KR20220108728A - Artificial tooth root, artificial bone and manufacturing method thereof - Google Patents

Abstract

Disclosed in the present specification is an artificial tooth root and a method of manufacturing the artificial tooth root by 3D printing. Since the artificial tooth root according to the present disclosure is made of a ceramic material, the artificial tooth root exhibits excellent biocompatibility with respect to the alveolar bone compared to a titanium material.

Description

Artificial tooth root, artificial bone and manufacturing method thereof

The present invention relates to an artificial tooth root, an artificial bone, and a method for manufacturing the same.

Ceramic material is a high value-added material that is widely used in various fields such as structure, environment and energy as well as biomedical fields such as medical implants, artificial bones, and artificial teeth. In general, ceramic powder is mixed with a liquid (polymer, etc.) to form a ceramic slurry, paste, or dough, and it is manufactured into a component material having a three-dimensional shape using various molding techniques. do.

Today, various ceramic-based 3D printing technologies that can manufacture ceramic materials are being developed. Specifically, the FDM (Fused Deposition Modeling) method in which a solid plastic material that melts in heat is pulled like a skein and melted little by little, and laser light is applied to a photocurable resin. SLA (Stereo Lithography Apparatus) method using the principle that the injected part is cured by injection Sintering) method, and DLP (Digital Light Processing) method using the principle of partially curing by irradiating light to the lower part of the storage tank in which the photocurable resin is stored.

Among them, the photocurable 3D printing method is a method of manufacturing a complex shape through a lamination technology that laminates two-dimensional surfaces by selectively irradiating UV or visible light on a composite containing a photocurable material. Compared to 3D printing technology, the technological maturity is relatively low. This is because it is difficult to prepare a high-fill photocurable ceramic slurry having a high ceramic content and flowability suitable for 3D printing in order to form a high-quality ceramic structure. There is a problem in that the flowability is lowered by increasing. In addition, in the photo-curing 3D printing method, when the content of the pigment increases when the two-dimensional surfaces are laminated, the interlayer adhesion between the layers of the sculpture may be weakened, and thus the formation of the sculpture may be difficult.

In addition, since dental implant treatment surgically implants a screw-shaped titanium fixture after drilling into the alveolar bone (gum bone), inflammation may occur in the alveolar bone, and alveolar bone necrosis may occur.

In addition, since the titanium-based alloy is used, problems with low esthetics, low biocompatibility, dissolution of titanium, and hypersensitivity to titanium occur. In order to solve this problem, in the field of titanium-based fixtures, low biocompatibility is improved and bone formation is induced by controlling the surface roughness through a process or by coating a ceramic on the surface.

Rather than the current industry approach, it is necessary to improve the screw-shaped fixture shape and the fundamental problem of titanium material. In the present specification, a thread-shaped ceramic artificial tooth root is proposed as an alternative to solve the above problem.

In addition, the technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly to those of ordinary skill in the art to which the present invention belongs from the description below. can be understood

The artificial tooth root according to an embodiment for solving the above problem may include a ceramic component and a plurality of fluid channels may be formed. The artificial tooth root is composed of an inner body and an outer body, and the fluid channel may be formed more in the outer body than the inner body. The external body is composed of a plurality of layers, and more fluid channels may be formed in the outermost external body forming the surface of the artificial tooth root than in the first external body in contact with the internal body. The ceramic component may include tetragonal zirconia, and may further include at least one of alumina, hydroxyapatite, and tricalcium phosphate. The artificial tooth root is composed of an inner body and an outer body, and the outer body may further include at least one of alumina, hydroxyapatite, and tricalcium phosphate than the inner body.

In addition, the artificial tooth root according to another embodiment may include a ceramic component, and may include at least one of alumina, hydroxyapatite, and tricalcium phosphate. The artificial tooth root is composed of an inner body and an outer body, and the outer body may further include at least one of alumina, hydroxyapatite, and tricalcium phosphate than the inner body.

Since the artificial tooth root according to the present disclosure is made of a ceramic material, it exhibits excellent biocompatibility for alveolar bone compared to a titanium material, and exhibits superior esthetics compared to a titanium material.

In addition, since the artificial tooth root according to the present disclosure can form a natural connection with the alveolar bone, there is no need to configure a thread for coupling with the alveolar bone on the surface, and the artificial tooth root is simply inserted into the alveolar bone internal cavity from which the existing root is removed. It also has the effect of minimizing surgical invasion in the sense that it only needs to be done.

In addition, the present disclosure proposes a method capable of producing an artificial tooth root exhibiting the above effects by a 3D printer.

1 to 6 are views for explaining individual embodiments of an artificial tooth root.
7 to 10 are views for explaining individual embodiments of a 3D printing method for manufacturing an artificial tooth root.

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as "comprise", "comprising" or "having" are intended to designate the presence of an embodied feature, step, component, or a combination thereof, but one or more other features or steps; It should be understood that the possibility of the presence or addition of components, or combinations thereof, is not precluded in advance.

Also in the present invention, when it is said that each layer or element is formed "on" or "over" each layer or element, it means that each layer or element is formed directly on each layer or element, or other It means that a layer or element may additionally be formed between each layer, on the object, on the substrate.

Since the invention may have various changes and may have various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the invention.

The present specification discloses a ceramic material applicable to an artificial tooth root and artificial bone, and a method for generating an artificial tooth root and artificial bone using the same. For example, an artificial tooth root for dental implant treatment may be manufactured with the teachings disclosed herein. Hereinafter, an artificial tooth root will be described as an example, but the following description may also be applied to an artificial bone.

In an embodiment, the artificial tooth root may be made of a ceramic material. In an embodiment, 3D shape data may be obtained from a patient in need of dental implant treatment from his or her actual natural root, and a ceramic artificial root for the corresponding root may be personalized using the 3D printing method.

In addition, the thread-shaped ceramic artificial tooth root may be composed of a plurality of layers. For example, it is composed of an inner body having a bending strength that can withstand external stress, and an outer body having pores and/or channels advantageous for bone formation and excellent bonding to alveolar bone in order to be joined with alveolar bone after being implanted in human alveolar bone can be Here, the pore and the channel may form a fluid channel. The inner body and the outer body may have different materials, or even if they are made of the same material, the density or mixing ratio of the materials may be different from each other. For example, the artificial tooth root may be manufactured in an inclined structure so that the inner body is denser than the outer body. Hereinafter, an artificial tooth root according to the present disclosure will be described by way of example.

Example 1

1 is a diagram illustrating a configuration of an artificial tooth root according to an embodiment. In one embodiment, the artificial tooth root may be densely composed of a single material. For example, the artificial tooth root may be made of a tetragonal zirconia (ZrO ₂ ) (3Y-ZrO ₂ ) single material. The tetragonal zirconia referred to herein and in the description below may include yttria. For example, the tetragonal zirconia may be partially stabilized ZrO ₂ (3Y-ZrO ₂ ) containing 3 mol% yttria.

Alternatively, the artificial tooth root may be composed of a tetragonal zirconia composite including at least one alumina (Al ₂ O ₃ ), hydroxyapatite (HAP), and/or tricalcium phosphate (TCP). For example, the ceramic artificial tooth root is composed of tetragonal zirconia alone or, tetragonal zirconia-alumina composite, tetragonal zirconia-TCP composite, tetragonal zirconia-HAP composite, tetragonal zirconia-alumina-TCP composite, tetragonal zirconia- It may be composed of a tetragonal zirconia composite, such as an alumina-HAP composite, a tetragonal zirconia-TCP-HAP, and/or a tetragonal zirconia-alumina-TCP-HAP composite.

Zirconia and alumina have excellent mechanical properties, no foreign body reaction or less when implanted in the body, and have excellent mechanical properties compared to bioactive ceramic materials. The tetragonal zirconia-alumina composite has superior fracture toughness and low specific gravity compared to tetragonal zirconia. TCP and HA are bioactive bioceramics, and through complexation with bioinert bioceramics, ZrO ₂ , Al ₂ O ₃ , after the artificial tooth root is implanted in the alveolar bone, the artificial tooth root contacts the alveolar bone to form a strong bond.

When the artificial root is made of a single material, the minimum relative density of the material constituting the artificial root may be limited to be 97%. Alternatively, the relative density of the material may be limited so that the bending strength of the artificial tooth root has a value between 200 MPa and 1200 MPa.

Here, the relative density of 97% or more may mean the relative density of the constituent materials (even if various materials are configured). Here, the relative density 　 97% means that the measured density is 3% lower than the theoretical density. In ceramics, a high relative density is advantageous to resist external stress because mechanical properties are lowered when the density is low. Here, the relative density can be calculated by dividing the measured density of the material by the theoretical density of the material. Here, the theoretical density is the theoretical density of the material (the intrinsic property of the material). Here, the density measurement target may be an apparent density or a bulk density.

Meanwhile, the artificial tooth root may be manufactured to have a porous structure or a channel structure. The porous structure and/or channel structure of the artificial tooth root surface is filled with an osteogenic material flowing in from the alveolar bone, so that the porous structure and/or the channel structure helps the biocompatibility of the artificial root to the alveolar bone and bone formation therebetween. will give

To this end, for example, a porous structure may be formed on the surface of the artificial tooth root for bone formation and bonding in the portion in contact with the alveolar bone. The porous structure of the surface may play the role of pores. And by continuously forming these pores inward from the surface of the artificial tooth root, it is possible to form a predetermined channel structure. For example, the porous structure may form a predetermined channel structure so that the bone-forming material can be introduced into the artificial tooth root. For example, a channel structure such as a scaffold structure or a gyrod structure may be formed in the artificial tooth root. This application can be implemented by performing 3D modeling of the artificial tooth root 3D model as a scaffold structure or a gyrod structure. In the case of a single material and a single structure, in order to implement pores/channels in the artificial tooth root, a porous structure may be formed to the same extent on the entire artificial tooth root, not just the surface.

Example 2

2 is a diagram illustrating a configuration of an artificial tooth root according to another exemplary embodiment. The artificial tooth root may be composed of a plurality of layers. For example, it is composed of an inner body having a bending strength that can withstand external stress, and an outer body having pores and/or channels advantageous for bone formation and excellent bonding to alveolar bone in order to be joined with alveolar bone after being implanted in human alveolar bone can be

For example, pores or channels may not be formed in the inner body, but pores or channels may be formed in the outer body. To this end, even if the outer body is composed of the same material, the density or mixing ratio of the material may be different from each other. For example, the artificial tooth root may be manufactured in an inclined structure so that the inner body is denser than the outer body. For example, the minimum relative density of the inner body may be constrained to be 97%. Alternatively, the relative density of the material may be limited so that the bending strength of the inner body has a value between 200 MPa and 1200 MPa. The relative density of the outer body may have a lower value than that of the inner body. Alternatively, the bending strength of the outer body may be lower than that of the inner body. For example, the inner body may have a porosity of 0.1% or less in order to exhibit high strength using the material in Example 1. In addition, the first outer body in contact with the inner body may use the same material as the inner body, but the porosity may be 5%. And the second outer body in contact with the first outer body may use the same material as the inner body, but the porosity may be 10%. In this way, the porosity of the outer body can be gradually increased by 5% as it goes from the inside to the outside surface. In one embodiment, the porosity of the outermost body in contact with the surface may be limited to 30%. Here, the gradual increase rate of 5% is only an example, and the gradual increase rate may be selected and used as a predetermined percentage.

The area of the internal body can occupy at least 50% (e.g. when the external body has a high specific gravity) and up to 100% (e.g. when the external body does not exist) based on the cross section of the artificial tooth root. If the area of the inner body is less than 50% of the cross-section of the artificial root, cracks may occur due to the stress generated during mastication. When the area of the inner body is 50% based on the cross section of the artificial tooth root, the porous structure of the outer body can be applied up to 50% based on the cross section of the artificial tooth root.

Example 3

3 is a view showing an artificial tooth root according to another embodiment. The artificial tooth root according to an embodiment is composed of a plurality of layers of an inner body and an outer body, and may be composed of a slanted functional material rather than a porous structure in order to secure biocompatibility.

For example, the inner body may be composed of tetragonal zirconia and/or a zirconia composite (e.g. a composite containing the aforementioned alumina, HAP, TCP, etc.). However, the outer body may be composed of a zirconia composite containing HAP or TCP.

In addition, the inner body may limit the content of HAP or TCP to a predetermined content in order to achieve bending strength. And, the external body may be limited to a predetermined content or more for alveolar bone bonding.

In one embodiment, the internal body may be limited so that the content of HAP is 10 wt% or less (or less). And the external body may be limited so that the content of HAP is more than (or more than) 10wt%. Furthermore, the artificial tooth root can be manufactured so that the HAP content of the outer portion of the outer body constituting the surface of the artificial tooth root is higher than the HAP content of the inner portion of the outer body facing the inner body to implement a predetermined inclination function. . 4, the inner body is formed of Z (401) material, the first outer body in contact with the inner body is formed of ZA1 (402) material, and the second outer body in contact with the first outer body is ZA2 (403) material, the third outer body forming a surface material in contact with the second outer body may be formed of ZA3 (404) material.

When TCP is used as the inclined material, in the same way, the inner body is formed of ZH1 (405) material, the first outer body in contact with the inner body is formed of ZH2 (406) material, and the first outer body in contact with the first outer body is formed of ZH2 (406) material. The second outer body may be formed of a ZH3 (407) material, and the third outer body in contact with the second outer body and forming a surface material may be formed of a ZH4 (408) material.

Meanwhile, as shown in FIG. 4 , the maximum content of HAP and/or TCP may be limited not to exceed 40 wt% in order to limit the appropriate bending strength to 224 MPa or more. For example, the maximum content of HAP and/or TCP of the exogenous body in the surface portion may be limited not to exceed 40 wt%. Alternatively, the maximum content of HAP and/or TCP may be limited to a content for limiting an appropriate bending strength (e.g. bending strength) to 200 MPa or more. In one embodiment, the maximum content of HAP and/or TCP may be limited not to exceed 40 wt% in order to limit the appropriate bending strength to 200 MPa or more. In another embodiment, the maximum content of HAP and/or TCP may be limited in order to limit the proper bending strength to 300 MPa or more. In another embodiment, the maximum content of HAP and/or TCP may be limited not to exceed 30 wt% in order to limit the appropriate bending strength to 400 MPa or more.

In addition, when alumina is used, the content of alumina in the inner body may be at least 0 wt %, and in this case, the inner body may be composed of only tetragonal zirconia. And the maximum alumina content of the outer body may be 50wt%. In addition, the alumina content between the outer layers may be formed in a inclined structure to have the highest content with respect to the layer of the outer body (e.g. the outermost body) close to the surface.

When the warp material is used together with alumina, the content of the alumina and the warp material may be applied according to the above description. For example, in the case of a tetragonal zirconia-alumina-HAP composite, alumina may be used in an amount of 0 to 50 wt%, and HAP may be used in an amount of 0 to 30 wt%. For example, the inner body may be composed of 100 wt% of tetragonal zirconia, 0 wt% of alumina, and 0 wt% of HAP. In addition, the first external body may be composed of 80 wt% of tetragonal zirconia, 10 wt% of alumina, and 10 wt% of HAP. In addition, the outermost body may be composed of 20 wt% of tetragonal zirconia, 50 wt% of alumina, and 30 wt% of HAP.

As another example, in the case of the tetragonal zirconia-alumina-TCP composite, alumina may be used in an amount of 0 to 50 wt%, and TCP may be used in an amount of 0 to 30 wt%. For example, the inner body may be composed of 100 wt% of tetragonal zirconia, 0 wt% of alumina, and 0 wt% of TCP. In addition, the first external body may be composed of 80 wt% of tetragonal zirconia, 10 wt% of alumina, and 10 wt% of TCP. And, the outermost body may be composed of 20 wt% of tetragonal zirconia, 50 wt% of alumina, and 30 wt% of TCP.

Example 4

5 is a view showing an artificial tooth root according to another embodiment. The artificial tooth root according to an embodiment is composed of a plurality of layers of an inner body and an outer body, and the outer body may be made of a slanted functional material having a porous structure to ensure biocompatibility.

For example, as in Example 3 above, the inner body may be composed of tetragonal zirconia and/or a zirconia composite (e.g. a composite containing the aforementioned alumina, HAP, TCP, etc.). However, the outer body may be composed of a zirconia composite containing HAP or TCP. In addition, the artificial tooth root according to the present embodiment may be manufactured by including the porous structure in the external body as in the second embodiment.

An example of this is shown in FIG. 6 . The inclined structure of the artificial tooth root according to the material composition is shown in Fig. 6 (a), which shows an example of the artificial tooth root according to the third embodiment. And, the inclined structure of the artificial tooth root according to the porosity is shown in Fig. 6 (b), which shows an example of the artificial tooth root according to the second embodiment. On the other hand, the artificial tooth root showing both the characteristics of FIGS. 6 (a) and 6 (b) may be an artificial tooth root model in which HAP is adopted as an inclined structure and porosity is applied as an inclined structure as an example of Example 4 .

Manufacturing method

As previously disclosed, the artificial tooth root according to the present disclosure has a predetermined internal structure within the tooth root. In this regard, it is difficult to manufacture a real artificial tooth root made of ceramic material by using a conventional mold or cutting method.

Therefore, ceramic 3D printing technology can be applied to fabricate a personalized, thread-shaped artificial root. To this end, the shape and structure of the artificial tooth root surface can be controlled through 3D modeling.

In an embodiment, an artificial tooth root identical to the shape of a real human tooth root may be manufactured by the 3D printing method. The basic concept for 3D printing on a ceramic slurry material is shown in FIGS. 7 to 9 . 7 discloses a principle of crosslinking between a monomer and an oligomer by a photoinitiator. 8 shows a conceptual diagram of an operation of a 3D printer performing ceramic 3D printing using this concept.

The 3D printer of FIG. 8 may include a stage 810 , a water tank 820 , and a light irradiation unit 830 . A ceramic slurry may be accommodated in the water tank 820 . The stage 810 descends so that the space between the bottom of the water tank 820 and the lower surface of the stage 810 forms a predetermined space (e.g. a space for forming one ceramic slide that is one unit of 3D printing), The ceramic slurry remaining in the space of is cured by the curing light irradiated to the water tank 820 through the light source 831 and the reflector 832 . As a result, one unit of ceramic slide is formed, and 3D printing can be performed by repeating this process a number of times. 8 shows a bottom-up 3D print in which a 3D print is laminated downward on the lower surface of the stage, but as shown in FIG. ) 3D printing may be applied. When the bottom-up 3D printing is applied, there is an advantage that an external body can be additionally added to the pre-formed artificial tooth root, as shown in FIG. 10 . 10 shows an example in which the outer body 1320 is stacked on the outside of the inner body 1310 in a bottom-up manner. As shown in FIG. 10 , a pre-generated inner body 1310 may be positioned above the stage 1110 . As the stage 1110 descends to the lower surface of the water tank, it can be immersed in the slurry 1210 in the water tank from the lower surface of the inner body 1310 . By irradiating hardening light to the slurry surface 1322 corresponding to the outer body 1320 while being submerged from the lower surface of the inner body 1310, one ceramic slide, which is one unit of printing on the outer body 1320, is generated. can As the descent of the stage 1110 and curing of the slurry surface 1322 corresponding to the outer body 1320 are repeated, the outer body 1320 in contact with the inner body 1310 may be generated by the 3D printing method.

Meanwhile, the "slurry" described above generally refers to a liquid state with low fluidity containing a high concentration of suspended material, and should be understood as meaning including a paste and a dough state.

First, the ceramic slurry composition according to an embodiment of the present invention may include at least one of a ceramic powder, a photocurable binder, a dispersant, and a photocurable initiator.

Ceramic powder is a main material when manufacturing a structure using 3D printing, and the ceramic according to an embodiment of the present invention is a tetragonal zirconia and/or alumina (Al ₂ O) as described in Examples 1 to 4 above. ₃ ), hydroxyapatite (HAP) and / or tricalcium phosphate (TCP) may be a tetragonal zirconia composite including at least one. Meanwhile, in the present invention, the ceramic powder may be included in an amount of 60 to 90 wt% based on the total weight of the slurry composition.

In addition, the ceramic powder stabilized with 2 to 8 mol% of yttria (Y) based on the total composition of the ceramic powder, specifically, those stabilized with 3 to 5 mol% of yttria (Y) may be used. When the ceramic powder is stabilized with the yttria in the mol% range, the zirconia powder and the like can be prepared in the form of granules, and in the case of such granules, a relatively large amount of the ceramic component is contained in the slurry composition compared to the powder. Therefore, it is possible to increase the density during lamination. However, as the amount of yttria (Y) used for stabilization increases, there may be a problem that the flexural strength of the finally manufactured output decreases, so it is preferable to stabilize it within the mol% range.

The photocurable binder serves to form an adhesive force between the ceramic powders to help form a compact and a structure, and may be a mixture of a photocurable monomer and a photocurable oligomer.

Specifically, when only a low-shrinkage monomer is included as a photocurable binder, the film adhesion is strong, but the metal adhesion is weak. In the process, there may be a problem that the cured layer film remains, and problems occur during the manufacturing process of the molded body and structure, such as a problem in the post-processing after molding due to weak brittleness. There may be a problem in that it is difficult to increase the packing density because it is difficult to contain the ceramic powder in a high content due to the viscosity of

Accordingly, the photocurable binder according to an embodiment of the present invention has a ratio of 8 to 25 parts by weight of the photocurable monomer to 2 to 15 parts by weight of the photocurable oligomer, specifically 10 to 16 parts by weight of the photocurable monomer to 3 to 3 parts by weight of the photocurable oligomer. It may be a mixture mixed in a ratio of 9 parts by weight, and if it has a composition mixed in a ratio by weight as described above, it has an appropriate level of bonding between monomers and oligomers, and after the creation of a cured layer in the 3D printing process of the SLA/DLP method It is possible to prevent the problem that the cured layer remains on the film even when the platform is raised, and at the same time, it is possible to secure a high level of packing density.

In addition, in the present invention, the photocurable binder may include two or less functional groups. Specifically, in the monomers and oligomers constituting the photocurable binder, when there is one functional group, a linear bond is generally formed between adjacent monomers and oligomers, and when there are two functional groups, a branched bond is generally formed. do. On the other hand, when there are 3 to 4 functional groups, a cross-linked bond is formed, and when there are 5 or more functional groups, a network bond is formed.

For example, in the slurry composition of the present invention, when the functional groups of the monomers and oligomers constituting the photocurable binder are three or more, the bonding density between the monomers and the oligomers is significantly increased due to the formation of crosslinks or network bonds, especially UV irradiation When it is cured and solidified, there is a problem in that the adhesion between the layers is reduced due to shrinkage.

Accordingly, the photocurable binder used in the present invention may include at least one of a photocurable monomer and a photocurable oligomer. In this case, at least one of the photocurable monomer and the photocurable oligomer may include two or less functional groups. For example, the photocurable binder according to an embodiment comprises a bifunctional monomer and a bifunctional oligomer, or comprises a monofunctional monomer and a bifunctional oligomer, or a bifunctional monomer and a monofunctional oligomer. It may be configured to include, or may be configured to include, a monofunctional monomer and a monofunctional oligomer. Accordingly, by minimizing the photocuring shrinkage during UV irradiation, excellent flexural strength is expressed in the final output, the interlayer adhesion is improved, and structural stability of the finally produced output can be secured.

In more detail, the photocurable monomer may be at least one selected from a monofunctional monomer and a bifunctional monomer.

For example, in the case of a monofunctional monomer, stearyl acrylate (Stearyl Acrylate), tetrahydrofufuryl acrylate (Tetrahydrofufuryl Acrylate), lauryl acrylate (Lauryl Acrylate), ethoxylate (n) nonyl phenol acrylate (Ethoxylate ( n) Nonyl Phenol Acrylate), Isodecyl Acrylate, Cycloaliphatic Acrylate, Methoxy polyethylene glycol monoacrylate, Alkoxylated phenol Acrylate ), Triethylene glycol ethyl ether Methacrylate, Carprolactone Acrylate, Polypropylene glycol Monomethacrylate, Cyclic trimethylolpropane foam acrylate trimethylolpropane formal Acrylate, Phenoxy benzyl Acrylate, 3,3,5-trimethylcyclohexyl Acrylate, Isobornyl Acrylate, Isobornyl Isobornyl Metacrylate, 4-tert-butylcyclohexyl acrylate, Benzyl Acrylate, Biphenylmethyl Acrylate, Phenol (EO)n Acrylic Phenol (EO)n Acrylate, Phenoxyethyl Methacrylate and N,N-Dimethyl It may be at least one selected from the group consisting of acrylamide (N,N-dimethyl acrylamide).

As another example, in the case of a bifunctional monomer, 1,6-hexanediol diacrylate (1,6-Hexanediol diacrylate), 1,6-hexanediol dimethacrylate (1,6-Hexanediol dimethacrylate), 1,6 -Hexanediol (EO)n diacrylate (1,6-Hexanediol (EO)n Diacrylate), alkoxylated hexanediol diacrylate, 1,4-butanediol dimethacrylate (1, 4-Butanediol Dimethacrylate), Bisphenol A (EO)n Diacrylate, Cyclohexane dimethanol diacrylate, Ethoxylated bisphenol A dimethacrylate A dimethacrylated), diethylene glycol diacrylate, tripropyleneglycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate , propoxylate (2) neopentyl glycol diacrylate (Propoxylated (2) neopentyl glycol diacrylate), tricyclodecane dimethanol diacrylate, 1,3 butylene glycol dimethacrylate (1, 3 Butylene glycol dimethacrylate), Hydroxy pivalic acid neopentyl glycol Diacrylate, Neopentylglycol (PO)n Diacrylate, Ethylene glycol dimethacrylic rate (E It may be at least one selected from the group consisting of thylene glycol dimethacrylate, triethylene glycol diacrylate, and triethylene glycol dimethacrylate.

The photocurable oligomer may include an oligomer having two or less functional groups. For example, a urethane oligomer (e.g. urethane acrylate), an oligomer containing a phosphoric acid group (e.g. phosphoric acid-modified acrylate), an oligomer containing a carboxylic acid group (e.g. a carboxylic acid-modified acrylate), and an epoxy oligomer (e.g. epoxy acrylic) rate) at least one oligomer selected from the group consisting of; The oligomer as described above makes it possible to secure high adhesion to a platform (printing bed) used as a metal (metal) material in 3D printing in which the SLA/DLP method is mixed. On the other hand, when only the urethane oligomer is used as the photocurable oligomer, the adhesiveness to the metal is poor, and a problem in that the cured layer and the film remain in the process of separating the cured layer and the film may occur. Accordingly, when using a urethane oligomer, the binder may further include an oligomer or an epoxy oligomer including an acidic group having high metal adhesion. Here, the oligomer including an acidic group may be an oligomer including a phosphoric acid group (e.g. phosphoric acid-modified acrylate) or an oligomer including a carboxylic acid group (e.g. carboxylic acid-modified acrylate).

Meanwhile, in one embodiment of the present invention, the photocurable binder including the photocurable monomer and the photocurable oligomer may be 10 to 40 wt% based on the total weight of the composition.

The dispersing agent serves to prevent dispersion and re-agglomeration of the ceramic powder (filler) so that the ceramic powder can be sufficiently included in the product. It may include at least one selected from the group consisting of a copolymer compound and a polyester/polyether-based compound having a phosphoric acid group and an amine group. Meanwhile, in one embodiment of the present invention, the dispersant used may be 1 to 5 wt% based on the total weight of the composition.

The photoinitiator absorbs light when irradiated with ultraviolet light or LED and emits light in the form of a radical to enable bonding between the monomer and the oligomer, thereby making it a solid polymer. , a photoinitiator having a wavelength range of 370 to 420 nm may be used.

On the other hand, in the present invention, when the slurry composition is for laminating a thin film with a thickness of 15 μm or less per layer (e.g. 10 to 15 μm), the photocuring initiator has a wavelength of less than 360 nm, for example, 250 to It may include at least one selected from a short-wavelength initiator having a wavelength of 360 nm, a medium-wavelength initiator, or a mixture thereof.

The short-wavelength initiator or the medium-wavelength initiator according to an embodiment of the present invention is 1-hydroxycyclohexyl phenyl ketone, benzophenone, 4-methylbenzophenone, 4- Benzoyl-4'-methyldiphenylsulfide (4-Benzoyl-4'-Methyldiphenylsulfide), methyl phenylglyoxylate (Methyl phenylglyoxylate), methyl-o-benzoylbenzoate (Methyl o-benzoylbenzoate), benzyl dimethyl ketal (Benzil dimethyl) ketal), 4-phenylbenzophenone, 2-ethylhexyl-4-dimethylaminobenzoate, ethyl-4-dimethylaminobenzoate , Hydroxy-2-methylphenyl-propane-1-one, 2-benzyl-2- (dimethylamino) -1- [4- (morpholinyl) phenyl] -1-butanone (2-Benzyl-2-(dimethylamino)-1-[4-(morpholinyl)phenyl]-1-butanone), 2-dimethylamino-2-(4-methyl-benzyl)-1-( 4-morpholin-4-yl-phenyl)butan-1-one (2-Dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)butan-1-one) , oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone](Oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl) ] propanone]), 2-hydroxy-2-methyl-1-phenyl propan-1-one (2-hydroxy-2-methyl-1-phenyl propan-1-one) can be at least one selected from the group consisting of have.

On the other hand, in the present invention, when the slurry composition is for laminating a thin film (thick film) having a thickness of more than 15 µm per layer (e.g. 20 µm), the photocuring initiator is 360 nm or more, specifically 360 to It may include a long-wavelength initiator having a wavelength of 450 nm.

Long wavelength initiator according to an embodiment of the present invention is isopropylthioxanthone (Isopropylthioxanthone), 4,4'-bis (diethylamino) benzophenone (4,4'-Bis (diethylamino) benzophenone), 2,4- Diethyl thioxanthone (2,4-diethylthioxanthone), 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide (2,4,6-Trimethylbenzoyl-diphenyl phosphine oxide), phosphine oxide (Phosphine oxide), bis (2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide), bis-(etha 5-2,4,-cyclopentadien-1-yl) -Bis[2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl]titanium ((Bis-(eta 5-2,4-cyclopentadien-1-yl)-Bis[2,6 -difluoro-3-(1H-pyrrol-1-yl)-phenyl]titanium) may be at least one selected from the group consisting of.

On the other hand, when the type of initiator is varied according to the thickness of the thin film (or thick film) as described above, the curing speed and curing ability control according to the thickness are optimized, so that excellent interlayer adhesion can be secured. The photocuring initiator according to an embodiment of the present invention may be 0.01 to 1 wt% based on the total weight of the composition.

As described above, the ceramic slurry composition according to the present invention increases the ceramic filling density in 3D printing, particularly in 3D printing using a SLA/DLP method, and minimizes photocuring shrinkage, thereby providing excellent flexural strength (flexural strength) in the range of 200 to 1,000 MPa. strength), improve interlayer adhesion, and secure structural stability.

In particular, the ceramic slurry composition according to the present invention uses a photocurable monomer and an oligomer containing two or less functional groups, and optimizes the composition and type to use it as a photocurable binder, particularly SLA/DLP method In this mixed 3D printed output, it is easy to develop proper flowability, high interlayer adhesion, high flexural strength of 500 MPa or more, and excellent structural stability.

Hereinafter, the operation and effect of the invention will be described in more detail through specific examples of the invention. However, this is presented as an example of the invention and the scope of the invention is not limited in any sense by this.

Preparation Examples 1 to 19

Ceramic slurry compositions were prepared with the components and composition ratios shown in Tables 1 to 4 below as follows. Specifically, after mixing the photoinitiator with the monomer, the photoinitiator was completely dissolved by stirring at 300 rpm or more in a stirrer for 2 hours, and a binder (oligomer and/or dispersing agent) was mixed thereto, followed by stirring at 200 rpm or more for 30 minutes. Finally, the ceramic powder was mixed therein, and the ceramic slurry composition was completed by stirring at 1,500 rpm for 10 minutes using a paste mixer.

On the other hand, the ceramic slurry composition was manufactured as a 3D structure by stacking the ceramic slurry composition using a 3D printing method in which the SLA/DLP method was mixed. On the other hand, the SLA / DLP method, as disclosed in Figure 8, a printing bed; a water tank unit including at least one water tank located at the lower end of the printing bed; a water tank moving means for moving the water tank; a light irradiation unit located at the bottom of the water tank; and a control unit for controlling the water tank moving means to move the water tank may be subjected to the following process using a 3D printer (see FIG. 8 ).

STEP 1: Form a shallow slurry layer on the film in the water bath. At this time, the distance between the platform (printing bed) and the water bath is sufficiently spaced to create a slurry layer. STEP 2: The platform is lowered to cure one laminate to make the gap between the platform and the film about 1 mm, and the slurry in STEP 1 is positioned between the platform and the film. STEP 3: A cured layer is formed by curing the slurry by irradiating UV penetrating the film from the bottom of the film. STEP 4: After forming one cured layer, lift the platform upward to separate the cured layer from the film. STEP 5: Repeat steps 1 to 4 above.

Preparation Example 1 Production Example 2 Production Example 3 Preparation 4 Production Example 5 Preparation 6 Preparation 7 3 mol% yttria stabilized zirconia 85 75 60 50 50 8 mol% yttria stabilized zirconia 75 alumina 75 25 silica 25 Long wavelength initiator: omnirad 819 (Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide) 0.2 0.3 0.5 0.3 0.3 0.3 0.3 THFA (Tetrahydrofufuryl Acrylate monofunctional monomer) 8.8 14.8 23.6 14.8 14.8 14.8 14.8 Urethane acrylate 3.5 5.8 9.3 5.8 5.8 5.8 5.8 Phosphoric acid modified acrylate 1.5 2.5 4 2.5 2.5 2.5 2.5 dispersant 1.0 1.6 2.6 1.6 1.6 1.6 1.6 Flexural strength (MPa) 780 510 230 170 340 390 240

The results in Table 1 are examples prepared by changing the type of ceramic or the content of the ceramic, and it was confirmed that the flexural strength of 200 MPa or more was secured in all of the other preparations except Preparation Example 4.

Production Example 2 Preparation 8 Preparation 9 Production Example 10 Production Example 11 3 mol% yttria stabilized zirconia 75 75 75 75 75 Long wavelength initiator: omnirad 819 0.3 0.02 1.0 1.5 Short wavelength initiator: omnirad 184 (1-hydroxycyclohexyl phenyl ketone) 0.3 1.5 THFA 14.8 15.08 14.1 14.8 14.8 Urethane acrylate 5.8 5.8 5.8 5.8 5.8 Phosphoric acid modified acrylate 2.5 2.5 2.5 2.5 2.5 dispersant 1.6 1.6 1.6 1.6 1.6 Curing degree at 10㎛ lamination OK OK OK OK OK Hardening at 50㎛ lamination OK OK OK uncured OK Flexural strength (MPa) 510 220 360 270 350

The results in Table 2 are examples prepared by changing the type of photoinitiator or the content of the photoinitiator. In all of the preparation examples except Preparation Example 10, sufficient curing degree is secured regardless of the layer thickness, and 200 MPa It was confirmed that the above flexural strength was secured.

Production Example 2 Preparation 12 Production Example 13 Preparation 14 3 mol% yttria stabilized zirconia 75 75 75 75 omnirad 819 0.3 0.3 0.3 0.3 THFA (Tetrahydrofufuryl Acrylate monofunctional monomer) 14.8 HDDA (1,6 Hexanediol diacrylate bifunctional monomer) 14.8 TMPTA (Tetrahydrofufuryl Acrylate trifunctional monomer) 14.8 DPHA (Tetrahydrofufuryl Acrylate hexafunctional monomer) 14.8 Urethane acrylate 5.8 5.8 5.8 5.8 Phosphoric acid modified acrylate 2.5 2.5 2.5 2.5 dispersant 1.6 1.6 1.6 1.6 Flexural strength (MPa) 510 320 110 60

The results in Table 3 are examples prepared by mixing materials having different monomer functional groups, and it was confirmed that all of the preparation examples except Preparation Examples 13 and 14 secured flexural strength of 200 MPa or more.

Production Example 2 Production Example 15 Preparation 16 Preparation 17 Preparation 19 3 mol% yttria stabilized zirconia 75 75 75 75 75 omnirad 819 0.3 0.3 0.3 0.3 0.3 THFA 14.8 14.8 14.8 14.8 14.8 Urethane acrylate 5.8 5.8 5.8 3.3 8.3 Phosphoric acid modified acrylate 2.5 Carboxylic acid modified acrylates 2.5 2.5 Epoxy Acrylate 2.5 2.5 dispersant 1.6 1.6 1.6 1.6 1.6 platform adhesion OK OK OK OK NG Flexural strength (MPa) 510 540 500 570 -

In Examples 1 to 19 described above, the flexural strength is the flexural strength measured after the manufactured product is separated from the platform, washed and sintered. Washing was performed in a manual and semi-automatic manner using alcohol, and degreasing was performed at a temperature of 500° C. for 2 hours, and then sintered at a temperature of 1500° C. for 2 hours for densification. The results in Table 4 are preparation examples according to whether or not a special oligomer is used, and it was confirmed that, in all preparations except Preparation Example 19, sufficient platform adhesion was ensured and flexural strength of 200 MPa or more was ensured. In particular, in the case of Preparation Example 19, it was confirmed that the result of the lamination was not attached to the platform because normal output was not performed, and only a portion was attached to the film of the water tank, which corresponds to a defect.

Preparation 20 Preparation 21 Preparation 22 Preparation 23 Production Example 24 Production Example 25 Preparation 26 3 mol% yttria
Stabilized Zirconia 80 80 80 80 80 80 80 omnirad 819 0.25 0.25 0.25 0.25 0.25 0.25 0.25 THFA 12.75 12.75 12.75 12.75 12.75 12.75 12.75 Urethane acrylate 3.7 3.7 3.2 3.2 2.7 2.2 Phosphoric acid modified acrylate 1.5 2.0 2.6 Carboxylic acid modified acrylates 1.5 2.0 2.6 Epoxy Acrylate 2.5 3.0 dispersant 1.8 1.8 1.8 1.8 1.8 1.8 1.8 platform adhesion NG NG OK OK NG OK OK Flexural strength (MPa) - - 610 600 580 650

The results in Table 5 are preparation examples according to the amount of special oligomer used, and as in Preparation Examples 22, 23, 25 and 26, the oligomer containing an acidic group is 8.5% or more of the liquid binder (corresponding to the photocurable binder described above), preferably Preferably, it was confirmed that, when the content was 10% or more, more preferably 11.14% or more, sufficient platform adhesion was ensured, and at the same time, flexural strength of 200 MPa or more was secured. And, when the oligomer containing an epoxy group is included in 14% or more, preferably 15% or more, and more preferably 16.7% or more of the liquid binder, sufficient platform adhesion is ensured, and at the same time, flexural strength of 200 MPa or more is secured. For example, in the example of Table 5, in Preparation Example 20, in which 8.4% of phosphate-modified acrylate in the liquid binder was included, platform adhesion was insufficient, but in the liquid binder, 11.14% of phosphate-modified acrylate was included. In Example 22, it can be seen that the platform adhesion is excellent. In Preparation Example 24 containing 13.9% of the epoxy acrylate in the liquid binder, the platform adhesion was insufficient, but in Preparation Example 25 containing 16.7% of the epoxy acrylate in the liquid binder, it was confirmed that the platform adhesion was excellent. The mixing ratio of the special oligomer in the liquid binder may be calculated by the following equation.

[Equation 1]

Mixing ratio of special oligomer in liquid binder = content of special oligomer / content of liquid binder

The liquid binder content in Equation 1 may be calculated as the total amount of binders used to prepare the liquid slurry as shown in the following Equation.

[Equation 2]

Liquid binder content = monomer content + oligomer content

In the example of Table 5, the monomer in Equation 2 may be THFA. And the oligomer may be urethane acrylate, phosphoric acid-modified acrylate, carboxylic acid-modified acrylate, and epoxy acrylate. Accordingly, Equation 2 can be used as follows.

[Equation 3]

Liquid binder content = THFA content + urethane acrylate content + phosphate-modified acrylate content + carboxylic acid-modified acrylate content + epoxy acrylate content

The content of the special oligomer in Equation 1 may be determined by the content of the oligomer containing an acid group and the oligomer containing the epoxy. For example, in the case of the example of Table 5, the special oligomer content can be calculated as shown in the following equation.

[Equation 4]

Special oligomer content = phosphoric acid-modified acrylate content + carboxylic acid-modified acrylate content + epoxy acrylate content

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

Claims (7)

contains a ceramic component,
Artificial root with multiple fluid channels. The method of claim 1,
The artificial tooth root is composed of an inner body and an outer body,
The fluid channel is an artificial tooth root formed more in the external body than the internal body. 3. The method of claim 2,
The outer body is composed of a plurality of layers,
An artificial tooth root in which more fluid channels are formed in the outermost external body forming the surface of the artificial tooth root than the first external body in contact with the internal body. The method of claim 1,
The ceramic component includes tetragonal zirconia,
An artificial tooth root further comprising at least one of alumina, hydroxyapatite and tricalcium phosphate. The method of claim 1,
The artificial tooth root is composed of an inner body and an outer body,
The external body is an artificial tooth root further comprising at least one of alumina, hydroxyapatite, and tricalcium phosphate than the internal body. contains a ceramic component,
An artificial tooth root comprising at least one of alumina, hydroxyapatite and tricalcium phosphate. 7. The method of claim 6,
The artificial tooth root is composed of an inner body and an outer body,
The external body is an artificial tooth root further comprising at least one of alumina, hydroxyapatite, and tricalcium phosphate than the internal body.

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