Coating composition comprising zwitterions and transparent orthodontic device coated surface-coated using same

Abstract

The present invention relates to a coating composition comprising zwitterions and a transparent orthodontic device surface-coated using same. As a coating layer is formed on the surface of the transparent orthodontic device, biocompatibility of the transparent orthodontic device can be increased, thereby reducing inflammation and improving compatibility with body tissues. In addition, the present invention relates to a transparent orthodontic device which can prevent the formation of a biofilm capable of causing adhesion, infection, and complications of microbial organisms on the surface of the transparent orthodontic device on which a coating layer is formed by the coating composition.

Description

Coating composition containing amphoteric ions and transparent orthodontic device surface-coated using the same

[0001] The present invention relates to a coating composition containing a zwitterionic ion and a transparent orthodontic device having a surface coated using the same.

[0002] In line with the current trend of prioritizing quality of life regardless of age, the orthodontic market for improving facial aesthetics is rapidly growing, with most removable orthodontic devices being manufactured from PMMA. The global orthodontic market is projected to grow at an annual rate of 8.9%, from $4.32 billion in 2018 to $6.63 billion by 2023. Within this trend, the development of premium PMMA source technology for therapeutic use is expected to create significant market expansion and growth opportunities.

[0003] However, most of the PMMA used in dentistry is imported entirely from companies such as Ivoclar Vivadent (Principality of Liechtenstein) and Lang (USA).

[0004] Research and development of antimicrobial biomaterials to secure global competitiveness is ongoing both domestically and internationally, but due to various limitations, they have not been developed into products. In particular, there are no therapeutic PMMA products that have the effect of inhibiting the adhesion of biofilms and oral bacteria.

[0005] Oral biofilms are implicated as a cause of not only localized oral diseases such as salivary proteins, dental caries, periodontitis, periapical inflammation, and peri-implantitis, but also infectious systemic diseases including those of the digestive and cardiovascular systems.

[0006] To address these issues, antibacterial agents or antibiotics are commonly used. However, these solutions can be toxic, destroying not only bacteria but also normal cells, and can lead to resistance.

[0007] Because orthodontic devices are worn for extended periods of time, bacterial growth and tartar buildup frequently occur. Even cleaning orthodontic devices with a brush or other cleaning tool can damage the device's surface and shorten its lifespan.

[0008] There is a need to develop solutions to address these issues.

[0009] [Prior Art Literature]

[0010] [Patent Document]

[0011] KR 10-2114824 B1

[0012] The purpose of the present invention is to provide a coating composition containing a zwitterionic ion and a transparent orthodontic device having a surface coated using the same.

[0013] Another object of the present invention is to provide a coating composition that can increase the biocompatibility of a transparent orthodontic device by forming a coating layer on the surface of the transparent orthodontic device, thereby reducing inflammation and improving compatibility with body tissues.

[0014] Another object of the present invention is to provide a transparent orthodontic device capable of preventing the attachment of microbial organisms to the surface of the transparent orthodontic device on which a coating layer is formed by the coating composition and the formation of a biofilm that may cause infection and complications.

[0015] To achieve the above object, the coating composition comprising a zwitterionic ion of the present invention comprises a zwitterionic ion and a photocurable monomer, and the zwitterionic ion may be sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC).

[0016] Additionally, the photocurable monomer may be a compound represented by the following chemical formula 1:

[0017] [Chemical Formula 1]

[0018]

[0019] Additionally, the coating composition may additionally include a photoinitiator.

[0020] In addition, the coating composition comprises 0.1 to 1 part by weight of a zwitterion and 1 to 5 parts by weight of a photoinitiator, based on 100 parts by weight of a photocurable monomer, and the zwitterion may comprise sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) in a weight ratio of 1:0.5 to 1:1.5.

[0021] A transparent orthodontic device according to another embodiment of the present invention is a transparent orthodontic device having a coating layer including zwitterionic ions formed thereon, and the coating layer may be formed by applying a coating composition including zwitterionic ions.

[0022] Additionally, the transparent orthodontic device may be printed by a 3D printer.

[0023] In addition, a coating composition including the zwitterionic ion may be applied to the transparent orthodontic device, and centrifuged to evenly apply the coating composition including the zwitterionic ion to the surface of the transparent orthodontic device.

[0024] The present invention can increase the biocompatibility of a transparent orthodontic device by forming a coating layer on the surface of the transparent orthodontic device, thereby reducing inflammation and improving compatibility with body tissues.

[0025] In addition, the present invention relates to a transparent orthodontic device capable of preventing the attachment of microbial organisms to the surface of the transparent orthodontic device on which a coating layer is formed by the above-described coating composition and the formation of a biofilm that may cause infection and complications.

[0026] Figure 1 is a flowchart illustrating a process for manufacturing a photocurable oligomer according to one embodiment of the present invention.

[0027] Figure 2 shows the GPC measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0028] Figure 3 shows the NMR measurement results for a photocurable oligomer according to one embodiment of the present invention.

[0029] Figure 4 shows the results of evaluating protein adsorption performance for a specimen including a coating layer according to one embodiment of the present invention.

[0030] Figure 5 shows the results of evaluating protein adsorption performance for a specimen including a coating layer according to one embodiment of the present invention.

[0031] The present invention relates to a coating composition comprising a zwitterionic ion and a photocurable monomer, wherein the zwitterionic ion is sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC).

[0032] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0033] The 3D printing of the present invention refers to a process of manufacturing a three-dimensional object by layering materials using 3D digital data. This specification focuses on 3D printing technologies such as DLP (Distal Light Processing), SLA (Stereo Lithography Apparatus), and PolyJet, but it should be understood that the technology can be applied to other 3D printing technologies as well.

[0034] The photocurable composition of the present invention refers to a polymer that is crosslinked and polymerized into a polymer network structure, and is a material that is cured by light irradiation. While the present specification focuses on UV light, the present invention is not limited to UV light and can be applied to other types of light.

[0035] Orthodontic treatment utilizes the ability of teeth to move when subjected to a certain force. The most common method for orthodontic treatment is fixed braces, which attach brackets to teeth and use elasticity, such as orthodontic wires and elastic bands, to move the teeth. Brackets are typically made of metal, but they have the disadvantage of being noticeable during treatment.

[0036] To address these shortcomings, transparent orthodontics was proposed. This procedure involves creating transparent orthodontic brackets that gradually change from the initial state of the teeth to the desired state, and then replacing them on the teeth to correct the alignment.

[0037] Specifically, the treatment using a transparent aligner was developed in 1997, and is a dental aligner developed by the American company "Align Technology, Inc." under the name "Invisalign System." The technical details of this device are disclosed in U.S. Patent Nos. 5,975,893 and 6,217,325.

[0038] The "Invisalign System" uses a special program to cut out each tooth on a computer using three-dimensional scan data of the teeth, and then creates 20 to 30 pairs of models step by step through virtual simulations to determine where the teeth should ultimately move. Then, a transparent plastic mold that allows teeth to be moved is made for each model and distributed to the patient.

[0039] The "Invisalign System" features a series of prepared plastic frame-type orthodontic devices that are gradually inserted into the teeth to gradually move the teeth to the final target point. Since the plastic frames are made of a transparent material and are not easily visible from the outside, they can be of great help in the daily social life of orthodontic patients. In addition, patients can put on and take off the orthodontic devices as needed.

[0040] The present invention relates to a coating composition capable of forming a coating layer containing zwitterionic ions on the surface of a transparent orthodontic device that can be used for orthodontic treatment.

[0041] Specifically, it comprises a zwitterionic and a photocurable monomer, wherein the zwitterionic is sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC).

[0042] The transparent orthodontic device having a coating layer formed as described above, unlike conventional transparent orthodontic devices, has a surface coated with a coating composition containing zwitterionic ions, and thus can exhibit effects such as reduction in biofilm thickness and biomass derived from saliva, reduction in antifouling ability and viability due to adhesion resistance to fungi and bacteria, and prevention of protein adsorption.

[0043] The above zwitterionic ions are sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC), and since both SBMA and MPC are included, due to the synergistic action of the zwitterionic ions, after forming a coating layer on the surface of a transparent orthodontic device, all zwitterionic ions that can exhibit effects such as reduction in biofilm thickness and biomass derived from saliva, reduction in antifouling ability and viability due to adhesion resistance to fungi and bacteria, and prevention of protein adsorption can be used without limitation.

[0044] The above photocurable monomer may be a compound represented by the following chemical formula 1:

[0045] [Chemical Formula 1]

[0046]

[0047] The above coating composition may further comprise a photoinitiator. The photoinitiator may be DPPO, and the photoinitiator may be included to form a coating layer through a subsequent process after the coating composition is applied to the surface of the transparent orthodontic device, as described below.

[0048] The above coating composition may contain 0.1 to 1 part by weight of a zwitterionic ion and 1 to 5 parts by weight of a photoinitiator, based on 100 parts by weight of a photocurable monomer. Within the above range, the zwitterionic ion and the photoinitiator in the coating composition are uniformly mixed and applied to the surface of the orthodontic device, thereby exhibiting effects such as reduction in the thickness and biomass of saliva-derived biofilm, antifouling ability and reduction in viability due to adhesion resistance to mold and bacteria, and prevention of protein adsorption. That is, when the zwitterionic ion is contained in an amount less than the above range, there is a problem that the above-described effect is insufficient, and when the zwitterionic ion is contained in an amount exceeding the above range, there is a problem that the zwitterionic ion in the coating composition is not completely dissolved and precipitates.

[0049] In addition, the zwitterionic ions included in the coating composition include sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) in a weight ratio of 1:0.5 to 1:1.5, and may be included in a weight ratio of 1:1. When SBMA and MPC are included within the above range, as described below, when forming a coating layer on the surface of a transparent orthodontic device, SBMA and MPC are uniformly distributed, and compared to a case where only one type of zwitterionic ion is included, the effects of reducing saliva-derived biofilm thickness and biomass, antifouling ability and viability due to adhesion resistance to fungi and bacteria, and preventing protein adsorption can be further increased.

[0050] The above coating composition may be prepared by mixing a photocurable monomer with a zwitterionic agent and a photoinitiator. Specifically, the mixing may be performed by stirring using a stirrer or by ultrasonic dispersion.

[0051] Mixing by the above ultrasonic dispersion can be produced by repeating ultrasonic dispersion for 1 to 5 seconds and pausing for 1 to 5 seconds, and dispersing for 30 to 90 minutes. Preferably, it can be produced by repeating ultrasonic dispersion for 1 to 2 seconds and pausing for 1 to 2 seconds, and dispersing for 50 to 70 minutes.

[0052] As described above, in order to prepare a coating composition, when the photocurable monomer and zwitterion are uniformly dispersed in the solvent phase by ultrasonic dispersion, the temperature rises to 50°C to 100°C. This is because the temperature increases as the photocurable monomer and zwitterion are uniformly dispersed in the solvent by ultrasonic dispersion.

[0053] When the above-described coating composition is prepared, it can be applied to a 3D printed transparent orthodontic device to form a coating layer.

[0054] The method for forming the above coating layer may involve applying the coating composition by spraying or dipping. The application method is not limited to the examples described above, and any method capable of uniformly applying the coating composition to the surface of a transparent orthodontic device may be used.

[0055] The above 3D printed transparent orthodontic device is, unlike the conventional transparent orthodontic device described above, manufactured to be customized for the patient and printed using a photocurable composition as described below. Unlike the conventional transparent orthodontic device, the transparent orthodontic device printed using the photocurable composition can precisely reproduce even the curved surface of the teeth and has high adhesion to the teeth, resulting in an excellent orthodontic effect.

[0056] The transparent orthodontic device of the present invention is manufactured by acquiring data on the patient's tooth structure and outputting the data, and can be manufactured with almost no difference in the deviation from the tooth structure of 50 to 80㎛, whereas the conventional transparent orthodontic device has a deviation from the patient's teeth of 200 to 300㎛, and thus cannot adhere closely, resulting in poor orthodontic effect. However, the transparent orthodontic device of the present invention is manufactured to be customized for the patient using 3D printing, and thus has a very small deviation from the patient's tooth structure, and thus can exhibit excellent orthodontic effects.

[0057] In addition, the transparent orthodontic device of the present invention is heated to 40°C or higher, and then fitted onto the patient's teeth to form a shape that is in close contact with the teeth, and the transparent orthodontic device in close contact with the teeth is restored to its original shape by body temperature, thereby correcting the teeth.

[0058] The transparent orthodontic device of the present invention is characterized in that it returns to its original shape when placed in heated water and then taken out. Specifically, the transparent orthodontic device of the present invention exhibits flexibility for a certain period of time when heat is applied, enabling shape deformation. By utilizing this property, before fitting the transparent orthodontic device to a patient's teeth, the device is immersed in water at 60 to 100°C, taken out, fitted to the teeth, and then simply pressed by hand, thereby causing the device to be deformed into a shape that adheres closely to the teeth.

[0059] Afterwards, when heat is supplied to the transparent orthodontic device by the body temperature in the oral cavity, restoration to the original output shape occurs.

[0060] That is, after being immersed in water of 60 to 100℃, fitted to the teeth, and then transformed into the same shape as the teeth, the transparent teeth orthodontic device of the present invention is transformed into a shape that matches the current tooth structure of the patient, and then when heat is supplied by body temperature, it is slowly restored to its original output shape, and at this time, the transparent teeth orthodontic device moves the teeth to the position to be corrected by the force that restores them to their original shape.

[0061] In other words, conventional orthodontic devices are manufactured as transparent orthodontic devices that are gradually adjusted to the position of the teeth to be corrected based on information obtained from the patient's dental structure. These devices are then fitted to the teeth and move the teeth based on the properties of the hard material. As explained above, conventional transparent orthodontic devices move teeth based on the properties of the material, and thus do not provide uniform force within the teeth, resulting in poor orthodontic effectiveness.

[0062] On the other hand, the transparent orthodontic device of the present invention, as described above, is in a state where it is deformed to the same state as the structure of the teeth when the transparent orthodontic device is first used, but when heat is provided by body temperature, the transparent orthodontic device is restored to its original shape and force is transmitted to the teeth. Since the force transmitted to the teeth is not a force due to the material of the orthodontic device, but is generated and transmitted by restoration of shape, a uniform force is provided to the entire teeth, and the teeth can move as a whole.

[0063] The transparent orthodontic device of the present invention, which exhibits the characteristics described above, is manufactured by printing using a 3D printer using the photocurable composition described below.

[0064] The photocurable composition may include an oligomer represented by the following chemical formula 2:

[0065] [Chemical Formula 2]

[0066]

[0067] [Chemical Formula 3]

[0068]

[0069] [Chemical Formula 4]

[0070]

[0071] [Chemical Formula 5]

[0072]

[0073] [Chemical Formula 6]

[0074]

[0075] [Chemical Formula 7]

[0076]

[0077] Here,

[0078] n is an integer from 1 to 100,

[0079] m is an integer from 1 to 50,

[0080] A, B, C and D are the same or different from each other and are repeating units each independently selected from the group consisting of compounds represented by chemical formulas 3 to 7,

[0081] a, b, c and d are the same or different and are each independently an integer from 1 to 30,

[0082] R1 and R2 are the same or different, and can each be independently selected from the group consisting of hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 1 to 30 carbon atoms.

[0083] The above photocurable oligomer is characterized by including a urethane acrylate structure as a main chain, a photocurable functional group bonded to the urethane structure, and including a soft functional group and a hard functional group in the compound.

[0084] The output exhibits flexible properties due to the soft functional group included in the photocurable composition, and can also exhibit heat resistance due to the hard functional group.

[0085] That is, by combining a photocurable functional group with a photocurable oligomer and utilizing a soft functional group and a hard functional group, a flexible effect can be exhibited by utilizing a carbon skeleton having a soft property at room temperature, and heat-resistant properties can also be exhibited by utilizing a carbon skeleton having a hard property at room temperature.

[0086] Since the above photocurable oligomer includes a carbon skeleton having hard properties, it can produce a 3D printing output that has excellent physical properties such as thermal properties, strength, elastic modulus, and tensile elongation, and can be restored to its original shape by heat.

[0087] In addition, since the photocurable oligomer contains a carbon skeleton with soft properties, its shape can be deformed by an external force after heat is provided.

[0088] In general, a composition for a 3D printer may include a photocurable oligomer for 3D printing; a monomer; a photoinitiator; and a stabilizer, as described below. The oligomer, monomer, photoinitiator, and stabilizer included in the composition all affect the physical properties of the output, but the oligomer has the greatest effect. Accordingly, in general, in order to improve the physical properties of a 3D output, only a carbon skeleton having a hard property is included, which can improve the physical properties of the output, but conversely, if the shape is deformed due to use, the shape cannot be restored, which is a problem in that it cannot be used multiple times.

[0089] The composition for a 3D printer of the present invention includes a carbon skeleton having a hard property and a carbon skeleton having a soft property, so that not only is it excellent in physical properties such as thermal properties, strength, elasticity, and tensile elongation, but also the flexible property of the soft functional group can be utilized together, so that when the shape is deformed by an external force in a state where heat is provided, it can be fixed in the deformed shape, and when heat is provided again, it can be restored to the original shape.

[0090] The above A, B and D are the same or different from each other, and may be repeating units independently selected from compounds represented by chemical formula 3 or 4.

[0091] The above C may be a repeating unit selected from the group consisting of compounds represented by chemical formulas 5 to 7.

[0092] Specifically, the photocurable oligomer represented by the above chemical formula 1 can be manufactured by a method for synthesizing a urethane acrylate series. Basically, it proceeds through a stepwise polymerization reaction of a diol and a diisocyanate, and in order to prevent gelation of the material due to an increase in molecular weight during the polymerization process of the material, an acrylic monomer without a reaction site is used as a suspension. The monomer used in the synthesis of the oligomer of the present invention as an available acrylic monomer may be Isobornyl acrylate, Cyclic Trimethylolpropane Formal Acrylate, Lauryl acrylate, Lauryl methacrylate, 3,5,3-trimethelhexyl acrylate, Tetrahydrofurfuryl acrylate, Tetrahydrofurfuryl methacrylate, Benzyl methacrylate, etc.

[0093] More specifically, diol was pre-introduced into the monomer base used as the primary monomer to stabilize it, and then diisocyanate was added. As the urethane reaction progressed, heat of reaction was generated, the urethane chain lengthened, and the molecular weight increased.

[0094] As the molecular weight increases, the viscosity of the material may also increase. If the above-mentioned molecular weight increase proceeds rapidly, the temperature rises rapidly, which also accelerates the urethane reaction, and as a result, the oligomer gels before reaching a sufficient molecular weight, making it unusable as a material. Therefore, in the present invention, in order to prevent this reaction, a solvent selected from the group consisting of Isobornyl acrylate, Cyclic Trimethylolpropane Formal Acrylate, Lauryl acrylate, Lauryl methacrylate, 3,5,3-trimethelhexyl acrylate, Tetrahydrofurfuryl acrylate, Tetrahydrofurfuryl methacrylate, Benzyl methacrylate, and mixtures thereof is used as a solvent for introducing the diol. The solvent does not participate in the reaction, and is used to control the reaction speed of the material and prevent a rapid increase in viscosity due to an increase in molecular weight. Additionally, the monomers used to synthesize the oligomer of the present invention must be free of functional groups capable of reactive urethane reactions, such as hydroxyl groups or urethane groups. Under the above conditions, the present invention can produce oligomers with excellent mass production and process stability.

[0095] In addition, the equivalent ratio of diol and diisocyanate was set to a state where the equivalent of diisocyanate was higher than that of diol, so that the oligomer terminal exists as an isocyanate group. A reaction catalyst including a Zn-based catalyst can be used during the reaction process. The catalyst may or may not be included. The catalyst is included to proceed the reaction more quickly, and the reaction can proceed even if it is not necessarily included, but even if it is included, the reaction can proceed with a very small amount added.

[0096] After the temperature increase was stopped due to the completion of the urethane reaction, 2-hydroxy acrylate and 2-hydroxy methacrylate were added dropwise to end-cap the ends of the oligomers.

[0097] The diols used for the preparation of the above oligomers are as follows:

[0098]

[0099] In addition, the diisocyanate for reacting with the above diol is as follows:

[0100]

[0101]

[0102] Additionally, monomers that may be included to terminate the urethane reaction or increase the molecular weight are as follows:

[0103]

[0104]

[0105]

[0106]

[0107] The compound represented by the above chemical formula 1 manufactured by the above manufacturing method can be selected from the group consisting of the following compounds:

[0108]

[0109]

[0110]

[0111]

[0112]

[0113] Here, p, p', p", q, q', q", r, s, t, u and v are integers from 1 to 100.

[0114] The photocurable oligomer may have a number average molecular weight (Mn) of 1,500 to 6,000, 1,500 to 5,500, or 1,600 to 5,000. The photocurable oligomer may have a weight average molecular weight (Mw) of 2,500 to 9,000, 3,000 to 8,500, or 3,500 to 8,000.

[0115] When a photocurable composition for 3D printing, described below, is manufactured using an oligomer having a number average molecular weight and a weight average molecular weight within the above range, and a transparent orthodontic device is manufactured using the same, the transparent orthodontic device can be printed in a manner customized to the patient's oral structure, and the orthodontic force can be increased using the same. In addition, when the transparent orthodontic device is immersed in water at 50 to 100°C and then deformed, the shape changes to the deformed shape, but when used while fitted on a tooth, the orthodontic device, which has been deformed by body temperature, gradually returns to its original shape, thereby exhibiting orthodontic force.

[0116] That is, conventional transparent orthodontic devices are manufactured from transparent plastic materials and can transmit sufficient force for correcting teeth. However, as described above, the transparent orthodontic devices are printed in accordance with the gradual movement state of the teeth, and are different from the current tooth structure of the patient. Therefore, they are not easy to wear when fitted to the teeth and can cause great pain even after wearing them.

[0117] On the other hand, when using the photocurable composition for 3D printing of the present invention, if the printed transparent orthodontic device is immersed in water at 50 to 100°C before use and then positioned on the patient's teeth to change its shape to fit the current, the shape of the orthodontic device gradually changes due to body temperature, so that it can exert a large orthodontic force without the patient feeling great pain.

[0118] The above photocurable oligomer may have a viscosity of 2,000 psi to 3,500 psi, 2,100 psi to 3,200 psi, or 2,200 psi to 3,000 psi. When a photocurable composition is manufactured using an oligomer having a viscosity within the above range, it can be provided with a viscosity suitable for use in a 3D printer.

[0119] The above monomer is a reactive monomer, and may specifically be an acrylate monomer.

[0120] More specifically, the acrylate monomer may be selected from the group consisting of a compound represented by the following chemical formula 8, a compound represented by the following chemical formula 9, and a mixture thereof:

[0121] [Chemical Formula 8]

[0122]

[0123] [Chemical Formula 9]

[0124]

[0125] The photoinitiator may be BP, TPO, DCP, BPO, DPPO, etc., and preferably DPPO (2-hydroxy-2-methylpropiophenone) may be used. However, the present invention is not limited to the above examples, and any photoinitiator capable of producing a photocurable composition may be used without limitation.

[0126] The above stabilizer may be selected from the group consisting of tertiary amines such as diethylethanolamine and trihexylamine, hindered amines, organic phosphates, and hindered phenols, but is not limited to the above examples, and any stabilizer capable of producing a photocurable composition may be used without limitation.

[0127] In addition to the above photoinitiator and stabilizer, other additives may be additionally included.

[0128] The above additives may include conventional additives such as leveling agents, slip agents or stabilizers to improve thermal and oxidation stability, storage stability, surface properties, flow properties and process properties.

[0129] The above UV resin comprises a photocurable oligomer of the present invention; and a monomer, and more specifically, may comprise a compound represented by the following chemical formula 1, a compound represented by the following chemical formula 7, and a compound represented by the following chemical formula 8 in a weight ratio of 1:1:1 to 2:1:1.

[0130] The coating composition containing the zwitterionic ion can be applied to the 3D printed transparent orthodontic device and centrifuged so that the coating composition containing the zwitterionic ion can be evenly applied to the surface of the transparent orthodontic device. However, the centrifugation process may not be performed separately if alcohol is additionally included in the coating composition. As described above, if alcohol is included in the coating composition, the viscosity of the coating composition is greatly reduced, so that it can be evenly applied to the surface of the transparent orthodontic device even without a separate centrifugation process.

[0131] The step of post-curing the transparent orthodontic device having the coating layer formed thereon can increase the conversion rate of unreacted monomers in the 3D printed transparent orthodontic device by irradiating the transparent orthodontic device having the coating layer formed thereon with UV under an inert gas atmosphere, and at the same time, increase the bonding strength between the coating layer and the transparent orthodontic device.

[0132] The above coating composition contains a zwitterionic ion and a photocurable monomer as described above. In addition, in the case of a transparent orthodontic device printed by a 3D printer, the above-described photocurable composition is cured and manufactured in the form of a orthodontic device. However, the transparent orthodontic device printed by the 3D printer contains an unreacted monomer, and the unreacted monomer contains an acrylic group, as the photocurable composition is not completely cured and generally shows a conversion rate of about 50 to 70%. As the coating composition is applied, the acrylic group chemically bonds with the zwitterionic ion and the photocurable monomer in the coating composition, and a more solid bond occurs through the above-described post-curing step.

[0133] The above post-curing step specifically irradiates UV light on a transparent orthodontic device having a coating layer formed in an inert gas environment to promote curing, thereby preventing deformation of the transparent orthodontic device, improving strength, preventing damage caused by external force, and increasing the bonding strength of the coating layer.

[0134] By carrying out the curing process in an inert gas environment, not only does the curing speed of the transparent orthodontic device increase, but its strength is also improved, preventing deformation and detachment of the coating layer even under high levels of impact.

[0135] In other words, when the curing process is performed using UV irradiation in an inert gas environment, the curing speed is accelerated by the inert gas, and the strength of the transparent orthodontic device can be improved. Furthermore, when the post-curing process is performed in an inert gas environment, the transparency of the transparent orthodontic device is further improved.

[0136] When a 3D printer using a DLP or SLA method is used to manufacture an orthodontic device, a transparent output is obtained. However, as described above, when a 3D printer using a DLP or SLA method is used to manufacture an output, unreacted monomers remain in the output. These unreacted monomers require additional curing. However, when the orthodontic device is exposed to the air during the post-curing process to cure these unreacted monomers, the photoinitiator in the orthodontic device comes into contact with oxygen to generate radicals, and the photocuring behavior is suppressed by the scavenging of the generated radicals.

[0137] That is, it is necessary to prevent the orthodontic device from contacting oxygen, and for this purpose, when performing the post-curing process in the present invention, post-curing is performed by irradiating UV in an inert gas environment, thereby blocking contact with oxygen.

[0138] When the above transparent orthodontic device is manufactured as a personalized output using 3D printing and used as an orthodontic device, if the transparency is not excellent and there is even a slight yellow tint, there is a risk of the user mistaking it for a poor dental condition, which could have a negative impact on the user's appearance.

[0139] To avoid these problems, the 3D printed object itself must be able to exhibit a degree of complete transparency.

[0140] When a conventional DLP or SLA printer is used to produce an output and then a product is manufactured through a post-curing process, some differences may occur depending on the type of photocurable polymer resin, but it usually has a yellowish tint, making it impossible to provide a completely transparent orthodontic device.

[0141] On the other hand, as in the present invention, when UV is irradiated in an inactive environment during the post-curing process, the curing speed is improved and the strength is improved by the UV irradiation, and the transparency of the transparent orthodontic device is improved.

[0142] That is, when a post-curing process such as that of the present invention is performed, it is possible to provide a completely transparent orthodontic device.

[0143] When a post-curing process is performed using UV in an inert gas environment, the curing speed is improved, which improves the production speed of the final product, and the strength is excellent, making it less susceptible to deformation due to external force.

[0144] The above inert gas is selected from the group consisting of nitrogen, argon, helium, krypton, neon and mixtures thereof, preferably nitrogen, but is not limited to the above examples, and any gas capable of blocking contact with oxygen as an inert gas can be used without limitation.

[0145] According to another embodiment of the present invention, a transparent orthodontic device is characterized by having a coating layer formed by a coating composition containing zwitterionic ions. The transparent orthodontic device is manufactured using the above-described manufacturing method, and the coating layer is formed on the surface, thereby exhibiting excellent anti-fouling properties, anti-reduction of viability, and anti-protein adsorption effects.

[0146] In addition, as described above, the post-curing process is performed in an inert gas environment, and thus, it is characterized by excellent transparency.

[0147] The above transparent orthodontic device may be printed using the photocurable composition for a 3D printer described above, but is not limited to the above example, and any material that can be used in the manufacture of a transparent orthodontic device may be applied.

[0148] That is, the transparent orthodontic device of the present invention is characterized by having a coating layer formed by the above-described coating composition, and is not limited to a transparent orthodontic device printed by the above-described photocurable composition for a 3D printer.

[0149] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0150] Manufacturing example

[0151] Preparation of photocurable compositions

[0152] Manufacturing Example 1 (Example 1)

[0153] Isobornyl acrylate was used as a solvent, and polypropylene glycol, cyclohexanedimethanol, and BHT were added, and stirred at 10 to 200 rpm at 10 to 50°C. Isophorone diisocyanate was added, and stirring was performed under the same temperature conditions while changing the stirring speed from 50 to 200 rpm. Afterwards, HEMA was added, and stirring was performed at 150 to 500 rpm at 50 to 250°C to produce an oligomer.

[0154] The intermediate compounds produced by the above reaction are as follows:

[0155]

[0156] The oligomer finally produced by reacting the above intermediate compounds is as follows:

[0157]

[0158] Here,

[0159] p and q are equal to or different from each other and are each independently an integer from 1 to 10.

[0160] The sequence of the manufacturing method of the above Example 1 is as shown in Fig. 1.

[0161] The GPC analysis results for the oligomer of Example 1 are as shown in Fig. 2. In addition, the NMR analysis results are as shown in Fig. 3.

[0162] The results of the analysis of the oligomer of Example 1 are summarized in Table 1 below:

[0163] Example 1GPCMn4179Mw6944PDI1.68NMRA(6.44)OB(5.89)OC(5.61)O(39.0)D(4.91)O(87.9)E(6.48)XF(6.49)XG(3.41)O

[0164] Manufacturing Example 2

[0165] 1 part by weight of DPPO as a photoinitiator was mixed with 100 parts by weight of UV resin in which the oligomer of Example 1, the compound represented by the above chemical formula 8, and the compound represented by the above chemical formula 9 were mixed in a weight ratio of 2:1:1, and a photocurable composition for a 3D printer was prepared by mixing and defoaming using a paste mixer.

[0166] [Chemical Formula 8]

[0167]

[0168] [Chemical Formula 9]

[0169]

[0170] Preparation of coating composition

[0171] A mixture was prepared by mixing 1 part by weight of a zwitterion and 5 parts by weight of DPP0 as a photocuring agent with respect to 100 parts by weight of a photocurable monomer represented by the following chemical formula 1, and using a tip ultrasonic processor, dispersing for 1 second at an output of 750 W, and resting for 1 second, repeating this process for 1 hour:

[0172] [Chemical Formula 1]

[0173]

[0174] MPC and SBMA were used as zwitterions, and the mixing ratio of MPC and SBMA is as shown in Table 2 below:

[0175] Example 2 Example 3 Example 4 Example 5 Example 6SBMA11111MPC10.10.51.52

[0176] Experimental example

[0177] The photocurable composition manufactured in the above Manufacturing Example 2 was placed in a 3D printer to manufacture a specimen, and then each specimen was placed in the coating composition of Examples 2 to 6, removed, and centrifuged.

[0178] Afterwards, the specimen was placed in a completely nitrogen atmosphere inside the curing machine and then post-cured by UV irradiation for 25 minutes.

[0179] Results of protein adsorption prevention experiment

[0180] The specimens prepared in the above experimental examples were immersed in fresh phosphate-buffered saline (PBS, Gibco) at room temperature for 1 hour. Each sample was then immersed in bovine serum albumin (BSA; Pierce Biotechnology) broth (2 mg of protein / mL in PBS, 100 μL). After incubation for 4 hours at 37°C in 5% CO2, unbound proteins were removed by washing twice with PBS. Afterwards, the amount of protein bound to the specimens was measured using micro-bicinchoninic acid (200 μL; Micro BCATM Protein Assay Kit, Pierce Biotechnology), and then incubated at 37°C for 30 minutes. The amount of surface-adsorbed protein was quantified based on the optical density (OD) at 562 nm measured using a microplate reader (Epoch, BioTek Instruments). The experimental results are shown in Figure 4.

[0181] As a control, a photocurable composition manufactured in Manufacturing Example 2 was manufactured into a specimen, and then a specimen without forming a separate coating layer was used. As a result of the experiment, it was confirmed that a large amount of protein was adsorbed in the control specimen. On the other hand, in the case of a specimen in which a coating layer was formed with a coating composition containing a zwitterion within the scope of the present invention, it was confirmed that the amount of adsorbed protein was significantly less, confirming that the effect of preventing protein adsorption was excellent.

[0182] Bacterial adsorption prevention experiment

[0183] Before conducting the bacterial adsorption inhibition experiment, all specimens were sterilized by ultraviolet irradiation. Actinomyces naeslundii (A. naeslundii) was cultured under anaerobic conditions using 3.8% BHI supplemented with 0.5% yeast extract (Becton Dickinson and Co. Sparks, MD, USA), 4 μg / mL resazurin (Sigma-Aldrich, St. Louis, MO, USA), 5 μg / mL hemin (Sigma-Aldrich, St. Louis, MO, USA), 0.05% L-cysteine ​​(Sigma-Aldrich, St. Louis, MO, USA), and 2 μg / mL vitamin K (Sigma-Aldrich, St. Louis, MO, USA).

[0184] After sufficient bacterial growth, 1 mL (108 cells / mL) of bacterial suspension was added to each sample in a 24-well plate and incubated at 37°C for 24 h. After incubation, the samples were gently washed twice with PBS to remove non-adherent bacteria. To assess bacterial colony forming units (CFU), attached bacteria were harvested by sonication (SH-2100, Saehan Ultrasonic, Seoul, Korea) in 1 mL of BHI for 5 min. 100 μL of this bacterial suspension was spread on an agar plate, incubated at 37°C for 24 h, and then colonies were counted.

[0185] The bacterial culture was centrifuged, and the bacterial pellet was resuspended in fresh medium until the optical density (OD) reached 0.55 (measured at a wavelength of 600 nm). The specimens were individually placed into each well of a 24-well plate containing 1 mL of medium and the bacterial cell suspension (OD = 0.55) and incubated for 24 h in a humidified atmosphere at 36°C. After incubation, each specimen was washed three times with Dulbecco's PBS (DBPS, Gibco BRL, USA) to remove loosely attached bacteria. Bacteria that were firmly attached to the substrate were fixed by passing the bottom of the sample over the flame of a Bunsen burner. The fixed sample was placed in 1 mL of a 0.1% gram crystal violet solution (Sigma-Aldrich, USA) and incubated at room temperature for 10 minutes. After the staining step, each sample was washed twice with 1 mL of DPBS and then placed in 1 mL of 95% ethanol to dissolve the crystal violet stain on the surface. 100 μL of the crystal violet solution dissolved for 10 minutes was added to each well of a 96-well plate, and the absorbance of the sample was measured at 570 nm using a microplate reader.

[0186] The experimental results are as shown in Fig. 5. The experimental results confirm that a large amount of bacteria were adsorbed in the control group. On the other hand, in the case of a specimen in which a coating layer was formed using a coating composition containing a zwitterionic compound within the scope of the present invention, the amount of adsorbed bacteria was significantly reduced, confirming the excellent effect of preventing bacterial adsorption.

[0187] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0188] The present invention relates to a coating composition containing a zwitterionic ion and a transparent orthodontic device having a surface coated using the same.

Claims

1. Contains a zwitterionic and photocurable monomer, The above zwitterions are sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC). A coating composition comprising a zwitterionic ion.

2. In paragraph 1, The above photocurable monomer is a compound represented by the following chemical formula 1. Coating composition containing zwitterionic ions: [Chemical Formula 1] 3. In paragraph 1, The above coating composition further comprises a photoinitiator. A coating composition comprising a zwitterionic ion.

4. In paragraph 3, The above coating composition comprises 0.1 to 1 part by weight of a zwitterion and 1 to 5 parts by weight of a photoinitiator, based on 100 parts by weight of a photocurable monomer. The above zwitterionic compound comprises sulfobetaine methacrylate (SBMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) in a weight ratio of 1:0.5 to 1:1.

5. A coating composition comprising a zwitterionic ion.

5. A transparent orthodontic device with a coating layer containing positive ions. The above coating layer is formed by applying a coating composition containing a zwitterionic agent according to any one of claims 1 to 4. Clear aligners.

6. In paragraph 5, The above transparent orthodontic device is printed by a 3D printer. Clear aligners.

7. In paragraph 5, The coating composition containing the zwitterionic ion is applied to the transparent orthodontic device, and centrifuged to evenly apply the coating composition containing the zwitterionic ion to the surface of the transparent orthodontic device. Clear aligners.

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