KR101137013B1 - Manufacturing method of dental zirconia implant members by injection molding and dental zirconia implant members using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a dental zirconia implant member and a dental zirconia implant member using the same, a method that can easily produce an implant member having aesthetically superior and high strength and toughness by injection molding a zirconia material and It relates to a dental zirconia implant member using the same.
The method for producing a dental zirconia implant member of the present invention is a molding step of injection molding by mixing a zirconia powder and a binder, and heated to 450 ℃ by heating for 35 to 45 hours to remove the binder contained in the molded body formed in the molding step After the heat treatment step of cooling and cooling the molded body heat-treated in the heat treatment step for 22 to 30 hours, the temperature is raised to 1400 ℃, the temperature is lowered to 1000 ℃ and the sintering step, and the molded product sintered in the sintering step into the mold And then a post-treatment step of densifying the tissue by applying heat under isostatic pressure.

Description

Manufacturing method of dental zirconia implant members using injection molding and dental zirconia implant members by injection molding and dental zirconia implant members using the same}

The present invention relates to a method for manufacturing a dental zirconia implant member and a dental zirconia implant member using the same, a method that can easily produce an implant member having aesthetically superior and high strength and toughness by injection molding a zirconia material and It relates to a dental zirconia implant member using the same.

Dental implants generally refer to the replacement of the missing natural tooth itself or a screw-shaped fixture to the alveolar bone to fuse with the bone for a period of time and then to the abutment on the abutment. It is a dental procedure that restores the original function of teeth by fixing prosthesis such as) and artificial crown.

As a material of such an implant, titanium having appropriate mechanical strength, biocompatibility, excellent corrosion resistance, and excellent osteoadhesion ability is most widely used as a dental implant. However, titanium has a problem that it takes a long time before bone adhesion occurs.

In addition, most titanium implants are processed using a cutting machine such as a lathe. In order to make an implant, a predetermined material is cut through a lathe to increase the consumption of used materials and a long processing time. There was an issue that took place.

Recently, alumina, hydroxyapatite (HA), and zirconia (Zirconia) ceramics have been studied as substitute materials for titanium.

Zirconia is a generic term for zirconium oxide (ZrO ₂ ), which shows chemical stability and volume stability. It has strength and fracture toughness, and does not cause toxic reaction when inserted into the human body and has excellent resistance to corrosion and abrasion. In addition, zirconia is made of ceramic to express tooth color, which is excellent in aesthetics and biocompatibility, and has high strength and toughness.

Because of these superior properties of zirconia, the scope of application is gradually increasing. However, zirconia has a good function in terms of function, but the high hardness of the material makes it impossible to process with ordinary tools, and the difficulty of forming and molding diamond tools is long and the processing period is long. As a result, capital investment is increasing, which is the main cause of cost increase.

Meanwhile, in the conventional dental implant, as shown in FIGS. 1 and 2, the fixture 3 is inserted into the alveolar bone 1 like the root of natural teeth, and the bone is adhered to the abutment 5. (3) is coupled to the fixing screw (7), the artificial crown (9) is mounted on it to complete the artificial tooth.

However, since the dental implant according to the prior art is a structure in which artificial crowns can be combined only when the abutment is coupled to the fixture, the fixture is implanted using a dental tool in a narrow space such as a real person's mouth. The procedure of fixing the abutment again is cumbersome.

In addition, the conventional implant is a problem that the fastening state of the fixing screw for fixing the abutment is gradually loosened or, in severe cases, the fixing screw is broken when repeated use of artificial teeth.

In addition, when the abutment is coupled to the fixture, bacteria or foreign substances may penetrate into the screw engagement site, which may cause inflammation around the gum.

The present invention has been made to improve the above problems and provides a method for producing an implant member and an implant member using the same by injection molding a zirconia material having aesthetically superior and high strength and toughness. Its purpose is to.

Another object of the present invention is to provide a method for producing an implant member formed by integrally forming an abutment and fixture by injection molding a zirconia material and an implant member using the same.

Method for producing a dental zirconia implant member of the present invention for achieving the above object comprises a molding step of injection molding by mixing a zirconia powder and a binder; A heat treatment step of heating for 35 to 45 hours to raise the binder to be contained in the molded body formed in the molding step, raising the temperature to 450 ° C., and then cooling it; A sintering step of heating the molded body heat-treated in the heat-treating step for 22 to 30 hours to raise the temperature to 1400 ° C., then to lower the temperature to 1000 ° C. and then to cool the molded body; And a post-treatment step of densifying the tissue by applying heat in an isostatic state after inserting the molded body sintered in the sintering step into a mold.

The heat treatment step is a first step of heating the molded body in the cooled state for 2 hours to gradually increase the temperature to 150 ℃, the second step of heating at 150 ℃ for 10 hours to gradually increase the temperature to 230 ℃, 230 ℃ And heating for 6 hours at 270 ° C., gradually increasing the temperature to 270 ° C., and heating at 270 ° C. for 2 hours, and heating at 270 ° C. for 9 hours to gradually warm up to 340 ° C. A fifth step, a sixth step of gradually heating the temperature to 450 ° C. by heating at 340 ° C. for 8 hours, and a seventh step of heating for 3 hours while maintaining the temperature at 450 ° C .;

The sintering step is a first step of heating the molded body in the cooled state for 7 hours to gradually increase the temperature to 700 ℃, and a second step of heating at 700 ℃ for 3 hours to gradually increase the temperature to 1000 ℃, and 1000 ℃ A third step of heating for 1 hour in a state of maintaining a state, a fourth step of heating for 13 hours at 1000 ° C. and gradually raising the temperature to 1400 ° C., and a fifth step of heating for 2 hours while maintaining a state of 1400 ° C. And a sixth step of gradually lowering the temperature to 1000 ° C. by heating at 1400 ° C. for 2 hours.

The molding step is a first step of mixing and melting 78 to 88% by weight of the zirconia powder and 12 to 22% by weight of the binder, and a second step of extruding the melt melt in the first step to form a pellet-shaped master batch; And a third step of injection molding the master batch into the injection machine.

And dental zirconia implant member of the present invention for achieving the above object is an implantation portion is implanted in the alveolar bone is formed on the outer peripheral surface; A fixing part formed at an upper part of the implantation part and fixing an artificial dental crown; A head portion formed on an upper portion of the fixing portion and coupled to a tool to rotate the placing portion and the fixing portion, wherein the placing portion, the fixing portion, and the head portion are injected with a mixture of zirconia powder and a binder. It is characterized by being formed integrally by molding.

As described above, the present invention, unlike the conventional titanium implant member, expresses the color of the tooth as a ceramic so that it is easily aesthetically pleasing, biocompatibility-friendly and high-strength and toughness by injection molding zirconia, which is poor in workability. Provided is a method of manufacturing an implant member capable of mass production.

In addition, by forming the zirconia material through injection molding, the conventional abutment and fixture are integrally formed to provide an implant member that is easy to perform the procedure and does not have to be loosened.

1 and 2 is a view showing an implant member according to the prior art,
3 is a block diagram showing a method of manufacturing an implant member according to an embodiment of the present invention;
4 is a perspective view showing an implant member according to an embodiment of the present invention.

Hereinafter, a method of manufacturing a dental zirconia implant member and a dental zirconia implant member using the same will be described in detail with reference to the accompanying drawings.

The method for manufacturing a dental zirconia implant member according to an embodiment of the present invention includes a molding step, a heat treatment step, a sintering step, and a post-treatment step.

First, in the forming step, the zirconia powder and the binder are mixed to form a specific shape.

The molding step is preferably a first step of mixing by mixing 78 to 88% by weight of the zirconia powder and 12 to 22% by weight of the binder and the first step of extruding the melt melt in the first step to make a pellet-shaped master batch And a third step of injection molding the master batch into the injection machine.

Zirconia is a compound represented by the formula ZrO ₂ . The average particle diameter of the zirconia powder applied in the present invention is about 0.1 μm or more and about 0.6 μm or less. In addition, the proportion of monoclinic crystals in the zirconia powder is generally about 70% by volume or more, preferably about 80% by volume or more. Small amounts of stabilizer may be added to the zirconia powder. As a stabilizer, CaO, Y ₂ O ₃ , CeO ₂ , MgO, CaO may be used alone or in combination of two or more. In addition to the stabilizer, a glassy material of P ₂ O ₅ , Na ₂ O may be added. P ₂ O ₅ , Na ₂ O together with the stabilizer to maintain the strength and sinterability of the sintered body during sintering.

Pure zirconia is stable monoclinic (monoclinic) from room temperature to about 1170 ℃, it is tetragonal to 2370 ℃, it is stable by transitioning to cubic (cubic) at a temperature higher than that and melted around 2700 ℃. The tetragonal system undergoes a volume expansion of about 3-5% while causing phase transformation to monoclinic system at 1070 ° C upon cooling. For this reason, pure zirconia is sintered at 1500 to 1600 ° C., which is a general sintering temperature range, and is destroyed at room temperature by stress due to volume expansion. At this time, the stabilizer mixed in the zirconia powder to obtain a stable tetragonal system at room temperature. The stabilizer lowers the t-m phase transition temperature to room temperature or less to cause the tetragonal system to metastabilize at room temperature.

The stabilizer is preferably added 0.1 to 1.0 parts by weight based on 100 parts by weight of zirconia powder.

Ethylene resin and paraffin wax are used as a binder. In this case, 50 to 100 parts by weight of paraffin wax is mixed with 100 parts by weight of ethylene resin. Another example of a binder is 67 parts by weight of M-7002 (North Industry Co., Ltd.), 52.6 parts by weight of P-155 (Chung Chung, Japan), and EVA (Hanhwa) based on 100 parts by weight of CB-1 (Samyang Chemical, Japan). Petrochemical, Korea) 12 parts by weight, SP-60R (NOF CO, Japan) 16.67 parts by weight, NAA-222S (NOF CO, Japan) 6.9 parts by weight, DOP (OCI CO, Japan) 16.43 parts by weight Can be. In addition, a conventional binder can be used.

The mixture of the above-mentioned zirconia powder and the binder is melted at 100 to 180 ° C. and sufficiently kneaded in a kneader, and then molded into an extruder in a size of 1 to 3 mm to make a pellet-shaped masterbatch. By using it in the form of a master batch in this way, it is possible to improve the accuracy and dispersibility of the compounding weighing, and to prevent particle scattering or loss.

The master batch is installed in the injection molding machine and filled into the inner cavity of the upper and lower molds, which are in close contact with each other, to be injection molded. By injection molding, it is possible to produce a molded article having high hardness, high density, and impact resistance. When injection molding, the injection temperature is appropriate 110 to 250 ℃, injection pressure 4-7MPa.

Since the binder is contained in the injection molded article, the binder is removed by performing a heat treatment step. In order to remove the binder, the molded body is put in a degreasing furnace, heated for 35 to 45 hours, heated to 450 ° C, and cooled. In the heat treatment step, it is important to adjust the temperature increase rate in consideration of the oxidation temperature and the oxidation amount of the binder.

Specifically, the heat treatment step is a first step of gradually heating the cooled molded body for 2 hours at room temperature to 150 ℃, and a second step of gradually heating to 150 ℃ for 10 hours at 150 ℃, A third step of heating at 230 ° C. for 6 hours and gradually raising the temperature to 270 ° C., a fourth step of heating at 270 ° C. for 2 hours, and heating at 270 ° C. for 9 hours to gradually increase to 340 ° C. A fifth step of heating up, a sixth step of heating at 340 ° C. for 8 hours and gradually raising the temperature to 450 ° C., and a seventh step of heating for 3 hours while maintaining the temperature at 450 ° C .;

The heat-treated molded body has mechanical properties through the sintering step. In the present invention, the sintering step is controlled to a sintering time at a temperature within 1400 ℃ for uniform shrinkage. The molded body is heated for 22 to 30 hours, heated up to 1400 ° C., lowered to 1000 ° C. and then cooled.

Specifically, the sintering step includes a first step of gradually heating the cooled molded body in a cooled state for 7 hours to 700 ° C. at room temperature, and a second step of gradually heating up to 700 ° C. for 3 hours at 700 ° C .; , A third step of heating for 1 hour while maintaining at 1000 ° C, a fourth step of heating for 13 hours at 1000 ° C and gradually raising the temperature to 1400 ° C, and heating for 2 hours while maintaining at 1400 ° C The fifth step and the sixth step of heating at 1400 ℃ for 2 hours to gradually lower the temperature to 1000 ℃.

By the sintering process, the molded body can maintain a constant shrinkage rate. The sintered molded body may further be subjected to a process for removing fine burrs after cooling. Alternatively, the process of removing the fine burr may be performed after the completion of the post-treatment step to be described later.

The sintered compact is put into a mold and then subjected to a post-treatment step by applying heat in an isostatic state. The post-treatment step is for densifying the tissue and removing defects through hot isostatic pressing (HIP).

To this end, after the molded product is put into a hot isostatic pressing machine, the molded article is naturally raised to 1100 to 1750 ° C. for 2 to 4 hours at a pressure of 700 to 1300 bar, then maintained for 0.5 to 2 hours, and then naturally cooled to 40 ° C. (Frozen).

It can be seen that the implant member manufactured by the above method has excellent mechanical properties with a sintered density of 99.1 to 99.9%, hardness of 15 to 17GPa, and fracture toughness of 4.0 to 5.5MPa · m ^1/2 .

An example of an implant member manufactured by the above-described method is shown in FIG. 4. The implant member 10 shown in FIG. 4 has a screw thread 13 formed on an outer circumferential surface thereof, and an implantation portion 11 to be implanted in the alveolar bone, and a fixing portion 15 formed on the implantation portion 15 and fixed to an artificial crown. ) And a head portion 15 formed on the fixing portion 15. The head portion 15 is a portion engaging with a tool for rotating the implant member, and is formed in a hexagon. And a hexagonal groove 19 that can be combined with the hexagon wrench is formed in the head portion 17.

The implant member 10 formed as described above is formed by integrating the conventional fixture 3 and the abutment 5 shown in FIG. 2 by injection molding. Therefore, the implant member of the present invention does not need to fasten the abutment to the upper part of the fixture using a fixing screw. Therefore, the procedure of implant is very simple and fast. In addition, since the structure does not fasten the abutment to the fixture using a fixing screw as in the prior art, it is possible to solve the problem of loosening the fastening state of the fixing screw.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, which is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. .

Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (5)

A molding step of injection molding by mixing the zirconia powder and the binder;
A heat treatment step of heating for 35 to 45 hours to raise the binder to be contained in the molded body formed in the molding step, raising the temperature to 450 ° C., and then cooling it;
A sintering step of heating the molded body heat-treated in the heat-treating step for 22 to 30 hours to raise the temperature to 1400 ° C., then to lower the temperature to 1000 ° C. and then to cool the molded body;
And a post-treatment step of densifying the tissue by applying heat in an isostatic state after inserting the molded product sintered in the sintering step into a mold. The method of claim 1, wherein the heat treatment step comprises: a first step of gradually heating the molded body in a cooled state for 2 hours and gradually raising the temperature to 150 ° C; A second step, a third step of heating at 230 ° C. for 6 hours and gradually raising the temperature to 270 ° C., a fourth step of heating for 2 hours in a state maintained at 270 ° C., and heating at 270 ° C. for 9 hours for 340 And a fifth step of gradually raising the temperature to 占 폚, a sixth step of heating at 340 占 폚 for eight hours and gradually raising the temperature to 450 占 폚, and a seventh step of heating for three hours while maintaining the temperature at 450 占 폚. A method for producing a dental zirconia implant member. The method of claim 1, wherein the sintering step comprises: a first step of gradually heating the molded body in a cooled state for 7 hours and gradually raising the temperature to 700 ° C, and a third step of gradually raising the temperature to 1000 ° C by heating for 3 hours at 700 ° C. Step 2, the third step of heating for 1 hour in the state maintained at 1000 ℃, the fourth step of heating for 13 hours at 1000 ℃ to gradually increase the temperature to 1400 ℃, and 2 hours in the state maintained at 1400 ℃ And a sixth step of heating for 1 hour at 1400 ° C. and a sixth step of gradually lowering to 1000 ° C., wherein the zirconia implant member is dental. According to any one of claims 1 to 3, wherein the molding step is a first step of melting by mixing 78 to 88% by weight of the zirconia powder and 12 to 22% by weight of the binder, and melting in the first step And a third step of extruding the melt to produce a pellet-shaped master batch, and a third step of inserting the master batch into an injection molding machine and injection molding the master batch. delete

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