CN116867461A

CN116867461A - Artificial tooth root, artificial bone and manufacturing method thereof

Info

Publication number: CN116867461A
Application number: CN202280011335.6A
Authority: CN
Inventors: 金钟国; 金垞润; 苏成珉
Original assignee: Aion Co Ltd
Current assignee: Aion Co Ltd
Priority date: 2021-01-26
Filing date: 2022-01-24
Publication date: 2023-10-10

Abstract

The present specification discloses an artificial tooth root and a method of manufacturing an artificial tooth root using 3D printing.

Description

Artificial tooth root, artificial bone and manufacturing method thereof

Technical Field

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

Background

Ceramic materials are high-added-value materials and are widely used in biomedical fields such as medical implants, artificial bones, artificial teeth and other various fields such as structures, environments and energy sources. In general, ceramic powders are mixed with a liquid (e.g., a polymer) to form a ceramic slurry (slurry), paste (paste), or dough (dough) form, and then fabricated into a component material having a three-dimensional shape using various molding techniques.

Today, various ceramic-based 3D printing techniques have been developed to produce ceramic materials, in particular, as in FDM (Fused Deposition Modeling), by drawing a heated melted solid plastic material into filaments and slightly melting and accumulating; SLA (Stereo Lithography Apparatus) irradiating a photocurable resin with a laser beam to cure the irradiated portion; SLS (Selective Laser Sintering), in the SLA system, a functional polymer or metal powder is used instead of a photocurable resin, and laser sintering is performed; DLP (Digital Light Processing) irradiating the bottom of a reservoir storing a photocurable resin with light to partially cure it, and the like.

Among them, the photo-curing 3D printing method is a method of manufacturing a complex shape using a lamination technique of selectively irradiating Ultraviolet (UV) or visible light region light to a composite material containing a photo-curing material to laminate two-dimensional surfaces, and has a low maturity compared to other 3D printing techniques. Since it is difficult to manufacture a high-quality ceramic structure with a high ceramic content and a high-filling photo-setting ceramic paste having fluidity (flowability) suitable for 3D printing, there is a problem in that, in particular, the paste viscosity increases rapidly with an increase in ceramic content, resulting in a decrease in fluidity. In addition, in the photocuring 3D printing method, when two-dimensional surfaces are laminated, an increase in pigment content weakens interlayer adhesion between layers of the mold, making the mold difficult to form.

In addition, since the dental implant treatment requires drilling holes in the alveolar bone (gum) and surgical placement of a titanium material fixture like a screw, the alveolar bone may become inflamed and may cause necrosis of the alveolar bone.

In addition, the use of titanium alloys causes problems such as poor aesthetic appearance, poor biocompatibility, elution of titanium, and allergy to titanium. To solve the problems, in the field of titanium-based fasteners, surface roughness is controlled by a process, or by coating a ceramic on the surface to improve low biocompatibility and promote osteogenesis.

Disclosure of Invention

Problems to be solved by the application

There is a further need to improve the screw shape retention pin form and the underlying problems in titanium materials over current industry efforts. In the present specification, in order to solve the above-mentioned problems, a full-size ceramic artificial tooth root is provided as a solution.

The technical problems to be solved by the present application are not limited to the above technical problems, and other technical problems not mentioned will become apparent to those skilled in the art from the following.

Means for solving the problems

To solve the problem, an artificial tooth root according to an embodiment includes a ceramic composition and is formed with a plurality of fluid passages. The artificial tooth root consists of an inner body and an outer body; the liquid passage is formed more in the outer body than in the inner body. The outer body is composed of a plurality of layers; more fluid passages are formed in the outermost outer body forming the surface of the artificial root than in the first outer body in contact with the inner body. The ceramic component comprises tetragonal zirconia; and at least one of alumina, hydroxyapatite and tricalcium phosphate. The artificial tooth root consists of an inner body and an outer body; the outer body further includes at least one of alumina, hydroxyapatite, and tricalcium phosphate as compared to the inner body.

In addition, an artificial tooth root according to another embodiment includes a ceramic composition; comprises at least one of alumina, hydroxyapatite and tricalcium phosphate. The artificial tooth root consists of an inner body and an outer body; the outer body further includes at least one of alumina, hydroxyapatite, and tricalcium phosphate as compared to the inner body.

Effects of the application

According to the artificial tooth root of the present disclosure, it is composed of a ceramic material, and thus, exhibits excellent biocompatibility to an alveolar bone as compared with a titanium material, and has excellent aesthetic appearance as compared with a titanium material.

In addition, according to the artificial tooth root of the present disclosure, it is possible to naturally bond with an alveolar bone, and thus, it is unnecessary to form a thread for bonding with an alveolar bone on a surface, and only the artificial tooth root is required to be inserted into and removed from an internal hole of an existing alveolar bone, thereby having an effect that surgical invasion can be minimized.

In addition, the present disclosure provides a method of manufacturing an artificial tooth root having the effect using 3D printing.

Brief description of the drawings

Fig. 1 to 6 are schematic views illustrating individual embodiments of an artificial tooth root.

Fig. 7 to 10 are schematic views illustrating respective embodiments of a 3D printing method for manufacturing an artificial tooth root.

Detailed Description

The terminology used in the description presented herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the application. There is no clear distinction in the context, and singular references include plural. In the present application, the terms "comprises" and "comprising" and the like mean that there is a feature, number, step, action, structure, component, or combination thereof described in the specification, and that the presence or additional possibility of one or more other features, numbers, steps, actions, structures, components, or combination thereof is not previously excluded.

In addition, in the present application, when each layer or element is referred to as being formed "on" or "over" other layers or elements, it means that each layer or element is formed directly on the other layers or elements, or that the other layers or elements may be further formed between layers, on an object, or on a substrate.

While the application is susceptible to various modifications and alternative embodiments, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. However, the present application is not limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present application.

Disclosed herein are ceramic materials suitable for use in artificial tooth roots, artificial bones and methods of using the materials to create artificial tooth roots, artificial bones. For example, the disclosure herein may make an artificial root for dental implant treatment. In the following, an artificial tooth root will be described as an example, but the following description is equally applicable to an artificial bone.

In one embodiment, the artificial root may be made of a ceramic material. In an embodiment, 3D shape data may be obtained from the actual natural root of a patient in need of dental implant treatment and used to make a personally customized ceramic artificial root for the root by a 3D printing method.

In addition, full-size ceramic artificial roots may be constructed from multiple layers. For example, the implant may include an inner body having bending strength capable of withstanding external stress, and an outer body having pores and/or channels which are well bonded to the alveolar bone and facilitate bone formation so as to be bonded to the alveolar bone after being implanted into the alveolar bone of a human body. Here, the pores and the channels may form fluid channels. The inner and outer bodies may be made of different materials or, even if made of the same material, may be of different material densities or proportions. For example, the artificial root may be manufactured in an inclined structure such that the density of the inner body is greater than the density of the outer body. Hereinafter, an artificial tooth root according to the present disclosure will be described with reference to examples.

Example 1

Fig. 1 is a schematic view showing the constitution of an artificial tooth root according to an embodiment. In one embodiment, the artificial root may be constructed of a single material in a dense structure. For example, the artificial tooth root may be made of tetragonal zirconia (ZrO ₂ )(3Y-ZrO ₂ ) A single material. Yttria may be included in the tetragonal zirconia referred to herein and in the following description. For example, the tetragonal zirconia may be a partially stabilized zirconia, zrO, containing 3mol% yttria ₂ (3Y-ZrO ₂ )。

In addition, the artificial tooth root may be made of a material including alumina (Al ₂ O ₃ ) At least one of Hydroxyapatite (HAP) and tricalcium phosphate (TCP). For example, ceramic artificial roots may be oxidized by a single tetragonal oxidationZirconium, or a tetragonal zirconia composite such as a tetragonal zirconia-alumina composite, a tetragonal zirconia-TCP composite, a tetragonal zirconia-HAP composite, a tetragonal zirconia-alumina-TCP composite, a tetragonal zirconia-alumina-HAP composite, a tetragonal zirconia-TCP-HAP and/or a tetragonal zirconia-alumina-TCP-HAP composite.

Zirconia and alumina have excellent mechanical properties, have no or little foreign body reaction when implanted in the body, and have superior mechanical properties compared with bioactive ceramic materials, so that the zirconia and alumina are materials with ensured stability for artificial joints bearing weight and repair treatment. The tetragonal zirconia-alumina composite has advantages of high fracture toughness and low specific gravity compared to tetragonal zirconia. TCP and HA are bioactive bioceramics, compatible with ZrO, for example ₂ 、Al ₂ O ₃ The biological inert biological ceramic is compounded, and after the artificial tooth root is implanted into the alveolar bone, the artificial tooth root and the alveolar bone can be contacted to form firm combination.

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

Here, a relative density higher than 97% means a relative density of constituent materials (even if composed of various materials). Here, a relative density of 97% means that the measured density is 3% lower than the theoretical density. In ceramics, a high relative density is advantageous against external stresses because a lower density reduces mechanical properties. Here, the relative density may be calculated by dividing the measured density of the material by the theoretical density of the material. Here, the theoretical density is a theoretical density (an inherent property of a material) that a material has. Here, the object of measurement of the density may be an apparent density or a bulk density.

In addition, the artificial tooth root may be manufactured to have a porous structure or a channel structure. By filling the porous structure and/or the channel structure of the artificial tooth root surface with osteogenic material flowing in from the alveolar bone, the porous structure and/or the channel structure may help the biocompatibility of the artificial tooth root with the alveolar bone and the osteogenesis therebetween.

For this purpose, a porous structure may be formed on the surface of the artificial root for osteogenesis and osseointegration, for example, at a portion in contact with the alveolar bone. The porous structure on the surface may act as pores. In addition, the pores may be continuously formed from the surface of the artificial root to the inside to form a prescribed channel structure. For example, the porous structure may form a predetermined channel structure to allow the osteogenic material to flow into the artificial root. For example, a channel structure such as a scaffold structure or a gyro structure may be formed in the artificial tooth root. This application may be achieved by three-dimensional modeling of a scaffold or gyroscope structure for an artificial root 3D model. In the case of a single material, a single structure, in order to achieve porosity/channels in the artificial root, the same degree of porosity may be formed throughout the artificial root, not just at the surface.

Example 2

Fig. 2 is a schematic view showing the constitution of an artificial tooth root according to another embodiment. The ceramic artificial tooth root may be composed of multiple layers. For example, the implant may include an inner body having bending strength capable of withstanding external stress, and an outer body having pores and/or channels which are well bonded to the alveolar bone and facilitate bone formation so as to be bonded to the alveolar bone after being implanted into the alveolar bone of a human body.

For example, the pores or channels may not be formed in the inner body, but may be formed in the outer body. For this reason, the outer body may be made of the same material with different material densities or proportions. For example, the artificial root may be manufactured in an inclined structure such that the density of the inner body is greater than the density of the outer body. For example, the minimum relative density of the endosomes may be limited to 97%. In addition, the relative density of the inner body may be limited so that the bending strength of the artificial root has a value between 200MPa and 1200 MPa. The relative density of the outer body may have a lower value than the inner body. Alternatively, the outer body may have a lower bending strength than the inner body. For example, the material of example 1 may be used for the inner body, but the porosity may be lower than 0.1% to achieve high strength. In addition, the first outer body contacting the inner body may use the same material as the inner body, but the porosity may be 5%. In addition, the second outer body contacting 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 increased by 5% 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, an increment rate of 5% is just an example, and the increment rate may be selected according to a prescribed percentage.

The area of the inner body may be from 50% minimum (e.g., when the ratio of the outer body is high) to 100% maximum (e.g., when no outer body is present) based on the cross-section of the artificial root. In the case where the area of the inner body is less than 50% based on the cross section of the artificial root, cracks may occur due to stress generated during chewing. In the case that the area of the inner body is 50% based on the artificial root cross section, the porous structure of the outer body may be up to 50% based on the artificial root cross section.

Example 3

Fig. 3 is a schematic view showing an artificial tooth root according to another embodiment. According to an embodiment of the artificial tooth root, the layers of the inner and outer bodies may be formed, but may be formed of a non-porous structure of an inclined functional material to ensure biocompatibility.

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

The inner body may limit the HAP or TCP content to a predetermined content to achieve bending strength. In addition, the outer body may be limited to a prescribed content or more to achieve alveolar bone bondability.

In one embodiment, the endosome may limit the content of HAP to less than 10 wt%. In addition, the exosome may limit the content of HAP to 10wt% or more. Further, the HAP content of the outer part of the outer body constituting the surface of the artificial tooth root may be made higher than the HAP content of the inner part of the outer body facing the inner body, so that the artificial tooth root achieves a prescribed tilting function. Referring to fig. 4, the inner body may be formed of a Z (401) material, the first outer body in contact with the inner body may be formed of a ZA1 (402) material, the second outer body in contact with the first outer body may be formed of a ZA2 (403) material, and the third outer body in contact with the second outer body and constituting the surface material may be formed of a ZA3 (404) material.

In the case of using TCP as the tilting material, the inner body may be formed of ZH1 (405), the first outer body contacting the inner body may be formed of ZH2 (406), the second outer body contacting the first outer body may be formed of ZH3 (407), and the third outer body contacting the second outer body and constituting the surface material may be formed of ZH4 (408).

In addition, as shown in fig. 4, the highest content of HAP and/or TCP may be limited to not more than 40wt% in order to limit the suitable bending strength to 224MPa or more. For example, the highest content of HAP and/or TCP may be limited to not more than 40wt% at the surface portion. Alternatively, the highest content of HAP and/or TCP may be limited to a content that limits the appropriate bending strength (e.g., bending strength) to 200MPa or more. In an embodiment, the highest content of HAP and/or TCP may be limited to not more than 40wt% in order to limit the suitable bending strength to 200MPa or more. In another embodiment, the highest content of HAP and/or TCP may be limited in order to limit the suitable bending strength to above 300 MPa. In another embodiment, the highest content of HAP and/or TCP may be limited to no more than 30wt% in order to limit the suitable bending strength to 400MPa or more.

In addition, in the case of using alumina, the content of alumina in the internal body may be at least 0wt%, and in this case, the internal body may be composed of tetragonal zirconia only. In addition, the highest alumina content of the outer body may be 50wt%. In addition, the alumina content between the layers of the outer body may form a gradient structure such that the layers of the outer body near the surface (e.g., the outermost outer body) have the highest content.

In the case of using a tilting material together with alumina, the contents of alumina and tilting material can be used as described above. For example, in the case of the tetragonal zirconia-alumina-HAP composite, the alumina is used in a range of 0 to 50wt% and the HAP is used in a range of 0 to 30wt%. For example, the endosome may be composed of 100wt% tetragonal zirconia, 0wt% alumina, and 0wt% HAP. In addition, the first outer body may be composed of 80wt% tetragonal zirconia, 10wt% alumina, and 10wt% HAP. In addition, the outermost layer outer body may be composed of 20wt% tetragonal zirconia, 50wt% alumina and 30wt% HAP.

As another example, in the case of the tetragonal zirconia-alumina-TCP composite, the alumina is used in a range of 0 to 50wt% and the TCP is used in a range of 0 to 30wt%. For example, the endosome may be composed of 100wt% tetragonal zirconia, 0wt% alumina, and 0wt% TCP. In addition, the first outer body may be composed of 80wt% tetragonal zirconia, 10wt% alumina, and 10wt% TCP. In addition, the outermost layer outer body may be composed of 20wt% tetragonal zirconia, 50wt% alumina and 30wt% TCP.

Example 4

Fig. 5 is a schematic view showing an artificial tooth root according to another embodiment. According to an embodiment of the artificial tooth root, the inner body and the outer body may be formed of a plurality of layers, but the outer body may be formed of an inclined functional material having a porous structure to secure biocompatibility.

For example, as in the foregoing example 3, the endosome may be composed of tetragonal zirconia and/or zirconia composites (e.g., composites containing the foregoing alumina, HAP, TCP, etc.). 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 also be manufactured including a porous structure in the outer body as in example 2.

This example 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 example 3. In addition, 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 example 2. In addition, an artificial tooth root having the characteristics of both fig. 6 (a) and fig. 6 (b) may be an artificial tooth root model using HAP as an example of embodiment 4 and porosity as an inclined surface structure.

Method of manufacture

As previously described, the artificial tooth root according to the present disclosure has a prescribed internal structure within the tooth root. Therefore, it is difficult to manufacture full-sized artificial roots of ceramic materials using conventional molds or cutting processes.

Thus, to make a custom full-sized artificial root, ceramic 3D printing techniques may be used. For this purpose, the shape and structure of the artificial root surface can be controlled by 3D modeling.

In an embodiment, an artificial root having the same shape as the root of a real person may be manufactured by a 3D printing method. Fig. 7 to 9 show the basic concept for 3D printing of ceramic slurry materials. Fig. 7 discloses the principle of cross-linking between monomers (monomers) and oligomers (oligomers) by means of photoinitiators (photoinitiators). Fig. 8 shows an operational conceptual diagram of a 3D printer for ceramic 3D printing using the concepts.

The 3D printer of fig. 8 may be composed of a stage 810, a water tank 820, and a light irradiation part 830. The water tank 820 may house ceramic slurry. The stage 810 is lowered so that a prescribed space (for example, a space forming one ceramic slide plate as one unit for performing 3D printing) is formed between the bottom of the water tank 820 and the lower surface of the stage 810, and the ceramic slurry remaining in the prescribed space is cured by curing light irradiated to the water tank 820 through the light source 831 and the reflection portion 832. Thereby forming a unit of ceramic sled, and 3D printing is accomplished by repeating the process a number of times. Fig. 8 shows bottom-up (bottom-up) 3D printing of a downward deposition of a 3D print on the underside of the platform, but top-down 3D printing of the platform immersed in a sink while depositing a sled on the platform may also be used as shown in fig. 9. When using top-down 3D printing, as shown in fig. 10, there is an advantage in that an outer body can be additionally formed on the shaped artificial tooth root. Fig. 10 shows an example of depositing an outer body 1320 from top to bottom on the exterior of an inner body 1310. As shown in fig. 10, the generated inner body 1310 is provided at the upper part of the stage 1110. By lowering the platform 1110 below the trough, the slurry 1210 is immersed in the trough from below the inner body 1310. When immersed from below the inner body 1310, curing light is irradiated onto the slurry surface 1322 corresponding to the outer body 1320, thereby generating a ceramic slide plate as a printing execution unit for the outer body 1320. By repeating the lowering of the platform 1110 and the curing of the slurry surface 1322 corresponding to the outer body 1320, the outer body 1320 in contact with the inner body 1310 may be created by a 3D printing method.

In addition, as previously mentioned, the term "slurry" generally refers to a liquid state of poor flowability containing a high concentration of suspended material, and is understood to include a paste (paste) or dough (dough) state.

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

The ceramic powder is the main material for manufacturing a structure by 3D printing, and the ceramic according to an embodiment of the present application, as described previously through embodiments 1 to 4, may be a ceramic powder including at least tetragonal zirconia and/or alumina (Al ₂ O ₃ ) Tetragonal zirconia composites of at least one of Hydroxyapatite (HAP) and/or tricalcium phosphate (TCP). In addition, in the present application, the ceramic powder may include 60wt% to 90wt% with respect to the total weight of the slurry composition.

In addition, the ceramic powder may be stabilized with 2 to 8mol% of yttrium (Y), particularly 3 to 5mol% of yttrium (Y), relative to the total composition of the ceramic powder. In the case of the above-mentioned ceramic powder stabilized with yttria in the mol% range, zirconia powder or the like may be produced in the form of particles (grains), and in the case of the particles, a relatively large amount of ceramic component may be contained in the slurry composition as compared with the powder, thereby improving the density at the time of lamination. However, as the amount of yttria (Y) used for stabilization increases, there may occur a problem that the flexural strength of the finally produced output is lowered, and therefore, stabilization in the above-described mol% range is preferable.

The photocurable adhesive serves to form an adhesive force between the ceramic powders to aid in forming the molded body and the structure, and may be a mixture of a photocurable monomer and a photocurable oligomer.

Specifically, if only a low shrinkage monomer is included as the photo-curing adhesive, the film adhesion is strong, but the metal adhesion is weak, and when 3D printing of SLA/DLP system to be described later is used, problems occur in the manufacturing process of the molded body and the structure, such as a problem that the cured layer remains in the film in the process of separating the cured layer and the film while the stage is lifted after the cured layer is created, problems may occur in the subsequent process after the molding due to the weak brittleness, and in the case of using only the oligomer, a problem that it is difficult to contain ceramic powder in a high content due to the viscosity of the oligomer itself, and it is difficult to improve the filling density may occur.

Accordingly, the photocurable adhesive according to an embodiment of the present application may be a mixture of 8 to 25 parts by weight of the photocurable monomer and 2 to 15 parts by weight of the photocurable oligomer, specifically, a mixture of 10 to 16 parts by weight of the photocurable monomer and 3 to 9 parts by weight of the photocurable oligomer, when combined in a ratio of the above parts by weight, has a proper level (level) of bonding between the monomer and the oligomer, so that a high level of packing density can be ensured while preventing the problem of the cured layer remaining on the film even if the stage rises after the cured layer is generated in the 3D printing process of SLA/DLP system.

In addition, in the present application, the photocurable adhesive may include two or more functional groups (functional groups). Specifically, in the monomers and oligomers constituting the photocurable adhesive, in the case of one functional group, a linear (linear) bond is generally formed between adjacent monomers and oligomers, and in the case of two functional groups, a branched (branched) bond is generally formed. In addition, in the case of three to four functional groups, a cross-linked bond is formed, and in the case of five or more functional groups, a network bond is formed.

As an example, in the slurry composition of the present application, when the functional groups of the monomer and oligomer constituting the photocurable adhesive are three or more, the bond density between the monomer and oligomer is significantly increased by the formation of a cross-linking bond or a network bond, and shrinkage occurs particularly when ultraviolet curing and solidification are performed, resulting in a problem of reduced adhesion between layers (layers).

Thus, the photocurable adhesive used in the present application may include at least one of a photocurable monomer and a photocurable oligomer. At this time, at least one of the photocurable monomer and the photocurable oligomer may include two or less functional groups. For example, the photo-curable adhesive according to an embodiment may include a dual functional group monomer and a dual functional group oligomer, or may include a single functional group monomer and a dual functional group oligomer, or may include a dual functional group monomer and a single functional group oligomer, or may include a single functional group monomer and a single functional group oligomer. Therefore, by minimizing the shrinkage of the photo-curing when irradiated with ultraviolet rays, excellent bending strength (Flexural Strength) is achieved in the final output, while the interlayer adhesion is improved, and structural stability of the final output is ensured.

Specifically, the photocurable monomer may be at least one selected from the group consisting of monofunctional monomers and difunctional monomers.

In the case of the monofunctional monomer, for example, it may be selected from octanoate Acrylate (stearylacrylate), tetrahydrofuran Acrylate (Tetrahydrofufuryl Acrylate), dodecyl Acrylate (laurylacrylate), (N) polyoxyethylene octanoate Phenol Acrylate (Ethoxylate (N) Nonyl Phenol Acrylate), isodecyl Acrylate (Isodecyl Acrylate), cycloalkyl Acrylate (Cycloaliphatic Acrylate), methoxypolyethylene glycol monoacrylate (Methoxy polyethylene glycol monoacrylate), alkyl ether Phenol Acrylate (Alkoxylated Phenol Acrylate), triethylene glycol diethyl ether methacrylate (Triethylene glycol ethyl ether Methacrylate), caprolactone Acrylate (Carprolactone Acrylate), polypropylene alcohol monomethacrylate (Polypropylene glycol Monomethacrylate), cyclotrimethyl trimethacrylate (Cyclic trimethylolpropane formal Acrylate), phenoxybenzoate (Phenoxy Benzyl Acrylate), 3, 5-trimethylcyclohexyl Acrylate (3, 5-trimethyl cycloheexyl Acrylate), isobornyl Acrylate (Isobornyl Acrylate), isobornyl methacrylate (Isobornyl Metacrylate), t-butylcyclohexyl Acrylate (4-tert-butylcyclohexyl Acrylate), benzoate (Benzyl Acrylate), bisbenzyl methacrylate (Biphenylmethyl Acrylate), phenol (EO) N Acrylate (Phenolate) N-Benzyl methacrylate (N-Phenoxyethyl Methacrylate), N-Dimethyl acrylamide).

As another example, in the case of the difunctional monomer, it may be selected from the group consisting of 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), alkylated hexanediol Diacrylate (Alkoylated hexanediol Diacrylate), 1,4-butanediol dimethacrylate (1, 4-Butanediol Dimethacrylate), bisphenol A (EO) n Diacrylate (bishenol A (EO) n Diacrylate), cyclohexane dimethanol Diacrylate (Cyclohexane dimethanol Diacrylate), ethoxylated Bisphenol A dimethacrylate (Ethoxylated Bisphenol A dimethacrylate), diethylene glycol Diacrylate (Diethylene glycol Diacrylate), triglycerol Diacrylate (Tripropyleneglycol Diacrylate), neopentyl glycol Diacrylate (Neopentyl glycol Diacrylate), dipropylene glycol Diacrylate (Dipropylene glycol Diacrylate), propoxylated neopentyl glycol Diacrylate (Propoxyiated (2) neopentyl glycol Diacrylate), tricyclodecane dimethanol Diacrylate (Tricyclodecane dimethanol Diacrylate), 1, 3-butanediol dimethacrylate (1,3 Butylene glycol dimethacrylate), hydroxy picolate (4) neopentyl glycol Diacrylate (39356), neopentyl glycol Diacrylate (3929), diethylene glycol Diacrylate (Neopentylglycol (PO)), and ethylene glycol Diacrylate (39356) One or more kinds of triethylene glycol diacrylate (Triethylene glycol Diacrylate) and triethylene glycol dimethacrylate (Triethylene glycol Dimethacrylate).

The photocurable oligomer may include an oligomer having two or more functional groups. For example, one or more oligomers selected from the group consisting of urethane oligomers (e.g., urethane acrylates), oligomers containing phosphate groups (e.g., phosphate modified acrylates), oligomers containing carboxylic acid groups (e.g., carboxylic acid modified acrylates), and epoxy oligomers (e.g., epoxy acrylates) may be included. The oligomer as described above can ensure high adhesion for a stage (print bed) used as a metal material particularly in 3D printing using the SLA/DLP system in combination. In addition, in the case of using only a urethane oligomer as the photo-curable oligomer, the adhesion to metal is lowered, and there is a possibility that the cured layer remains in the film during the separation of the cured layer and the film. Thus, in the case of using a polyurethane oligomer, the adhesive may further include an oligomer or an epoxy oligomer having an acid group of high metal adhesion. Here, the oligomer having an acid group may be an oligomer containing a phosphoric acid group (for example, phosphoric acid modified acrylate) or an oligomer containing a carboxylic acid group (for example, carboxylic acid modified acrylate).

In addition, in an embodiment of the present application, the photocurable adhesive comprising the photocurable monomer and the photocurable oligomer may be 10wt% to 40wt% with respect to the total weight of the composition.

The dispersing agent serves to disperse the ceramic powder (filler) and prevent reagglomeration so that the ceramic powder can be sufficiently contained in the product, and dispersing agents common in the art may be used. As an example, one or more compounds selected from the group consisting of a copolymer compound having an acidic group and a polyester/polyether (polyester/polyether) compound having a phosphate group and an amine group may be included. In addition, in one embodiment of the present application, the dispersant used may be 1wt% to 5wt% with respect to the total weight of the composition.

The photoinitiator plays a role of absorbing light and emitting light in the form of free radicals when irradiated with ultraviolet rays or LEDs, and realizing the coupling between monomers and oligomers, thereby forming a solid polymer, and particularly in a 3D printer, since LEDs can be used as light sources, a photoinitiator having a wavelength ranging from 370nm to 420nm can be used.

In addition, in the present application, in the case where the slurry composition is used to deposit a thin film having a thickness of 15 μm or less (e.g., 10 μm to 15 μm) per layer (layer), the photo-curing initiator may include one or more selected from a short wavelength initiator having a wavelength of less than 360 μm, e.g., having a wavelength of 250 to 360m, a medium wavelength initiator, or a mixture thereof.

The short-wavelength initiator or medium-wavelength initiator according to an embodiment of the present application may be selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone (1-hydroxycyclohexyl phenyl ketone), benzophenone (Benzophenone), 4-methylbenzophenone (4-methylbenzophenone), 4-Benzoyl-4 '-methylbenzophenone (4-Benzoyl-4' -methylvinylfluoride), methylbenzoyl glyceride (Methyl phenylglyoxylate), methyl-o-Benzoyl benzoate (Methyl o-benzobenzoate), benzyl dimethyl ketal (Benzil dimethyl ketal), 4-phenylbenzophenone (4-phenylbenzophenone), 2-Ethylhexyl-4-Dimethylaminobenzoate (2-methylhexenyl-4-dimethylbenzoate), ethyl-4-Dimethylaminobenzoate (Hydroxy-2-methylphenyl acetone) Hydroxy-2-methylbenzoyl-2- (Methyl-2-Benzoyl-2- (Methyl-2-Benzoyl) 2- [ Methyl-2-butanone ] -1-2- (2-Methyl-Benzoyl-1-2-butanone) 2-dimethyl-4-dimethylbenzoyl-4-dimethylbenzoate (2-Methyl-4-methylbenzophenone), more than one of the group consisting of 2-Dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-benzene) butan-1-one (2-dimethyl-amino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) bunan-1-one), oligomer [2-hydroxy-2-methyl-1- [4- (1-methyl vinyl) phenyl ] propanone ] (Oligo [2-hydroxy-2-methyl-1- [4- (1-methyl vinyl) phenyl ] propanone ]), and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (2-hydroxy-2-methyl-1-phenyl-1-one).

In addition, in the present application, in the case where the slurry composition is used to deposit a thin film having a thickness of 15 μm or more (e.g., 20 μm) per layer (layer), the photo-curing initiator may include a long wavelength initiator selected from those having a wavelength of more than 360 μm, for example, those having a wavelength of 360 to 450 m.

The long wavelength initiator according to an embodiment of the present application may be selected from the group consisting of isopropyl thioxanthone (Isopropylthioxanthone), 4'-Bis (diethylamino) benzoketone (4, 4' -Bis (diethylamino) benzophenone), 2,4-diethyl thioflavone (2, 4-diethyl thioxanthone), 2,4,6-trimethyl benzoyl-diphenyl Phosphine oxide (2, 4,6-trimethyl benzoyl-diphenyl Phosphine oxide), phosphine oxide (phosphorus oxide), bis (2, 4,6-trimethyl benzoyl) -phenyl Phosphine oxide (Bis (2, 4,6-trimethyl benzoyl) -phenyl Phosphine oxide), bis- (H5-2, 4-cyclopentadien-1-yl) -Bis [2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl ] titanium (s- (a 5-2, 4-cyclic-1-Bis [2, 6-phenyl) -Bis [2, 6-diphenyl ] propane-1-yl) -phenyl ] titanium (Bis- (2, 4, 6-trimethyl-phenyl) -phenyl-1-Bis- (1-phenyl) -phenyl-Bis- (1-hydroxy-phenyl) and 1-Bis- (1-phenyl) sulfide.

In addition, in the case where the kind of the initiator is changed according to the thickness of the thin film (or thick film) as described above, the optimum curing speed and curing ability can be adjusted according to the thickness, thereby having an effect that excellent interlayer adhesion can be ensured. According to an embodiment of the present application, the photo-curing initiator may be 0.01wt% to 1wt% with respect to the total weight of the composition.

As described above, the ceramic slurry composition according to the present application can improve ceramic packing density while minimizing photocuring shrinkage in 3D printing, particularly in 3D printing using SLA/DLP mode, to achieve excellent flexural strength (Flexural Strength) in the range of 200MPa to 1000MPa, improve interlayer adhesion, and ensure structural stability.

In particular, the ceramic slurry composition according to the present application uses a photocurable monomer and oligomer containing two or more functional groups (functional groups), and optimizes its combination and kind for use as a photocurable adhesive, thereby easily achieving proper fluidity and high interlayer adhesion and high flexural strength (Flexural Strength) of 500MPa or more, excellent structural stability, especially in a 3D printout in which SLA/DLP mode is used in combination.

The operation and effects of the present application will be described in detail below with reference to specific examples of the present application. This is merely an example of the present application and is not intended to limit the scope of the present application.

Production examples 1 to 19

The ceramic slurry compositions were prepared as follows, with the ingredients and composition ratios shown in tables 1 to 4 below. Specifically, after mixing the photoinitiator with the monomer, the mixture was stirred in a stirrer at a rotation speed of 300rpm or more for 2 hours to completely dissolve the photoinitiator, and after mixing the binder (oligomer and/or dispersant) with the mixture, the mixture was stirred at a rotation speed of 200rpm or more for 30 minutes. Finally, the ceramic powder was mixed therein, stirred with a paste mixer and stirred at 1500rmp for 10 minutes to complete the ceramic slurry composition.

In addition, the ceramic paste composition was laminated in a 3D printing system using a SLA/DLP system in combination to manufacture a 3D structure. In addition, as shown in fig. 8, the SLA/DLP mode may be to perform the following process using a 3D printer, wherein the 3D printer includes: a print bed; a water tank portion including at least one water tank located at a lower end of the print bed; a water tank moving device for moving the water tank; the light irradiation part is positioned at the lower end of the water tank; and a control unit for controlling the water tank moving device to move the water tank (see fig. 8).

The first step: forming a thin slurry layer on the thin film of the water tank; at this time, the space between the stage (print bed) and the water tank is sufficiently separated to form a slurry layer; a second part: lowering the stage so that a gap between the stage and the film becomes 1mm in order to cure one laminate, thereby curing one laminate, and placing the slurry of the first step between the stage and the film; and a third step of: forming a cured layer by irradiating ultraviolet curing paste penetrating through the film to the lower end; fourth step: after forming a solidified layer, lifting the platform upwards and separating the solidified layer from the film; fifth step: repeating the first to fourth steps.

[ Table 1]

The results in Table 1 show examples of production with a changed ceramic type or a changed ceramic content, and it can be seen that the flexural strength of 200MPa or more was ensured in all production examples except production example 4.

[ Table 2]

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The results in Table 2 show examples of production by changing the type of photoinitiator or changing the content of photoinitiator, and it can be seen that all production examples except production example 10 ensure a sufficient degree of curing and a flexural strength of 200MPa or more regardless of the layer thickness.

[ Table 3]

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The results in Table 3 show examples of production of materials having different numbers of mixed monomer functional groups, and it can be seen that flexural strength of 200MPa or more was ensured in all production examples except production examples 13 and 14.

[ Table 4]

	Production example 2	Production example 15	PREPARATION EXAMPLE 16	Production example 17	Production example 19
						3mol% 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
Polyurethane acrylic ester	5.8	5.8	5.8	3.3	8.3
						Phosphoric acid modified acrylic ester	2.5
Carboxylic acid modified acrylic ester		2.5		2.5
						Epoxy acrylates			2.5	2.5
Dispersing agent	1.6	1.6	1.6	1.6	1.6
						Platform adhesion	OK	OK	OK	OK	NG
Flexural Strength (MPa)	510	540	500	570	-

The flexural strength in the foregoing examples 1 to 19 was measured after the manufactured product was separated from the stage and washed, and after sintering. The cleaning is performed manually and semi-automatically with alcohol, degreasing is performed at 500 ℃ for 2 hours, and then sintering is performed at 1500 ℃ for 2 hours, so as to perform densification. The results of Table 4 show that the flexural strength of 200MPa or more was ensured while ensuring sufficient adhesion to the platform in the production examples other than production example 19, depending on the production examples of the specific oligomer used or not. In particular, in production example 19, since there was no normal output, the lamination result was not adhered to the stage, and only a part of the lamination result was adhered to the film of the water tank, which was a problem.

[ Table 5 ]

The results of Table 5 show that, according to the production examples of the amounts of the specific oligomers used, the oligomers containing an acid group in the liquid adhesive (corresponding to the aforementioned photocurable adhesive) contained 8.5% or more, preferably 10% or more, more preferably 11.14% or more, and that, while securing a sufficient adhesive force, the flexural strength of 200MPa or more was secured in the production examples 22, 23, 25 and 26. In addition, it can be seen that the epoxy group-containing oligomer is contained in the liquid adhesive in an amount of 14% or more, preferably 15% or more, more preferably 16.7% or more, and that the flexural strength of 200MPa or more can be ensured while sufficient adhesive strength can be ensured. For example, in the example of table 5, it can be seen that in example 20 containing 8.4% of phosphoric acid modified acrylate in the liquid adhesive, the plateau adhesion was insufficient, but in example 22 containing 11.14% of phosphoric acid modified acrylate in the liquid adhesive, there was excellent plateau adhesion. It can be seen that in example 24, which contained 13.9% of epoxy acrylate in the liquid adhesive, the plateau adhesion was insufficient, but in example 25, which contained 16.7% of epoxy acrylate in the liquid adhesive, there was excellent plateau adhesion. The ratio of the specific oligomer in the liquid binder can be calculated by the following mathematical formula:

[ mathematics 1]

Ratio of specific oligomer in liquid adhesive = specific oligomer content/liquid adhesive content

The liquid binder content in the formula 1 may be calculated as the sum of binders used to manufacture the liquid slurry, as follows:

[ math figure 2]

Liquid binder content = monomer content + oligomer content

In the case of the example of table 5, the monomer in formula 2 may be THFA. In addition, the oligomer may be urethane acrylate, phosphoric acid modified acrylate, carboxylic acid modified acrylate, and epoxy acrylate. Therefore, the following equation 2 may be used:

[ math 3]

Liquid binder content = THFA content + polyurethane acrylate content + phosphoric acid modified acrylate content + carboxylic acid modified acrylate content + epoxy acrylate content

The specific oligomer content in the formula 1 may be determined as the content of the oligomer containing an acid group and the oligomer containing an epoxy resin. For example, in the case of the examples of Table 5, the specific oligomer content can be calculated according to the following formula:

[ mathematics 4]

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

The above-described embodiments are provided to illustrate the present application and not to limit it, and it should be understood by those skilled in the art that the present application may be modified, changed, or equivalent. But is intended to be encompassed within the scope of the appended claims without departing from the spirit and scope of the application.

Industrial applicability

The present specification discloses a method for manufacturing an artificial tooth root.

Claims

1. An artificial tooth root comprising a ceramic composition and formed with a plurality of fluid passages.

2. The artificial tooth root of claim 1, wherein: the artificial tooth root consists of an inner body and an outer body; the liquid passage is formed more in the outer body than in the inner body.

3. The artificial tooth root of claim 2, wherein: the outer body is composed of a plurality of layers; more fluid passages are formed in the outermost outer body forming the surface of the artificial root than in the first outer body in contact with the inner body.

4. The artificial tooth root of claim 1, wherein: the ceramic component comprises tetragonal zirconia; and at least one of alumina, hydroxyapatite and tricalcium phosphate.

5. The artificial tooth root of claim 1, wherein: the artificial tooth root consists of an inner body and an outer body; the outer body further includes at least one of alumina, hydroxyapatite, and tricalcium phosphate as compared to the inner body.

6. An artificial tooth root comprising a ceramic component; comprises at least one of alumina, hydroxyapatite and tricalcium phosphate.

7. The artificial tooth root of claim 6, wherein: the artificial tooth root consists of an inner body and an outer body; the outer body further includes at least one of alumina, hydroxyapatite, and tricalcium phosphate as compared to the inner body.