body 11 having a through hole 13 at the center.
[0040]
A bone defect hole having a diameter of 6 mm and a depth of 3 mm is formed in the diaphysis of the rabbit femur, and the porous body 11 is placed in the bone defect, and the bone repair device 1 is installed using the through-hole 13. Fixed. After this fixation, the gingival epithelial tissue was sutured.
[0041]
After 8 weeks, the gingival epithelial tissue was incised, and the bone repair device 1 was removed using a screwdriver. As a result, a new bone was formed up to the same height as the upper end of the bone defect hole, and the new bone was a hard, high-quality bone in which the tip of the tweezers was not easily pierced.
[0042]
As a comparative example, the porous body 11 was placed in a bone defect hole, and a polyethylene plate having a thickness of 500 μm was sutured with surrounding living tissue to seal the bone defect hole. And the bone repair condition in a bone defect hole was confirmed like the Example (comparative example 1). As another comparative example, the bone defect hole was naturally healed without any particular treatment, and the bone repair status in the bone defect hole was confirmed in the same manner as in the example (Comparative Example 2).
[0043]
In Comparative Example 1, the upper end of the new bone was about 1 mm lower than the upper end of the bone defect hole, and the central portion was depressed, and fibrous connective tissue was present there.
[0044]
On the other hand, in Comparative Example 2, the new bone was only thinly formed on the entire bottom surface, and fibrous connective tissue was present thereon.
[0045]
As described above, the embodiment of the present invention was remarkably good as compared with the comparative example.
[0046]
As mentioned above, although embodiment of this invention was illustrated, it cannot be overemphasized that this invention can be set as arbitrary forms, unless it deviates from the objective of invention, without being limited to these embodiment.
[0047]
【The invention's effect】
As described above, the bone repair device according to the present invention includes the rod-shaped core body having a bone embedded portion on the distal end side and the umbrella member fixed to the rear end portion of the core body, whereby the core It is possible to seal the tooth extraction wound with the above-mentioned umbrella member by embedding and fixing the bone embedding portion on the distal end side of the body in the bone of the tooth extraction wound bottom. At this time, stitching is not necessarily required for fixing the umbrella member. And since the said umbrella member is always supported by the said core, the fine movement of an umbrella member and the sealing defect of the extraction tooth | wound by the deviation | shift of an umbrella member can be prevented. As a result, it is possible to prevent the generation of soft tissue in the extracted tooth and promote the active formation of new bone.
[0048]
In addition, when a layer made of a calcium phosphate-based material is applied to the surface of the umbrella member of the bone repair device having the above configuration facing the distal end side of the core body, this layer is close to the upper end of the bone exposed in the tooth extraction wound. Will be located. Therefore, by providing a layer of calcium phosphate-based material, which is a material having new bone forming ability, on the surface facing the distal end side of the umbrella member, this layer generates new bone, in particular, new bone toward this layer. Has the effect of promoting the formation of This makes it difficult for the central part of the new bone to sink, so that the supportability of the implant to be implanted can be raised to a high level.
[0049]
In addition, when a layer made of a calcium phosphate material is applied around the core body, in particular, osteogenic cells such as undifferentiated mesenchymal cells infiltrate into pores such as a porous body of carboxymethyl chitin. By arranging a porous body that provides an environment in which bone formation is promoted and is promoted to form a bone, the formation of new bone toward the core can be enhanced by placing the porous body around the core during use.
[0050]
Next, when the umbrella member is made of a transparent material, after the gingival epithelial incision, the formation of new bone can be visually confirmed without moving the bone repair device.
[0051]
In addition, by forming the umbrella member in an inclined roof shape, more new bones can be formed in the axial direction of the core body.
[Brief description of the drawings]
1A and 1B are perspective views of a bone repair device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is an explanatory diagram of a use state of the bone repair device of FIG. 1; FIG.
FIG. 4 is an explanatory diagram of a use state showing another use form of the bone repair device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bone restoration device 2 Core body 3 Umbrella member 4 Bone embedded part 5 Groove 6 Circumferential groove 7 Through-hole 9 Layer 11 which consists of calcium phosphate-type material Porous body 12 Layer B which consists of calcium phosphate-type material B Dental extraction wound B1 Levee part

Claims (4)

A bone repair device having a rod-shaped core body having a male screw on the distal end side and an inclined roof-shaped umbrella member fixed to the rear end portion of the core body,
The umbrella member has a through-hole into which the core body is inserted at a central portion,
The core body is substantially cylindrical and has a circumferential groove formed along the outer peripheral side surface on the rear end side, and the through hole of the umbrella member is engaged with the circumferential groove. Features bone repair device . The bone repair device according to claim 1, wherein the thickness of the umbrella member is smaller at the end than at the center in a cross-sectional view .   3. The bone repair device according to claim 1, wherein the end face on the rear end side of the core body has a tightening groove having both ends opened. 4.   The bone repair device according to any one of claims 1 to 3, wherein the umbrella member is made of a transparent material.

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