JPH1072681A - Treatment of surface of titanium or titanium alloy having bone conductivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily treating the surface of inexpensive titanium or a titanium alloy having bone conductivity capably of improving the precipitating rate of hydroxyapatite(HAP). SOLUTION: Titanium or a titanium alloy 1 is mechanically polished by using polishing paper 2 in an electrolytic soln. 3 having a compsn. close to that of a biological liquid to remove oxidized coating film, and after that, as it is, new surface coating film is reformed in this electrolytic soln. 3. The surface coating film in which calcium and phosphate contained in the electrolytic soln. 3 are present is reformed on the surface of the titanium or titanium alloy 1. In this way, the titanium or titanium alloy for living bodies excellent in bone conductivity can easily be obtd. only by mechanically polishing it in the electrolytic soln. having a compsn. close to that of a biological liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating the surface of titanium or a titanium alloy for use in a living body such as an artificial tooth root or an artificial joint.
It is intended to improve osteoconductivity such as cell inducibility and facilitate processing.

[0002]

2. Description of the Related Art One of the characteristics required for a metallic material for a living body to be implanted in a living body such as an artificial tooth root or an artificial joint is one of the properties of the osteoconductive property of a metallic material having an interface with a living body, especially a bone cell. It is necessary to generate a substance called hydroxyapatite (HAP) derived from a living body on the surface of the material, and it is required to efficiently increase the deposition rate of hydroxyapatite (HAP).

For this reason, it has been proposed that calcium is present on the surface by a method of immersing in a solution containing an alkali or alkaline earth metal ion and then performing a heat treatment or a method of ion-implanting calcium.

[0004]

However, the method of heat treatment and the method of ion-implanting calcium after immersion in such a solution containing an alkali or alkaline earth metal ion are complicated in the treatment for living organisms. However, there is a problem that the cost of producing titanium or a titanium alloy is somewhat high.

[0005] Such hydroxyapatite (HA)
Research on improving the efficiency of the deposition rate of P) led to the study of bone conduction by removing the oxide film on the surface of titanium or titanium alloy as the base metal material and forming a new surface film containing calcium and phosphorus. It was found that the performance could be improved.

The present invention provides a surface treatment method for titanium or a titanium alloy which can improve the deposition rate of hydroxyapatite (HAP) based on the above research results, is easy to treat, and has low osteoconductivity. It is assumed that.

[0007]

According to a first aspect of the present invention, there is provided a method of surface treating titanium or titanium alloy having osteoconductivity, wherein the titanium or titanium alloy is treated with an electrolyte solution having a composition close to a biological fluid composition. After mechanical polishing, a new surface film is regenerated in the electrolyte solution to impart osteoconductivity to the surface of the titanium or titanium alloy.

According to the surface treatment method of titanium or titanium alloy having osteoconductivity, the titanium or titanium alloy is mechanically polished in an electrolyte solution close to the composition of a biological fluid to remove an oxide film. A new surface film is regenerated in this electrolyte solution as it is, and a surface film in which calcium and phosphorus contained in the electrolyte solution are present on the surface of the titanium or titanium alloy is regenerated.

[0009] This makes it possible to easily obtain biological titanium or titanium alloy having excellent osteoconductivity simply by mechanically polishing in an electrolyte solution having a composition close to that of the biological fluid.

According to a second aspect of the present invention, there is provided a surface treatment method for osteoconductive titanium or a titanium alloy, wherein the pH of the electrolyte solution close to the composition of the biological fluid is set to 7 in addition to the configuration of the first aspect. .3 to 5.0.

[0011] According to the surface treatment method of titanium or titanium alloy having osteoconductivity, the pH of the electrolyte solution close to the composition of the biological fluid to be mechanically polished by immersing titanium or titanium alloy is adjusted to 7.3 to 5. Since it is set to 0, it is possible to more easily obtain biological titanium or titanium alloy having excellent osteoconductivity.

Here, titanium or a titanium alloy refers to pure titanium for industrial use or an alloy thereof, and alloy elements of the titanium alloy include Ca, P, O, Fe, Al, V, Sn, and M.
o and Pd.

As an electrolyte solution having a composition close to that of a biological fluid, for example, a Hanks' solution containing no organic substance can be used.

Furthermore, osteoconductivity refers to biocompatibility, osteogenic ability, cell inducibility, etc. Usually, materials having excellent osteoconductivity are immersed in a Hanks' solution immersion close to the composition of extracellular fluid. Since it is known that hydroxyapatite (HAP) precipitates quickly on the material surface, it can be evaluated by the deposition rate of hydroxyapatite (HAP).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The method of surface treatment of osteoconductive titanium or titanium alloy according to the present invention will be specifically described below with reference to FIG.

In this method of surface treatment of titanium or titanium alloy having osteoconductivity, pure titanium (pure titanium for industrial use) or titanium alloy 1 for biological use which has been conventionally used as a biological metal is used as a test material. Used.

The titanium or titanium alloy 1 is mechanically polished to remove an oxide film on the surface, and is polished using, for example, a water-resistant abrasive paper 2. Hanks having a composition close to the extracellular fluid composition which is an example of the close electrolyte solution 3 and containing no organic matter
'It is performed while immersed in the solution.

First, titanium or titanium alloy 1 is 3 μm.
After mirror polishing with diamond paste, # 1200 water-resistant emery paper 2 in Hanks' solution 3
Is used to polish the surface, and the oxide film is removed.

As the Hanks 'solution which is an example of the electrolyte solution 3 having a composition close to the biological fluid, a Hanks' solution having a pH of 7.3 or 5.0, for example, was used. The pH 7.3 solution was a normal Hanks 'solution as it was, and the pH 5.0 solution was adjusted by adding hydrochloric acid or carbonic acid to the normal Hanks' solution.

The titanium or titanium alloy 1 from which the oxide film has been removed by mechanical polishing is held in a state of being immersed in the Hanks' solution 3 so that a new surface film is formed again on the polished surface. To

This polished titanium or titanium alloy 1
The formation of a new surface film on the surface of is performed by, for example, leaving it in a Hanks' solution for 5 minutes to stabilize the formation.

Thereafter, titanium or titanium alloy 1 is H
It is taken out from the anks' solution and subjected to ultrasonic cleaning in pure water to complete the surface treatment.

In order to examine the osteoconductivity of the titanium or titanium alloy thus surface-treated, various surface analyzes as shown in Table 1 were performed.

For comparison, a surface analysis of titanium or a titanium alloy similarly polished in pure water was also performed, and the results are also shown.

[0025]

[Table 1]

As apparent from Table 1, the pH was 5.0.
Or, in the surface film of titanium or titanium alloy whose surface film was regenerated in the electrolyte solution of 7.3, as shown by the relative atomic ratio by X-ray photoelectron spectroscopy (XPS), Ca
And that P exists.

Further, it can be seen that the binding energy of P in this surface film is very close to that of titanium phosphate, and that Ca exists as divalent.

Further, the presence distribution of each element from the surface of the surface-treated titanium or titanium alloy regenerated surface film was examined by Auger electron spectroscopy (AES), and the results are shown in FIG. Note that the sputtering time on the horizontal axis in FIG. 2 is a value corresponding to the depth direction from the surface, and 1
The depth per second corresponds to 0.02 nm.

As is apparent from FIG. 2, P is present in the entire surface of the regenerated surface film as indicated by a white circle, and Ca is localized in a portion near the pole surface as indicated by a black circle. I understand.

From the analysis results of the regenerated surface film of titanium or titanium alloy subjected to such a surface treatment, it was found that after the oxide film of titanium or titanium alloy was removed, the surface film was regenerated in an electrolyte solution. It is considered that surface adsorption of Ca occurs after P is incorporated into the film as titanium phosphate.

It is considered that calcium phosphate precipitates with the surface adsorption of Ca as a nucleus.

Next, in order to confirm the osteoconductivity of the titanium or titanium alloy obtained by performing the surface treatment,
Titanium or a titanium alloy obtained by performing a surface treatment on the ordinary Hanks' solution of 7.3 was immersed for 60 minutes, and the elements on the surface were analyzed by X-ray photoelectron spectroscopy (XPS). The results are shown in Table 2. Was.

[0033]

[Table 2]

As is clear from Table 2, in the case of titanium or a titanium alloy in which a regenerated surface film was formed by these surface treatments, the amount of Ca on the surface was large even when immersed in a Hanks' solution for only 60 minutes, and in particular, pH5. In the case where the regenerated surface film was formed by performing mechanical polishing in an electrolyte solution of 0.0, it was found that more Ca was present.

Further, after the titanium or titanium alloy on which the regenerated surface film was formed by these surface treatments was immersed in a Hanks' solution having a pH of 7.3 for 30 days, the weight of each sample was measured, and the increase was illustrated. This is shown in FIG.

As apparent from FIG. 2, Hanks
´The weight gain of titanium or titanium alloy that has been mechanically polished in solution to form a regenerated surface film is 20 to 50 times that of titanium or titanium alloy that has undergone the same surface treatment in pure water. It is clear that calcium phosphate precipitation is much higher.

Therefore, it is expected that calcium phosphate deposition is accelerated in titanium or titanium alloy which has been subjected to mechanical polishing in a Hanks' solution to form a regenerated surface film, thereby improving osteoconductivity.

[0038]

As described above in detail with the embodiments, according to the surface treatment method for osteoconductive titanium or titanium alloy according to claim 1 of the present invention, titanium or titanium alloy is produced. Since the oxide film was removed by mechanical polishing in an electrolyte solution close to the body fluid composition, a new oxide film was regenerated in this electrolyte solution as it was. The oxide film in which calcium and phosphorus contained in the solution are present can be regenerated.

Thus, simply by mechanically polishing in an electrolyte solution having a composition close to that of a biological fluid, it is possible to obtain easily and inexpensively a titanium or titanium alloy for a living body having excellent osteoconductivity.

According to the method of surface treating titanium or titanium alloy having osteoconductivity according to claim 2 of the present invention, an electrolyte solution having a composition close to a biological fluid composition in which titanium or titanium alloy is immersed and mechanically polished. PH of 7.3 to 5.0
As a result, it is possible to obtain titanium or a titanium alloy for living organisms having more excellent osteoconductivity.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view according to an embodiment of a surface treatment method for osteoconductive titanium or a titanium alloy according to the present invention.

FIG. 2 is a diagram showing an embodiment of a surface treatment method for osteoconductive titanium or titanium alloy according to the present invention;
3 is a graph showing the results of elemental analysis near the surface of pure titanium polished in Hanks' solution No. 3;

FIG. 3 is a view showing a Hank according to an embodiment of the surface treatment method for osteoconductive titanium or titanium alloy according to the present invention;
It is a graph which shows the amount of weight increase of the sample which immersed pure titanium polished in s 'solution and pure water in Hanks' solution for 30 days.

[Explanation of symbols]

 1 Titanium or titanium alloy 2 Abrasive paper 3 Electrolyte solution close to biological fluid composition

Claims (2)

[Claims] 1. After mechanically polishing titanium or a titanium alloy in an electrolyte solution close to the composition of a biological fluid, a new surface film is regenerated in the electrolyte solution so that the surface of the titanium or titanium alloy has an osteoconductive property. Surface treatment method for titanium or titanium alloy having osteoconductivity, characterized in that the surface treatment is performed. 2. The pH of an electrolyte solution close to the composition of the biological fluid.
3. The surface treatment method for osteoconductive titanium or titanium alloy according to claim 2, wherein 7.3 is set to 7.3 to 5.0.