JPH0345266A - Filling material for bone-defective part and bone-vacant part - Google Patents

Abstract

PURPOSE:To obtain the superior shape holding performance of a filling material in the initial stage after operation and prevent the leak of filling material by using the filling material containing a specific hydraulic calcium phosphate composition and a specific kind of hydroxyapatite particles. CONSTITUTION:The gap part generated between bone and an artificial material such as artificial joint is charged with a filler material containing the hydraulic calcium phosphate composition having a Ca/P molar ratio of 1.400-1.497 which is formed by mixing alpha-type tertiary calcium phosphate and primary calcium phosphate and containing hydroxyapatite particles having the shortest diameter of 0.1-10.0mm, and then the artificial bone material can be fixed. In this case, the hydroxyapatite particle possesses the superior shape holding performance in the initial stage after operation, and the leak of the filling material after operation can be prevented.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a filling material for bone defects and bone voids, and more specifically, it relates to a filling material for bone defects and bone voids, and more specifically, for filling material for filling gaps between bone and other artificial materials such as artificial joints. The present invention relates to a filling material for bone defects and bone voids that can fill the bone and fix artificial bone materials.

<Prior Art> Conventionally, a bone defect and bone cavity filling material is known in which the bone defect and bone cavity filling material is filled with hydroxyapatite having a crystallite size of 5OA to 10 μm and integrated with bone tissue. (For example, Japanese Patent Laid-Open No. 56-54841). Furthermore, the shortest diameter of the bone defect part, bone void part, and bone resorption part is 0.1 to 3.0 mm, and the specific surface area shape factor φ is 6.
A filler filled with hydroxyapatite having a molecular weight of 3 to 15 is also known (for example, Japanese Patent Laid-Open No. 61-20558). The hydroxyapatite used in these known filling materials for bone defects and bone voids has excellent biocompatibility, and the powders mentioned above are suitable for filling irregularly shaped bone defects and bone voids. Hydroxyapatite in the form of solid or granular forms is most suitable.

However, even if powdered or granular hydroxyapatite is compacted, it may not retain its shape after compaction, and bone tissue forms around the incision site two to three weeks after the surgery and fixes it. Previously, filling material may leak from the incision site, slowing healing of the filling site.

In this way, maintaining the initial shape of the filled and consolidated hydroxyapatite particles promotes healing.
extremely important.

In order to solve these problems, a filling material for bone defects and bone voids has been proposed that has excellent shape retention in the initial period after surgery and can prevent leakage of the filling pad after surgery (Japanese Patent Application Laid-Open No. 64--76861).

However, the self-curing material used for the filling material is p
Because it is cured with an organic acid aqueous solution of H5 or less, there is a problem that elution during and after curing lowers the pH around the filled area and irritates living organisms.

<Problems to be Solved by the Invention> Therefore, the main object of the present invention is to provide a method for filling bone defects and bone voids that contains hydroxyapatite particles that have excellent shape retention in the initial period after surgery and that does not irritate the living body. It is to provide materials.

Another object of the present invention is to provide a filling material for bone defects and bone voids that contains hydroxyapatite particles that can prevent leakage of the filling material after surgery and that does not irritate living organisms.

<Means for Solving the Problems> According to the present invention, the C a /P molar ratio of the mixture of α-type tertiary calcium phosphate and monobasic calcium phosphate is 1.4. A bone defect and bone void filling material is provided that includes a hydraulic calcium phosphate composition of OO-1,498 and hydroxyapatite particles having a shortest diameter of 0.1 to 10.0 m.

The present invention will be explained in more detail below.

The filling material for bone defects and bone voids of the present invention is characterized by containing a specific hydraulic calcium phosphate composition and specific hydroxyabatai 1-particles, and is particularly characterized by the retention of the initial shape of the filling material. and leakage of the filling material can be prevented.

Hydroxyapatite (c
As (p O4) 30 H) particles, hydroxyapatite particles obtained by heat treatment at 700° C. or higher are particularly preferable because new bone is generated quickly. The upper limit temperature of the heat treatment is not particularly limited, but since the hydroxyapatite particles start to decompose, it is preferably below the decomposition temperature. Hydroxyabatais 1 to 1 to which can be used in the present invention may be those synthesized artificially by known production methods such as a wet method, a dry method, or a hydrothermal method, or may be natural products obtained from bones etc. You may also use one. In the present invention, the hydroxyapatite particles used have a shortest diameter of 0.1 to 10.
It is an essential requirement that it be 0 mm. If the shortest diameter of the hydroxyapatite particles is less than 0.1+nm, the size of the pores formed when the particles come into contact with each other becomes unsuitable for the entry of body fluid components, which is not preferable. On the other hand, 10. If it exceeds Onwn, it is not preferable because the amount of filling into bone defects and bone voids will decrease, and the amount of hydroxyapatite particles as a structural material will decrease. Furthermore, since the gaps between particles become larger, it takes a long time for bone tissue to completely fill the gaps;
In addition, when used in the dental field, when filling the jawbone to create a jawbone, that is, to make the jaw thicker and taller when the jaw has become thinner and lower due to tooth extraction due to alveolar pyorrhea, etc. This is not preferable because significant unevenness occurs, causing problems in appearance and functionality.

It is desirable that the specific surface area shape coefficient φ of the hydroxyapatite particles or particles preferably used in the present invention is 6.3 to 15. Here, the specific surface area shape coefficient φ is a coefficient determined from the relationship between the specific surface area and particle size of particles, and is
It is displayed using the following formula.

S=φ/ρD (In the formula, S: specific surface area, D2 particle diameter, ρ: coarse particle density.) The above specific surface area can be determined by a fluid permeation method, etc., and the average particle diameter of the particles is It can be determined by microscopic ff1l observation, etc. When φ is less than 6.3, the filling material tends to move after being filled into a predetermined area, and as a result, it is difficult for bone tissue to adhere to the particle surface, and it is difficult to restore the jawbone to a high degree during jawbone construction. This is not desirable because it makes it difficult to do so.

If φ exceeds 15, the particles become nearly acicular and may easily break and become powdered after filling, which is not preferable. Further, powdered hydroxyapatite flows out to other parts of the living body and has an adverse effect on the living body, which is undesirable.

The hydraulic calcium phosphate composition used in the present invention contains α-type tertiary calcium phosphate and monobasic calcium phosphate at a Ca/P molar ratio of 1.4. OO~1.4.97
, preferably 1.450 to 1.495. At this time, the Ca/P molar ratio is 1.4
If it is outside the range of 00 to 1.4.97, the time required for curing becomes longer, so it is necessary to set the Ca/P molar ratio within the above range.

As the monocalcium phosphate, commercially available products can be preferably used, but usually most of it is monohydrate (Ca (H2P
O4) 2H20), partially anhydrous (Ca()I2p
o,)z), and in the present invention, both the l-hydrate and the anhydride can be used equally.

In the filling material for bone defects and bone voids according to the present invention, the content of the hydraulic calcium phosphate composite is preferably 5 to 95% by weight based on the total weight of the filling material.

If the amount of hydraulic calcium phosphate compound in the filler is less than 5% by weight, the retention of the initial shape will be insufficient,
On the other hand, if it exceeds 95% by weight, the amount of hydroxyapatite particles used in combination becomes too small, resulting in a significant decrease in biocompatibility, which is not preferable since it cannot function effectively as a biological filler.

The hydraulic calcium phosphate compound which can be preferably used in the filling material for bone defects and bone voids according to the present invention can be hardened in about 10 to 80 minutes by simply mixing with water. In this case, since the curing liquid is water, the pH is around neutral and therefore does not irritate living organisms. Such a hydraulic calcium phosphate composition is very preferable compared to the conventionally known calcium phosphate cements 1 to 1 which contain α-type tertiary calcium phosphate as a main component and use an acid in the curing liquid.

Bone defect and bone void filler according to the present invention.

The hydraulic calcium phosphate compound kneaded with water as described above is used in combination with hydroxyapatite particles. Therefore, it is possible to improve the operability during mixing and improve the wettability of the mud (kneading = 7), so it is possible to smoothly fill narrow spaces and areas with complex shapes.
Moreover, by previously containing a surfactant in the powder and/or water, the fixability of the hydroxyapatite particles can also be improved. Examples of the surfactant include synthetic polymer compounds such as polyethylene glycol, biopolymers such as methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, etc., and derivatives of these compounds, but they are not toxic to living organisms. Any compound or derivative thereof can be used as long as it has a lubricating effect, a thickening effect, a wetting effect, an emulsifying effect, etc. These compounds and their derivatives may be used alone or in a mixture of two or more. These polymer compounds may be commercially available.

In order to use the bone defect and bone void filling material of the present invention, there is a method of mixing hydroxyapatite particles and a hydraulic calcium phosphate composition, filling the bone defect and bone void, and then curing the hydroxyapatite particles. A method of filling the bone defect and bone void with apatite particles and then covering the filled part with a hydraulic calcium phosphate compound, or a method of curing the filler material in advance and then filling the bone defect and bone void, etc. be able to.

<Examples> The present invention will be explained in more detail below with reference to Examples, but these Examples are not intended to limit the present invention in any way.

As a hydraulic calcium phosphate composition, α-type tertiary calcium phosphate and monobasic calcium phosphate were used at a Ca/P molar ratio of 1.400.1.4.50.1.475.1.49.
Powder materials mixed in proportions of 0 and 1.497, respectively, were used. As a hydroxyapatite particle, the shortest diameter is 0.
．． Using hydroxyapatite particles that are 3nwn,
The weight ratio of the hydraulic calcium phosphate composition to the hydroxyapatite particles is 5:95.30, 0.50:5
They were mixed at a ratio of 0:0, 70:30 and 95:5, and then kneaded with water and hardened. A cured product could be produced at any ratio, and hydroxyapatite selectively gathered at the bottom due to the difference in specific gravity between the hydraulic calcium phosphate composite and the hydroxyapatite 1-particles. When such a structure is used as a filling material for bone defects and bone voids, it is recommended to use hydroxyabatais 1 to 1, which have high biocompatibility.
This is very convenient because the particles are in direct contact with the living bone and the hardened body of the hydraulic calcium phosphate composite covers the top thinly like a lid. Therefore, the biocompatibility of hydroxyapatite 1- could be maximized, and the cured product of the hydraulic calcium phosphate composition could effectively prevent leakage of hydroxyapatite, which was ideal.

Using a hydraulic calcium phosphate composition and hydroxyapatite particles having the same composition as in Example 1, only the hydroxyapatite particles were first filled as a filling material for bone defects and bone voids, and then water was added. The kneaded hydraulic calcium phosphate composition was filled and hardened by pouring it from above, and the hydroxyapatite particles were covered in a lid-like manner. Similar to Example 1, the results were good.

<Effects of the Invention> As described above, the filling material for bone defects and bone voids of the present invention has extremely excellent shape retention in the initial period after surgery, and can prevent leakage of the filling material from the incision site. , thus exhibiting significant effects in promoting healing.

Claims (1)

[Claims] The Ca/P molar ratio obtained by mixing α-type tertiary calcium phosphate and monobasic calcium phosphate is 1.400 to 1.49.
7 hydraulic calcium phosphate composition and the shortest diameter is 0.1
A filling material for bone defects and bone voids, comprising hydroxyapatite particles of ~10.0 mm.