KR20040040834A - Titanium oxide-coated material for implanting in living body and method for the preparation thereof - Google Patents

Abstract

PURPOSE: Provided is a method for manufacturing bio-implant material, coated with thin film of titanium dioxide by chemical vapor deposition using a titanium-containing organometal compound, in a large amount by a simple process. CONSTITUTION: The method for manufacturing a bio-implant material comprises: introducing a titanium-containing organometal compound as a titanium precursor and oxygen-containing gas or organic substances into a reactor through a separate line, while contacting them with a substrate for a bio-implant material under a pressure of 10-3 to 1,000 mmHg and a temperature ranged from room temperature to 1,000 deg.C to form titanium dioxide film on the substrate.

Description

TITANIUM OXIDE-COATED MATERIAL FOR IMPLANTING IN LIVING BODY AND METHOD FOR THE PREPARATION THEREOF}

The present invention relates to a bio-implant material coated with a titanium oxide thin film, in particular a titanium oxide-coated titanium implant material and a method of manufacturing by organometallic chemical vapor deposition thereof.

Clinical results have shown that implant materials made of pure titanium have been successfully used in patients with partial or edentulous for a long time. Titanium is a very reactive metal on the periodic table of the elements, but titanium is well used in vivo.

Titanium implant material requires direct contact with living bones to have a good prognosis for a long time. Osseointegration is defined as the structural and functional coupling that allows the implant material and bone tissue to be in direct contact with the living bone or to transmit external load directly into the bone tissue without intervening connective tissue. Factors that determine bone integration include biocompatibility of materials, surface structure, surface microstructure, state of bone quality, surgery during implantation, state of prosthetic load, and the like.

Titanium implant materials are used a lot because of their high biocompatibility, in part because of their robust and stable oxide film that helps cells and substrates adhere well at the tissue interface. The composition and purity of the implant material surface, as well as the thickness and structure of the surface oxide film, affect the biocompatibility of the implant material. The characteristic structure and structure of this oxide film can vary depending on the technique of treating the metal surface.

As a surface treatment method of a bio-implant material, there are methods such as anodization, plasma oxidation, chemical vapor deposition (CVD) and physical vapor deposition (PVD). The use of thermal or electrochemical oxidation increases the thickness of the oxide film on the surface of the material. It is known that the method of processing the surface of the implant material affects the properties of the surface and also affects the bioreaction occurring on the surface. Studies on bone bonding by removal torque from Carlsson et al. Showed better removal torque values for implant materials with rough surfaces treated by spraying. Kurt et al.'S cell adhesion experiments also showed better cell responses in coarse-grained materials treated with spraying or sandpaper. Coarse-sided implant materials are getting better results than smooth-faced implant materials due to increased surface area and improved cell response.

In particular, as an implant for artificial teeth, it has been reported to form a titanium oxide layer on titanium screws by anodization to improve binding to bone (Y.-T. Sul et al., Biomaterials Vol. 23, pp. 1809-1817 (2002)), which is oxidized by heat treatment to form a titanium oxide layer. However, such anodization or heat treatment oxidation has a limitation in controlling the composition and thickness of the titanium oxide layer.

Accordingly, the present inventors are able to deposit a large area, and are advantageous for mass production, and can easily control the thickness and composition ratio, and can be deposited at a low temperature. The coated implant material was developed.

Accordingly, an object of the present invention is to simply manufacture a large amount of a bio-implant material coated with a titanium oxide thin film by chemical vapor deposition using a titanium-containing organometal.

1 is a schematic diagram of an organometallic chemical vapor deposition apparatus used in the present invention,

2A and 2B are scanning electron microscopy (SEM) photographs and an energy dispersive X-ray spectrometer (EDS) of a titanium oxide film coated directly on a titanium material for a bio-implant prepared from an embodiment according to the present invention, respectively. ) Analytical data,

Figure 3 shows the X-ray diffraction (XRD) θ-2θ scan results of the titanium oxide thin film directly coated on the titanium material for biological implants prepared from the embodiment according to the present invention,

4A and 4B are runner electron microscopes showing that the surface roughness of the titanium oxide film coated directly on the titanium material for bio-implants prepared from the examples according to the present invention is changed according to the position of the implant material in relation to the flow of the reaction gas. SEM) photo.

In order to achieve the above object, in the present invention, the pressure of 10 ^-3 to 1,000 mmHg and the range of room temperature to 1,000 ℃ while injecting the titanium-containing organometallic and oxygen-containing gas or organic as a titanium precursor into the reactor through a separate line Provided is a method for producing a titanium oxide thin film-coated bio-implant material by organometallic chemical vapor deposition (MOCVD), comprising contacting a bio-implant material substrate at a temperature of to form a titanium oxide film on the substrate.

The present invention also provides a titanium oxide thin film coated bio-implant material prepared by the above method.

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

The bio-implant material for coating titanium oxide thin film that can be used in the present invention can be used all of the conventional implant materials used for bone integration in vivo, and particularly preferably those of titanium.

Titanium-containing organometals used as titanium precursors in the present invention include tetrakis diethylamido titanium (Ti [N (C ₂ H ₅ ) ₂ ] ₄ ), tetrakis dimethylamido titanium (Ti [N (CH ₃ ) ₂ ] ₄ ), titanium t-butoxide (Ti (OC ₄ H ₉ ^t ) ₄ ), titanium (IV) ethoxide (Ti (OC ₂ H ₅ ) ₄ ), titanium isopropoxide (Ti (OC ₃ Organic titanium compounds such as H ₇ ⁱ ) ₄ ).

In addition, in the present invention, the oxygen-containing gas used for forming the oxide thin film of titanium may include O ₂ , O ₃ , NO ₂ , water vapor, and CO ₂ , and the like may include methyl ethyl ketone (C ₂ H ₅ COCH ₃ ), tetrahydrofuran and the like.

In the method of the present invention it is suitable to maintain the pressure of the reactor to 10 ^-3 to 1,000 mmHg, there is a problem that the reaction rate is slowed if the pressure in the reactor is lower than 10 ^-3 mmHg. In addition, the temperature of the reactor is maintained at room temperature to 1,000 ℃, the crystalline film is not formed at a temperature lower than the room temperature, the gas phase pre-reaction prevails at a temperature higher than 1,000 ℃ to reduce the quality of the resulting film.

If necessary, in addition to the titanium oxide thin film formed by the MOCVD of the present invention, a metal such as Ca can be added in a conventional manner to make the trait excellent.

The titanium oxide based film coated by the present invention was found to contain two phases of polycrystalline titanium dioxide (TiO ₂ ) and oxygen-deficient phase (TiO _x ) from X-ray diffraction (XRD) scan results (see FIG. 3). ).

The method for producing a titanium oxide thin film-coated implant material by MOCVD according to the present invention can provide a titanium oxide thin film having excellent surface roughness and uniform thickness, and thus can be used as a dental implant orthopedic bio implant material such as an artificial tooth. It can be advantageously used for mass production of.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are for illustrative purposes of the present invention and are not intended to limit the protection scope defined by the appended claims.

Example

Titanium implant substrate (4 mm diameter, 10 mm long threaded type) using the organometallic chemical vapor deposition apparatus shown in FIG. The titanium oxide thin film was coated on it. Titanium isopropoxide (TIP, Ti (OC)₃H₇ ⁱ)₄) And O₂Was used, and argon was used as the carrier gas. TIP and O through separate lines₂Were each injected into the reactor. At this time, the pressure and temperature in the reactor were constant at 5 mmHg and 400 ° C., respectively, and the flow rates of each reactant were 40 sccm of argon and 20 to 40 sccm of TIP, respectively.₂Titanium coating was carried out over about 3 hours with adjustment in the range of 20-40 sccm.

The thickness of the titanium oxide film formed after the coating was about 1.8 μm, and the surface shape and component analysis of the coating layer were performed by scanning electron microscopy (SEM), and X-ray diffraction (XRD) was used to confirm the image. θ-2θ scan.

1) SEM results

Electron micrographs of the surface of the titanium oxide coating layer coated on the titanium implant is shown in Figure 2a. Figure 2a is an enlarged view of the upper flat portion (arrow) of the threaded titanium implant by 10,000 times, the picture is not smooth and can be seen that the surface is quite rough. Figure 2b is a component analysis of the coating layer was measured by an energy dispersive X-ray spectrometer (EDS), it can be seen that the titanium oxide film is coated because only titanium and oxygen atoms are detected.

The surface shape of the upper side surface of the implant shown in FIG. 4A is shown to be no different from the shape of the upper side. On the other hand, an unusual shape appeared on the side shown in Fig. 4b. As shown in the picture, a comb-like surface is created. This is probably due to the flow of the reactant in the reactor, which can be said to improve the implant surface roughness.

2) XRD results

X-ray diffraction (XRD) measurement results of the titanium oxide thin film surface coated on the titanium implant is shown in FIG. It can be seen that the anatase phase of titanium dioxide exists as a polycrystal, and that the oxygen vacancies escape and TiO _x (1 <x <2), which is a phase lacking oxygen, is formed.

In addition, the binding force with the bone of the maxillary molar portion of the implant coated as described above was measured by the following animal experiment.

Ten identical species of rabbits weighing more than 3.5 kg each were used. The implant was subjected to ultrasonic cleaning and autoclaving in ethanol prior to use. Surgery was performed under sterility and no antibiotics were taken for pretreatment. General anesthesia includes Xylazire (Rompun ^R , Bayer Chemical Co., Korea, 5mg / kg Kg) and Ketamine (Ketara ^R , Korea, Yuhan Corporation Product, 35 mg / kg body weight). The surgical site was shaved and partial anesthesia was performed on the tibial area with 2 ml of 2% Lidocane ^R (Korea's Kwang Myung Chemical).

The surgical site was washed with iodine and 70% alcohol sponge before surgery. The tibial section was incised to expose the bone and then the screw-type titanium implant was implanted by the conventional Brenemak implant system. A control group was placed in the right tibia and an experimental group was placed in the left tibia. The surgical site was stitched layer by layer with 4-0 absorbent sutures and 1 ml of antibiotics (Baytril ^R , Bayer Chemicals, Korea) and 1 ml of Castosal ^R (Bayer Chemicals, Korea) as metabolic accelerators. Subcutaneous muscle injection. The surgical site was pressed to prevent and protect inflammation.

Eight weeks after implantation, the rabbits were killed to dissect the surgical site. The implants were exposed to carefully remove the bones that had risen over the screws and the square-holes of the screws were exposed to measure removal torque. Removal torque was measured using a digital torque gauge MGT-15 (Imada, Inc., USA) and the highest removal torque value was recorded when fracture of the implant and bone was made. The obtained removal torque value was 1.66 lbs in the control group and 3.82 lbs in the experimental group. The removal torque value was increased in the artificial tooth in which the titanium oxide thin film was grown, indicating that the bone integration performance was improved.

According to the present invention, a method of coating a bio-implant material with a titanium oxide thin film by an organometallic chemical vapor deposition method is advantageous for mass production, easy doping concentration control, low temperature deposition, and a titanium oxide thin film having excellent surface roughness can be obtained. have. The titanium oxide-coated implant material formed in accordance with the present invention increased the integration force with bone in vivo by more than twice the removal torque value compared to the uncoated control. Therefore, the present invention can be advantageously used for the production of a dental or orthopedic biological implant material such as an artificial tooth.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (9)

Titanium-containing organometallic and oxygen-containing gases or organics as titanium precursors are introduced into the reactor via separate lines while at the pressure of 10 ⁻³ to 1,000 mmHg and at temperatures ranging from room temperature to 1,000 ° C. A method for producing a titanium oxide thin film-coated bio-implant material by organometallic chemical vapor deposition, comprising contacting a substrate to form a titanium oxide film on a substrate. The method of claim 1, Wherein the bio-implant material is titanium or a titanium containing metal. The method of claim 1, Wherein the bio-implant material is an artificial tooth. The method of claim 1, The titanium-containing organometal is selected from the group consisting of tetrakis diethylamido titanium, tetrakis dimethylamido titanium, titanium t-butoxide, titanium (IV) ethoxide and titanium isopropoxide. The method of claim 1, And wherein the oxygen-containing gas is O ₂ , O ₃ , NO ₂ , water vapor or CO ₂ . The method of claim 1, The oxygen-containing organic is methylethylketone (C ₂ H ₅ COCH ₃ ) or tetrahydrofuran. The method of claim 1, Characterized in that the thickness of the coated titanium oxide thin film ranges from 10 nm to 100 μm. The method of claim 1, And wherein the coated titanium oxide thin film has a ratio of at least one oxygen / titanium. A bio-implant material coated with a titanium oxide thin film prepared by the method according to any one of claims 1 to 8.