JPH06296678A - Production of packing material for defective part, gap part and absorptive part of bone - Google Patents

Abstract

PURPOSE:To easily obtain the packing material which is dense and has excellent strength by baking the granules obtd. by drying and pulverizing the packing material consisting of hydroxy apatite particles which are specified in the extreme minor diameter and the hole diameter of the plural recesses on the surface right after introducing air bubbles into a slurry. CONSTITUTION:The fine powder of the hydroxy apatite is first slurried at the time of producing the packing material which is so formed as to be fixed into the packing points of the defective part, gap part and absorptive part of the bones, to accelerate the formation of the neo-bone in an early time at these packing points and to be integrated with the osseoustissues of the living body. The content of the fine powder of the hydroxy apatite in the slurry is specified to be 60 to 70wt.% at this time. The dry material obtd. by drying the slurry right after introducing the air bubbles into the slurry is then pulverized to the grains having 0.1 to 3.0mm extreme minor diameter by a know method and thereafter, the granules are baked to obtain the packing material particles 1 having the extremely high density and including the plural recesses 11, 12 of several mum to 500mum on the surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is fixed to a filling portion of a bone defect portion, a bone void portion and a bone resorption portion, promotes early formation of new bone at the filling portion, and is integrated with living bone tissue. The present invention relates to a method for producing a bone defect portion, a bone void portion, and a bone resorption portion filling material that can be made into a material.

[0002]

2. Description of the Prior Art In conventional dental treatment or orthopedic treatment, other parts of the patient himself / herself are used to repair bone lost due to diseases such as periodontal disease, absorption of alveolar bone after tooth extraction, traffic accident or bone tumor. Bone transplantation of
In the repair method, since bone tissue other than the damaged portion is removed, the physical and psychological burden on the patient is extremely large, and a sufficient amount of autogenous bone cannot be collected to fill a wide range of bone defects. There is. Therefore, in order to solve the above-mentioned problems, various metal alloys, organic substances, and the like have been proposed as substitutes for hard tissues of living bodies. However, the above-mentioned various metal alloys and organic substances generally have a problem that when they are used in a biological environment, they are accompanied by foreign matter reactions such as poor solubility and toxicity to the living body.

[0003] Recently, ceramic-based materials such as a filler made of a sintered body or a single crystal of alumina, tricalcium phosphate or hydroxyapatite, which has excellent affinity with living organisms and does not have the above-mentioned defects, have been attracting attention. . Of these, hydroxyapatite can be expected to form new bone early after filling, and since it has the advantage of coming into contact with new bone without the intermediary of connective tissue like alumina, it is particularly useful as a material with excellent biocompatibility. Are known. The filler using the hydroxyapatite is roughly classified into a porous filler having continuous air holes connecting the surface and the inside and a dense filler having almost no pores inside due to its structural characteristics. It
Even if the porous filler is granular, it is fixed to the filling site without moving easily after filling and has an excellent early bone formation ability, but a load is applied to the filling site after filling or after suturing. In that case, the porous filler is destroyed, and there is a drawback in that strength is weak such that the filled portion sinks.

Further, although the dense packing material is excellent in strength, when it is in a granular form, it has a drawback that it moves from the packed portion unless it is compacted and packed, and therefore it has excellent biocompatibility. The problem of delayed bone formation arises.

Further, as a filling material which can be fixed and filled in a filling place, a dense filling material having a shortest diameter of 0.1 to 3.0 mm and a specific surface area shape factor φ of 6.3 to 15 ( JP-A-61-2558) has been proposed. However, even with this filling material, the current situation is that the fixing to the filling location is still insufficient.

There is also known a filler in which the internal structure of the hydroxyapatite particles is dense or porous having continuous pores and has a plurality of depressions on the surface. The filling material having the depressions on the surface is fixed at the filling portion,
It is also excellent in the ability to form new bone.

However, when the internal structure is a filler having continuous pores, there is a problem in strength. On the other hand, in the case of a dense material, its production is carried out in two steps: formation of a dense portion and formation of a recessed portion on the surface. However, there is a drawback that the manufacturing becomes complicated.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a depression which is excellent in biocompatibility and early bone formation ability and which is surely fixed to a filling portion without performing compaction filling or the like. An ideal bone defect part, a bone void part, which has an internal structure that is more densely formed than porous granules, has sufficient practical strength, and has no adverse effect during surgery, and It is an object of the present invention to provide a manufacturing method capable of easily obtaining a bone resorption part filler.

[0009]

According to the present invention, a bone defect having hydroxyapatite particles having a shortest diameter of 0.1 to 3.0 mm and having a plurality of depressions having a pore diameter of several μm to 500 μm on the surface thereof. A method for producing a filling material for bone parts, bone voids and bone resorption parts, wherein hydroxyapatite fine powder is made into a slurry, and immediately after entraining bubbles in the slurry, it is dried, and then the shortest diameter is 0.1 to 3.0 mm. A method for producing a filling material for a bone defect portion, a bone void portion, and a bone resorption portion, which comprises pulverizing into granules and then firing the granules.

The present invention will be described in more detail below. In the production method of the present invention, first, the hydroxyapatite fine powder is made into a slurry. The particle size of the hydroxyapatite fine powder is preferably 0.1 to 90 μm, and the content of the hydroxyapatite fine particles in the slurry is preferably 60 to 70% by weight.

Then, air bubbles are entrained in the obtained slurry and then immediately dried. The bubbles can be entrained in the slurry by a method such as stirring the slurry well, but for the purpose of facilitating the entrainment of the bubbles in the slurry, preferably 1 part is added to 100 parts by weight of the slurry.
-10 parts by weight of combustible organic material may be added. The flammable organic substance may be any substance that forms a depression after firing, and preferably polyvinyl alcohol, ammonium naphthalene sulfonate, polycarboxylic acid ammonium salt and the like can be mentioned. The drying temperature is not particularly limited as long as it is a normal drying temperature, and for example, 80
It can be performed at about ° C.

Then, the dried product thus obtained is pulverized by a known method into granules having a shortest diameter of 0.1 to 3.0 mm, and then the granules are fired to have desired depressions on the surface and the inside is impregnated. It is possible to obtain the filler particles which are more densely formed than the porous granules obtained in (1). That is, by crushing a slurry dried product containing a lot of bubbles, it is possible to form cracks from weakly bubbled parts, thus forming desired depressions on the surface part, and the inside has such strength that it does not break even by the crushing. The resulting structure has the bubbles contained therein, that is, the particles have a higher density than the porous granules obtained by the impregnation method. The firing temperature is 700 to 120.
0 ° C. is preferable, and firing at 1000 to 1200 ° C. is particularly preferable for further increasing the strength as a filler.

Further, the surface of the filling material has an edge in an uneven portion formed by a depression, but if a large amount of the edge is present, it may have an unfavorable effect on living tissue around the filling portion, and In some cases, when using a syringe or the like for filling, the extrusion port of the syringe may clog, which may hinder the filling operation. Therefore, it is preferable to completely remove or reduce the edge. The edge can be removed by treating it with a pot mill or the like.

A bone defect obtained by the production method of the present invention,
Bone void and bone resorption filler are particles made of hydroxyapatite with excellent bone formation promoting ability. The filler is fixed on the surface of the particles at the filling point, and new bone cells adhere and grow. In order to improve the above, the surface of the particle is provided with a plurality of depressions having a specific shortest diameter.

The shortest diameter of the produced particles of bone defect portion, bone void portion and bone resorption portion, that is, particles composed of hydroxyapatite is in the range of 0.1 to 3.0 mm. When the shortest diameter of the particles is less than 0.1 mm, when filling the bone defect portion, the bone void portion and the bone resorption portion, the gap formed by the particles coming into contact with each other is an unsuitable size for the infiltration of body fluid components. In addition, since the particles are fine, the particles are pushed out of the body from the sutured part by body fluid such as blood after filling, or easily move to other parts of the body, and it is difficult to fix the part to the part requiring filling. Becomes On the other hand, when the shortest diameter exceeds 3.0 mm, the amount of filling in the bone defect portion, the bone void portion and the bone resorption portion becomes small, and the gap between the particles is too large, so the gap is filled with bone tissue. It takes a long time to exhaust, and when used in the field of dentistry, when filling in a tooth extraction fossa, etc., there are problems in appearance and function due to remarkable unevenness on the mucosal surface, so it is necessary to be within the above range. is there.

Further, the depressions formed on the surface of the particles as the filler are such that when the filler is filled in the bone defect portion, the bone void portion and the bone resorption portion, the adjacent filler materials are locked together. Fixed, as a whole, to firmly fix the filling material to the desired filling location, and further, the irregularities formed by the depressions are for improving the attachment and proliferation of new bone cells, The hole diameter of the depression must be in the range of several μm to 500 μm, and in order to further increase the strength of the filler, it is preferable to set the hole diameter in the range of several μm to 100 μm. When the pore diameter is less than several μm, the adjacent fillers do not engage with each other, and the filler easily moves from a desired filling location to another portion. When it exceeds 500 μm, the strength is reduced. Must be within range.
The depth of the depression is preferably in the range of several μm to 50 μm. When the depth of the depression is less than several μm,
In the adjacent filler, the irregularities formed by the depressions are not sufficiently engaged with each other, and the attachment of new bone cells at an early stage cannot be expected. If it exceeds 50 μm, the strength decreases, which is not preferable.

Further, the recesses formed on the surface of the particles are preferably 10 to 100% of the entire surface of the filler, and the specific surface area shape factor φ of the particles is 6.3.
It is preferably in the range of -15. If the specific surface area shape factor φ exceeds 15, the shape of the particles becomes needle-like, and the particles may be easily broken and pulverized due to external force after filling. It is not preferable because it adversely affects the living body such as spillage. On the other hand, if it is less than 6.3, the filling material is likely to move from the filling portion to another portion after filling, and the generation of attachment of bone tissue to the surface of the filling material is delayed, which is not preferable.

[0018]

According to the manufacturing method of the present invention, the surface is several μm to 5 μm.
Possess a plurality of pits of 00 μm to securely fix it to a desired filling site, promote the early attachment and proliferation of new bone cells, and have a porous structure whose internal structure is obtained by the impregnation method. It is possible to easily obtain a bone defect portion, a bone void portion, and a bone resorption portion filling material that is more densely formed than the granule and has sufficient strength.

[0019]

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these.

[0020]

[Example 1, Comparative Examples 1 and 2] Hydroxyapatite synthesized by a wet method (hereinafter referred to as HAp) was fired at a temperature of 800 ° C.
After calcination for 2 hours, use a ball mill to obtain an average particle size of 9
The particles were pulverized to 0 μm or less to obtain HAp fine particles. The resulting HAp fine particles are mixed with water to give a solid HAp concentration of 7
A 0 wt% HAp slurry (hereinafter referred to as HAp slurry A) was prepared. At the time of making the slurry, in Example 1, 2 parts by weight of ammonium polycarboxylic acid salt was added to 100 parts by weight of the slurry, and the mixture was well stirred and mixed for a few dozen minutes in order to well entrap air bubbles. Then, the obtained HAp slurry is dried at 80 ° C., then calcinated at a calcination temperature of 1200 ° C. for 1 hour and crushed to form a plurality of dents on the entire surface of the particle, and then the shortest diameter is 0.5 to 1 The 0.0 mm particles were sieved.
Finally, edge treatment was performed with a pot mill to obtain a desired filler (Example 1). When the hole diameter of the depression formed on the surface of the obtained filler was measured by a scanning electron microscope, it had a hole diameter of several μm to 100 μm, and the depth was several μm.
It was m to 50 μm.

An enlarged perspective view of the obtained filler particles is shown in FIG. 1, and a plan view in which the surface of the filler particles is further enlarged is shown in FIG.
Shown in (1a) and (1b). In FIG. 1, 1 is a filler particle obtained in Example 1, and a plurality of depressions 11 having a small pore diameter and a plurality of depressions 12 having a large pore diameter are formed on the entire surface of the granular filler material 1. As shown in (1a) and (1b), the surface of the granular filler 1 had a portion in which the small pore diameters 11 were dense and a portion in which the small pore diameters 11 were dense around the large pore diameter 12.

Further, the HAp slurry A was impregnated in a urethane resin having a network structure and dried at 80 ° C.
After calcination at 200 ° C. for 1 hour and pulverization, sieving was performed in the same manner as above to obtain a porous granular filler having a shortest diameter of 0.5 to 1.0 mm (Comparative Example 1). Furthermore, after pulverizing the dried product of HAp with an impeller breaker, a firing temperature of 12
Baking at 00 ° C for 1 hour, sieving in the same manner as above, and performing edge treatment with a pot mill to obtain a shortest diameter of 0.5.
A dense granular filler having a size of 1.0 mm was obtained (Comparative Example 2).

[0023]

[Test Example] A 4 mm x 4 mm x 3 mm bone defect portion was prepared in the mandible of an adult dog, and the filler obtained in Example 1 and Comparative Examples 1 and 2 was applied to the bone defect portion according to a conventional method. After sterilization, it was filled by press fitting. One week after the operation, palpation observation was performed, and four weeks after the operation, the adult dog was sacrificed to prepare a sample, and the formation state of new bone tissue at the filling material site was observed. The filling material obtained in Example 1 facilitates the filling operation into the bone defect portion, and is already reliably fixed to the bone defect portion at the time of palpation for one week after the operation, and exhibits the same state as the jaw bone. It was Furthermore, in the tissue specimen observation after 4 weeks, the formation of new bone tissue was remarkably observed around the filler granules adjacent to the bone, and the formation of bone tissue was observed up to the center of the filler-filled portion. It was
However, in the porous granular filler obtained in Comparative Example 1, it was difficult to fill because the filler was crushed by the press-fitting when filling the bone defect portion. In addition, the filler that could be barely filled was destroyed during palpation for one week after the operation or by normal chewing, and was discharged from the filling site before preparation of the specimen, and the tissue specimen was not observed. Further, with the dense filler obtained in Comparative Example 2, the filling operation can be easily performed as in Example 1, and the filler can be fixed to the bone defect portion 4 weeks after the operation. However, at the time of palpation one week after surgery, the filling material was not securely fixed. Therefore, when observing the formation state of new bone tissue in the tissue specimen observation, the filling material was placed in the center of the site filled with the filling material. Up to now no new bone tissue has been formed and therefore each filler particle was not able to prematurely integrate with new bone.

[Brief description of drawings]

FIG. 1 is an enlarged perspective view of a bone defect portion, a bone void portion, and a bone resorption portion filler obtained in Example 1, (1
a) is a plan view further enlarging a part of the filler surface of FIG.
(1b) is a plan view in which a different portion of the same surface is further enlarged.

[Explanation of symbols]

 1: Filler body, 11: Small pore diameter depression, 12: Large pore diameter depression.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiyasu Takeuchi 2270 Yokose, Yokose-cho, Chichibu-gun, Saitama Sanryo Mining & Cement Co., Ltd.

Claims (2)

[Claims] 1. The shortest diameter of the hydroxyapatite particles is 0.1 to 3.0 mm, and the surface has a pore size of several μm.
A method for manufacturing a bone defect portion, a bone void portion, and a bone resorption portion filler having a plurality of recesses of 500 μm, wherein hydroxyapatite fine powder is made into a slurry, and immediately after entraining air bubbles in the slurry, drying is performed, Then the shortest diameter 0.1-3.
A method for producing a filling material for a bone defect portion, a bone void portion and a bone resorption portion, which is characterized by crushing to 0 mm into granules and then firing. 2. The method for producing a bone defect portion, a bone void portion and a bone resorption portion filling material according to claim 1, wherein the slurry contains a combustible organic substance.