JP2008200439A - Implant fixing member and manufacturing method thereof - Google Patents

Abstract

In implant treatment in dentistry and oral surgery, the alveolar bone or the jaw bone can be supplemented and regenerated, the bone tissue can be strengthened to stably support the implant, and can be easily processed into an arbitrary shape. An implant fixing member and a manufacturing method thereof are provided.
A hydroxyapatite ceramic porous granule having a porosity of 60% or more and 80% or less and an average pore diameter of 100 μm or more and 600 μm or less and having communication holes between adjacent pores is bonded with a bioabsorbable material. And constitutes an implant fixing member.
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Description

  More particularly, the present invention relates to an implant fixation member for a dental region for reinforcing an implant embedded portion of an alveolar bone or a jaw bone in implant treatment, and a method for manufacturing the same.

In recent years, implant treatment has been developed and attracted attention as a new dental treatment method. This implant treatment is a method in which a metal that becomes an artificial tooth root is embedded in an alveolar bone or a jawbone, and an artificial tooth similar to a natural tooth is attached using this metal as a base.
Implants are superior to dentures in that they are superior in stability, can retain sufficient biting force, and have the advantages of being unnatural in appearance and being able to bite like your own teeth. .

However, in implant treatment, it is necessary that a sufficient amount of alveolar bone or jawbone remains that can sufficiently support the implant.
The alveolar bone does not exist in a tissue dependent on a tooth, i.e., where there is no tooth, and is not formed when there is no natural tooth. Moreover, if left as it is after tooth extraction, it becomes insensitive to irritation, and the alveolar bone is absorbed and thins and decays.
Furthermore, due to severe periodontal disease or accidents, the alveolar bone and jawbone may be absorbed or damaged by surrounding tissues.

Thus, when the amount and state of the alveolar bone and the jawbone are not sufficient, it is difficult to implant the implant as it is.
Therefore, before the implant treatment, for example, if the maxillary alveolar bone has thinned, the alveoli so that the root can be planted by a method called socket lift or sinus lift (maxillary sinus lift) A procedure is performed to increase bone thickness.
In the case of the mandible, treatments such as filling the thin bone by filling granule such as hydroxyapatite or transplanting autologous bone to the part lacking bone.

  By the way, the hydroxyapatite is a main component of bone, has compatibility with autologous bone, etc., and has characteristics such as fixing by absorption into living tissue over time. is there. In addition, the ceramic has been used as a suitable material for artificial bones since it has the advantage of having excellent strength characteristics and no biological harm.

  Furthermore, among the hydroxyapatite ceramics, in particular, the cells that form bones easily invade into the inside, and since nutrients and the like can be sufficiently supplied to the cells, the porosity is high and each pore is entirely A proposal has already been made that a ceramic porous body having a configuration that communicates with each other is suitable (see, for example, Patent Document 1).

In addition, as a material having high biocompatibility and mechanical strength, an implant in which a ceramic coating layer is formed from crystallized glass mainly composed of diopsite on the surface of a metal substrate has been proposed (for example, Patent Document 2). reference).
Japanese Patent No. 3400740 Japanese Patent Laid-Open No. 6-197947

  However, even in an implant as described in Patent Document 2, the base metal itself of the artificial tooth root of the implant is still covered with a ceramic coating layer made of crystallized glass. Thus, since it is an artificial object, and it takes a long time for the ceramics of crystallized glass to function as bone, it is considered that the burden on the patient is great.

  Therefore, in order to stably support the implant and obtain good biocompatibility, it is ideal that the implant is directly implanted, and for this purpose, the implant implant has various shapes of the implant. Accordingly, a technique for forming a sufficient amount and state of alveolar bone or jawbone and strengthening the bone tissue has been demanded.

  The present invention has been made in order to solve the above technical problem, and in the treatment of implants in dentistry and oral surgery using the hydroxyapatite ceramic porous body having the excellent characteristics as described above, the alveolar bone or the jawbone An object of the present invention is to provide an implant fixing member that can stably support an implant by reinforcing and regenerating the bone tissue, and can stably support the implant, and a method for manufacturing the same. It is.

The implant fixing member according to the present invention is an alveolar bone or jaw bone implant fixing member, which is composed of an aggregate of porous hydroxyapatite ceramic granules, and the adjacent granules are joined to each other.
By using such a ceramic porous body as an implant fixing member, bone regeneration is promoted, and bone having a strength that can stably support an implant embedded inside can be formed at an early stage. it can.

The ceramic porous granule preferably has a porosity of 60% or more and 80% or less, an average pore diameter of 100 μm or more and 600 μm or less, and a communication hole between adjacent pores.
By setting the porous state of the porous granule as described above, the bone regeneration effect can be enhanced and the implant can be stably supported inside the fixing member. Bone formation can be promoted.

The granules are preferably joined with a bioabsorbable material.
As a result, the joint portion does not remain in the body, and the living tissue can enter the portion absorbed by the living body, thereby further promoting bone formation.

Also, the method for manufacturing an implant fixing member according to the present invention is the above-described method for manufacturing an implant fixing member, wherein the ceramic porous body granule is formed by rotating a ceramic porous sintered body in a pot and cutting a sharp portion. It is characterized by producing in.
If the granule has few sharp parts, there is no risk of damaging the oral cavity, and the granule filling density can be increased when joining in the mold.

  As the pot, it is preferable to use a ceramic container from the viewpoint of preventing mixing of impurities derived from the pot into the porous granule.

Moreover, it is preferable that the said pot has a convex part in an inner surface.
By using the pot having such a shape, the contact and collision frequency between the granules increases, and it is possible to quickly prepare a granule having a suitable shape in which a sharp portion is removed.

As described above, according to the implant fixing member of the present invention, it is possible to easily cope with various shapes and sizes of the embedded portion of the implant by appropriately adjusting the required amount of the ceramic porous granule. In addition, by using the granules as a joined body, it is possible to prevent the granules from being scattered to other than the target site, and the regeneration of bone is promoted, and the implant embedded inside the fixing member is stably supported. It is possible to form bones with such a strength as possible.
Therefore, according to the implant fixing member, the alveolar bone or the jawbone can be promoted for replenishment / regeneration, the bone tissue is strengthened, and the strength can be increased early enough to stably support the implant. Therefore, implant treatment can be performed effectively.
Moreover, according to the manufacturing method of the implant fixing member which concerns on this invention, when constructing the above implant fixing members, a suitable porous granule can be produced easily.

Hereinafter, the present invention will be described in more detail.
The implant fixing member according to the present invention comprises an aggregate of hydroxyapatite ceramic porous granules, and the adjacent granules are joined to each other, and is applied to an alveolar bone or jaw bone implant fixing member.
As described above, the amount of the necessary porous granule can be appropriately adjusted according to a predetermined mold corresponding to the shape and size of the implant embedded part by configuring the implant fixing member with a granule joined body. The implant fixing member can be easily obtained with a desired shape and size.
Moreover, by using granules as a joined body, it is possible to prevent the granules from scattering to places other than the target portion.

The ceramic porous granule used for the implant fixing member is made of hydroxyapatite.
Hydroxyapatite is a main composition component of bone, is relatively excellent in mechanical properties such as strength, and is a suitable material excellent in biocompatibility. In addition, after several years, it is gradually absorbed into living tissue and has an advantage of being excellent in substituting with living bone.
The hydroxyapatite may be one in which a part of the hydroxyl group or a part of the phosphate group is substituted with a carbonate group.

The hydroxyapatite ceramic porous granule preferably has a porosity of 60% or more and 80% or less, an average pore diameter of 100 μm or more and 600 μm or less, and a communication hole between adjacent pores.
By forming the implant fixing member with the porous ceramic body granule having such a structure, the bone regeneration effect of hydroxyapatite itself can be further enhanced, and the implant embedded inside the fixing member can be stably provided. Bone having a strength that can be supported can be formed at an early stage.

When the porosity of the porous granule is less than 60%, it becomes difficult for cells to enter and adhere to the inside of the fixing member, and circulation of blood or the like also becomes difficult.
On the other hand, when the porosity exceeds 80%, sufficient strength of the member cannot be obtained and breakage easily occurs.

The average pore diameter of the porous granule is preferably 100 μm or more and 600 μm or less, and preferably has communication holes between adjacent pores.
By setting the pore diameter and the communication state as described above, it is possible to promote the ease of cell invasion, the invasion speed, the culture speed, and the like, and it is possible to promote bone regeneration as a whole.

The method for producing the porous ceramic body of hydroxyapatite as described above is not limited, and a known method can be used. In particular, it can be formed by stirring and foaming of a slurry containing hydroxyapatite. preferable.
According to the stirring foaming, a high porosity, a porosity property, etc. suitable as an implant fixing member as described above can be easily controlled, and a porous body having a relatively high strength can be obtained.

As a method for producing a porous ceramic body of hydroxyapatite by stirring and foaming, for example, a method as described in Patent Document 1 (Japanese Patent No. 3400740) can be used. A specific manufacturing method is shown below.
First, a hydroxyapatite powder and a crosslinkable resin such as polyethyleneimine are added to water to which a dispersant has been added, and mixed by stirring to prepare a raw material slurry.
Furthermore, a foaming agent such as polyoxyethylene lauryl ether is added and foamed with stirring to homogenize and stabilize the bubbles to prepare a foam slurry.
Next, a crosslinking agent (gelling agent) such as sorbitol polyglycidyl ether is added to the foam slurry, and the mixture is stirred and mixed to prepare a porous slurry.
The porous slurry is cast and molded to form a porous gelled body (crosslinked body) in a state where the foam structure is maintained, and then fired to obtain a ceramic porous body.

The ceramic porous body (ceramic porous sintered body) obtained as described above is processed into granules having a desired size by cutting and grinding.
In that case, it is preferable that the granules for use in the implant fixing member according to the present invention are prepared by rotating the ceramic porous sintered bodies in a pot and cutting off sharp portions.
If the granule has a sharp portion, the oral cavity may be damaged. Moreover, if there are few sharp parts, when a granule is joined in a type | mold, many can be filled and a tap density can be made high.
In addition, it is preferable that the size of the granule is a particle size of 5 to 0.5 mm from the viewpoints of handleability and filling properties.

As the pot, a ceramic container such as alumina or zirconia is preferably used.
When a plastic container such as polyethylene is used, the plastic part is easily peeled off, and impurities derived from the pot are easily mixed in the porous granule.

Moreover, it is preferable that the pot inner surface has a convex portion.
Due to this convex part, the contact and collision frequency between the granules in the pot increase, and it is possible to quickly prepare granules having a suitable shape in which sharp portions are shaved.
As a specific method for producing the hydroxyapatite ceramic porous granule, for example, a 3 mm square block of a hydroxyapatite porous sintered body having a porosity of 75% and an average pore diameter of 150 μm prepared using the above-described known method is used. Is rotated in an alumina pot having a large number of convex portions on the inner surface. Thereby, the granule which sharpened the sharp part is prepared.

A bioabsorbable material such as tripotassium phosphate is preferably used for joining the granules obtained as described above.
The joint portion does not remain in the body, and the living tissue can invade the portion absorbed by the living body, thereby further promoting bone formation.
Specifically, by tapping and packing the granules into a mold of a predetermined size, into which a slurry of β-tricalcium phosphate is poured and dried, and then the dried body is fired at 1100 ° C. Thus, an implant fixing member made of a joined body of granules can be obtained.
According to such a manufacturing method, by appropriately adjusting the amount of necessary porous granule according to the shape and size of the mold, an implant fixing member having a desired shape made of a granule joined body can be easily produced. be able to.

An implant treatment procedure using the above-described implant fixing member will be described below.
First, a hole is drilled in the alveolar bone or the jawbone, the implant fixing member is embedded in the hole, and once closed with gums, the mucous membrane is sutured. In about 1 to 3 months, bone cells grow on the whole fixing member, and bone is also formed inside the fixing member. This bone is all or mostly formed by autologous bone. Thereby, the alveolar bone or the jawbone is strengthened.
Next, the mucous membrane in the portion where the implant fixing member is embedded is cut open, a hole is drilled in the implant fixing member, and the implant is embedded. This part is closed again with gingiva, the mucous membrane is sutured, and the implant and bone are firmly joined for about 1 to 3 months.
Thereafter, the head of the implanted implant is exposed, and a base for connecting artificial teeth is attached. Then, the artificial tooth mold is taken and attached, and the implant treatment is completed.

When the implant fixing member is embedded in the bone and the surface is exposed in the oral cavity, before the bone is formed inside the ceramic porous body, it is easy for bacteria to invade and proliferate. It is preferable to close the mucous membrane and suture the mucous membrane until the bone is regenerated.
Moreover, in order to prevent the propagation of various bacteria and suppress the occurrence of infectious diseases, silver ions or the like having a bactericidal action may be added to the implant fixing member.

The size of the implant fixing member is appropriately adjusted according to the amount and state of the alveolar bone or jaw bone of the implant embedding portion, but is usually about 10 mm in height, and the whole is embedded in the alveolar bone or jaw bone. Like that.
Further, in order to sufficiently form the reinforced bone around the implant, it is preferable that the above-described implant fixing member having a thickness of 1 mm or more is uniformly around the implant.
The implant fixing member is preferably chamfered and the corners are rounded so as not to damage the gums and mucous membranes.

The implant fixing member as described above can also be configured as an implant composite material in which an implant is embedded in advance. That is, the implant and its fixing member may be integrated in advance before the implant is embedded in the bone.
As a result, treatment in the oral cavity can be omitted, and since the above-described implant fixing member according to the present invention is used, autogenous bone regeneration for stably supporting the implant is also performed. Simplification and shortening can be achieved.

Claims (6)

  An implant fixing member for an alveolar bone or a jaw bone, comprising an aggregate of hydroxyapatite ceramic porous granules, wherein the adjacent granules are joined to each other.   The ceramic porous granule has a porosity of 60% or more and 80% or less, an average pore diameter of 100 µm or more and 600 µm or less, and a communication hole between adjacent pores. The implant fixation member as described.   The implant fixing member according to claim 1 or 2, wherein the granules are joined with a bioabsorbable material.   2. The method of manufacturing an implant fixing member according to claim 1, wherein the ceramic porous granule is produced by rotating ceramic porous sintered bodies in a pot and cutting a sharp portion. Manufacturing method of member.   The method for manufacturing an implant fixing member according to claim 4, wherein a ceramic container is used as the pot.   The said pot has a convex part in an inner surface, The manufacturing method of the implant fixing member of Claim 4 or Claim 5 characterized by the above-mentioned.