COMPOSITION FOR FORMING TRANSPARENT ORTHODONTIC DEVICE, METHOD OF PREPARING TRANSPARENT ORTHODONTIC DEVICE, AND TRANSPARENT ORTHODONTIC DEVICE PREPARED BY USING THE METHOD

Abstract

Provided are a composition for forming a transparent orthodontic device, a method of preparing a transparent orthodontic device, and a transparent orthodontic device prepared by using the method. The composition includes 100 parts by weight of a first photocurable compound represented by Formula 1, 35 parts by weight to 75 parts by weight of a second photocurable compound represented by Formula 2, 15 parts by weight to 65 parts by weight of a third photocurable compound represented by Formula 3, 5 parts by weight to 40 parts by weight of a fourth photocurable compound represented by Formula 4, and 1 part by weight to 15 parts by weight of a fifth photocurable compound represented by Formula 5.

Claims

1. A composition for forming a transparent orthodontic device, the composition comprising: 100 parts by weight of a first photocurable compound represented by Formula 1; 35 parts by weight to 75 parts by weight of a second photocurable compound represented by Formula 2; 15 parts by weight to 65 parts by weight of a third photocurable compound represented by Formula 3; 5 parts by weight to 40 parts by weight of a fourth photocurable compound represented by Formula 4; and 1 part by weight to 15 parts by weight of a fifth photocurable compound represented by Formula 5: [Formula 1] R′CH.sub.2[C(CH.sub.3)(R)CH.sub.2].sub.2CH.sub.2R′(R=H or CH.sub.3, R′=NHCO.sub.2CH.sub.2CH.sub.2O.sub.2CC(CH.sub.3)=CH.sub.2) ##STR00005## [Formula 3] CH.sub.2=C(CH.sub.3)COOCH.sub.2CH.sub.2OH ##STR00006## [Formula 5] CH.sub.2=C(CH.sub.3)COO(CH.sub.2CH.sub.2O).sub.3COC(CH.sub.3)=CH.sub.2.

2. The composition of claim 1, further comprising an acrylic resin in an amount of 0.5 parts by weight to 5 parts by weight based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound.

3. The composition of claim 1, further comprising a photoinitiator in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound.

4. The composition of claim 1, further comprising an antioxidant in an amount of 0.1 parts by weight to 2 parts by weight based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound.

5. The composition of claim 1, wherein the composition is free of a pigment.

6. The composition of claim 1, further comprising the composition is free of a solvent.

7. The composition of claim 1, further comprising the composition has a viscosity of 300 cps to 800 cps.

8. The composition of claim 1, wherein the composition is liquid, photo-curable, and is used for three-dimensional printing.

9. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 1; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

10. A transparent orthodontic device prepared by the method of claim 9.

11. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 2; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

12. A transparent orthodontic device prepared by the method of claim 11.

13. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 3; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

14. A transparent orthodontic device prepared by the method of claim 13.

15. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 3; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

16. A transparent orthodontic device prepared by the method of claim 15.

17. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 3; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

18. A transparent orthodontic device prepared by the method of claim 17.

19. A method of forming a transparent orthodontic device, the method comprising: preparing the composition of claim 4; preparing a partially cured transparent orthodontic device by three-dimensional printing the composition; and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device.

20. A transparent orthodontic device prepared by the method of claim 19.

Description

BRIEF DESCRIPTION OF DRAWING

[0041] FIG. 1 shows a flowchart illustrating a method of preparing a transparent orthodontic device according to an embodiment of the present disclosure.

MODE OF DISCLOSURE

[0042] Hereinafter, a composition for forming a transparent orthodontic device according to an embodiment of the present disclosure will be described in detail.

[0043] A composition for forming a transparent orthodontic device according to an embodiment of the present disclosure includes 100 parts by weight of a first photocurable compound represented by Formula 1, 35 parts by weight to 75 parts by weight of a second photocurable compound represented by Formula 2, 15 parts by weight to 65 parts by weight of a third photocurable compound represented by Formula 3, 5 parts by weight to 40 parts by weight of a fourth photocurable compound represented by Formula 4, and 1 part by weight to 15 parts by weight of a fifth photocurable compound represented by Formula 5:

[0044] [Formula 1]

[0045] R′CH.sub.2[C(CH.sub.3)(R)CH.sub.2].sub.2CH.sub.2R′(R=H or CH.sub.3, R′=NHCO.sub.2CH.sub.2CH.sub.2O.sub.2CC(CH.sub.3)=CH.sub.2)

##STR00003##

[0046] [Formula 3]

[0047] CH2=C(CH.sub.3)COOCH.sub.2CH.sub.2OH

##STR00004##

[0048] [Formula 5]

[0049] CH.sub.2=C(CH.sub.3)COO(CH.sub.2CH.sub.2O).sub.3COC(CH.sub.3)=CH.sub.2.

[0050] The first photocurable compound may be a mixture in which an isomer in which R is H and an isomer in which R is CH.sub.3, are mixed in a certain ratio. For example, the first photocurable compound may have a molecular formula of C.sub.23H.sub.38N.sub.2O.sub.8 and a molecular weight of 470.56.

[0051] When the amount of each of the first photocurable compound, the second photocurable compound, the third photocurable compound, and the fourth photocurable compound is within the corresponding range, a transparent orthodontic device which has excellent flexural strength, a long elongation at break, and a suitable level of flexural modulus of elasticity and thus is not easily broken, and which is mostly made of a resin and thus does not damage a normal tooth due to a soft surface, may be prepared.

[0052] Each of the photo-curable compounds may be ultraviolet (UV) curable.

[0053] In an embodiment, the composition for forming a transparent orthodontic device may further include 0.5 parts by weight to 5 parts by weight of an acrylic resin based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound. When the amount of the acrylic resin is within the above range, the overall properties (i.e., properties other than flexural strength, elongation at break, and flexural modulus of elasticity) of the transparent orthodontic device may be improved.

[0054] The acrylic resin may include Dianal BR-83 (manufactured by Mitsubishi Rayon, a glass transition temperature of 105° C., a weight average molecular weight of 40,000), Dianal BR-87 (manufactured by Mitsubishi Rayon, a glass transition temperature of 105° C., a weight average molecular weight of 25,000), Dianal BR-60 (manufactured by Mitsubishi Rayon, a glass transition temperature of 75° C., a weight average molecular weight of 70,000), Dianal BR-77 (manufactured by Mitsubishi Rayon, a glass transition temperature of 80° C., a weight average molecular weight of 65,000), or a combination thereof.

[0055] In an embodiment, the composition for forming a transparent orthodontic device may further include 1 part by weight to 20 parts by weight of a photoinitiator based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound. When the amount of the photoinitiator is within the range, a curing time of the composition for forming a transparent orthodontic device may be appropriate and the storage stability thereof may be improved, and the cured product (i.e. the final transparent orthodontic device) may have a wrinkle-free and smooth surface.

[0056] The photoinitiator may include acetophenone, benzyl, benzoin, benzophenone, 2-benzoylbenzoic acid, 4,4′-bis(diethylam ino)benzophenone, 4,4′-bis(dimethylamino)benzophenone, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin ethyl ether, 4-benzoylbenzoic acid, 2,2′-bis( 2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole, methyl 2-benzoylbenzoate, 2-(1,3-benzodioxol-5-yl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone, (±)-camphorquinone, 2-chlorothioxanthone, 4,4′-dichlorobenzophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4-diethylthioxanthene-9-one,diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, 1,4-dibenzoylbenzene, 2-ethylanthraquinone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone 2-isopropylthioxanthone, lithium phenyl (2,4,6-trimethylbenzoyl)phosphinate, 2-methyl-4′-(methylthio)-2-morpholinopropiophenone, 2-isonitrosopropiophenone, 2-phenyl-2-(p-toluenesulfonyloxy)acetophenone, phenylbis (2,4,6-trimethylbenzoyl)phosphine oxide, or a combination thereof.

[0057] In an embodiment, the composition for forming a transparent orthodontic device may further include 0.1 parts by weight to 2 parts by weight of an antioxidant based on 100 parts by weight of the total weight of the first photocurable compound, the second photocurable compound, the third photocurable compound, the fourth photocurable compound, and the fifth photocurable compound. When the amount of the antioxidant is within the above range, sufficient antioxidant effects may be obtained and may not adversely affect other properties of the transparent orthodontic device.

[0058] The antioxidant may include: a hindered phenol-based compound such as 2,6-di -tert-butyl-para-cresol, or 4,4′-methylenebis (6-tert-butyl-ortho-cresol); an aromatic amine-based compound such as dioctyldiphenylamine or phenylalpha-naphthalene; a sulfur compound; a phosphorus compound; a dialkyldithiophosphate (e.g., sulfurized fat, dicetyl sulfide, dibenzyldisulfide, or alkyldithiophosphates), which is a complex of sulfur and phosphorous; disalicylidine diaminopropane; didodecylthio benzimidazole; or a combination thereof.

[0059] In an embodiment, the composition for forming a transparent orthodontic device may not include a pigment.

[0060] The composition for forming a transparent orthodontic device may have a viscosity of 300 cps to 800 cps. The term “viscosity” used herein refers to a viscosity measured at room temperature (25° C.) using DV-quat heometer RPM (shear rate: 25/s) prepared by Brookfield Corporation.

[0061] The composition for forming a transparent orthodontic device may not include a solvent. However, the present disclosure is not limited thereto, and the composition for forming the transparent orthodontic device may further include a solvent.

[0062] The solvent may include ethanol, methanol, isopropanol, butanol, water, methylene glycol, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexylene glycol, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, cyclohexanone, cyclohexane, methylene chloride, chloroform, carbon tetrachloride, trichloroethylene, perchloroethylene, methyl glycol acetate, toluene, benzene, diethyl ether, benzyl alcohol, glycerin, or a combination thereof.

[0063] The composition for forming a transparent orthodontic device may further include an additive such as a stabilizer and a plasticizer.

[0064] The stabilizer may include benzophenone, oxanilide, benzotriazole, halogenated benzotriazole, triazine, or a combination thereof.

[0065] The plasticizer may include glycerin, propylene glycol, polyethylene glycol, ethylene glycol, sorbitol, mannitol, or a combination thereof.

[0066] The composition for forming a transparent orthodontic device may be a liquid (or suspension), photocurable, and used for 3D printing.

[0067] Hereinafter, a method of preparing a transparent orthodontic device according to an embodiment of the present disclosure will be described in detail.

[0068] FIG. 1 shows a flowchart illustrating a method of preparing a transparent orthodontic device according to an embodiment of the present disclosure.

[0069] Referring to FIG. 1, a method of preparing a transparent orthodontic device according to an embodiment of the present disclosure may include preparing a composition for forming a transparent orthodontic device (S10), preparing a partially cured transparent orthodontic device by 3D printing the composition for forming a transparent orthodontic device (S20), and preparing a final transparent orthodontic device by fully curing the partially cured transparent orthodontic device (S30).

[0070] In process S10, the mixing ratio of the five types of photocurable compounds, the acrylic resin, the photoinitiator, and the antioxidant may be appropriately controlled within the composition range of the composition for forming a transparent orthodontic device so as to obtain a transparent orthodontic device having the target flexural strength, the target elongation at break, and the target flexural modulus of elasticity.

[0071] Process S20 may be performed by a 3D printer, and the shape of the transparent orthodontic device may be formed by partially curing the composition for forming a transparent orthodontic device by continuously or intermittently irradiating ultraviolet rays onto the composition for forming a transparent orthodontic device printed during the 3D printing process. The term “partially curing” used herein refers to a condition where the curing rate is 40% to 90%.

[0072] In process S30, the partially cured transparent orthodontic device is completely cured using a separate curing device, thereby preparing a final transparent orthodontic device. The term “completely curing” used herein refers to a condition where the curing rate is 99% to 100%.

[0073] Hereinafter, a transparent orthodontic device prepared by the method of preparing the transparent orthodontic device, will be described in detail.

[0074] The transparent orthodontic device has outstanding mechanical properties (high flexural strength, high elongation at break, and an appropriate level of flexural modulus of elasticity) and high transparency.

[0075] Hereinafter, examples of the present disclosure will be described, but the present disclosure is not limited to the following examples.

[0076] Examples 1-1 to 1-9 and Comparative Examples 1-1 to 1-8: Preparation of Composition for Forming Transparent Orthodontic Device

[0077] Prepared was a composition for forming a transparent orthodontic device including: diurethane dimethacrylate represented by Formula 1 (Cas No. 72869-86-4, the mixture of a material in which R is H and a material having in which R is CH.sub.3, and a molecular formula: C.sub.23H.sub.38N.sub.2O.sub.8)(PP1), bisphenol A ethoxylate dimethacrylate represented by Formula 2 (Cas No. 41637-38-1)(PP2), hydroxyethyl methacrylate represented by Formula 3 (Cas No. 868-77-9)(PP3), a urethane acrylate oligomer represented by Formula 4 (Cas No. 106556-00-7)(PP4), and triethylene glycol dimethacrylate represented by Formula 5 (Cas No. 109-16-0)(PP5), which are photocurable compounds; Dianal BR-83 (manufactured by Mitsubishi rayon, a glass transition temperature 105° C., a weight average molecular weight 40,000), which is an acrylic resin; phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Cas No. 162881-26-7), which is a photoinitiator; and 2,6-di-tertiary-butyl-para-cresol, which is an antioxidant. The materials and amounts used in respective Example and Comparative Example are shown in Table 1. In Table 1, a unit of each value is parts by weight. In addition, the amount of each of the acrylic resin, the photoinitiator, and the antioxidant is based on 100 parts by weight of the total weight of the five kinds of photocurable compounds.

TABLE-US-00001 TABLE 1 Examples 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 Photocurable PP1 100 100 100 100 100 100 100 100 100 compound PP2 55 35 75 55 55 55 55 55 55 PP3 40 40 40 15 65 40 40 40 40 PP4 23 23 23 23 23 5 40 23 23 PP5 7 7 7 7 7 7 7 1 15 Acrylic resin 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Photoinitiator 6 6 6 6 6 6 6 6 6 Antioxidant 1 1 1 1 1 1 1 1 1 Comparative Example 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 Photocurable PP1 100 100 100 100 100 100 100 100 compound PP2 30 80 55 55 55 55 55 55 PP3 40 40 10 70 40 40 40 40 PP4 23 23 23 23 1 45 23 23 PP5 7 7 7 7 7 7 0.5 20 Acrylic resin 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Photoinitiator 6 6 6 6 6 6 6 6 Antioxidant 1 1 1 1 1 1 1 1

[0078] Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-6: Preparation of Transparent Orthodontic Devices

[0079] Each of the compositions for forming transparent orthodontic devices prepared according to Examples and Comparative Examples, was used for printing with a 3D printer and partially cured to prepare a partially cured transparent orthodontic device. Then, the partially cured transparent orthodontic device was completely cured using a curing device to prepare a final transparent orthodontic device. The 3D printer and the curing device were manufactured as a set, and were prepared by Ray Dent Studio Corporation. For each of the composition for forming a transparent orthodontic device, three transparent orthodontic devices were prepared using the corresponding composition.

[0080] Evaluation Example 1: Evaluation of Mechanical Properties of Transparent Orthodontic Device

[0081] The flexural strength, flexural modulus of elasticity (flexural modulus), and elongation at break of each of the transparent orthodontic devices prepared according to Examples and Comparative Examples were measured using a tensile strength tester. Results thereof are shown in Table 2. Here, the elongation at break refers to a distance by which a pusher descends until a specimen obtained by cutting long is broken, when the central portion of the specimen is pushed downwards by the pusher in the state where the specimen is placed on and perpendicular to a pair of elongated supports spaced from each other and disposed in parallel to each other (that is, a distance by which the pusher descends from a starting point at which the pusher initially contacts the specimen to a point at which the specimen is broken).

[0082] Evaluation Example 2: Evaluation of Transparency of Transparent Orthodontic Device

[0083] The sensory test was performed on each of the transparent orthodontic devices prepared according to Examples and Comparative Examples. Specifically, the five trained evaluators participated to carry out the sensory test as described below. That is, the level of transparency of each transparent orthodontic device was evaluated in a 5-point method by visual observation, and the respective scores were averaged and shown in Table 2 below. Here, the higher the score for each item, the higher the similarity of the corresponding item.

TABLE-US-00002 TABLE 2 Examples 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 Flexural 107.88 98.91 95.03 90.12 91.21 105.41 91.56 90.26 99.13 strength (MPa) Flexural 1948.26 1880.34 1881.3 1801.31 1832.45 1966.03 1983.66 1926.24 1982.84 modulus of elasticity (MPa) Elongation at 16.79 16.98 17.62 16.12 17.46 19.41 21.13 21.93 20.55 break (mm) Transparency 4.5 4.6 4.7 4.8 4.5 4.6 4.6 4.9 4.8 Comparative Example 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 Flexural 102.78 70.11 73.66 75.42 80.11 82.03 89.98 95.78 strength (MPa) Flexural 1511.32 1370.64 1470.3 1532.44 1512.51 1471.90 1581.90 1474.86 modulus of elasticity (MPa) Elongation at 11.98 4.96 6.42 7.72 4.01 12.24 13.56 12.16 break (mm) Transparency 4.6 4.5 4.7 4.8 4.6 4.5 4.8 4.9

[0084] Referring to Table 2, it can be seen that in terms of flexural strength and elongation at break, the transparent orthodontic devices prepared according to Examples 2-1 to 2-9 exhibited excellent properties compared to the transparent orthodontic devices prepared according to Comparative Examples 2-1 to 2-8.

[0085] Referring to Table 2, it can be seen that in terms of flexural strength, flexural modulus of elasticity, and elongation at break, the transparent orthodontic devices prepared according to Examples 2-1 to 2-9 exhibited excellent properties compared to the transparent orthodontic devices prepared according to Comparative Examples 2-2 to 2-7.

[0086] However, the transparent orthodontic devices prepared according to Comparative Examples 2-1 and 2-8 exhibited similar flexural strengths to but significantly smaller flexural modulus of elasticity and elongation at break than the transparent orthodontic devices prepared according to Examples 2-1 to 2-9.

[0087] In addition, it can be seen that the transparent orthodontic devices prepared according to Examples 2-1 to 2-9 and Comparative Examples 2-1 to 2-8 all showed high transparency.

[0088] Although embodiments of the present disclosure have been described with reference to the drawings and the embodiments, these embodiments are an example only, and those skilled in the art would understand that various modifications and other equivalent embodiments can be derived therefrom. Therefore, the scope of the present disclosure should be determined by the appended claims.