KR960010743B1 - Artificial implant and the method thereof - Google Patents

Abstract

The structure of artificial tooth implant (I) consists of (1) a tooth body, (2) a linking layer, and (3) a contacting layer of 20-50% pore space. (2) is coated by spraying the hot melted mixture of alum and calcium phosphate 1:1.8-10.5 on (1). (3) is coated in 100-300 micron thickness by spraying the same mixture on (2) and treated by 0.1M sodium hydroxide or calcium hydroxide solution to solve alum to have 1-50 micron size of pores.

Description

Composite implant material and its manufacturing method

1 is a cross-sectional view of a composite implant of the present invention.

* Explanation of symbols for the main parts of the drawings

1: metal implant base material 2: dense layer of first layer

3: multi-process surface layer of 2nd layer

The present invention relates to a composite implant material used for artificial tooth roots, artificial joints, and the like, particularly a composite implant material having excellent strength and toughness and excellent biocompatibility, and a method of manufacturing the same.

In general, implant materials of Co-Cr alloys, Ti alloys or stainless steels have recently been used in many medical applications. However, if the metal implant material is placed in the body for a long time after implantation in vivo, rapid ions of the rapid implant material are eluted by the tissue fluid or body fluid in the body or due to contact and friction with the tissue in the body to corrode the implant material. In addition, the rapid ions eluted from the metal implant material may damage macrophages of the living body or invade the cells of the living body to generate inflammatory cells or giant cells.

For this reason, the surface of the implant base material is coated with biocompatible apatite hydroxide or tricalcium phosphate (Japanese Patent Publication No. 63-46165), or surface treatment such as coating with a stable material in vivo using plasma arc (Japan Patent Publication No. 64-52471) has been proposed to prevent the elution of the metal ions constituting the implant base material and to impart biocompatibility.

However, when the coating is formed on the metal base material as in these methods, the resulting surface layer becomes relatively dense, and the surface layer is dense so that bone cells cannot grow and enter into the implant material after implantation in the body. Therefore, the bond between the implant and the living hard tissue (bone) depends only on the chemical bonding force that occurs on the surface of the coating, there was a disadvantage that the sufficient bonding force between the implant material and the bone is not secured.

Accordingly, an object of the present invention is to form a porosity in the composite implant in order to solve the problem of weak bonding force with the living body tissue of such a conventional implant material to enter the bone cells into the processing of the composite implant material after a certain period of time To grow into bone.

That is, the purpose is to provide rapid fixation and stabilization of the implant material in vivo by simultaneously pursuing a mechanical bond between the implant material and the biological hard tissue (bone) and bone grown up to the inside of the pores.

In addition, the present invention has a high strength, high toughness, and in particular, to provide a composite implant excellent in biocompatibility.

Hereinafter, the present invention will be described in detail.

The present invention provides a composite implant material comprising a metal implant base material (1) and a dense layer (2) of calcium phosphate compound of the first layer thereon, wherein the porous surface layer (3) of the second layer of calcium phosphate compound is further added. It is a composite implant material characterized by the above-mentioned.

In addition, the present invention is a method for producing a composite implant material in which a dense layer (2), which is the first layer, is formed of a calcium phosphate compound by a plasma spraying method on a metal implant base material (1) made of titanium or titanium alloy. The calcium compound powder is mixed in a weight ratio of 1: 1.8 to 1: 0.5, and plasma-sprayed on the dense layer 2 of the first layer, which is then treated with an alkaline solution to produce pores in which the aluminum is removed. It is a method for producing a composite implant material, characterized in that the porous surface layer 3 of the second layer is further formed.

Hereinafter, the present invention will be described in more detail.

That is, the present invention forms an uneven surface by blasting with aluminum oxide crystal grains on the surface of the metal implant base material 1 such as titanium or titanium alloy. The uneven surface of the metal implant base material 1 thus formed increases the mechanical bonding force between the metal implant base material 1 and the dense layer 2 of the calcium phosphate compound described later.

Subsequently, plasma spraying of at least one calcium phosphate compound powder such as tricalcium phosphate and apatite hydroxide having a calcium: phosphorus molar ratio (Ca / P) of about 1.5 and 1.67 to the metal implant base material 1 was carried out at 30 to 50 μm. By forming the dense layer 2, which is a relatively close first layer of thickness, the metal implant base material 1 is isolated from the body fluid or the body tissue to prevent elution of metal ions from the metal implant base material 1.

In the above, plasma spraying means that metal or ceramic powder particles enter a high temperature plasma fluid and are melted instantaneously, and are loaded into a high-speed plasma fluid to collide with a strong force on a base material for coating purposes. It is a coating method to form a surface coating layer by returning to the original solid state and at the same time flattened by the impact received by the impact on the metal implant base material.

Subsequently, in order to form the porous surface layer 3 of the second layer on the dense layer 2 of the first layer, aluminum powder and calcium phosphate compound powder are mixed at an appropriate ratio and coated by plasma spraying. Since aluminum is an amphoteric element, it has a property of being easily dissolved in an acid or an alkaline solution, whereas calcium phosphate compound powder is gradually dissolved in an acidic solution, but has stable properties in an alkaline solution.

Therefore, when plasma-coated powder in which aluminum powder and calcium phosphate compound powder are mixed at an appropriate ratio is plasma-coated on the dense layer 2 of the first layer, a composite layer composed of aluminum and calcium phosphate compound is present in the coating layer.

The above-mentioned aluminum powder and calcium phosphate compound powder such as calcium phosphate or apatite hydroxide are suitably in a weight ratio of about 1: 1.8 to about 1: 10.5.

When the composite layer thus formed is deposited in an alkaline solution such as sodium hydroxide or potassium hydroxide at about 0.1 molar concentration, the calcium phosphate compound remains as it is, but the portion where aluminum was present is selectively dissolved in the alkaline solution. Therefore, the calcium phosphate porous layer remaining after the aluminum is eluted has a small porosity of 20 to 50%, which is optimal for mechanical bonding between the living hard tissues in three dimensions.

The particle size of the aluminum and calcium phosphate compound powder is about 100 to 200 μm in order to form pores having a size in the range of 1 to 50 μm, which is suitable for growth of living tissue and firm bonding between the implant material and the bioscope. It is used to form a coating layer in the range of about 100 to 300㎛ thickness.

Since the size of the pores of the coating layer formed above is smaller than the starting particles due to the collision with the metal implant base material during the coating by the plasma spray method, particles larger than the pore diameter of the desired size should be used.

In addition, when the porosity of the porous surface layer 3 of the second layer is 20% or less, the binding force between the implant material and the living body tissue is not sufficient, and when 50% or more, the mechanical strength of the porous surface layer 3 itself is weak. As a result, a synergistic effect of the bonding force between the implant material and the biological hard tissue is not obtained.

In addition, in the above, when the pore size of the porous surface layer 3 of the second layer is 1 μm or less, the bonding force is not sufficient, and when the pore size is 50 μm or more, the strength of the porous surface layer 3 itself is unsuitable.

In addition, in the present invention, the plasma coating method can be used to form a plurality of layers from the metal implant base material to the surface layer, and the pore size and porosity of the layers can be arbitrarily changed to suit the required properties of each layer.

In addition, when the coating layer composed of aluminum and calcium phosphate is deposited in an alkaline solution for a predetermined time, only a portion of aluminum is selectively reacted and eluted, and the place where aluminum is present remains as three-dimensional continuous pores. As a solution, sodium hydroxide or potassium hydroxide solution is suitable, and it is more effective to combine sonication to completely elute aluminum.

Conventional implant material maintains a simple bond only on the surface of the collagen fibers and bone cells and the implant, but the oblique functional implant material according to the present invention is to enter the collagen fibers and bone cells not only into the pores formed on the surface but also after a certain period of time Is converted to bone and forms a strong bond directly with calcium phosphate.

Therefore, chemical and mechanical bonds are also formed in the pores, including the surface, between the living body tissue and the implant, so that the implant surface contains significantly stronger binding force than the conventional implant material, which relies only on chemical bonding.

That is, the composite implant material according to the present invention is the first layer to isolate the metal implant base material (1) of high strength and high toughness and the metal implant base material (1) from the body fluid in vivo to prevent metal ions from eluting from the metal implant Due to the dense layer of (2) and the porous surface layer (3) of the second layer having sufficient porosity and pore diameter, it induces the growth of living body tissues in vivo, and strongly binds to the living body tissues to achieve stability in the body. Will have.

That is, the composite implant material composed of a strong metal implant base material (1), a dense layer of calcium phosphate compound (2), and a porous surface layer of calcium phosphate compound (3) exhibits properties that complement each other's shortcomings. Done.

Hereinafter, the present invention will be described with reference to Examples.

Example

The surface of the metal implant base material of the artificial tooth root or artificial joint made of titanium was blasted with aluminum oxide particles having a thickness of about 50 μm to form irregularities on the surface, thereby removing foreign substances attached to the surface. On the surface of the blast-treated metal implant base material, a hydroxide sprayed apatite powder having a calcium: phosphorus molar ratio (Cs / P) of 1.67 was plasma sprayed to form a dense layer having a thickness of 50 μm. Subsequently, in order to prepare a porous surface layer, a mixed powder was prepared such that the aluminum powder having a size of 100 to 200 μm and the apatite hydroxide powder were 1: 1: 4.7 by weight, and then plasma coated to form a surface layer having a thickness of about 200 μm. The plasma sprayed implant was placed in a 0.1 mol sodium hydroxide solution and sonicated for about 3 minutes.

The aluminum-free implant was washed in flowing distilled water and then placed in an ultrasonic cleaner containing distilled water to remove sodium hydroxide solution that may be present in the pores. After completely removing the sodium hydroxide inside the pores of the porous surface layer, the composite implant material was put in a 100 ± 5 ℃ dryer for 24 hours to prepare a composite implant material having a porous surface layer of 30% porosity, the average pore diameter of 20㎛.

Claims (5)

A composite implant material comprising a metal implant base material (1) and a dense layer (2) of calcium phosphate compound thereon, the composite implant material further comprising a porous surface layer (3) of calcium phosphate compound thereon. The composite implant material according to claim 1, wherein the porous surface layer (3) has a porosity of 20 to 50%, a pore diameter of 1 to 50 mu m, and a thickness of 100 to 300 mu m. A method for producing a composite implant material of a dense layer (2), which is the first layer, of a high purity calcium phosphate compound on a metal implant base material (1) by plasma spraying, comprising aluminum powder and calcium phosphate compound powder in a weight ratio of 1: 1.8 to 1 : By mixing in the range of 10.5 and plasma-sprayed on the dense layer 2 of the first layer, and then treated with an alkaline solution to form the pores where the aluminum is removed, thereby forming the porous surface layer 3 of the second layer. Method for producing a composite implant, characterized in that formed. 4. The method of claim 3, wherein the particle size of the aluminum and calcium phosphate powder plasma sprayed on the porous surface layer (3) of the second layer is in the range of 100 to 200 mu m. 4. The method of claim 3, wherein the alkaline solution is 0.1 molar sodium hydroxide or potassium hydroxide solution.