JPH08257110A - Endosteal implant an manufacture thereof - Google Patents

Abstract

PURPOSE: To enable improvement in affinity, integrating property and fitting with respect to organic tissues and cells with out providing a cover layer comprising titanium or titanium oxide by forming an endosteal implant using a core body having an OH group on the surface thereof. CONSTITUTION: For example, in an artificial root, the surface of a core body 1 comprising titanium is purified rough by a sand blasting treatment and an ultrasonic washing. Then, the surface thus purified rough of the core body undergoes a hydrophilic treatment to form a hydrophilically treated surface 2. As a result, an OH group fitting better to an organic tissues and cells is introduced into the surface of the core body 1 to modify the surface to obtain an implant better fitting to the organic tissues without changes in affinity. The roughing of the surface may be performed in a range of the maximum surface roughness of 10-80μm. The roughing treatment may employs a method of etching by acid or alkali after the sand blasting treatment.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to endosseous implants such as artificial tooth roots, artificial joints and artificial bones.

[0002]

2. Description of the Related Art In recent years, intraosseous implants (for example, artificial tooth roots and artificial joints) have come to be used in many clinical settings. The properties required for such an intraosseous implant (hereinafter, referred to as “implant”) are, of course, excellent in strength and affinity with living tissues, but new bone tissues can be easily introduced into the surface layer portion. It is also extremely important to have a mechanism capable of invading and establishing the integrity of the new bone tissue and the implant. Therefore, there has been proposed an implant in which a coating layer made of a bioactive material having an excellent affinity for living tissue is plasma sprayed on the surface of a core body to form a sprayed coating having an uneven structure on the surface. (For example,
52-14095 gazette) Although this implant can cope with complicated shapes and reduce costs, the current bioactive material coating layer formed by plasma spraying has low adhesion strength to the core body. There was a problem.

Therefore, recently, a plasma coating of a coating layer made of titanium or titanium oxide, which has a high adhesion strength with the core body and an excellent affinity with living tissues, is formed on the surface of a metal core body such as titanium or titanium alloy. Many implants formed by the method have been proposed. (Reference: Plasma sprayed porous implant, Masakatsu Magome and others, Biomaterials Vol.8 No.3 (1
990))

[0004]

Usually, the surface of the core of this implant is cleaned and roughened by sandblasting in order to enhance the adhesion between the core and the coating layer made of titanium or titanium oxide. It is being appreciated. Therefore, the adhesion strength between the core and the coating layer made of titanium or titanium oxide is sufficiently large and there is no problem, but the sandblast material (alumina particles) used when the core surface is sandblasted is roughened. Since it remains as it is on the surface of the core body (hereinafter referred to as "penetration of the sandblast material"), there is a problem that there is a large variation in the adhesion strength between the core body and the titanium or titanium oxide coating layer. Further, although it has an excellent affinity with living tissues, it has a problem that it is inferior in compatibility (adhesion) with living tissues and cells as compared with an implant coated with a bioactive material.

The present invention has been made to solve the above problems, and has a good affinity with living tissues and cells equivalent to or better than conventional implants without providing a coating layer made of titanium or titanium oxide. The purpose is to provide an intraosseous implant having the properties, integrity, and familiarity (adhesiveness).

[0006]

The present invention firstly provides an "intraosseous implant (claim 1) comprising a core having OH groups on the surface". In addition, the present invention secondly provides that "the core is made of titanium or titanium alloy whose surface is roughened in the range of maximum surface roughness of 10 to 80 µm, and the surface of the roughened core has an OH group. The intraosseous implant according to claim 1 (claim 2) "is provided.

A third aspect of the present invention is a method for producing an intraosseous implant using a core having an OH group on the surface, wherein at least the surface of the core made of titanium or titanium alloy has a maximum surface roughness. In the range of 10 to 80 μm, and a method for producing an intraosseous implant, comprising a step of surface-modifying by introducing an OH group into the surface of the core body subjected to the surface-roughening treatment by a hydrophilic treatment. (Claim 3) "is provided.

In a fourth aspect of the present invention, "the method for producing an intraosseous implant according to claim 3 is characterized in that the roughening treatment of the surface of the core body is performed by sandblasting treatment and then ultrasonic cleaning. Claim 4) "is provided. The fifth aspect of the present invention is that the method for producing an intraosseous implant according to claim 3, wherein the roughening treatment of the surface of the core is performed by sandblasting and then etching with acid or alkali. Item 5) ”is provided.

The sixth aspect of the present invention is that "the roughening treatment of the surface of the core is performed by sandblasting and then anodic oxidation. Item 6) ”is provided. Further, the present invention is seventhly, "the surface roughening treatment of the core is a sandblasting treatment, followed by etching with an acid or alkali,
Furthermore, the intraosseous implant (claim 7) according to claim 3, which is performed by subsequent anodic oxidation.

In the eighth aspect of the present invention, "The surface of the core body subjected to the surface-roughening treatment is hydrophilized by adding hydrogen peroxide (H
The method for producing an intraosseous implant according to claims 3 to 7 is provided by irradiating an excimer laser after dropping or applying ₂ O ₂ ).
The ninth aspect of the present invention is that “excimer laser irradiation is 1
Output per pulse is 5 mJ / cm ^{2 to} 10 J / cm ²
ArF excimer laser (λ = 193 nm) or Kr
An F-excimer laser (λ = 248 nm) is used to provide the method for producing an intraosseous implant according to claim 8 (claim 9).

[0011]

In the implant of the present invention, titanium or titanium alloy having excellent biocompatibility is used as the core material. The core is washed as a pretreatment. In order to enhance the integrity of the new bone tissue and the implant, it is more preferable to impart a surface uneven structure corresponding to the surface shape of the coating layer by the conventional plasma spraying method to the core surface by sandblasting.

Sandblast material (alumina particles) when sandblasting is applied to the surface of the roughened core body.
However, since it remains on the roughened core surface,
Method of ultrasonic cleaning by ultrasonic deburring device, method of etching with acid or alkali, method of anodic oxidation, after etching with acid or alkali,
It is removed by a method of anodic oxidation.

The maximum surface roughness at this time is 20 to 40 μm.
The range is preferable, but the surface may be roughened in the case of etching with an acid or an alkali after the sandblast treatment or further performing anodic oxidation. However, 80
If it is more than μm, it causes excessive invasion to the bone. Also, 10
If it is less than μm, the affinity with new bone and the initial fixation force are poor.

In the method of performing ultrasonic cleaning with the ultrasonic deburring apparatus, it is difficult to remove the stab of the sandblast material by general ultrasonic cleaning, so ultrasonic cleaning by a new technique capable of deburring is preferable. As this device, it is preferable to use an ultrasonic deburring device "Aquatron" manufactured by S & C Corporation. However,
It is not limited to this.

Further, in the method of etching with an acid or an alkali, it is important that the unevenness formed on the surface of the core body by the sandblasting treatment is not changed as much as possible. Further, in the method of performing anodic oxidation or the method of performing anodic oxidation after etching with acid or alkali, a titanium oxide coating film is formed on the surface of the roughened core body, and titanium ion from the core body itself is formed. It plays the role of a protective film for preventing elution, and has the effect of significantly reducing the possibility of causing a metal allergic reaction.

Further, the core body is protected from corrosion in the living body. In addition, countless minute projections are present on the surface of titanium oxide, which has the effect of increasing the binding force with bone. As described above, the contact area with the bone is increased by roughening the surface of the core body by the sandblasting treatment, and the sticking of the sandblast material is removed, so that the affinity between the core body and the biological tissue becomes more stable.

As a method of hydrophilizing the surface of the core or the surface of the roughened core, hydrogen peroxide (H ₂ O ₂ ) is dropped or applied onto the surface of the core or the surface of the roughened core. Then, it is irradiated with an excimer laser. O generated by decomposition of H ₂ O ₂
The H group is bonded to the excited part of the core body surface or the roughened core body surface, and the surface is modified, so that the wettability with living tissues and cells is increased and the "familiarity (adhesion)" is improved. To be done.

Hydrogen peroxide (H₂O₂) Is usually commercially available
Anything can be used. Also, the excimer laser
-The output per pulse is 5 mJ / cm²-10J /
cm ²ArF excimer laser (λ = 193 nm),
Or, use KrF excimer laser (λ = 248 nm).
be able to. Output per pulse is 5 mJ / cm ²
Below, OH groups cannot be efficiently generated.
The output per pulse is 10 J / cm²Above
A strong abrasion occurs on the surface of the core, and the surface of the core is damaged.
It is not preferable because it receives a message.

Lasers other than excimer lasers
The same effect can be obtained even with (for example, a CO ₂ gas laser) depending on the irradiation conditions, and therefore it is not limited to the excimer laser. The confirmation of the OH group after the hydrophilization treatment is performed by preparing a plate-like sample, taking an infrared absorption spectrum by the specular reflection method with FT-IR (Fourier conversion infrared spectrophotometer), and analyzing it. It can be analyzed (identified). FT-IR can be analyzed (identified) by ordinary IR (dispersive infrared spectrophotometer), but its sensitivity is poor.
It is preferable to analyze (identify) with (Fourier transform infrared spectrophotometer). By grasping the irradiation conditions of the excimer laser and the analysis (identification) results of the OH groups, stable surface modification becomes possible.

Since the hydrophilic treatment is a reaction on the extreme surface,
There is no effect inside the core. Further, the implant after the hydrophilic treatment is washed, sterilized, and packaged, but the OH group is not removed in this step. The shape of the artificial tooth root may be any of blade type and cylinder type. Further, a screw may be used in the cylinder type. There may be a vent.

Further, the concavo-convex structure on the surface of the core may not be provided on the entire surface of various artificial tooth roots. For example, in the case of a cylinder type, the flange portion may not have this surface uneven structure. Rather, the cylinder-shaped collar may be mirror-finished. Further, regarding the hydrophilic treatment, there is no problem even if it is performed not only on the surface uneven structure portion of the core body but also on the collar portion. Further, in the artificial joint, it can be mainly used for a stem and a cup (artificial acetabulum). It can also be used on the surfaces of artificial bones, bone plates and bone screws.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.

[0023]

EXAMPLE FIG. 1 is a schematic sectional view showing an artificial tooth root of this example. This artificial tooth root was produced by the following method. First, the core 1 made of titanium (diameter 4 mm, length 10 mm
The surface of the shell was cleaned and roughened by sandblasting and ultrasonic cleaning (roughness: 20 to 40 μm), and the surface 3 of the core was hydrophilically treated to prepare the artificial tooth root shown in FIG.

[Analysis of OH Group After Hydrophilization Treatment] Next, the present inventor has conducted an O examination after hydrophilization treatment of the artificial tooth root sample of the present invention.
The following samples were prepared to confirm the state of the H group. First, the surface of a titanium plate having a length of 20 mm × 20 mm and a thickness of 2 mm is washed, and hydrogen peroxide (H ₂ O ₂ ) is dropped or applied on the surface to output 20 mJ / c per pulse.
control within the m ² ~80mJ / cm ² - Le while ArF excimer - The - (lambda = 193 nm) was irradiated with a sample of the core surface was surface-modified by replacing the OH group by hydrophilic treatment " The present invention sample S1 ”was produced.

Then, the surface is cleaned and sandblasted with alumina, and then ultrasonically cleaned by an ultrasonic deburring device manufactured by S & C Co., Ltd. to obtain a clean roughened surface (roughness 20).
"Invention sample S2" was manufactured in exactly the same manner as "Invention sample S1" except for the above. Further, the surface of the sample was subjected to sandblasting, followed by immersion (etching) in a mixed aqueous solution of 2.5% hydrofluoric acid and 3% nitric acid for several minutes to obtain a clean rough surface (roughness of 20 to 40 μm).
"Invention Sample S3" was prepared in exactly the same manner as in "1."

After the surface is sandblasted, hydrofluoric acid is added.
Immersion (etching) in a mixed aqueous solution of 2.5% and 3% nitric acid for a few minutes to clean and roughen the surface (roughness 20 to 40 μm), and then anodize in a phosphoric acid-sulfuric acid mixed solution to make the core surface uneven. "Invention sample S4" was prepared in exactly the same manner as "Invention sample S1", except that a titanium oxide film having a thickness of several microns was formed along the surface.

For comparison, samples "Comparative Samples HS1 to HS4" prepared in exactly the same manner except for the hydrophilic treatment.
Was prepared, and an infrared absorption spectrum of each sample was taken by FT-IR (Fourier conversion infrared spectrophotometer) by the specular reflection method and analyzed. As a result, a clear spectrum of OH groups could be analyzed (identified) from "invention samples S1 to S4".

After implanting samples S1 to S4 in the jawbone of an adult dog for 4 weeks, a tissue sample was prepared and the vicinity of the interface between the implant and the bone was observed. As a result, it was directly bonded to bone without intervening fibrous tissue and was covered with bone tissue.

[0029]

As described above, since the coating layer made of titanium or titanium oxide is eliminated, the conventional method (plasma spraying method) is used.
The factor of variation in adhesion strength with bone is eliminated.
In addition, since only the extremely surface portion of the roughened core body is subjected to hydrophilic treatment to introduce OH groups that have good compatibility (adhesiveness) with living tissues and cells to modify the surface, good compatibility with living tissues is achieved. There was no change in sex, and the compatibility (adhesion) with living tissues and cells was improved compared to conventional implants.

Further, even on the surface of the core body (the surface of which is not roughened due to roughening), the extreme surface thereof has a good affinity (adhesiveness) with living tissues and cells due to the hydrophilic treatment.
Since the H group was introduced and the surface was modified, there was no change in the good affinity with living tissues, and the familiarity (adhesion) with living tissues and cells was improved as compared with conventional implants.

[Brief description of drawings]

FIG. 1 is an artificial tooth root of an example (one type of implant)
It is a schematic sectional drawing which shows.

[Explanation of symbols]

 1 ... Core 2 ... Hydrophilized surface

Claims (9)

[Claims] 1. An intraosseous implant comprising a core body having an OH group on its surface. 2. The core body has a maximum surface roughness of 10 to 80 μm.
The intraosseous implant according to claim 1, characterized in that the surface is made of titanium or a titanium alloy having a surface roughened within the above range, and has an OH group on the surface of the roughened core body. 3. A method for producing an intraosseous implant using a core body having an OH group on the surface, wherein at least the surface of the core body made of titanium or a titanium alloy has a maximum surface roughness of 10 to 80 μm. A method for producing an intraosseous implant, which comprises a step of roughening treatment and a step of introducing an OH group into the surface of the core body subjected to the roughening treatment by hydrophilic treatment to modify the surface. 4. The method for producing an intraosseous implant according to claim 3, wherein the roughening treatment of the surface of the core body is performed by sandblasting treatment and then ultrasonic cleaning. 5. The method for manufacturing an intraosseous implant according to claim 3, wherein the roughening treatment of the surface of the core body is performed by sandblasting treatment and subsequent etching with acid or alkali. 6. The method for producing an intraosseous implant according to claim 3, wherein the roughening treatment of the surface of the core body is performed by sandblasting treatment and then anodic oxidation. 7. The intraosseous implant according to claim 3, wherein the roughening treatment of the surface of the core body is performed by sandblasting treatment, followed by etching with acid or alkali, and then anodic oxidation. 8. The hydrophilic treatment of the surface of the core body subjected to the surface roughening treatment is carried out after dropping or applying hydrogen peroxide (H ₂ O ₂ ) onto the surface,
The method for producing an intraosseous implant according to claim 3, which is performed by irradiating an excimer laser. 9. The excimer laser irradiation is ArF whose output per pulse is 5 mJ / cm ^{2 to} 10 J / cm ² .
9. The method for producing an intraosseous implant according to claim 8, which is performed by using an excimer laser (λ = 193 nm) or a KrF excimer laser (λ = 248 nm).