Dental resin composition, dental resin, preparation method of dental resin and dental restoration

Abstract

The invention provides a dental resin composition, a dental resin, a preparation method of the dental resin and a dental restoration. The dental resin composition comprises inorganic particles, a polymerizable monomer and a dispersing agent, the inorganic particles comprise barium glass powder with a first particle size and spherical silicon dioxide with a second particle size; the range of the first particle size D50 is 0.4-3 [mu] m, and the range of the second particle size D50 is 10-40 nm; the dispersing agent is a polyurethane type dispersing agent. According to the preparation method, a polyurethane-acrylate-epoxy hybrid network and a gradient interface phase can be constructed, long-chain steric hindrance and shear response design are realized through the structure, so that the viscosity of the resin is reduced, meanwhile, interface bonding is firmer through covalent bond bridging, and crown and bridge products are endowed with excellent properties of low viscosity, high wear resistance, high strength and high transparency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dental materials, in particular to a dental resin composition, a dental resin and a preparation method thereof and a dental restoration. BACKGROUND

[0002] The composite resin material is mainly composed of organic monomers, inorganic fillers, photoinitiating systems and part of additives, wherein the organic resin contains polymerizable groups, and a three-dimensional network structure is formed under the action of light curing, which can give the material a certain shape; and the inorganic filler mainly gives the composite material excellent mechanical properties, while reducing the shrinkage of the resin.

[0003] According to related reports, the phenomena of resin restoration breakage caused by insufficient mechanical properties, micro-leakage and secondary caries caused by polymerization shrinkage, etc. cause the clinical use effect of dental composite resin materials to be unsatisfactory.

[0004] In order to solve the above problems, it is tried to improve the mechanical properties of the composite resin material by developing reinforced fillers and optimizing the organic-inorganic interface, for example, CN115501121A prepares a porous SiO2 filler and a silanized non-porous SiO2 for compounding, wherein the porous filler forms a network structure of mutual hinge through the physical micromechanical interlocking effect of filler-resin, thereby improving the interface bonding force of organic-inorganic, but the process complexity of the porous filler is extremely high, resulting in high implementation cost of the composite resin; at the same time, the batch-to-batch porosity fluctuation of the porous SiO2 may affect the stability of the resin performance.

[0005] CN118615166A prepares an inorganic nanocluster body with a single component and a wide particle size distribution, and the bending strength of the composite resin prepared is 120-180MPa, but the dental restoration material needs to be clearly distinguished from the dental tissue, but the pure SiO2 composite resin obtained by the method has no X-ray blocking property, which is easy to cause misdiagnosis in the clinical end.

[0006] In summary, the current composite resin material still has the problems of low stability, insufficient wear resistance and low flexural modulus. SUMMARY

[0007] In view of the deficiencies in the prior art, the purpose of the present application is to provide a dental resin composition, a dental resin and a preparation method thereof and a dental restoration, which can obtain a dental resin material with excellent flexural strength, flexural modulus and wear resistance, and has a wide application prospect.

[0008] To achieve this purpose, the technical scheme adopted by the present application is as follows:

[0009] In a first aspect, the present invention provides a dental resin composition comprising: inorganic particles, polymerizable monomers, and a dispersant; wherein the inorganic particles comprise barium glass powder of a first particle size and spherical silica of a second particle size; the first particle size D50 ranges from 0.4 to 3 μm, and the second particle size D50 ranges from 10 to 40 nm; and the dispersant is a polyurethane-type dispersant.

[0010] When inorganic fillers are used as reinforcing components in composite resins, a single component cannot maximize the packing density. It is usually necessary to combine large and small particles to achieve effective filling. However, due to the huge differences in specific surface area and surface energy of fillers with different particle sizes, filler agglomeration is very likely to occur during the dispersion process, which in turn affects the overall mechanical properties of the composite resin material.

[0011] By using barium glass powder of different particle sizes and spherical silica of different particle sizes, dense packing of inorganic fillers is achieved, resulting in excellent effective filling capacity when mixed with organic systems. The combination of irregular and spherical powders can achieve a "gap-filling" effect between particle sizes, significantly improving the flexural strength and wear resistance of the composite material. Meanwhile, barium glass powder is a barium aluminum silicon series glass, whose main components include silica, alumina, barium oxide, etc. The biggest advantage of barium glass powder as an inorganic filler is that it contains the heavy metal barium element. When added to the resin matrix, the composite resin has X-ray radiopaque properties, which is beneficial for clinical examination of the restorative effect of composite resin in the oral cavity.

[0012] Simultaneously, an organic composition combining polymerizable monomers and dispersants is selected. The chosen dispersant is a polyurethane-type dispersant with groups on its surface that are compatible with acrylic resins, forming a firmly bonded organic-inorganic interface. This improves the flexural strength and wear resistance of the composite resin. Furthermore, the addition of the dispersant wets the powder surface, reducing surface energy. The dispersant's dispersion mechanism includes electrostatic stabilization, steric stabilization, and electro-steric stabilization mechanisms. A polyurethane dispersant with methacrylate end groups combines the interfacial control capabilities of polyurethane with the polymerizability of methacrylate. Through steric stabilization and electrostatic stabilization, it can synergistically inhibit filler agglomeration, while methacrylate end-group copolymerization can achieve strong interfacial bonding. The dental resin provided by this invention also possesses low viscosity, making it suitable for DLP-type 3D printing. The 3D printing composite resin prepared by this invention has a viscosity below 6000 mPa·s, a flexural modulus greater than 210 MPa after molding, and an wear value below 2 mm. 3 This improves the overall performance of 3D printing composite resin materials.

[0013] This invention has the following advantages:

[0014] 1. Improved wear resistance of composite resins. By compounding different types of inorganic fillers, a multi-level defense system of "rigid-hard-tough" can be constructed in the resin, improving its wear resistance. Compared with traditional single-component filler addition methods, this technical solution can achieve a balance and enhancement of mechanical properties, improving the product's durability.

[0015] 2. Reduced viscosity of composite resin. Using polyurethane dispersants can inhibit filler agglomeration through steric hindrance and reduce filler-resin friction, thereby lowering viscosity. Compared to the composition of traditional composite resins, dispersants help the filler to disperse evenly over a long period, improving the resin's anti-settling properties while reducing viscosity, resulting in better leveling properties during printing.

[0016] 3. Improved Transparency of Composite Resins. By compounding inorganic fillers with different refractive indices, the refractive index of the fillers can be made closer to that of traditional resin-based mixtures, thus enabling the production of composite materials with higher transparency. Compared to the traditional method of adding single-component fillers, this technical solution can more effectively control the resin transparency, resulting in products with better aesthetic effects.

[0017] Specifically, the first particle size ranges from 0.4 to 3 μm, for example, it can be 0.4 μm, 0.7 μm, 1 μm, 1.3 μm, 1.6 μm, 1.9 μm, 2.2 μm, 2.5 μm, 2.8 μm, or 3 μm, but is not limited to the listed values; other unlisted values ​​within this range also apply. The second particle size has a D50 of 10 to 40 nm, for example, it can be 10 nm, 14 nm, 17 nm, 20 nm, 24 nm, 27 nm, 30 nm, 34 nm, 37 nm, or 40 nm, but is not limited to the listed values; other unlisted values ​​within this range also apply.

[0018] Preferably, the polyurethane dispersant is a methylpropionic acid ester-terminated polyurethane dispersant.

[0019] In this invention, a polyurethane dispersant with methylpropionic acid ester end caps is preferred. Strong interfacial bonding can be achieved through copolymerization of methylpropionic acid ester end groups, resulting in better mechanical properties. If a polyurethane dispersant without end capping is used, it relies solely on physical adsorption (such as hydrogen bonding, van der Waals forces, etc.), which results in weak interfacial bonding and a relatively loose physical structure, leading to a weakening of the system's mechanical properties.

[0020] Preferably, the barium glass powder comprises a combination of at least two of the following: glass powder with a particle size D50 of 0.4–1 μm, glass powder with a particle size D50 of 1–2 μm, and barium glass powder with a particle size D50 of 2–3 μm.

[0021] This invention, through the combination of at least two of the above-mentioned barium glass powders, can significantly improve the bulk density, thereby achieving ultra-high filling of inorganic particles. When compounded with a polyurethane dispersant, it can achieve high wear resistance and high strength of dental resin at low viscosity.

[0022] Preferably, the mass ratio of the two types of glass powder is 0.8 to 1.2:1, for example, it can be 0.8:1, 0.82:1, 0.85:1, 0.88:1, 0.89:1, 0.9:1, 0.92:1, 0.95:1, 0.99:1, 1.0:1, 1.05:1, 1.08:1, 1.09:1, 1.1:1, 1.12:1, 1.13:1, 1.15:1, 1.18:1, or 1.2:1, etc.

[0023] Preferably, the barium glass powder has the composition BaO-Al2O3-SiO2-B2O3.

[0024] The present invention does not have a specific limitation on the composition of barium glass powder, and barium glass powder known to those skilled in the art can be used.

[0025] Preferably, the spherical silica includes any one or a combination of at least two of the following: spherical silica with a D50 of 10-20 nm, spherical silica with a D50 of 20-30 nm, or spherical silica with a D50 of 30-40 nm.

[0026] Preferably, the barium glass powder has an irregular shape.

[0027] The irregular shape described in this invention refers to a shape that is not conventionally recognized as spherical, cubic, or otherwise having an axis of symmetry or a central axis of symmetry. That is, the barium glass powder does not have an axis of symmetry or a central axis of symmetry. Due to its irregular shape and the presence of portions of different sizes, it exhibits superior filling properties when combined with spherical silica.

[0028] Preferably, the barium glass powder is silane-modified barium glass powder.

[0029] Preferably, the spherical silica is silane-modified spherical silica.

[0030] After being modified by a modifier, irregularly shaped barium glass powder and spherical silica have organic groups grafted onto their surfaces. These groups can form a strong chemical bond with the resin matrix, making it difficult for inorganic fillers to fall off when the composite material is worn.

[0031] Preferably, the silane-modifying modifier is KH570.

[0032] The present invention does not have any special requirements for the specific method of silane modification, and modification methods well known to those skilled in the art can be used.

[0033] Preferably, the polymerizable monomer comprises any one or a combination of at least two of bisphenol A dimethacrylate, bisphenol A glycerol dimethacrylate, urethane dimethacrylate, or ethoxybisphenol A dimethacrylate, wherein typical but atypical combinations are the combination of bisphenol A dimethacrylate and bisphenol A glycerol dimethacrylate, the combination of urethane dimethacrylate and bisphenol A glycerol dimethacrylate, the combination of bisphenol A dimethacrylate and urethane dimethacrylate, or the combination of ethoxybisphenol A dimethacrylate and urethane dimethacrylate.

[0034] Preferably, the number of ethoxy groups in the ethoxybisphenol A dimethacrylate is 1 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0035] Preferably, the polyurethane dispersant includes Sago9030, Dispers 685, BYK-P-104, BYK-W-907, BYK-W-961, or BYK-110, or at least two of these, wherein a typical but non-limiting combination is Sago 9030 and The combination of Dispers 685, BYK-P-104 and Combinations of Dispers 685, Sago 9030 and BYK-P-104, BYK-W-907 and BYK-W-961, and BYK-W-907 and BYK-110.

[0036] Preferably, the dental resin composition comprises, by weight fraction, 10-30 parts polymerizable monomer, 10-80 parts barium glass powder, 10-80 parts spherical silica and 1-5 parts dispersant.

[0037] The polymerizable monomer can be 10 to 30 parts, for example, 10, 13, 15, 17, 19, 22, 24, 26, 28 or 30 parts, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] The amount of barium glass powder is 10 to 80 parts, for example, 10, 18, 26, 34, 42, 49, 57, 65, 73 or 80 parts, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] The amount of spherical silica is 10 to 80 parts, for example, 10, 18, 26, 34, 42, 49, 57, 65, 73 or 80 parts, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] The present invention preferably controls the mass fractions of barium glass powder and spherical silica within the above-mentioned range, which can better improve the nano-reinforced skeleton performance of spherical silica, improve wear resistance and long service life of the material; it can also improve the interlayer bonding force during ultraviolet printing and improve the mechanical properties of the material.

[0041] The dispersant is 1 to 5 parts, for example, 1 part, 1.5 parts, 1.9 parts, 2.4 parts, 2.8 parts, 3.3 parts, 3.7 parts, 4.2 parts, 4.6 parts or 5 parts, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the mass ratio of the dispersant to the inorganic particles is 1:(6-75), for example, it can be 1:6, 1:6.5, 1:7, 1:8, 1:9, 1:10, 1:15, 1:20, 1:25, 1:30, 1:45, 1:50, 1:60 or 1:75, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 1:(9-75).

[0043] In this invention, if the amount of dispersant added is too high, it will hinder the polymerization of active monomers and oligomers and reduce the crosslinking density. If the amount of dispersant added is too low, the filler will not be able to be dispersed evenly, resulting in agglomeration and a sharp increase in viscosity.

[0044] Preferably, the dental resin composition further includes an active diluent.

[0045] Preferably, the reactive diluent comprises any one or a combination of at least two of the following: acrylomorpholine, cyclic trimethylolpropane formal acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, tricyclodecanediethanol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, or tri(2-hydroxyethyl) isocyanurate triacrylate. Typical but non-limiting combinations include: a combination of acrylomorpholine and cyclic trimethylolpropane formal acrylate; a combination of acrylomorpholine and cyclic trimethylolpropane formal acrylate; a combination of hydroxyethyl methacrylate and cyclic trimethylolpropane formal acrylate; a combination of acrylomorpholine and hydroxyethyl methacrylate; a combination of tripropylene glycol diacrylate and hydroxyethyl methacrylate; and a combination of acrylomorpholine and tri(2-hydroxyethyl) isocyanurate triacrylate.

[0046] Preferably, the amount of active diluent in the dental resin composition is 10 to 20 parts by weight fraction, for example, 10, 12, 13, 14, 15, 16, 17, 18, 19 or 20 parts, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] Preferably, the dental resin composition further includes a photoinitiator.

[0048] Preferably, the photoinitiator comprises any one or a combination of at least two of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-isopropylthioxanthone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, wherein a typical but non-limiting combination is 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-phenyl-1- Combinations of acetone, combinations of 2-isopropylthioxanthanone and 2-hydroxy-2-methyl-1-phenyl-1-propanone, combinations of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2-isopropylthioxanthanone, combinations of 1-hydroxycyclohexylphenyl ketone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and combinations of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0049] Preferably, the amount of photoinitiator in the dental resin composition is 0.5 to 2 parts by weight, for example, 0.5 parts, 0.7 parts, 0.9 parts, 1 part, 1.2 parts, 1.4 parts, 1.5 parts, 1.7 parts, 1.9 parts or 2 parts, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0050] Preferably, the dental resin composition further includes colorants.

[0051] Preferably, the pigment includes any one or a combination of at least two of titanium oxide, iron oxide yellow, iron oxide red, or iron oxide black, wherein typical but non-limiting combinations are combinations of titanium oxide and iron oxide yellow, combinations of iron oxide red and iron oxide yellow, combinations of titanium oxide and iron oxide red, combinations of titanium oxide and iron oxide black, and combinations of iron oxide black and iron oxide yellow.

[0052] Preferably, the amount of pigment in the dental resin composition is 1.5 to 3 parts by weight, for example, 1.5 parts, 1.7 parts, 1.9 parts, 2 parts, 2.2 parts, 2.4 parts, 2.5 parts, 2.7 parts, 2.9 parts or 3 parts, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0053] Preferably, the dental resin composition further includes an antifoaming agent.

[0054] Preferably, the defoamer includes any one or a combination of at least two of the following: silicone defoamer 1100, defoamer 5200, silicone defoamer 2200, silicone defoamer 3300, or silicone defoamer 4400. Typical but non-limiting combinations include the combination of silicone defoamer 1100 and defoamer 5200, the combination of silicone defoamer 2200 and defoamer 5200, the combination of silicone defoamer 1100 and silicone defoamer 3300, and the combination of silicone defoamer 4400 and defoamer 5200.

[0055] Preferably, the amount of defoamer in the dental resin composition is 0.1 to 0.5 parts by weight, for example, 0.1, 0.15, 0.19, 0.24, 0.28, 0.33, 0.37, 0.42, 0.46 or 0.5 parts, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0056] Preferably, the dental resin composition further includes a polymerization inhibitor.

[0057] Preferably, the polymerization inhibitor comprises any one or a combination of at least two of hydroquinone, p-tert-butylcatechol, p-hydroxyanisole, 2,6-di-tert-butyl-p-methylphenol, 4,4'-dihydroxybiphenyl, or bisphenol A, wherein typical but non-limiting combinations are the combination of hydroquinone and p-tert-butylcatechol, the combination of 2,6-di-tert-butyl-p-methylphenol and p-tert-butylcatechol, the combination of hydroquinone and 2,6-di-tert-butyl-p-methylphenol, the combination of 4,4'-dihydroxybiphenyl and p-tert-butylcatechol, the combination of hydroquinone and bisphenol A, and the combination of p-hydroxyanisole and 2,6-di-tert-butyl-p-methylphenol.

[0058] Preferably, the amount of polymerization inhibitor in the dental resin composition is 0.05 to 0.1 parts by weight, for example, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts or 0.1 parts, etc., but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0059] In a second aspect, the present invention provides a method for preparing the dental resin composition described in the first aspect, the method comprising:

[0060] The first mixture of polymerizable monomer, reactive diluent, defoamer and polymerization inhibitor is stirred to obtain the first material.

[0061] The first material and the dispersant are mixed in a second process, and then stirred in a second process to obtain the second material.

[0062] Under the third stirring conditions, the third spherical silica and the second material are mixed to obtain the third material.

[0063] The fourth mixture of barium glass powder and the third material is stirred to obtain the fourth material.

[0064] The fourth material is sequentially ball-milled and degassed to obtain a dental resin composition.

[0065] The method for preparing the dental resin composition provided by this invention strictly limits the order of addition of each substance, so that the dispersant is uniformly premixed in the polymerizable monomer, and then the inorganic particles are added to the composition in a specific ratio and order. This enables the compounding of irregular and spherical powders to achieve a "gap filling" effect between particle sizes, thereby significantly improving the flexural strength and wear resistance of the composite material.

[0066] Preferably, the first mixing is carried out at a temperature of 40 to 60°C, such as 40°C, 43°C, 45°C, 47°C, 49°C, 52°C, 54°C, 56°C, 58°C, or 60°C, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0067] Preferably, the first mixing is carried out under light-protected conditions.

[0068] Preferably, the rotational speed of the first mixing is 600 to 800 rpm, for example, it can be 600 rpm, 620 rpm, 645 rpm, 660 rpm, 680 rpm, 710 rpm, 730 rpm, 750 rpm, 770 rpm or 800 rpm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0069] Preferably, the stirring time for the first mixing is 10 to 20 minutes, for example, it can be 10 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0070] Preferably, the second mixing includes: adding the dispersant in batches under stirring conditions of 600 to 800 rpm, and then performing a second stirring after the dispersant has been added. For example, the stirring speed can be 600 rpm, 620 rpm, 645 rpm, 660 rpm, 680 rpm, 710 rpm, 730 rpm, 750 rpm, 770 rpm, or 800 rpm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0071] Preferably, the second stirring speed is 800-1000 rpm, for example, it can be 800 rpm, 820 rpm, 845 rpm, 860 rpm, 880 rpm, 910 rpm, 930 rpm, 950 rpm, 970 rpm or 1000 rpm, but is not limited to the listed values, other unlisted values ​​in this range are also applicable.

[0072] Preferably, the second stirring time is 30 to 60 minutes, for example, it can be 30 minutes, 34 minutes, 37 minutes, 40 minutes, 44 minutes, 47 minutes, 50 minutes, 54 minutes, 57 minutes or 60 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0073] Preferably, between the second stirring and the third stirring, the second material system is first subjected to vacuum treatment.

[0074] Preferably, the single vacuuming time is 3 to 8 minutes, for example, it can be 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes or 8 minutes.

[0075] Preferably, the number of vacuuming cycles is 4 to 8, for example, 4, 5, 6, 7 or 8 times.

[0076] Preferably, the rotation speed of the third stirring is 300 to 500 rpm, for example, it can be 300 rpm, 320 rpm, 345 rpm, 360 rpm, 380 rpm, 410 rpm, 430 rpm, 450 rpm, 4708 rpm or 500 rpm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0077] Preferably, the spherical silica is added in batches.

[0078] This invention preferably uses spherical silica added in batches, which significantly improves the initial dispersion efficiency and the wettability of the filler surface, resulting in a more uniform and stable final dispersion. If the silica is not added in batches, the slurry viscosity will increase sharply and the filler will be difficult to disperse, leading to defects in the final product's rheological properties and stability.

[0079] Preferably, the amount of spherical silica added in each batch is the same.

[0080] Preferably, the spherical silica is produced in 3 to 5 batches.

[0081] Preferably, the fourth stirring includes performing a first sub-stirring after the materials are mixed, and then performing a second sub-stirring.

[0082] Preferably, the rotational speed of the second sub-stirring is greater than that of the first sub-stirring.

[0083] The present invention preferably increases the rotation speed to the speed of the second sub-stirring after the materials are mixed, which has the advantages of significantly optimizing rheological properties and shortening the process time by depolymerizing the hard agglomerate structure of the filler.

[0084] Preferably, the rotation speed of the first sub-stirring is 300 to 500 rpm, for example, it can be 300 rpm, 320 rpm, 345 rpm, 360 rpm, 380 rpm, 410 rpm, 430 rpm, 450 rpm, 4708 rpm or 500 rpm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0085] Preferably, the stirring time of the first sub-stirring is 10 to 30 minutes, for example, it can be 10 minutes, 13 minutes, 15 minutes, 17 minutes, 19 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or 30 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0086] Preferably, the rotation speed of the second sub-stirring is 600 to 800 rpm, for example, it can be 600 rpm, 620 rpm, 645 rpm, 660 rpm, 680 rpm, 710 rpm, 730 rpm, 750 rpm, 770 rpm or 800 rpm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0087] Preferably, the stirring time of the second sub-stirring is 60 to 120 minutes, for example, it can be 60 minutes, 67 minutes, 74 minutes, 80 minutes, 87 minutes, 94 minutes, 100 minutes, 107 minutes, 114 minutes or 120 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0088] Preferably, the degassing treatment is a vacuum stirring degassing treatment.

[0089] Thirdly, the present invention provides a dental resin, wherein the raw material of the dental resin is the dental resin composition described in the first aspect.

[0090] Fourthly, the present invention provides a method for preparing the dental resin described in the third aspect, the method comprising: subjecting the dental resin composition described in the first aspect to photocuring printing and photocuring molding to obtain the dental resin.

[0091] Preferably, the temperature for photocuring printing is 15 to 35°C, for example, it can be 15°C, 18°C, 20°C, 22°C, 24°C, 27°C, 29°C, 31°C, 33°C or 35°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0092] Preferably, the wavelength of the photopolymerization printing is 355-410nm, such as 355nm, 362nm, 368nm, 374nm, 380nm, 386nm, 392nm, 398nm, 404nm or 410nm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0093] Preferably, the optical power of the photocuring molding is 100–200 mW / cm². 2 For example, it could be 100mW / cm 2 112mW / cm 2 123mW / cm 2 134mW / cm 2 145mW / cm 2 156mW / cm 2 167mW / cm 2 178mW / cm 2 189mW / cm 2 Or 200mW / cm 2 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0094] Preferably, the photocuring time is 10 to 30 minutes, for example, 10 minutes, 13 minutes, 15 minutes, 17 minutes, 19 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or 30 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0095] Fifthly, the present invention provides a dental restoration, which is any one of a single crown, inlay, high inlay, crown, bridge, veneer or implant superstructure, and the dental restoration includes the dental resin described in the third aspect.

[0096] Compared with the prior art, the present invention has at least the following beneficial effects:

[0097] (1) The dental resin composition provided by the present invention is compounded with irregular barium glass powder with multi-level particle size and spherical silica, and achieves ultra-high filling of inorganic filler through extreme packing density; at the same time, a polyurethane dispersant (methacrylic acid ester-terminated reactive polyurethane dispersant) is introduced to generate a "polyurethane-acrylate-epoxy hybrid network" and a "gradient interface phase", and the above structure realizes long chain steric hindrance and shear response design, thereby reducing resin viscosity.

[0098] (2) The dental resin obtained by printing and curing the dental resin composition provided by the present invention has the effects of high wear resistance, high strength and high permeability;

[0099] (3) The dental resin provided by the present invention can be printed using 3D printing equipment to make crown and bridge resin, and can be used for upper teeth of removable dentures, single crowns, inlays and veneers, etc., with broad application prospects. Detailed Implementation

[0100] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0101] It should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0102] While CAD / CAM cutting technology has achieved digital transformation, its inherent limitations remain unavoidable: ① The cutting process results in the removal of up to 80% of prefabricated ceramic blocks, increasing material production costs; ② It cannot integrate heterogeneous components such as metal frameworks, resin gingiva, and ceramic crowns in a single processing step, hindering the development of personalized immediate loading solutions. With technological advancements, 3D printing dental technology, with its inherent advantage of layer-by-layer manufacturing, offers a transformative solution to these challenges: ① Additive manufacturing has a material loss rate of less than 5%, significantly reducing the application cost of high-value materials; ② Combined with intraoral scanning and design software, the entire process of "impression-design-printing-placement" can be completed within 3 hours, making it particularly suitable for clinical emergencies such as immediate implant restoration. However, current 3D printed crown and bridge resin materials generally suffer from insufficient mechanical properties, high viscosity limitations, and poor aesthetic results, failing to meet actual customer needs. Therefore, developing a low-viscosity, highly wear-resistant 3D printed dental resin that meets high aesthetic requirements (stronger durability and longer functional lifespan) is essential.

[0103] The type of inorganic particles plays a decisive role in the physicochemical and mechanical properties of dental composite resins. Barium glass powder, due to its X-ray blocking properties, has been widely used in 3D printing dental resins; however, focusing on a single filler component prevents the composite resin from achieving excellent mechanical properties. Secondly, limitations in the dispersion process lead to high resin viscosity, affecting its leveling properties and operability in practical use, failing to meet the requirements of ease of use and wide compatibility in specific application scenarios. This results in poor mechanical properties and leveling properties in 3D printed crown and bridge resins, leading to problems such as poor durability and short functional lifespan.

[0104] Therefore, this invention enhances the filling effect and density of the resin by mixing barium glass powder with different particle sizes, other types of inorganic particles, and polymerizable monomers, thereby improving the wear resistance and flexural strength of the dental resin. Furthermore, to improve the leveling properties of the dental resin composition, a method using polyurethane-type dispersants is proposed. These dispersants permanently chemically anchor and strengthen the interface, utilize steric hindrance to achieve low-viscosity dispersion, and deeply integrate into the resin network through double bond copolymerization, simultaneously overcoming the strength-rheological property contradiction in highly filled resin systems.

[0105] The following detailed description uses specific examples. For ease of experimental comparison, the barium glass powder used in the following examples is 27wt% BaO-10wt% Al2O3-55wt% SiO2-8wt% B2O3.

[0106] Example 1

[0107] This embodiment provides a dental resin composition, which, based on a total weight fraction of 100 parts, comprises 12 parts of polymerizable monomer, 60 parts of barium glass powder, 15 parts of spherical silica with a D50 of 15 nm, 1 part of dispersant (Sago9030), 9 parts of reactive diluent (4 parts of tricyclodecanedimethylethanol diacrylate + 5 parts of cyclic trimethylolpropane trimethacrylate), 1 part of photoinitiator ((2,4,6-trimethylbenzoyl)diphenylphosphine oxide), 1.5 parts of pigment (titanium oxide), 0.4 parts of defoamer (5200 defoamer), and 0.1 parts of polymerization inhibitor (p-hydroxyanisole).

[0108] The polymerizable monomer comprises 4 parts of bisphenol A-dimethacrylate glycidyl ester and 8 parts of dimethacrylate carbamate;

[0109] The barium glass powder comprises 30 parts of barium glass powder with a particle size D50 of 0.4 μm and 30 parts of barium glass powder with a particle size D50 of 3 μm.

[0110] Both the barium glass powder and the spherical silicon dioxide are barium glass powder and spherical silicon dioxide modified with KH570.

[0111] This embodiment also provides a method for preparing the dental resin composition, the method comprising:

[0112] The first mixture of polymerizable monomer, reactive diluent, defoamer, polymerization inhibitor, colorant and photoinitiator was stirred at 600 rpm for 20 minutes under light-protected and 50°C conditions to obtain the first material.

[0113] The dispersant was added in batches (5 batches, each with the same amount) under stirring at 600 rpm. After the dispersant was added, the mixture was stirred at 900 rpm for 50 minutes to ensure that the dispersant was completely dissolved, and the second material was obtained. The second material system was vacuumed 5 times, 5 minutes each time.

[0114] Under a third stirring condition of 400 rpm, a third mixture of spherical silica and the second material is obtained to obtain a third material; the spherical silica is added in 4 batches, with the same amount of spherical silica added in each batch;

[0115] The fourth mixture of barium glass powder and the third material was stirred at 400 rpm for 25 minutes, and then stirred at 700 rpm for 100 minutes to obtain the fourth material.

[0116] The fourth material is transferred to a ball mill jar, ball milled at 256 rpm for 120 minutes, and then transferred to a vacuum-capable container for vacuum stirring and degassing until no bubbles are visible to the naked eye, thus obtaining a dental resin composition.

[0117] Example 2

[0118] This embodiment provides a dental resin composition, which, based on a total weight fraction of 100 parts, comprises 12 parts of polymerizable monomer, 60 parts of barium glass powder, 15 parts of spherical silica with a D50 of 20 nm, and a dispersant ( 1 part of Dispers685, 9 parts of reactive diluent (4 parts of tricyclodecanedimethylethanol diacrylate + 5 parts of cyclic trimethylolpropane trimethacrylate), 1 part of photoinitiator ((2,4,6-trimethylbenzoyl)diphenylphosphine oxide), 1.5 parts of pigment (iron oxide yellow), 0.4 parts of defoamer (5200 defoamer), and 0.1 parts of polymerization inhibitor (p-hydroxyanisole).

[0119] The polymerizable monomer comprises 4 parts of bisphenol A-dimethacrylate glycidyl ester and 8 parts of dimethacrylate carbamate;

[0120] The barium glass powder comprises 30 parts of barium glass powder with a particle size D50 of 1 μm and 30 parts of barium glass powder with a particle size D50 of 2 μm.

[0121] Both the barium glass powder and the spherical silicon dioxide are barium glass powder and spherical silicon dioxide modified with KH570.

[0122] This embodiment also provides a method for preparing the dental resin composition, the method comprising:

[0123] The first mixture of polymerizable monomer, reactive diluent, defoamer, polymerization inhibitor, colorant and photoinitiator was stirred at 800 rpm for 10 min under light-protected and 60°C conditions to obtain the first material.

[0124] The dispersant was added in batches (5 batches, each with the same amount) under stirring at 800 rpm. After the dispersant was added, the mixture was stirred at 1000 rpm for 30 minutes to ensure that the dispersant was completely dissolved, thus obtaining the second material. The second material system was then vacuumed 4 times, for 8 minutes each time.

[0125] Under a third stirring condition of 300 rpm, spherical silica and the second material are mixed to obtain a third material; the spherical silica is added in 5 batches, with the same amount of spherical silica added in each batch;

[0126] The fourth mixture of barium glass powder and the third material was stirred at 500 rpm for 10 minutes, and then stirred at 600 rpm for 120 minutes to obtain the fourth material.

[0127] The fourth material is transferred to a ball mill jar, ball milled at 250 rpm for 130 minutes, and then transferred to a vacuum-capable container for vacuum stirring and degassing until no bubbles are visible to the naked eye, thus obtaining a dental resin composition.

[0128] Example 3

[0129] This embodiment provides a dental resin composition, which, based on a total weight fraction of 100 parts, comprises 12 parts of polymerizable monomer, 60 parts of barium glass powder, 15 parts of spherical silica with a D50 of 10 nm, 1 part of dispersant (BYK-110), 9 parts of reactive diluent (4 parts of tricyclodecanedimethylethanol diacrylate + 5 parts of cyclic trimethylolpropane trimethacrylate), 1 part of photoinitiator ((2,4,6-trimethylbenzoyl)diphenylphosphine oxide), 1.5 parts of pigment (iron oxide red), 0.4 parts of defoamer (5200 defoamer), and 0.1 parts of polymerization inhibitor (p-hydroxyanisole).

[0130] The polymerizable monomer comprises 4 parts of bisphenol A-dimethacrylate glycidyl ester and 8 parts of dimethacrylate carbamate;

[0131] The barium glass powder comprises 30 parts of barium glass powder with a particle size D50 of 0.6 μm and 30 parts of barium glass powder with a particle size D50 of 2.5 μm;

[0132] Both the barium glass powder and the spherical silicon dioxide are barium glass powder and spherical silicon dioxide modified with KH570.

[0133] This embodiment also provides a method for preparing the dental resin composition, the method comprising:

[0134] The first mixture of polymerizable monomer, reactive diluent, defoamer, polymerization inhibitor, colorant and photoinitiator was stirred at 600 rpm for 20 minutes under light-protected and 40°C conditions to obtain the first material.

[0135] The dispersant was added in batches (4 batches, each with the same amount) under stirring at 600 rpm. After the dispersant was added, the mixture was stirred at 800 rpm for 60 minutes to ensure that the dispersant was completely dissolved, and the second material was obtained. The second material system was vacuumed 8 times, 3 minutes each time.

[0136] Under a third stirring condition of 500 rpm, a third mixture of spherical silica and the second material is obtained to obtain a third material; the spherical silica is added in 3 batches, and the amount of spherical silica added in each batch is the same;

[0137] The fourth mixture of barium glass powder and the third material was stirred at 300 rpm for 30 minutes, and then stirred at 800 rpm for 60 minutes to obtain the fourth material.

[0138] The fourth material is transferred to a ball mill jar, ball milled at 260 rpm for 115 minutes, and then transferred to a vacuum-capable container for vacuum stirring and degassing until no bubbles are visible to the naked eye, thus obtaining a dental resin composition.

[0139] Example 4

[0140] This embodiment provides a dental resin composition, which is the same as in Example 1 except that the barium glass powder includes 30 parts of barium glass powder with a particle size D50 of 0.8 μm and 30 parts of barium glass powder with a particle size D50 of 3 μm, and the dispersant is BYK-W-907.

[0141] Example 5

[0142] This embodiment provides a dental resin composition, which, based on a total weight fraction of 100 parts, comprises 30 parts of polymerizable monomer, 25.45 parts of barium glass powder, 20 parts of spherical silica with a D50 of 40 nm, 5 parts of dispersant (BYK-W-907), 14 parts of reactive diluent (6 parts acryloylmorpholine + 8 parts tripropylene glycol diacrylate), 2 parts of photoinitiator (1-hydroxycyclohexylphenyl ketone), 3 parts of pigment (iron oxide yellow and iron oxide red in a mass ratio of 1:1), 0.5 parts of defoamer (4400 defoamer), and 0.05 parts of polymerization inhibitor (hydroquinone).

[0143] The polymerizable monomer comprises 15 parts of bisphenol A glycerol dimethacrylate and 15 parts of ethoxylated bisphenol A dimethacrylate (the number of ethoxy groups is 5);

[0144] The barium glass powder comprises 12.7 parts of barium glass powder with a particle size D50 of 0.4 μm and 12.75 parts of barium glass powder with a particle size D50 of 1.5 μm;

[0145] Both the barium glass powder and the spherical silicon dioxide are barium glass powder and spherical silicon dioxide modified with KH570.

[0146] The preparation method of the dental resin composition in this embodiment is the same as that in Example 1, and will not be repeated here.

[0147] Example 6

[0148] This embodiment provides a dental resin composition, which, based on a total weight fraction of 100 parts, comprises 10 parts of polymerizable monomer, 55.22 parts of barium glass powder, 10 parts of spherical silica with a D50 of 20 nm, 2 parts of dispersant (BYK-W-907), 20 parts of reactive diluent (10 parts of tripropylene glycol diacrylate + 10 parts of dipropylene glycol diacrylate), 0.5 parts of photoinitiator (2-hydroxy-2-methyl-1-phenyl-1-propanone), 2 parts of pigment (iron oxide black), 0.2 parts of defoamer (1100 defoamer), and 0.08 parts of polymerization inhibitor (bisphenol A).

[0149] The polymerizable monomer comprises 5 parts of urethane dimethacrylate and 5 parts of bisphenol A dimethacrylate glycidyl ester;

[0150] The barium glass powder comprises 27.61 parts of barium glass powder with a particle size D50 of 0.8 μm and 27.61 parts of barium glass powder with a particle size D50 of 2.3 μm;

[0151] Both the barium glass powder and the spherical silicon dioxide are barium glass powder and spherical silicon dioxide modified with KH570.

[0152] The preparation method of the dental resin composition in this embodiment is the same as that in Example 1, and will not be repeated here.

[0153] Example 7

[0154] This embodiment provides a dental resin composition, which is the same as that in Example 1 except that the dispersant is replaced with BYK220S, and will not be described again here.

[0155] Example 8

[0156] This embodiment provides a dental resin composition. Except that the weight of the dispersant is 0.5 parts and the weight of the barium glass powder is adjusted to 60.5 (the two particle sizes of barium glass powder are adjusted proportionally), that is, the mass ratio of dispersant to inorganic particles is 1:151, the rest of the dental resin composition is the same as in Example 1, and will not be repeated here.

[0157] Example 9

[0158] This embodiment provides a dental resin composition. Except that the weight of the dispersant is 10 parts and the weight of the barium glass powder is adjusted to 51 (the two particle sizes of barium glass powder are adjusted proportionally), that is, the mass ratio of dispersant to inorganic particles is 1:6.6, the rest of the dental resin composition is the same as in Example 1, and will not be repeated here.

[0159] Example 10

[0160] This embodiment provides a dental resin composition. Except for the fact that the proportion of spherical silica with a D50 of 15 nm is 5 parts and the proportion of barium glass powder is adaptively adjusted to 70 parts (the two particle sizes of barium glass powder are adjusted proportionally), the dental resin composition is the same as that in Example 1, and will not be repeated here.

[0161] Example 11

[0162] This embodiment provides a dental resin composition. Except for the fact that the proportion of spherical silica with a D50 of 15 nm is 25 parts and the proportion of barium glass powder is adaptively adjusted to 50 parts (two types of barium glass powder with equal particle sizes are adjusted), the dental resin composition is the same as in Example 1, and will not be repeated here.

[0163] Comparative Example 1

[0164] This comparative example provides a dental resin composition, which is the same as in Example 1 except that no dispersant is added, the amount of bisphenol A-dimethacrylate glycidyl ester is adjusted to 5 parts, spherical silica is not added, and barium glass powder is replaced with 75 parts of barium glass powder with a particle size D50 of 3 μm. It will not be described again here.

[0165] Comparative Example 2

[0166] This comparative example provides a dental resin composition, which is the same as in Example 1 except that spherical silica is not added and the barium glass powder is replaced with 25 parts of barium glass powder with a particle size of 0.4 μm and 50 parts of barium glass powder with a particle size of 3 μm. It will not be described again here.

[0167] Comparative Example 3

[0168] This comparative example provides a dental resin composition, wherein the dispersant is replaced with... Except for PA4101, everything else is the same as in Example 1, and will not be repeated here.

[0169] Comparative Example 4

[0170] This comparative example provides a dental resin composition, which is the same as in Example 1 except that 15 parts of spherical silica with a D50 of 15 nm are replaced with 15 parts of spherical barium glass powder with a D50 of 15 nm. The rest will not be repeated here.

[0171] Comparative Example 5

[0172] This comparative example provides a dental resin composition, which is the same as in Example 1 except that 15 parts of spherical silica with a D50 of 15 nm are replaced with 15 parts of spherical silica with a D50 of 5 nm. The details will not be repeated here.

[0173] Comparative Example 6

[0174] This comparative example provides a dental resin composition, which is the same as in Example 1 except that 15 parts of spherical silica with a D50 of 15 nm are replaced with 15 parts of spherical silica with a D50 of 50 nm. The rest will not be repeated here.

[0175] For ease of experimental comparison, the molding method of the above-mentioned dental resin composition includes: the dental resin composition is cured by light at 405nm and 25℃ and the light power is 150mw / cm. 2 The dental resin is obtained by photocuring in a light box for 15 minutes. However, this does not mean that the dental resin composition provided by the present invention can only be photocured and printed under these conditions. It can also be carried out under photocuring and printing conditions well known to those skilled in the art, which will not be elaborated here.

[0176] The test method for evaluating the performance of the 3D printed crown bridge materials formulated in the examples and comparative examples is as follows.

[0177] Viscosity testing method: This experimental method refers to Part 4 of GB-T10247-2008 "Viscosity Measurement Methods": Rotation method; The relationship between the dynamic viscosity of the fluid and the torque is η=AM / n1.

[0178] Where η is the dynamic viscosity of the fluid, measured in Pa·s; M is the viscous torque of the fluid acting on the cylinder (cone), measured in Newton-meters (N·m); n1 is the rotational speed of the cylinder (cone), measured in radians per second (rad / s); and A is a constant, measured in cubic meters (m³). 3 ).

[0179] Flexural strength and flexural modulus testing methods: The experimental methods in this paper refer to section 7.6 of YY0710—2009 "Polymer-based Crown and Bridge Materials in Dentistry".

[0180] Abrasion resistance test method: This test method refers to YY / T0113-2015 "Test method for abrasion resistance of dental composite resin".

[0181] Sandpaper pre-grinding: Adjust the grinding machine to the shortest stroke and the speed to 65. Clamp the small column with a diameter of 6.7 mm and a height of 11.2 mm with a clamp, add a 25 g weight, and dry grind with 600 grit sandpaper 75 times. After grinding, ultrasonically clean the sample with anhydrous ethanol for 2 minutes, and dry the upper and lower surfaces of the sample with cold air from a hair dryer. Weigh the sample and record the mass as m1.

[0182] Abrasion test: The abrasion machine was set to the shortest stroke of the 339 abrasion machine, the speed was 65, and one 100g and one 25g weight were added. The sample was wet-ground 1500 times with 2000-grit sandpaper and deionized water. After grinding, the sample was sonicated in anhydrous ethanol for 2 minutes, and then the upper and lower surfaces of the sample were blown with cold air for 2.5 minutes each. The sample was weighed immediately and recorded as m2.

[0183] The density of the ground sample was measured using a density balance, and the wear resistance of the three small columns was measured separately. The wear volume of the sample was calculated according to the following formula: ΔV=(m1-m2) / ρ; where: ΔV—sample volume loss, in cubic millimeters (mm) 3 m1—Sample mass before grinding, in milligrams (mg); m2—Sample mass after grinding, in milligrams (mg); ρ—Sample density, in milligrams per cubic millimeter (mg / mm³) 3 ).

[0184] The test results of the above embodiments and comparative examples are shown in Table 1.

[0185] Table 1

[0186]

[0187] In Table 1, " / " indicates that there is no relevant data.

[0188] The following points can be observed from Table 1:

[0189] (1) As can be seen from Examples 1 to 6, the dental resin composition provided by the present invention can obtain a dental resin with high flexural strength, flexural modulus and wear resistance, wherein the flexural strength is above 201 MPa, the flexural modulus is above 12.3 GPa and the wear resistance is above 1.93 mm. 3 Within a specified range; under optimal conditions, the flexural strength is above 216 MPa, the flexural modulus is above 12.6 GPa, and the wear resistance is below 1.86 mm. 3 within;

[0190] (2) Comparing Examples 1 and 7, it can be seen that, under the same conditions, Example 1 used a methylpropionate-terminated polyurethane dispersant, while Example 7 used an unterminated polyurethane dispersant, BYK220S. The results show that the viscosity of the dental resin composition in Example 7 increased significantly, and the printing performance decreased. Furthermore, the use of an unterminated polyurethane dispersant relied solely on physical adsorption (such as hydrogen bonding, van der Waals forces, etc.), resulting in weak interfacial bonding and a loose physical structure, which led to a decrease in the mechanical properties of the system. The final flexural strength was only 196 MPa, and the flexural modulus decreased to 12.1 GPa, but the wear reached 1.96 mm. 3 This demonstrates that the polyurethane dispersant with methyl propionate end-capping in this invention can better improve the mechanical properties and abrasion resistance of dental resins.

[0191] (3) Comparing Examples 1 and 8-9, it can be seen that the mass ratio of dispersant to inorganic particles in Example 8 is too low, resulting in the inorganic particles not being fully wetted and the modified layer on the glass powder surface not being fully coated. This leads to the inorganic particles easily agglomerating and unevenly dispersing in the system, directly causing a significant increase in slurry viscosity and a severe decrease in mechanical and wear resistance. In Example 9, when the dispersant is added in excess, a plasticizing effect occurs, reducing the overall crosslinking density of the system and causing a decrease in the mechanical properties of the system. At the same time, the excess small molecules of dispersant may dissolve, posing a risk to biocompatibility, and the wear resistance decreases significantly. This indicates that the dental resin composition provided by the present invention, by controlling the mass ratio of dispersant to inorganic particles within a reasonable range, can improve the mechanical properties and wear resistance of dental resin while effectively reducing the viscosity of the slurry.

[0192] (4) Comparing Examples 1 and 10-11, it can be seen that when the spherical silica content is too low in Example 10, the nano-reinforced skeleton is sparse and the crack passivation sites are reduced, resulting in a decrease in the wear resistance of the finished product compared to Example 1, and a shortening of the long-term service life of the material. When the spherical silica content is too high in Example 11, the ultra-high specific surface area of ​​SiO2 will adsorb excessive resin and dispersant, resulting in a reduction in free resin and an abnormal increase in the viscosity of the slurry. For the final printed product, excessive silica will induce Rayleigh scattering, leading to an increase in the ultraviolet light attenuation rate and poor interlayer bonding, thereby affecting the mechanical properties of the material. This indicates that the present invention preferably controls the mass fraction of spherical silica and barium glass powder within a reasonable range, which can significantly improve the material properties of dental resin.

[0193] (5) By comparing Example 1 with Comparative Examples 1 and 2, this performance difference proves that the multi-particle size distribution and the combination design of adding spherical silica used in Example 1, compared with the current simple filling system of single large-particle glass powder, can bring higher strength and wear resistance through multi-scale interface effects and steric hindrance. By comparing Example 1 with Comparative Example 1, it is shown that the combination of nano-silica and irregularly shaped barium glass powder plays an irreplaceable role in improving the mechanical properties of composite resin materials. Among them, the high specific surface area of ​​nano-silica can enhance the resin-filler interface bonding and effectively fill micron-sized particles. The gaps; through the comparison of Example 1 and Comparative Example 3, it is shown that the molecular design of the dispersant must be strictly matched with the properties of the filler and the resin system; through the comparison of Example 1 and Comparative Examples 4-6, it can be seen that after replacing spherical silica with spherical barium glass powder in an equal amount in Comparative Example 4, the volume fraction of barium glass powder decreases but the mass fraction remains unchanged due to its higher density. The particle interaction within a unit volume is enhanced, and the viscosity of the resin slurry increases, which is not conducive to the spreading and leveling of the molding process; at the same particle size, the surface activity and grafting density of barium glass powder are slightly lower than those of SiO2, resulting in slightly weaker interfacial bonding force, which affects the mechanical properties of the finished product. In Comparative Example 5, when the particle size of spherical silica decreases, its specific surface area increases sharply, affecting the viscosity of the resin slurry, and thus affecting its leveling and printing accuracy during the printing process; at the same time, its high viscosity will limit the maximum amount of filler that can be added, resulting in limited improvement or even a decrease in mechanical properties. In Comparative Example 6, the spherical silica particles have increased size and decreased specific surface area, resulting in insufficient resin binding sites. This leads to filler stratification or sedimentation during long-term storage, which will disrupt the uniformity of printed layers in subsequent use; at the same time, the mechanical reinforcement efficiency decreases.

[0194] In summary, this invention, by compounding different types of inorganic particles and using polyurethane-type dispersants, can improve the wear resistance and permeability of composite resins while reducing their viscosity, making it suitable for 3D printing crown and bridge resins.

[0195] The present invention has been illustrated with the above embodiments to illustrate its detailed features, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the selected technical features, additions of auxiliary technical features, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A dental resin composition, characterized in that, The dental resin composition comprises: inorganic particles, polymerizable monomers, and dispersants; The inorganic particles include barium glass powder with a first particle size and spherical silicon dioxide with a second particle size. The first particle size D50 ranges from 0.4 to 3 μm, and the second particle size D50 ranges from 10 to 40 nm; The dispersant is a polyurethane type dispersant.

2. The dental resin composition according to claim 1, characterized in that, The barium glass powder includes at least two of the following: glass powder with a particle size D50 of 0.4 to 1 μm, glass powder with a particle size D50 of 1 to 2 μm, and barium glass powder with a particle size D50 of 2 to 3 μm. Preferably, the spherical silica includes any one or a combination of at least two of the following: spherical silica with a D50 of 10-20 nm, spherical silica with a D50 of 20-30 nm, or spherical silica with a D50 of 30-40 nm. Preferably, the barium glass powder is silane-modified barium glass powder; Preferably, the spherical silica is silane-modified spherical silica.

3. The dental resin composition according to claim 1 or 2, characterized in that, The polymerizable monomers include any one or a combination of at least two of the following: bisphenol A dimethacrylate, bisphenol A glycerol dimethacrylate, urethane dimethacrylate, or ethoxybisphenol A dimethacrylate. Preferably, the number of ethoxy groups in the ethoxybisphenol A dimethacrylate is 1 to 10; Preferably, the polyurethane dispersant includes Sago9030, Dispers 685, BYK-P-104, BYK-W-907, BYK-W-961 or BYK-110, or a combination of at least two of them.

4. The dental resin composition according to any one of claims 1 to 3, characterized in that, The dental resin composition comprises, by weight fraction, 10-30 parts polymerizable monomer, 10-80 parts barium glass powder, 10-80 parts spherical silica and 1-5 parts dispersant; Preferably, the mass ratio of the dispersant to the inorganic particles is 1:(6-75).

5. The dental resin composition according to any one of claims 1 to 4, characterized in that, The dental resin composition further includes an active diluent; Preferably, the reactive diluent comprises any one or a combination of at least two of the following: acrylomorpholine, cyclic trimethylolpropane acetal acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, tricyclodecanediethanol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, or tri(2-hydroxyethyl)isocyanurate triacrylate. Preferably, the amount of active diluent in the dental resin composition is 9 to 20 parts by weight. Preferably, the dental resin composition further includes a photoinitiator; Preferably, the photoinitiator comprises any one or a combination of at least two of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-isopropylthioxanthone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. Preferably, the photoinitiator in the dental resin composition is 0.5 to 2 parts by weight. Preferably, the dental resin composition further includes colorants; Preferably, the amount of pigment in the dental resin composition is 1.5 to 3 parts by weight. Preferably, the dental resin composition further includes an antifoaming agent; Preferably, the amount of defoamer in the dental resin composition is 0.1 to 0.5 parts by weight. Preferably, the dental resin composition further includes a polymerization inhibitor; Preferably, the polymerization inhibitor comprises any one or a combination of at least two of hydroquinone, p-tert-butylcatechol, p-hydroxyanisole, 2,6-di-tert-butyl-p-methylphenol, 4,4'-dihydroxybiphenyl, or bisphenol A; Preferably, the amount of polymerization inhibitor in the dental resin composition is 0.05 to 0.1 parts by weight.

6. A method for preparing the dental resin composition according to any one of claims 1 to 5, characterized in that, The preparation method includes: The first mixture of polymerizable monomer, reactive diluent, defoamer and polymerization inhibitor is stirred to obtain the first material; The first material and the dispersant are mixed in a second step, and then stirred again to obtain the second material. Under the third stirring condition, the third spherical silica and the second material are mixed to obtain the third material; The fourth mixture of barium glass powder and the third material is stirred to obtain the fourth material. The fourth material is sequentially ball-milled and degassed to obtain a dental resin composition.

7. The preparation method according to claim 6, characterized in that, The first mixing was carried out at 40–60°C; Preferably, the rotational speed of the first mixing is 600-800 rpm; Preferably, the second mixing includes: adding the dispersant in batches under stirring conditions of 600-800 rpm, and then performing a second stirring after the dispersant has been added; Preferably, the second stirring speed is 800-1000 rpm; Preferably, the second stirring time is 30-60 minutes; Preferably, between the second stirring and the third stirring, the second material system is first subjected to vacuum treatment; Preferably, the spherical silica is added in batches; Preferably, the fourth stirring includes performing a first sub-stirring after the materials are mixed, and then performing a second sub-stirring; Preferably, the rotational speed of the second sub-stirring is greater than that of the first sub-stirring.

8. A dental resin, characterized in that, The raw material for the dental resin is the dental resin composition as described in any one of claims 1 to 5.

9. A method for preparing the dental resin of claim 8, characterized in that, The method comprises: obtaining a dental resin by photocuring printing and photocuring molding of the dental resin composition according to any one of claims 1 to 5.

10. A dental prosthesis, characterized in that, The dental restoration is any one of a single crown, inlay, high inlay, crown, bridge, veneer, or implant superstructure; the dental restoration includes the dental resin as described in claim 8.

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