KR100850568B1 - Method for manufacturing ceramic implant having a porous surface and the implant manufactured by the method - Google Patents

Abstract

A method for manufacturing a ceramic implant and the implant manufactured by the method are provided to maintain beauty even in retraction of gingiva and to prevent bone loss by elution of metal ions, by using ceramic as a main material. A method for manufacturing a ceramic implant having a porous surface comprises the steps of: forming a molded product by molding ceramic powder in a regular shape(S1); forming a pre-sintered product by pre-sintering the molded product at a high temperature(S3); generating slurry solution by mixing distilled water, ceramic powder, and a pore generator(S5); depositing the pre-sintered product in the slurry(S7); and forming a pore by finally sintering the deposited pre-sintered product at a high temperature and dissolving or volatilizing the pore generator in the slurry(S9).

Description

Method for manufacturing ceramic implant having a porous surface and the implant manufactured by the method

1 is an enlarged view of an implant and a porous surface formed according to a manufacturing method according to an embodiment of the present invention

Figure 2a is an electron micrograph of the porous surface formed by the slurry of 5% by weight of zinc oxide added.

2b is an electron micrograph of the porous surface formed by the slurry to which zinc oxide is added 7% by weight.

2C is an electron micrograph of the porous surface formed by the slurry to which 9% by weight of zinc oxide is added.

Figure 2d is an electron micrograph of the porous surface formed by the slurry is added 3% by weight of zinc oxide, 14% by weight of polymethyl methacrylate (PMMA) bead

Figure 3 is a graph of the EDS analysis of the porous surface formed according to the manufacturing method according to an embodiment of the present invention.

Figure 4 is a graph of the results of evaluation of cell adhesion for the implant having a porous surface formed according to the manufacturing method according to an embodiment of the present invention and a conventional implant.

5 is a flow chart of a manufacturing method according to an embodiment of the present invention.

The present invention relates to a method for producing a porous surface on the surface of the ceramic implant, in particular, the pores are formed by volatilization or decomposition of the pore-forming agent at a high temperature to show a uniform pore distribution and to control the content of the pore-forming agent And the mechanical strength is excellent and the color is similar to that of natural teeth, so the esthetics can be maintained even when the gingival is retracted, and the dissolution of metal ions can be fundamentally prevented. It relates to an implant produced by the manufacturing method.

Implants are substitutes for alveolar bones in place of the missing natural teeth of the patient, usually made of metal or ceramic materials.

Among them, metal implants have a unique metallic feel when the gingiva is retracted, and aesthetics are degraded due to the lack of light transmission, and the implant and alveolar bone buried in the alveolar bone by various chewing pressures. There is a possibility that metal ions elute due to friction.

 In the case of ceramic implants, when blasting is performed by modifying the surface of the implant to secure fixing force and stability, surface defects such as cracks or scratches are generated on the surface of the implant, Fracture is likely to occur. In addition, the method of modifying the surface by the plasma spray method is likely to cause early peeling of the fixture and the spray layer after implantation in the human body by amorphization of the surface of the thermal spray material by the ultra-high temperature (about 10,000 ℃ or so). In addition, since the elastic modulus of the ceramic is excessively higher than that of the alveolar bone, it is disadvantageous to disperse the stress, and thus there is a high risk of bone loss due to concentration of stress.

The present invention has been made in order to solve the problems of the prior art, the object of the present invention is that the main material is ceramic, so the aesthetics can be maintained even when the gingiva is retracted and metal ions can be fundamentally prevented dissolution of metal ions It is to provide an implant manufacturing method and the implant that can prevent bone loss due to elution.

It is another object of the present invention that surface defects can be prevented because no blasting can be prevented and fractures due to surface defects can be prevented, and furthermore, the screw part of the fixture and the porous surface are firmly attached by co-sintering, so that It is to provide an implant manufacturing method and implants thereof in which there is no possibility of premature detachment of the porous surface due to amorphous.

Still another object of the present invention is that the pores are formed by volatilization or decomposition of the pore-forming agent, so that there is no crack, the pore distribution is uniform, and an implant manufacturing method capable of adjusting the porosity by adjusting the amount of the pore-forming agent and its It is to provide an implant.

Still another object of the present invention is to provide a method for producing an implant and an implant thereof, which can secure a wide contact area with a bone by forming a porous surface to ensure excellent fixation force and stable operability.

The present invention is implemented by the embodiment having the following configuration in order to achieve the above object.

According to one embodiment of the invention, the molding method of the present invention, the molding step of forming a molded body by molding the ceramic powder in a predetermined form, and the pre-sintering step of forming a plasticized body by pre-sintering the molded body at a high temperature, A slurry generation step of producing a slurry solution by mixing distilled water, ceramic powder and a pore-forming agent, a deposition step of depositing the plasticizer in the slurry, and finally sintering the deposited plasticizer at a high temperature to form pores in the slurry. A final sintering step of decomposing or volatilizing the agent to form pores.

According to another embodiment of the present invention, the manufacturing method of the present invention, the molding step is characterized in that the molding by mixing a stabilized zirconia powder or stabilized zirconia powder and alumina powder.

According to another embodiment of the present invention, the manufacturing method of the present invention, the pre-sintering step, characterized in that the molded body by heat treatment for a predetermined time at 900 ~ 1300 ℃.

According to another embodiment of the present invention, the production method of the present invention, the slurry generation step is characterized in that the addition of an organic binder to improve the adhesion between the plasticized body and the slurry.

According to another embodiment of the present invention, the method of the present invention is characterized in that the pore-forming agent is a composite of zinc oxide powder or zinc oxide powder and PMMA bead.

According to another embodiment of the present invention, the production method of the present invention, the slurry generation step is added to the organic binder 2 to 20% by weight relative to the distilled water to produce a solution and then the ceramic powder and the pore-forming agent compared to the solution It is characterized by mixing by 1 to 29% by weight, respectively.

According to another embodiment of the present invention, the production method of the present invention, the slurry generation step is characterized in that the mixing of the dispersant further for the dispersion of the slurry.

According to another embodiment of the present invention, the manufacturing method of the present invention, the dispersing agent is selected from the group consisting of cationic surfactants such as anionic surfactants such as polycarboxylate, ethyl acrylate, ammonium salt, amine salt It is characterized by.

According to another embodiment of the present invention, the manufacturing method of the present invention, the final sintering step, to form a porous surface by decomposing or volatizing the pore-forming agent by the final sintering of the plasticizer to which the slurry is applied at 1300 ~ 1600 ℃ It is characterized by.

According to another embodiment of the present invention, the manufacturing method of the present invention is characterized in that the porosity can be adjusted by adjusting the content ratio of the pore-forming agent.

According to another embodiment of the present invention, the implant of the present invention, in the ceramic implant having a porous surface formed on the surface of the implant-shaped core core formed by sintering the ceramic powder, the porous surface is the main component of the ceramic powder It consists of a scaffold portion and the pores formed by decomposition or volatilization of the pore-forming agent, the skeleton portion is characterized in that to ensure a large contact area with the alveolar bone.

Applicants will now be described with reference to the accompanying drawings, the embodiments above.

1 is an enlarged view of an implant and a porous surface formed according to a molding method according to an embodiment of the present invention. As shown in FIG. 1, the implant or fixture comprises a central core 1 and a porous surface 2.

Since the core core 1 is formed by sintering a stabilized zirconia powder alone or a composite of a stabilized zirconia powder and an alumina powder, which will be described later, the core core 1 can maintain aesthetics similar to the color of natural teeth.

The porous surface 2 is composed of pores 21 and 22 which are spaces formed by volatilization or decomposition of a pore-forming agent in a slurry applied to the surface of the core, and a skeleton 23 surrounding the pores, which will be described later. Formed by the process.

In order to create an implant as described above is to follow the molding method as follows.

The ceramic implant molding method includes a molding step S1, a sintering step S3, a slurry generation step S5, a deposition step S7, and a final sintering step S9.

The molding step (S1) is selected from the ceramic powder, preferably a stabilized zirconia (3Y-TZP) powder only or one of the composite mixture of the stabilized zirconia powder and alumina (Al ₂ O ₃ ) powder and pressing (Die-Pressing) By using a molding method such as injection molding or cold isostatic pressing, the molded body having an implant shape, that is, the central core 1 is formed.

In the preliminary sintering step (S3), the molded body is heat-treated at a high temperature, preferably at a temperature of 900 to 1300 ° C. for a predetermined time, preferably 1 to 4 hours, to form a plasticized body.

The slurry generation step (S5) is a step of first wet mixing distilled water, the ceramic powder and a pore-forming agent to form a slurry. Here, the pore-forming agent is included in the slurry applied to the plasticizer, and includes all materials capable of forming pores by decomposition or volatilization in the sintering process. For example, zinc-based compounds, starch, carbon powder, excess organic binder. , Polymer precursors, and the like, preferably zinc oxide and PMMA bead are suitable. In addition, the porosity may be adjusted by adjusting the content ratio of the pore-forming agent. At this time, in order to improve the bonding strength between the slurry and the plasticizer, an organic binder may be added. It is also possible to add a dispersant for the dispersion of the slurry. As an example of the dispersant, anionic surfactants such as polycarboxylate, ethyl acrylate, and the like may be used, or cationic surfactants such as ammonium salt and amine salt may be used. As a preferred embodiment, a slurry in which 1 to 29% by weight of stabilized zirconia powder and 1 to 29% by weight of zinc oxide powder is mixed with a solution in which an organic binder is added in an amount of 2 to 20% by weight with respect to distilled water, and another pore-forming agent As the slurry is preferably mixed 5 to 20% by weight of the PMMA bead compared to the mixed slurry. If necessary, 0.2 to 1% by weight of the dispersant may be added to the stabilized zirconia powder and the zinc oxide powder.

The deposition step (S7) is to immerse the plasticized body in the slurry solution for a predetermined time, for example about 5-30 seconds so that the slurry is uniformly applied to the central core surface of the plasticized body.

The final sintering step (S9) sinters the plasticized body to which the slurry is applied at a high temperature, for example, at a temperature of 1300 to 1600 ° C. for about 1 to 4 hours to volatilize pore formers such as zinc oxide or zinc oxide and PMMA bead in the slurry. Or disintegrate to form pores therein. At the final sintering temperature of 1300 ~ 1600 ° C, the stabilized zirconia in the slurry is sintered as it is, and only the remaining pore-forming agent is volatilized or decomposed and disappeared. As shown in FIGS. 1 to 2A through this process, pores ( 21), (22) are formed and the remaining stabilized zirconia is produced in the form of a skeleton 23 surrounding the pores. Furthermore, the skeleton 23 has a large contact area with the alveolar bone, thereby showing an excellent fixation force.

Applicants will be described below through the various experiments that the pore forming agent is volatilized or decomposed during the sintering process, the fact that the porosity can be adjusted by adjusting the content ratio of the pore forming agent, and the test examples of the present invention is compared Demonstrate good adhesion.

       Referring to the embodiment of the present invention configured as described above is as follows

 The examples do not limit the scope of the invention.

Psalm Fabrication

Test Example 1 Die-pressing stabilized zirconia (3Y-TZP) powder to produce a molded body in the form of a one-body implant (integrated abutment and fixture), the upper molded body at 950 ℃ After heat treatment at temperature for 2 hours to form a plasticized body, 5 wt% of stabilized zirconia powder and zinc oxide powder were added to the solution formed by adding 10 wt% of organic binder to distilled water to distilled water, respectively, 0.5% by weight of the ammonium phosphate-based stabilized zirconia powder and zinc oxide powder was added to a slurry solution prepared by wet mixing for 6 hours, and the plasticizer was immersed for 10 seconds and then taken out to dry sufficiently, followed by 2 at a temperature of 1450 ° C. By sintering for a period of time to prepare an implant forming a pore by volatilizing or decomposition of zinc oxide, this is called Test Example 1.

Test Example 2 Although it is almost similar to Test Example 1 above, in preparing a slurry solution, the weight ratio of the ceramic powder and pore-forming agent added to the solution is somewhat different. Specifically, the stabilized zirconia powder is 3% by weight of the solution. And zinc oxide powder is added to 7% by weight relative to the solution to prepare a slurry, and the implant is prepared through the same process as the above deposition and sintering process, this is called Test Example 2.

Test Example 3 Although it is almost similar to Test Example 1 above, in preparing a slurry solution, the weight ratio of the ceramic powder and pore-forming agent added to the solution is somewhat different. Specifically, the stabilized zirconia powder is 1% by weight of the solution. And zinc oxide powder is 9% by weight relative to the solution to prepare a slurry, and the implant is prepared through the same process as the above-described deposition and sintering process, this is called Test Example 3.

Test Example 4 Although it is almost similar to Test Example 1 above, in preparing a slurry solution, the weight ratio of ceramic powder and pore-forming agent added to the solution is somewhat different. Specifically, the stabilized zirconia powder is 3% by weight of the solution. The zinc oxide powder is added 7% by weight relative to the solution to prepare a mixed slurry. The composite slurry is prepared by adding 14% by weight of PMMA bead to the mixed slurry, and the implant is subjected to the same process as described above. Prepare it and call it Test Example 4.

Comparative Example: The stabilized zirconia (3Y-TZP) powder was press-molded to sinter the molded article in the form of an implant at a temperature of 1450 ° C. for 2 hours, and then blasted using alumina powder to form roughness on the surface of the sintered compact, and the roughness Ra The average of the values is 0.51 mu m.

Experiment 1: Zinc Oxide Remaining

Applicant analyzed the composition of the surface by using EDS (Energy Dispersive X-ray Spectroscopy) for Test Example 1, the results are shown in FIG. As shown in FIG. 3, only zirconium (Zr), hafnium (Hf), and oxygen (O) components were observed on the surface, and no zinc (Zn) components were observed. Accordingly, it was confirmed that the zinc components were all volatilized or decomposed during the sintering process and that the pores 21 were formed at the disappeared positions as shown in FIG. 2A.

Experiment 2: Possibility of Porosity Control and Observation of Skeleton Shape

Applicant, SEM (Scanning Electron) for Test Example 1, Test Example 2, Test Example 3 to determine whether the porosity can be adjusted by adjusting the content ratio of the pore-forming agent, that is, zinc oxide and the shape of the skeleton surrounding the pores Microscopy) pictures were taken (5000 × magnification) and shown in FIGS. 2A-2B-2C. The ratio of the stabilized zirconia-zinc oxide powder to the organic binder solution is 5-5% by weight in Figure 2a, 3-7% by weight in Figure 2b, 1-9% in Figure 2c, the higher the content ratio of zinc oxide It was confirmed that the ratio of the pores 21 is increased, and the ratio of the skeleton 23 gradually decreases.

Experiment 3: cell adhesion evaluation

Applicants conducted cell adhesion experiments for Comparative Example and Test Example 1. First, MG-63, a human osteoblast like cell, is suspended in serum free DMEM at a concentration of 2x10 ⁵ cells / ml. Then, Test Example 1 and Comparative Example are placed in a 24 well (culture dish), and 1 ml per well is dispensed. After incubation for 2 hours in an incubator at 37˚C, 5% CO ₂ , remove the unattached cells by washing twice with PBS. Formalin (10% formaldehyde in PBS) was fixed at 4 ° C. for 2 hours, formalin was removed, and 0.04% cresyl violet (in 20% methanol) was added to 500 µl of each well for 30 minutes to stain the cells. Test Example 1 and Comparative Example was washed twice with distilled water to remove cresyl violet. 300 μl of 0.1 M citric acid (in 50% ethanol) was added per well to elute cresyl violet stained on the cells. Taking 200 μl of the eluate and measuring the absorbance at a wavelength of 595 nm using a Spectrophotometer (Beckman coulter, Inc., DTX 880). FIG. 4 is a graph illustrating the absorbance of Comparative Example and Test Example 1. FIG. As shown in FIG. 4, the Y axis of the graph shows absorbances of the eluates of Test Example 1 and Comparative Example at a wavelength of 595 nm, and the absorbance of Test Example 1 was higher than that of Comparative Example. This means that more cells of Test Example 1 than cells of Comparative Example. In detail, the more cells, the stronger the staining, so that the color of the eluate is darker. Therefore, the more cells, the higher the absorbance.

As a result, the cell adhesion of Test Example 1 is superior to that of the Comparative Example, it can be confirmed that Test Example 1 is advantageous for bone growth compared to the Comparative Example.

The present invention has the following effects by the above configuration.

In the present invention, since the material is ceramic, the esthetics can be maintained even when the gingiva is retracted, and the dissolution of metal ions can be fundamentally prevented, thereby preventing bone loss due to the dissolution of metal ions.

According to the present invention, surface bleeding can be prevented since blasting can be prevented, and fracture due to surface defect can be prevented. Furthermore, the screw part of the fixture and the porous surface are firmly attached by simultaneous sintering, thereby premature peeling of the porous surface is achieved. It has the effect that it is unlikely to occur.

According to the present invention, since pores are formed by volatilization or decomposition of the pore-forming agent, there is no crack and uniform distribution of pores, and by controlling the amount of the pore-forming agent, the implant can be easily controlled. Have

Another object of the present invention, by forming a porous surface can ensure a wide contact area with the bone can be obtained the effect of ensuring excellent fixing force and stable operability.

Claims (11)

A molding step of forming a molded body by molding the ceramic powder into a predetermined form; Pre-sintering the molded body at a high temperature to form a plasticized body; Slurry generation step of producing a slurry solution by mixing distilled water, ceramic powder and pore forming agent, Depositing the plasticized body in the slurry; And finally sintering the deposited plasticized body at a high temperature to decompose or volatize the pore-forming agent in the slurry to form pores to form a ceramic implant. The method of claim 1, wherein the forming step is a ceramic implant manufacturing method, characterized in that the molding with a stabilized zirconia powder or a mixture of stabilized zirconia powder and alumina (Al ₂ O ₃ ) powder. The method of claim 1, wherein the sintering step, the ceramic implant manufacturing method, characterized in that the molded body by heat treatment for a predetermined time at a temperature of 900 ~ 1300 ℃. The method of claim 1, wherein the slurry generation step of the ceramic implant, characterized in that for adding the organic binder to improve the adhesion between the plastic body and the slurry. The method of claim 1, wherein the pore-forming agent is a ceramic implant, characterized in that the zinc oxide powder. The method of claim 5, wherein the slurry generation step is to add 2 to 20% by weight of the organic binder to the distilled water to produce a solution, and then to add a mixed zirconia powder and zinc oxide powder 1 to 29% by weight compared to the solution, respectively. Ceramic implant manufacturing method characterized in that. 5. The method of claim 4, wherein the slurry generation step further comprises mixing a dispersant to disperse the slurry. 8. The method of claim 7, wherein the dispersant is at least one selected from the group consisting of anionic surfactants such as polycarboxylate, ethyl acrylate and the like, cationic surfactants such as ammonium salts and amine salts. According to any one of claims 1 to 8, The final sintering step, characterized in that to form a porous surface by decomposing or volatizing zinc oxide by sintering the plasticized body to which the slurry is applied at 1300 ~ 1600 ℃ Ceramic implant manufacturing method. 9. The method of claim 1, wherein the porosity can be adjusted by adjusting the content ratio of the pore-forming agent. 10. In a ceramic implant having a porous surface formed on the surface of an implant-type core core formed by sintering ceramic powder, the porous surface is composed of pores formed by decomposition or volatilization of a skeleton and a pore-forming agent mainly composed of ceramic powder. , The skeleton is a ceramic implant, characterized in that to ensure a wide contact area with the alveolar bone.

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