阅读说明：本技术 一种牙科用渐变色树脂陶瓷修复材料及其制备方法 (Dental gradient resin ceramic repair material and preparation method thereof ) 是由 张佳新 刘乾乾 乔春梅 于 2021-09-01 设计创作，主要内容包括：本发明提供一种牙科用渐变色树脂陶瓷修复材料及其制备方法,所述制备方法包括：(1)制备至少两层不同颜色的糊状物料,分别将不同颜色的糊状物料在一定速度、真空度为-0.01～-0.1MPa条件下进行分散,得到至少两层不同颜色的平均粒度在0.1mm～5mm的颗粒物料；(2)将至少两层不同颜色的颗粒物料平铺在模具中,在0.5～5MPa的压力下使层间结合紧密,得到渐变色树脂陶瓷修复材料的半成品；(3)将步骤(2)得到的半成品在60～200℃、2～50MPa下聚合固化,得到多层渐变色树脂陶瓷修复材料。本发明制备的树脂陶瓷修复材料无可见的层间颜色过渡、渐变效果自然,有足以承受口腔内的咬合压的机械强度。(The invention provides a dental gradient resin ceramic restoration material and a preparation method thereof, wherein the preparation method comprises the following steps: (1) preparing at least two layers of pasty materials with different colors, and dispersing the pasty materials with different colors under the conditions of a certain speed and a vacuum degree of-0.01 to-0.1 MPa respectively to obtain at least two layers of granular materials with different colors and average particle sizes of 0.1mm to 5 mm; (2) flatly paving at least two layers of granular materials with different colors in a mold, and tightly combining the layers under the pressure of 0.5-5 MPa to obtain a semi-finished product of the gradually-changed resin ceramic repair material; (3) and (3) polymerizing and curing the semi-finished product obtained in the step (2) at the temperature of 60-200 ℃ and under the pressure of 2-50 MPa to obtain the multilayer gradient color resin ceramic repair material. The resin ceramic repair material prepared by the invention has no visible interlayer color transition, has natural gradual change effect and has mechanical strength enough to bear the occlusion pressure in the oral cavity.)

1. A preparation method of a dental gradient color resin ceramic restoration material is characterized by comprising the following steps:

(1) preparing at least two layers of pasty materials with different colors, and respectively dispersing the pasty materials with different colors to obtain at least two layers of granular materials with different colors;

(2) sequentially spreading at least two layers of particle materials with different colors in a mould, and then tightly combining the layers to obtain a semi-finished product of the gradually-changed resin ceramic repair material;

(3) and (3) polymerizing and curing the semi-finished product obtained in the step (2) to obtain the multilayer gradient color resin ceramic repair material.

2. The method of claim 1, step (1) being characterized in that the pasty mass is prepared by: adding a polymerizable monomer, an initiator, an inorganic filler and a coloring agent into a mixing device, and stirring to prepare a uniform paste; or adding the polymerizable monomer, the initiator, the inorganic filler and the colorant into a mixing device in batches and stirring to prepare uniform paste;

preferably, the at least two layers of differently coloured particulate material obtained in step (1) have an average particle size of from 0.1mm to 5 mm.

3. The preparation method according to claim 1, wherein the rotation speed during the dispersion in the step (1) is 20 to 150r/min, preferably 60 to 120 r/min;

preferably, the vacuum degree in the dispersion in the step (1) is-0.01 to-0.1 MPa, and is preferably-0.07 to-0.09 MPa;

preferably, the interlayer bonding in the step (2) is performed under a pressure of 0.5 to 5MPa, preferably 1 to 3 MPa;

preferably, the pressure during polymerization and curing in the step (3) is greater than the pressure during tight bonding between layers in the step (2), preferably 2 to 50MPa, and more preferably 10 to 30 MPa;

preferably, the temperature of the polymerization curing in the step (3) is 60 to 200 ℃, and preferably 100 to 150 ℃.

4. The preparation method according to claim 2, characterized in that the weight ratio of the polymerizable monomer to the inorganic filler in the raw materials for preparing the at least two layers of pasty materials with different colors is 10:90-90:10, preferably 15: 85-40: 60;

preferably, the weight of the initiator accounts for 0.01 to 10 weight percent of the total weight of the polymerizable monomer and the inorganic filler, and preferably 0.1 to 5 weight percent;

preferably, the colorant accounts for 0.01 wt% to 3 wt%, preferably 0.1 wt% to 1 wt%, of the total weight of the polymerizable monomer and the inorganic filler.

5. The method according to any one of claims 1 to 4, wherein the raw material for preparing the at least two layers of pasty materials with different colors further comprises other additives, preferably any one or a combination of at least two of an accelerator, a cross-linking agent, a fluorescent agent, a polymerization inhibitor, an antibacterial agent, an ultraviolet absorber, a discoloration inhibitor, a viscosity modifier, a wetting agent, an antioxidant, a stabilizer or a diluent;

preferably, the other additive accounts for 0-5 wt% of the total weight of the polymerizable monomer and the inorganic filler, and preferably 0.01 wt% to 1 wt%.

6. The production method according to any one of claims 1 to 3, wherein the polymerizable monomer is a radical resin monomer comprising any one of a monofunctional monomer compound, a difunctional monomer compound, or a trifunctional or higher monomer compound, or a combination of at least two of them;

preferably, the monofunctional monomer compound includes methyl (meth) acrylate, ethyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isoamyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, dodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (N, N-dimethylamino) ethyl (meth) acrylate, 2, 3-dibromopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, triethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol (meth) acrylate, N, Any one or a combination of at least two of diethylene glycol (meth) acrylate, methoxy diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, N-methylol (meth) acrylamide, N-succinyl (meth) acrylamide, or 10- (meth) acryloyloxydecyl dihydrogen phosphate;

preferably, the difunctional monomer compound includes any one or a group of at least two of ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, urethane dimethacrylate, bisphenol a glycidyl (meth) acrylate (2, 2-bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl) propane), 2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, or 2, 2-bis (4- (meth) acryloyloxypolyethoxyphenyl) propane Combining;

preferably, the trifunctional or higher monomer compound includes any one of trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetra (meth) pentaerythritol acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, or N, N' - (2,2, 4-trimethylhexamethylene) bis (2- (aminocarboxy) propane-1, 3-diol) tetramethylacrylate, or a combination of at least two thereof.

7. The method according to any one of claims 1 to 4, wherein the refractive index of the polymerizable monomer after polymerization is 1.52 to 1.58, preferably 1.53 to 1.55.

8. The production method according to any one of claims 1 to 5, wherein the inorganic filler comprises an inorganic filler A and an inorganic filler B, wherein the inorganic filler A has an average particle diameter of 0.1 to 10 μm and the inorganic filler B has an average particle diameter of 10 to 40 nm;

preferably, the inorganic filler a includes any one or a combination of at least two of silica, aluminum silicate, alumina, titania, zirconia, fluorine glass, borosilicate glass, soda glass, barium aluminosilicate glass, strontium-or zirconium-containing glass, glass ceramic, fluoroaluminosilicate glass, synthetic glass obtained based on a sol-gel process, fumed silica, calcium fluoride, strontium fluoride, calcium carbonate, kaolin, clay, mica, aluminum sulfate, calcium sulfate, barium sulfate, titanium oxide, calcium phosphate, hydroxyapatite, calcium hydroxide, strontium hydroxide, or zeolite;

preferably, the inorganic filler B comprises any one of silica, zirconia, titania, zirconia, zinc oxide, calcium phosphate, hydroxyapatite or a combination of at least two thereof;

preferably, the refractive index of the inorganic filler A is 1.52-1.58, and the refractive index of the inorganic filler B is 1.43-1.50.

9. The production method according to any one of claims 1 to 8, characterized in that the inorganic filler is an inorganic filler surface-treated with a surface treatment agent;

preferably, the surface treatment agent comprises any one or a combination of at least two of gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropyltriethoxysilane, or gamma-aminopropyltrimethoxysilane, preferably gamma-methacryloxypropyltrimethoxysilane;

preferably, the surface treatment agent is used in an amount of 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, relative to 100 parts by weight of the inorganic filler raw material;

preferably, the initiator is selected from one or a combination of at least two of dicumyl peroxide, tert-butyl peroxide, benzoyl peroxide, tert-butyl peroxyacetate and tert-butyl peroxybenzoate;

preferably, the colorant may be at least one of zinc white, titanium white, antimony white, vermilion, cadmium red, iron red, chromium oxide, cerium praseodymium yellow, lemon yellow, chrome yellow, zinc yellow, iron yellow, bismuth yellow, barium yellow, zirconium vanadium yellow, iron black, carbon black, or graphite.

10. The dental gradient-color resin ceramic restorative material produced by the production method according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of medical materials, and relates to a dental gradient resin ceramic repair material and a preparation method thereof.

Background

With the rapid development of CAD/CAM technology, people have higher and higher requirements on the speed and performance of dental restoration. At present, the machinable dental repair materials matched with the CAD/CAM technical system mainly comprise ceramic materials and resin repair materials according to the materials. The two materials have advantages and disadvantages in dental restoration effect, and the ceramic material has higher mechanical and aesthetic properties, and meanwhile, the brittleness and high abrasion resistance of the ceramic material can not neglect the damage caused by relative natural teeth; the resin material still occupies a large proportion in CAD/CAM cutting because of low price, good toughness, easy processing and cutting, short repair period, no abrasion to jaw teeth. However, resin materials cannot be used for permanent repair because of their low strength, poor wear resistance, short service life, and other drawbacks. The resin ceramic repairing material is a novel dental repairing material, and the performance of the resin ceramic repairing material is closer to that of natural teeth. The composite material has the characteristics of excellent biocompatibility, hardness, thermal stability, elasticity of a resin material and the like of a ceramic material, effectively overcomes the defect of easy brittle fracture of the ceramic material, optimizes the brittleness and wear resistance of the ceramic material, and simultaneously improves the mechanical property of the resin material.

However, the color of natural tooth is gradually changed, the color tone gradually deepens from the cut end to the neck, the transparency is gradually reduced, the aesthetic effect of the single-color resin ceramic repair material cannot meet the use requirement of a patient, and a multilayer gradually-changed color resin ceramic repair material is needed.

WO 2009/154301 a1 discloses a method of manufacturing a dental restoration, in which a mold having an outer shape with a block body on the inner surface is partially filled with a resin material containing an inorganic filler; then, carrying out rotary stirring, and curing the polymer after uniformly stirring; by repeating this process, a composite resin block having a color gradient can be produced. However, since the materials each of which is independently polymerization-hardened are polymerized again to form a laminated structure, the boundaries between layers are easily made sharp, and the interlayer bonding is weakened.

WO 2018/074583a1 discloses a method for producing a multilayer composite resin material, in which a paste obtained by uniformly mixing a polymerizable monomer, an inorganic filler initiator, a colorant and the like is charged into 3 cylinder containers, and the three pastes having different colors are charged into a mold through a charging nozzle at the same time. During the filling process, the material of the outer layer flows in such a way that it presses against the central layer, which is filled in such a way that it diffuses towards the outer layer. In the composite material block filled and molded in the mold in this state, no air bubbles are generated in the boundary layer, and the thickness of the three layers is almost uniform. However, this method requires the paste to be prepared to have a high fluidity, limits the content of the inorganic filler, and has a ratio relationship between different polymerizable monomers, resulting in low mechanical properties. Further, in natural teeth, the thicknesses of different colors are not uniformly distributed, but the three-layer thickness of the multi-layered composite resin material prepared by this method is almost uniform, which is not consistent with the aesthetic effect of natural teeth.

CN 105362084A discloses a preparation method of a multi-layer color composite material for dentistry, which comprises the steps of mixing a polymer monomer matrix, an inorganic filler, an initiator, a coloring agent and a grinding aid, grinding for 0.5-2h, drying to obtain precursor powder of a single-color composite material, sequentially adding the precursor powder of the composite materials with different colors into a dry pressing mold, preparing a pre-forming blank under the condition of 20-30MPa, and pressurizing and heating the prepared pre-forming blank of the multi-layer color composite material to obtain the multi-layer color composite material for dentistry. The preparation method needs to add a volatile organic solvent as a grinding aid to uniformly mix the polymer monomer matrix, the inorganic filler, the initiator and the colorant; after the material is uniformly ground, the volatile grinding aid needs to be removed through drying treatment. The preparation process has complicated working procedures, and the grinding aid is easy to remain, so that the performance of the composite material is reduced.

In conclusion, the problems of obvious interlayer boundary, low mechanical strength, complex preparation process and the like exist in many multilayer gradient resin ceramic repair materials at present. It is desired to develop a resin ceramic prosthetic material which has no delamination, has a natural gradation effect, has a mechanical strength sufficient to withstand an occlusion pressure in the oral cavity, and is easy to prepare.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a dental gradient resin ceramic repairing material and a preparation method thereof. The resin ceramic repair material has no layering and natural gradual change effect, and has mechanical strength enough to bear occlusion pressure in the oral cavity.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a method for preparing a dental gradient resin ceramic restorative material, comprising the steps of:

(1) preparing at least two layers of pasty materials with different colors, and respectively dispersing the pasty materials with different colors to obtain at least two layers of granular materials with different colors;

(2) sequentially spreading at least two layers of particle materials with different colors in a mould, and then tightly combining the layers to obtain a semi-finished product of the gradually-changed resin ceramic repair material;

(3) and (3) polymerizing and curing the semi-finished product obtained in the step (2) to obtain the multilayer gradient color resin ceramic repair material.

According to the invention, by utilizing the preparation method, the granular material is prepared firstly, and the granular material is utilized to carry out pressing and curing, so that a color gradient layer can be formed among different color layers, the gradient effect is natural, no obvious layering exists, and the mechanical strength is better.

Preferably, the pasty mass is prepared by: adding a polymerizable monomer, an initiator, an inorganic filler and a coloring agent into a mixing device, and stirring to prepare a uniform paste; or adding the polymerizable monomer, the initiator, the inorganic filler and the colorant into a mixing device in batches and stirring to prepare uniform paste.

Preferably, the particle size of the at least two layers of differently coloured particulate material obtained in step (1) is in the range of 0.1mm to 5mm, for example 0.1mm, 0.3mm, 0.5mm, 1mm, 2mm, 3mm, 4mm or 5 mm.

Preferably, the rotation speed during the dispersion in the step (1) is 20-150 r/min (for example, 20r/min, 25r/min, 30r/min, 40r/min, 50r/min, 70r/min, 90r/min, 100r/min, 120r/min, 150r/min, etc.), and preferably 60-120 r/min.

Preferably, the degree of vacuum at the time of the dispersion in the step (1) is-0.01 to-0.1 MPa (e.g., -0.01MPa, -0.03MPa, -0.05MPa, -0.08MPa or-0.1 MPa), preferably-0.07 to-0.09 MPa.

Preferably, the step (2) of making interlayer bonding tight is performed under a pressure of 0.5 to 5MPa (e.g., 0.5MPa, 0.8MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa or 5MPa), preferably 1 to 3 MPa.

Preferably, the pressure at the time of the polymerization curing in the step (3) is higher than the pressure at the time of the interlayer bonding in the step (2), preferably 2 to 50Mpa (for example, 3Mpa, 5Mpa, 8Mpa, 10Mpa, 15Mpa, 18Mpa, 20Mpa, 25Mpa, 28Mpa, 30Mpa, 35Mpa, 40Mpa, 45Mpa, or 50Mpa), and more preferably 10 to 30 Mpa.

Preferably, the temperature at the time of polymerization curing in step (3) is 60 to 200 ℃ (e.g., 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 120 ℃, 150 ℃, 180 ℃ or 200 ℃), preferably 100 to 150 ℃.

Preferably, the weight ratio of the polymerizable monomer to the inorganic filler in the raw materials for preparing the at least two layers of pasty materials with different colors is 10:90-90:10, such as 10:90, 15:85, 20:80, 22:78, 25:75, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 and the like, and preferably 15: 85-40: 60.

Preferably, the weight of the initiator is 0.01 wt% to 10 wt%, such as 0.01 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, preferably 0.1 wt% to 5 wt%, based on the total weight of the polymerizable monomer and the inorganic filler.

Preferably, the colorant comprises 0.01 wt% to 3 wt%, such as 0.01 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, or 3 wt%, preferably 0.1 wt% to 1 wt%, of the total weight of the polymerizable monomer and the inorganic filler.

Preferably, the raw materials for preparing the at least two layers of pasty materials with different colors further comprise other additives, and the other additives are preferably any one or a combination of at least two of an accelerator, a cross-linking agent, a fluorescent agent, a polymerization inhibitor, an antibacterial agent, an ultraviolet absorbent, an anti-discoloration agent, a viscosity regulator, a wetting agent, an antioxidant, a stabilizer or a diluent.

Preferably, the other additive is 0 to 5 wt%, such as 0.01 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt% or 5 wt%, preferably 0.01 wt% to 1 wt%, based on the total weight of the polymerizable monomer and the inorganic filler.

Preferably, the polymerizable monomer may be any known radical resin monomer used in dental materials without any limitation, but it is generally suitable to use a radical resin monomer including any one of a monofunctional monomer compound, a difunctional monomer compound, or a trifunctional or higher monomer compound, or a combination of at least two thereof.

Preferably, the monofunctional monomer compound includes, but is not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isoamyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, dodecyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2- (N, N-dimethylamino) ethyl (meth) acrylate, 2, 3-dibromopropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, triethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, propylene glycol, 2-hydroxy acrylate, 2-hydroxy-2-hydroxy acrylate, 2-hydroxy-2-hydroxy acrylate, 2-2, 2-hydroxy-2, 2-hydroxy-2, 2-hydroxy-, Any one or a combination of at least two of ethylene glycol (meth) acrylate, diethylene glycol (meth) acrylate, methoxy diethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, N-methylol (meth) acrylamide, N-succinyl (meth) acrylamide, or 10- (meth) acryloyloxydecyl dihydrogen phosphate.

Preferably, the difunctional monomer compound includes, but is not limited to, any one of or at least one of ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, urethane dimethacrylate, bisphenol a glycidyl (meth) acrylate (2, 2-bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl) propane), 2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane or 2, 2-bis (4- (meth) acryloyloxypolyethoxyphenyl) propane A combination of the two.

Preferably, the trifunctional or higher monomer compound includes, but is not limited to, any one of trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetra (meth) pentaerythritol acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, or N, N' - (2,2, 4-trimethylhexamethylene) bis (2- (aminocarboxy) propane-1, 3-diol) tetramethylacrylate, or a combination of at least two thereof.

Preferably, the refractive index of the polymerizable monomer after polymerization is 1.52 to 1.58, for example 1.52, 1.53, 1.54, 1.55, 1.56, 1.57 or 1.58, preferably 1.53 to 1.55.

The inorganic filler includes an inorganic filler A and an inorganic filler B, wherein the inorganic filler A has an average particle diameter of 0.1 to 10 μm (e.g., 0.5 μm, 0.8 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm), and the inorganic filler B has an average particle diameter of 10 to 40nm (e.g., 10nm, 15nm, 18nm, 20nm, 23nm, 25nm, 28nm, 30nm, 35nm, 38nm, or 40 nm).

Preferably, the inorganic filler a includes any one or a combination of at least two of silica, aluminum silicate, alumina, titanium dioxide, zirconia, various glasses (including fluorine glass, borosilicate glass, soda glass, barium aluminosilicate glass, strontium-or zirconium-containing glass, glass ceramics, fluoroaluminosilicate glass, and also synthetic glass obtained by a sol-gel method, and the like), fumed silica, calcium fluoride, strontium fluoride, calcium carbonate, kaolin, clay, mica, aluminum sulfate, calcium sulfate, barium sulfate, titanium oxide, calcium phosphate, hydroxyapatite, calcium hydroxide, strontium hydroxide, or zeolite. These inorganic fillers may be used as an aggregate, and there may be mentioned a silica-zirconia composite oxide aggregate obtained by mixing a silica sol and a zirconia sol and applying spray drying and heat treatment, and the like.

Preferably, the inorganic filler B includes any one or a combination of at least two of silica, zirconia, titania, zirconia, zinc oxide, calcium phosphate, hydroxyapatite, and the like.

Preferably, the refractive index of the inorganic filler A is 1.52 to 1.58, such as 1.52, 1.53, 1.54, 1.55, 1.56, 1.57 or 1.58. And the refractive index of the inorganic filler (B) is 1.43 to 1.50, for example, 1.43, 1.45, 1.48, 1.50, etc.

In order to improve the affinity of the inorganic filler with the polymerizable monomer and to improve the chemical bonding property of the inorganic filler with the polymerizable monomer to improve the mechanical strength of the cured product, it may be surface-treated with a surface treatment agent (e.g., a coupling agent). Examples of the surface treatment agent include: gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropyltriethoxysilane, gamma-aminopropyltrimethoxysilane or a combination of at least two thereof. Preferably gamma-methacryloxypropyltrimethoxysilane is used.

As a method for treating the inorganic filler with the surface treatment agent, the following methods can be mentioned: the recycling method may be utilized by heating each of the filler and the surface treatment agent in a solvent such as alcohol for several tens of minutes to about 10 hours, preferably in the range of 1 hour to 5 hours. If it is desired to promote hydrolysis of the surface treatment agent, water or acidic water (e.g., acetic acid) is added to the solvent, and the mixture is heated and recycled within the above range, and then the solvent is removed under normal pressure or reduced pressure, for example, a drying method.

The amount of the surface treatment agent to be used varies depending on the particle diameter of the inorganic filler, but is usually 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, per 100 parts by weight of each filler. The particle diameter or particle diameter distribution of each filler after the surface treatment is almost the same as that of the filler before the treatment.

Preferably, the initiator is selected from one or a combination of at least two of dicumyl peroxide, tert-butyl peroxide, benzoyl peroxide, tert-butyl peroxyacetate and tert-butyl peroxybenzoate.

Preferably, the colorant may be at least one of zinc white, titanium white, antimony white, vermilion, cadmium red, iron red, chromium oxide, cerium praseodymium yellow, lemon yellow, chrome yellow, zinc yellow, iron yellow, bismuth yellow, barium yellow, zirconium vanadium yellow, iron black, carbon black, or graphite.

In the present invention, the mixing device may be any known mixing device such as a stirred tank, kneader, or mixer.

In the invention, at least two layers of granular materials with different colors prepared in the step (1) need to be stored at the temperature of lower than 35 ℃.

In another aspect, the invention provides a dental gradient-color resin ceramic restoration material prepared by the preparation method. The dental gradient resin ceramic restoration material has no layering, has natural gradient effect and has mechanical strength enough to bear occlusion pressure in the oral cavity.

Compared with the prior art, the invention has the following beneficial effects:

the resin ceramic repair material prepared by the method has no interlayer delamination, natural interlayer transition effect, mechanical strength enough to bear the occlusion pressure in the oral cavity, simple preparation method and easy operation.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The compounds used in the examples of the present invention and the abbreviations for the compounds are shown below.

UDMA: urethane dimethacrylate

Bis-GMA: 2, 2-bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl) propane

TEGDMA: triethylene glycol dimethacrylate

BPO: benzoyl peroxide

γ -MPS: gamma-methacryloxypropyltrimethoxysilane

Inorganic filler

1: amorphous barium boron aluminosilicate glass powder GM27884, 0.7 μm (D50)

2: amorphous barium boron aluminosilicate glass powder GM27884, 0.18 μm (D50)

3: fumed silica OX-50, 40nm (D50)

Example 1

(1) Amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.7 mu m and fumed silica (OX-50) with D50 of 40nm are modified by gamma-methacryloxypropyl trimethoxysilane respectively to obtain modified glass powder and modified fumed silica.

(2) To 70g of Urethane Dimethacrylate (UDMA) and 30g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 1.

(4) Stirring the pasty materials with different colors for 20min under the conditions of 100r/min and-0.09 MPa respectively to obtain granular materials with the average particle size of 1.2 mm.

(5) And weighing the granular materials of each layer according to the color transition sequence, sequentially loading the granular materials into a compression molding die, and paving. And tightly combining the layers under the pressure of 2MPa to obtain a semi-finished product of the multilayer gradient resin ceramic repair material.

(6) And pressing the prepared semi-finished product of the multilayer gradient color resin ceramic repair material for 2h under the conditions of 120 ℃ and 10MPa for polymerization and solidification to obtain the multilayer gradient color resin ceramic repair material.

TABLE 1

Example 2

(1) The modified glass powder was obtained using amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.7 μm in the presence of gamma-methacryloxypropyltrimethoxysilane.

(2) To 70g of Urethane Dimethacrylate (UDMA) and 30g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 2.

(4) Stirring the pasty materials with different colors for 20min under the conditions of 80r/min and-0.09 MPa respectively to obtain granular materials with the average granularity of 5 mm.

(5) And weighing the granular materials of each layer according to the color transition sequence, sequentially loading the granular materials into a compression molding die, and paving. And tightly combining the layers under the pressure of 3MPa to obtain a semi-finished product of the multilayer gradient resin ceramic repair material. Granular material

(6) And pressing the prepared multilayer gradient resin ceramic repair material semi-finished product for 4h under the conditions of 100 ℃ and 15MPa for polymerization and solidification to obtain the multilayer gradient resin ceramic repair material.

TABLE 2

Example 3

(1) Amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.18 mu m and fumed silica (OX-50) with D50 of 40nm are modified by gamma-methacryloxypropyl trimethoxysilane respectively to obtain modified glass powder and modified fumed silica.

(2) To 70g of Urethane Dimethacrylate (UDMA) and 30g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 3.

(4) Stirring pasty materials with different colors for 30min at 90r/min and-0.08 MPa to obtain granular materials with average particle size of 2.1 mm.

(5) And weighing the granular materials of each layer according to the color transition sequence, sequentially loading the granular materials into a compression molding die, and paving. And tightly combining the layers under the pressure of 2MPa to obtain a semi-finished product of the multilayer gradient resin ceramic repair material.

(6) And pressing the prepared multilayer gradient resin ceramic repair material semi-finished product for 4h under the conditions of 100 ℃ and 10MPa for polymerization and solidification to obtain the multilayer gradient resin ceramic repair material.

TABLE 3

Example 4

(1) Amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.18 mu m is modified by gamma-methacryloxypropyl trimethoxy silane to obtain modified glass powder.

(2) To 65g of 2, 2-Bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy) phenyl) propane (Bis-GMA) and 35g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 4.

(4) Stirring the pasty materials with different colors for 50min under the conditions of 110r/min and-0.08 MPa respectively to obtain granular materials with the average granularity of 0.1 mm.

(5) And weighing the granular materials of each layer, sequentially loading the granular materials into a compression molding die, and paving. And tightly combining the layers under the pressure of 3MPa to obtain a semi-finished product of the multilayer gradient resin ceramic repair material. Granular material

(6) And pressing the prepared multilayer gradient resin ceramic repair material semi-finished product for 4h under the conditions of 100 ℃ and 15MPa for polymerization and solidification to obtain the multilayer gradient resin ceramic repair material.

TABLE 4

Number of layers

Modified glass powder

Polymerizable monomer composition

Titanium white

Iron oxide red

Iron oxide yellow

Iron oxide black

1

79.70147％

19.92537％

0.07610％

0.18463％

0.11217％

0.00026％

2

79.67859％

19.91965％

0.08193％

0.19878％

0.12077％

0.00028％

3

79.61006％

19.90251％

0.09941％

0.24117％

0.14652％

0.00034％

4

79.54164％

19.88541％

0.11685％

0.28348％

0.17223％

0.00040％

5

79.47333％

19.86833％

0.13426％

0.32572％

0.19789％

0.00046％

Comparative example 1

(1) Amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.18 mu m and fumed silica (OX-50) with D50 of 40nm are modified by gamma-methacryloxypropyl trimethoxysilane respectively to obtain modified glass powder and modified fumed silica

(2) To 70g of Urethane Dimethacrylate (UDMA) and 30g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 3.

(4) Sequentially putting paste materials with different colors into a die, maintaining the pressure for 1min at the pressure of 2MPa by using a press after adding each layer of paste material, and then polymerizing and curing for 1h at the temperature of 100 ℃ and under the pressure of 10MPa to obtain the multilayer gradient color resin ceramic repair material.

Comparative example 2

(1) Amorphous barium boron aluminosilicate glass powder GM27884 with D50 of 0.7 mu m and fumed silica (OX-50) with D50 of 40nm are modified by gamma-methacryloxypropyl trimethoxysilane respectively to obtain modified glass powder and modified fumed silica.

(2) To 70g of Urethane Dimethacrylate (UDMA) and 30g of triethylene glycol dimethacrylate (TEGDMA), 1.0g of Benzoyl Peroxide (BPO) as a thermal initiator was added as a polymerizable monomer composition.

(3) The modified filler, polymerizable monomer composition, colorant and other additives were mixed into uniform paste-like materials of different colors according to the formulation in Table 5.

(4) The paste of different colors is filled into the press-forming die simultaneously using a syringe. Polymerizing and curing for 2h at 120 ℃ and 8 MPa.

TABLE 5

The test methods for evaluating the performance of the dental curable compositions prepared in examples and comparative examples are as follows.

(1) Particle size test

The method comprises the following steps: and shooting the prepared particles into a computer by using a high-definition camera, scanning a two-dimensional image on the computer, and carrying out measurement statistics and editing processing on a pixel group of the characteristic point to obtain the particle size.

(2) Bending Strength test

The method comprises the following steps: the composite resin block was cut into test pieces of 1.2 × 4.0 × 18mm, the surface was polished by wet-grinding with 2000-mesh sandpaper, and a three-point bending test was performed using a tensile tester under conditions of a fulcrum pitch of 12mm and a crosshead speed of 1.0mm/min, and the evaluation was performed on the average value of ten samples.

(3) Fracture toughness

The method comprises the following steps: the composite resin block was processed into test specimens having a size of (4.0 ± 0.2) mm (3.0 ± 0.2) mm (44 ± 1) mm. A V-groove is formed on a surface with a width of 3mm, and the depth of the V-groove is about (1.0 +/-0.2) mm. The test was carried out using a tensile tester, with the sample bar with the V-groove facing down, at a span of 40mm and a crosshead speed of 0.5 mm/min. The breaking load force (N) was recorded and calculated.

(4) Water absorption and dissolution

The method comprises the following steps: processing the composite resin block intoMeasuring the diameter and thickness of the sample to calculate the volume V of the sample; it was dried to constant weight at 37 ℃ and recorded as m₁(ii) a Soaking the constant-weight sample in pure water at 37 ℃, taking out after 7 days, weighing, and recording as m₂(ii) a Finally, the mixture is placed in an oven at 37 ℃ and dried to constant weight, and is marked as m 3.

Water absorption value rho_ws

ρ_ws＝(m₂-m₃)/V

Dissolution value rho_sl

ρ_sl＝(m₁-m₃)/V

The performance test results are shown in table 6:

TABLE 6

As can be seen from Table 6, the resin ceramic repair material prepared by the invention has no obvious layering, natural color transition and good gradual change effect, and has the advantages of bending strength of more than 215MPa, elastic modulus of 7.2-9.5Gpa and fracture toughness of 2.22-2.53 MPa.m^1/2The water absorption value is 25.69-28.32 mu g/mm³The dissolution value is 0.87-1.31 mu g/mm³。

The applicant states that the present invention is described by the above examples to describe the dental gradient resin ceramic restorative material and the preparation method thereof, but the present invention is not limited to the above examples, i.e., it does not mean that the present invention must be implemented by the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.