KR20160149923A

KR20160149923A - abutment screw for preventing unfastening and manufacturing method thereof

Info

Publication number: KR20160149923A
Application number: KR1020150087767A
Authority: KR
Inventors: 정운조
Original assignee: (주)오티앤티
Priority date: 2015-06-19
Filing date: 2015-06-19
Publication date: 2016-12-28

Abstract

The present invention relates to an implant abutment screw having a releasing preventing function, and a method for producing the same. A diamond-like carbon (DLC) thin film layer is formed on the surface of a dental implant abutment screw, so the implant abutment screw can effectively prevent screw release by improving wear resistance and by reducing a frictional coefficient. The implant abutment screw having a releasing preventing function according to the present invention comprises: a titanium or titanium alloy material base material; a chrome material buffer layer formed on the surface of the base material by an arc ion plating scheme; and a DLC thin film layer having low frictional coefficient properties and formed on the surface of the buffer layer by a filtered cathodic vacuum arc-type vacuum arc depositing scheme.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an abutment screw for an implant,

The present invention relates to an abutment screw for an implant having an anti-loosening function and a method of manufacturing the same. More particularly, the present invention relates to a denture-like abutment screw, The present invention relates to an abutment screw for an implant and a method of manufacturing the same, which can effectively prevent screw loosening by lowering the coefficient of friction.

In general, a dental implant refers to a substitute of a lost natural tooth, or a screw-shaped artificial tooth fixture is fastened to the alveolar bone to be fused with the bone for a predetermined period, and then abutment refers to a dental procedure that restores the original function of the tooth by fixing the prosthesis such as an abutment and an artificial tooth (crown).

A conventional implant includes a fixture in which a thread is formed on an outer circumferential surface so as to be able to be placed on an alveolar bone and a hexagonal head portion is protruded on an upper portion of the fixture and an insertion hole and a hexagonal groove portion are formed on the inner upper and lower portions, And an abutment screw in which a thread is formed at the lower end of a head portion in which a hexagonal wrench groove is recessed at the center of the upper end.

The abutment of the conventional implant configured as described above is constructed so that a hexagonal groove portion is inserted into a hexagonal head portion protruding from the upper end of a fixture that is inserted into the jawbone, and then the abutment screw is inserted through the insertion hole of the abutment After inserting, the threaded portion of the abutment screw is fastened to the fastener of the fixture using a fastening tool so that the abutment is firmly fixed. Then, the outer circumferential surface of the upper end of the abutment is fastened to the artificial tooth Is inserted and bonded.

However, in such a conventional implant, when the artificial tooth is used for repetitive chewing, there is a problem that the fastening state of the abutment screw fixing the abutment is gradually released.

The most fundamental cause of screw loosening is the loss of preload. The electric charge is the tensile force inside the screw when tightening the screw. When tightening the screw, 90% of the initial tightening force is used to overcome the frictional force, and only 10% is generated in the electric charge. Therefore, when a coating capable of lowering the frictional force is applied to the surface of the abutment screw, more tightening force can be converted into the charge, and the screw loosening phenomenon can be improved.

Korean Patent No. 10-1158555 discloses a method of forming an implant and a silver coating film having a silver coating film formed thereon.

Although the patent discloses that a silver coating layer is formed on the surface of the fixing screw to prevent the screw from loosening, the silver coating layer has a problem of low abrasion resistance and shear strength.

Korean Patent No. 10-1158555: Method for forming implant coating and silver coating film having silver coating film formed

The present invention has been made to overcome the above-mentioned problems, and it is an object of the present invention to provide a dental abutment screw which is formed by forming a DLC (Damon-like carbon) thin film layer on the surface of a dental abutment screw, thereby improving abrasion resistance and reducing friction coefficient, The present invention provides an abutment screw for an implant and a method of manufacturing the same.

In order to accomplish the above object, an abutment screw for an implant having an anti-loosening function according to the present invention comprises: a substrate made of a titanium or titanium alloy material; A buffer layer of chromium material formed on the surface of the substrate by arc ion plating; And a diamond-like carbon (DLC) thin film layer formed on the surface of the buffer layer by a vacuum arc evaporation method of a filtered cathodic vacuum arc method and having a low friction coefficient characteristic.

And the friction coefficient of the DLC thin film layer is 0.110 to 0.123.

In order to achieve the above object, the present invention provides a method of manufacturing an abutment screw for an implant having an anti-loose function, comprising the steps of: forming a buffer layer of a chrome material on a surface of a base material made of titanium or a titanium alloy material by arc ion plating; Wow; And forming a diamond-like carbon (DLC) thin film layer having a low friction coefficient characteristic on the surface of the buffer layer by a vacuum arc evaporation method of a filtered cathodic vacuum arc method.

The buffer layer was formed by injecting 200 sccm of argon gas and 200 sccm of nitrogen gas under the conditions of a pressure of 10 mTorr, a temperature of 350 캜, an arc power of 60 A and a bias voltage of 200 V, and arc discharging for 60 minutes. The DLC thin film layer was formed at a pressure of 1.0 10 ^-4 Pa , A temperature of 60 캜, a bias voltage of 100 V, and a filter applied voltage of 40 V for 40 to 50 minutes.

As described above, according to the present invention, the DLC (Damon-like carbon) thin film layer is formed on the surface of the dental abutment screw, thereby improving the wear resistance and reducing the friction coefficient, thereby effectively preventing screw loosening.

1 is a cross-sectional view showing a state in which an implant according to an embodiment of the present invention is placed,
2 is a schematic view showing an arc ion plating apparatus for forming a buffer layer,
3 is a result of the friction coefficient test,
4 shows the hardness test results.

Hereinafter, an abutment screw for an implant having a release preventing function according to a preferred embodiment of the present invention and a method for manufacturing the same will be described in detail.

1, a dental implant 1 typically includes a fixture 3 that is placed in the alveolar bone 2, an abutment 4 that is coupled to the top of the fixture 3, And an abutment screw 7 for fixing the screw 4 to the fixture 3. And an artificial crown 5, which is designed to reproduce the same shape and function as natural teeth, is coupled to the upper part of the abutment 4.

The abutment screw of the present invention includes a base material, a buffer layer formed on the surface of the base material, and a DLC thin film layer formed on the surface of the buffer layer.

The substrate is made of pure titanium or a titanium alloy for improving bone fusion.

Titanium alloys can be formed by adding other metals such as aluminum (Al), tantalum (Ta), niobium (Nb), vanadium (V), zirconium (Zr), platinum (Pt), palladium (Pd), yttrium , Magnesium (Mg), tin (Sn), and molybdenum (Mo). For example, Ti-6Al-4V, Ti-6Al-7Nb, Ti-30Nb, Ti-13Nb-13zr, Ti-15Mo, Ti-35.3Nb-5.1Ta-7.1Zr, Ti- 4.6Zr, Ti-29Nb-13Ta-2Sn, Ti-29Nb-13Ta-4.6Sn, Ti-29Nb-13Ta-6Sn and Ti-16Nb-13Ta-4Mo.

The buffer layer is formed between the substrate and the DLC thin film layer to increase the adhesion of the DLC thin film layer.

In the present invention, the buffer layer is formed by including chromium. And chromium or chromium nitride (CrN) pure with chromium.

The buffer layer is preferably formed on the surface of the substrate by an arc ion plating method. The buffer layer may be formed to a thickness of 100 to 500 nm. When the buffer layer is formed by the arc ion plating (AIP) method, the deposition rate is fast and the adhesion is excellent.

A DLC thin film layer is formed on the outer surface of the buffer. For example, the thickness may be 50 to 500 nm.

The DLC thin film layer has excellent physical properties such as high hardness, abrasion resistance, lubricity, and smooth surface roughness. In particular, the DLC thin film layer has characteristics of low coefficient of friction, that is, low coefficient of friction, thereby effectively preventing screw loosening.

The friction coefficient of the DLC thin film layer applied to the present invention is 0.110 to 0.123, and has an excellent low friction coefficient characteristic.

The main cause of the screw loosening of the abutment screw is the loss of the preload. Charge is the tensile force inside a screw when tightening a screw. When tightening a screw, 90% of the initial tightening force is used to overcome the frictional force, and only 10% of the tightening force occurs in the charge. Therefore, by forming a DLC thin film layer having a low coefficient of friction on the surface of the abutment screw, more tightening force is converted into charge when the abutment screw is tightened, so that the screw loosening phenomenon can be improved.

Chemical and physical vapor deposition methods such as CVD and PVD can be applied to form the DLC thin film layer, but it is preferable to apply the vacuum arc vapor deposition method in order to form a thin DLC film layer having a better physical property.

The vacuum arc vapor deposition is a high energy of the ions generated compared to other physical vapor deposition method, a high ionization rate of addition, the sp ³ / sp ² fraction increases because of the high ion flux (flux) has a high hardness and a density close to the diamond, the substrate It is possible to deposit a DLC thin film having good adhesion to the substrate and high durability. DLC thin films deposited by vacuum arc evaporation are also called amorphous diamond thin films or ta-C (tetrahedral amorphous carbon) thin films.

Since the vacuum arc evaporation method uses solid graphite as the carbon source, the hydrogen content can be originally prevented, and the third element can be easily added through the atmospheric gas injection.

However, the vacuum arc evaporation method has a problem that non-ionized macron-sized macroparticles in addition to ionized particles enter the coating film and deteriorate the film quality. To solve this problem, it is desirable to apply a vacuum arc vapor deposition method using a filtered cathodic vacuum arc (FCVA) method in which non-ionized macroparticles are filtered using a magnetic field.

BACKGROUND ART [0002] Generally, a vacuum arc vapor deposition apparatus using a magnetic field filtration arc method includes an arc plasma generating unit for generating plasmaized ions by generating a spark in a graphite target object mounted in a vacuum chamber, And a filter portion for removing the non-ionized particles from the ions by a magnetic force and forming a thin film on the substrate. As the filter part, mainly X-bend type, Double bend type, T-bend type, S-bend type and the like can be applied.

The DLC thin film layer formed on the surface of the buffer layer has a very thin film (thickness: 50 to 500 nm) and has a hardness of 25 to 60 GPa, which is excellent in wear resistance.

Hereinafter, a method for manufacturing an abutment screw for an implant having an anti-loosening function will be described.

First, a buffer layer of a chrome material is formed on the surface of a substrate by an arc ion plating method.

A cleaning process may be carried out to clean the surface of the substrate before forming the buffer layer. For example, substrates are cleaned by ultrasonication in acetone and ethanol for 15 minutes each, followed by washing with deionized water and drying.

After the substrate is washed, a buffer layer is formed on the surface of the substrate. An example of an arc ion plating apparatus for performing a coating by the arc ion plating method is shown in FIG.

The arc ion plating apparatus 20 shown in FIG. 2 includes a chamber 21 provided with a gas inlet capable of introducing gas and a gas outlet connected with a vacuum pump 23 so as to allow the gas to flow out, An arc generating source 27 for one or a plurality of arc welding sources 27 for melting and evaporating the target 25 caused by arc evaporation by arc discharge and a material ionized by accelerating electrons And a holder 28 to which a negative potential bias voltage is applied via a bias generating source 29 so as to attract the bias voltage. It is needless to say that a conventional arc ion plating apparatus can be used.

In order to perform the reaction using the arc ion plating apparatus, the vacuum pump 23 is operated while the target 25 of chromium material and the base material 10 are mounted in the chamber 21, A vacuum is formed, and arc discharge is performed to form a coating film on the surface of the substrate 10. Argon gas and nitrogen gas are used as the gas. During arc discharge, negative (-) potential bias voltage of 100 to 1,000 V is applied to the holder 28 to discharge.

As an example of the arc discharge condition, an arc power at a chamber pressure of 1 to 30 mTorr, 20 to 500 ° C, 30 to 100 A, 100 to 500 sccm of argon gas and 100 to 500 sccm of nitrogen gas under a negative potential bias voltage of 100 to 1,000 V And arc discharge for 30 to 120 minutes. The chromium evaporated from the chromium target through the arc discharge reacts with nitrogen to form a Cr-N nitride-based buffer layer on the surface of the substrate.

Next, a DLC thin film layer is formed on the surface of the buffer layer by a vacuum arc vapor deposition method using a magnetic field filtering arc method.

Commercial products can be used with a vacuum arc arc evaporator of a magnetic field filtration type. For example, the I60FA model from Isys is available.

The vacuum arc evaporator generates sparks in a graphite target body mounted in a vacuum chamber to generate plasmaized ions and then removes non-ionized particles from the plasmaized ions from the filter section and forms a thin film on the substrate . The deposition condition may be, for example, a vacuum chamber pressure of 1 × 10 ^-4 to 10 ^-3 Torr, a temperature of 20 to 300 ° C., and a voltage applied to the filter unit of 10 to 500 V.

Hereinafter, the present invention will be described by way of examples. However, the following examples are intended to illustrate the present invention in detail, and the scope of the present invention is not limited to the following examples.

(Example)

A pure titanium abutment screw base was ultrasonically cleaned in acetone and ethanol for 15 minutes each, then washed with deionized water and dried. And the substrate was mounted on a holder in the chamber of the arc ion plating apparatus shown in Fig. A chromium target was placed inside the chamber, and argon and nitrogen gas were injected into the chamber at 200 sccm, respectively, for 60 minutes Arc discharge was performed to form a buffer layer on the substrate. The pressure in the chamber at the time of coating was 10 mTorr, temperature 350 캜, arc power 60 A, 200 V negative bias voltage.

After forming a buffer layer, a DLC thin film layer was deposited on the surface of the buffer layer by using an S-bend vacuum arc evaporator (I60FA, Isys, Korea). The deposition was performed for 40 to 150 minutes at a pressure of 1.0 x 10 < ^-4 > Pa, a temperature of 60 DEG C, a DC bias voltage of 100 V, and a voltage of 40 V applied to the filter portion.

In order to test the friction coefficient of the DLC thin film layer formed in the above embodiment, the test was commissioned to the Materials Research Institute of the Korea Institute of Machinery & Materials.

The experimental results are shown in Table 1 and FIG. The DLC-40 specimen was deposited for 40 minutes to form a DLC thin film layer, and the DLC-50 specimen was deposited for 50 minutes to form a DLC thin film layer. Two DLC-40 and DLC-50 specimens were prepared.

division Coefficient of friction DLC-50 (1) 0.110 + - 0.01 DLC-50 (2) 0.128 + 0.02 DLC-40 (1) 0.119 ± 0.01 DLC-40 (2) 0.123 + - 0.01

Referring to Table 1 and FIG. 3, it was confirmed that the specimens manufactured according to the Examples had a low coefficient of friction coefficient of 0.110 to 0.123, which is a coefficient of friction of the DLC thin film layer.

Such a DLC thin film layer is expected to reduce the coefficient of friction of the abutment screw to effectively prevent screw loosening.

In order to test the hardness of the DLC thin film layer formed in the above example, the test was commissioned to the Inha University Joint Instrument Center.

The experimental results are shown in Table 2 and FIG. The 40 xls specimen was deposited for 40 minutes to form a DLC thin film layer. The 50 xls specimen was deposited for 50 minutes to form a DLC thin film layer. The 150 xls specimen was deposited for 150 minutes to form a DLC thin film layer.

division An average hardness (GPa) of 30 to 40 nm, 40 xls 43.52 50 xls 60.1 150 xls 25.15

Referring to Table 2 and FIG. 4, it was confirmed that the hardness of the specimens prepared according to the Examples was high, indicating that the hardness of the DLC thin film layer was approximately 43 to 60 GPa. In particular, a deposition time of 40 to 50 minutes seems appropriate. When the deposition time was increased to 150 minutes, the thickness of the DLC thin layer was increased but the hardness was lowered.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

20: arc ion plating device 21: chamber
23: Vacuum pump 25: Target
27: arc source 28: holder

Claims

A substrate of titanium or titanium alloy material;
A buffer layer of chromium material formed on the surface of the substrate by arc ion plating;
And a diamond-like carbon (DLC) thin film layer formed on the surface of the buffer layer by a vacuum arc evaporation method of a filtered cathodic vacuum arc method and having a low friction coefficient characteristic. Abutment screw for implant.

The abutment screw for an implant according to claim 1, wherein the friction coefficient of the DLC thin film layer is 0.110 to 0.123.

Forming a buffer layer of a chrome material on the surface of a base material made of titanium or a titanium alloy material by an arc ion plating method;
Forming a diamond-like carbon (DLC) thin film layer having a low friction coefficient characteristic by a vacuum arc evaporation method of a filtered cathodic vacuum arc method on the surface of the buffer layer; Of the abutment screw for an implant.

4. The method according to claim 3, wherein the buffer layer is formed by injecting 200 sccm of argon gas and 200 sccm of nitrogen gas under the conditions of a pressure of 10 mTorr, a temperature of 350 캜, an arc power of 60 A and a bias voltage of 200 V and arc-
Wherein the DLC thin film layer is formed by depositing at a pressure of 1.0 x 10 < ^-4 > Pa, a temperature of 60 DEG C, a bias voltage of 100 V and a filter applied voltage of 40 V for 40 to 50 minutes. A method of manufacturing a nut screw.