KR20070011200A - Fabrication of implant with nanotube structure by anodizing - Google Patents

Abstract

A process of reforming surface of a porous implant with nano-tube structure is provided to form titanium oxide film in a uniform nano-tube form on surface of the implant and improve osseo-integration on the surface of the implant by adopting anode oxidation of the implant in electrolyte containing fluorine compound and acidic solution. The process includes electro-chemical surface reformation of the implant made of titanium and titanium alloy to form nano-tube form of oxidation coating layer on the surface of the implant. The electro-chemical reformation is performed by preparing an electrolyte which includes 0.1-1.5M H3PO4, H2SO4 solution and 0.5-2.0wt.% of fluorine compound; treating the implant at room temperature to 100deg.C under 2-50V of application voltage for several seconds to hours and with use of the electrolyte; and post heat treating the implant at 200 to 700deg.C.

Description

Fabrication of nanotube-shaped porous implant surface modification {Fabrication of implant with nanotube structure by anodizing}

Figure 1 is a photograph of the structure of the nanotube oxide film formed on the surface of pure titanium by observing the electron microscope.

Figure 2 is a photograph of the structure of the nanotube oxide film formed on the surface of pure titanium with a transmission microscope.

Degree. 3 is an atomic force micrograph showing the surface roughness of the nanotube oxide film formed on the surface of pure titanium.

Degree. 4 is the XPS analysis curve of the nanotube oxide film formed on the surface of pure titanium.

FIG. 5 is a photograph observing the structure of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface with an electron microscope. FIG.

6 is a photograph of the structure of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface observed with a transmission microscope.

Degree. 7 is an atomic force micrograph showing the surface roughness of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface.

Degree. 8 is an XPS analysis curve of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface.

Degree. 9 Photo Nanotube Formation on Implant Fixture Surface

In the present invention, the surface of the implant should be excellent in biocompatibility because the surface of the implant is in contact with the surrounding biological tissues for a long time, and should have the characteristics and functions to give a suitable environment for cells and tissues. Importantly, the surface of titanium and titanium alloys, which are widely used as implant materials, relates to surface modification methods that can play an important role in overall cell interaction such as cell adhesion, proliferation, differentiation and death.

  Titanium and titanium alloys do not have biological activity, so the bone formation reaction is slow and the healing period is long, and the adhesion between the bone and the implant is weak. In order to compensate for these disadvantages, many attempts have been made to increase the surface area of the implant, to change the surface shape, or to improve bone adhesion through physical and chemical surface treatment. The surface modification method includes a method of blasting particles of various diameters on the surface, and a method of sand treatment after the particle injection (sandblasted acid etched), but there are problems of grain boundary corrosion due to residual particles on the surface or acid treatment. In addition, there is a plasma spray method and a hydroxyapatite coating method, but when the bone quality is too hard, there are disadvantages that the grains on the surface may be separated.

 Titanium and titanium alloys are known to have good biocompatibility due to the titanium oxide film formed on the surface. As a method for forming such an oxide film, a method of heat treatment (Korean Patent Application No. 98-23074), a method of etching with an etching solution after thermal oxidation (No. 98-23075), an electrolyte such as NaOH, phosphoric acid, sulfuric acid, or oxalic acid And electrochemically anodizing (Int. J. Adhesion and Adhesives. 3. 133 (1983), J. Biomed. Eng. Res., 21, 273 (2000)).

However, the dense oxide film formed by thermal oxidation does not form a porous film suitable for cellular action, and the porous film formed by anodization is difficult to control the structure and the uniformity of the pores is low, thereby reducing compatibility with bone.

SUMMARY OF THE INVENTION An object of the present invention is to provide a surface modification technique for forming a uniform nanotube-shaped titanium oxide film that can play an important role in cellular activities such as cell adhesion, proliferation and differentiation on the implant surface of titanium and titanium alloy.

According to the present invention, surface modification of an implant made of titanium and a titanium alloy is achieved by forming a uniform oxide film on the surface of the implant through a change in process parameters by an electrochemical method.

Looking at the process for the present invention,

 The implant material used in the present invention is an alloy containing pure titanium and a titanium alloy, that is, Ta, Nb, Al, V, Zr and the like in a certain ratio. In order to remove impurities of the material was washed with acetone, alcohol, distilled water.

 The electrolytic solution for the electrochemical treatment (anodic oxidation) is mixed with an aqueous solution of a fluorine compound containing fluorine and an aqueous solution of an acid such as phosphoric acid (H 3 PO 4) and sulfuric acid (H 2 SO 4) in a proportion.

 For the formation of titanium nanotubes, the concentration of the electrolyte, which is a process variable, that is, the concentration of the fluorine compound is 0.5 to 2.0 wt.%, The phosphoric acid and sulfuric acid are 0.5 to 1.5 M, and the applied voltage is 2 to 50 V for 10 seconds to 3 hours. Preferred process conditions are achieved throughout the process.

 The surface-treated material under optimum conditions was washed in distilled water and then dried for 12 to 24 hours at 40 ° C. to 100 ° C., followed by a heat treatment process at a temperature rising rate of 1 to 10 ° C./min at 200 to 700 ° C. for 1 to 2 hours. do.

In the following Examples the present invention will be described in detail.

Example 1

 The material used in this embodiment is a pure titanium and titanium alloy (Ti-10Ta-10Nb) having a diameter of 15 mm and a thickness of 2 mm.

 Pure titanium was used as an anode and a platinum plate was used as a cathode, and the distance between the two poles was 10 cm. In the electrolyte consisting of 1M H 3 PO 4 + 1.5wt% HF anodized for 10 minutes at an applied voltage of 20V and heat-treated at 200 ℃.

Figure 1 is a photograph of the structure of the nanotube oxide film formed on the surface of pure titanium by observing the electron microscope.

Figure 2 is a photograph of the structure of the nanotube oxide film formed on the surface of pure titanium with a transmission microscope.

Degree. 3 is an atomic force micrograph showing the surface roughness of the nanotube oxide film formed on the surface of pure titanium.

Degree. 4 is the XPS analysis curve of the nanotube oxide film formed on the surface of pure titanium.

Example 2

A Ti-10Ta-10Nb alloy was used as the anode and a platinum plate was used as the cathode, and the distance between the two poles was 10 cm. In the electrolyte consisting of 1M H 3 PO 4 + 1.5wt% HF anodized for 10 minutes at an applied voltage of 20V and heat-treated at 200 ℃.

FIG. 5 is a photograph observing the structure of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface with an electron microscope. FIG.

6 is a photograph of the structure of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface observed with a transmission microscope.

Degree. 7 is an atomic force micrograph showing the surface roughness of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface.

Degree. 8 is an XPS analysis curve of the nanotube oxide film formed on the Ti-10Ta-10Nb alloy surface.

Example 3

Degree. 9 Photo Nanotube Formation on Implant Fixture Surface

The nanotube-shaped oxide film prepared through the above process can improve bone adhesion by promoting cellular activities such as cell adhesion, proliferation, and differentiation compared to conventional surface treatment methods, and consequently, the healing period after implant placement is improved. It can bring a shortening effect.

Claims (2)

Implant surface modification method of forming an oxide film having a uniform nanotube shape by surface modification of an implant made of titanium and a titanium alloy by an electrochemical method The electrochemical treatment according to claim 1, wherein the electrochemical treatment is an electrolyte solution containing 0.5 to 2.0 wt.% Fluorine compound in 0.1 to 1.5 M H 3 PO 4 and H 2 SO 4 aqueous solution, an applied voltage of 2 V to 50 V in a temperature range of room temperature to 100 ° C., Surface modification method consisting of heat treatment at 200 ~ 700 ℃ after treatment for several seconds to several hours

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