Resin with gradually changed color and light transmittance, preparation method and application thereof, and artificial tooth simulating natural tooth

Abstract

The invention belongs to the technical field of dental materials, and particularly relates to resin with gradually-changed color and light transmittance, a preparation method and application of the resin and a false tooth simulating natural teeth. The resin with the gradually changed color and light transmittance is formed by hot pressing of multiple layers of materials; the light transmittance and chromaticity of each layer of materials are strictly controlled, the absolute value of the difference value of the light transmittance of every two adjacent layers of materials in the multiple layers of materials is 1-7%, and the absolute value of the difference value of the light transmittance of the first layer and the last layer is larger than 20%; the color difference value of two adjacent layers of materials in the multiple layers of materials is smaller than 1, and the color difference value of the first layer and the last layer is larger than 4. The resin with gradually changed color and light transmittance provided by the invention is natural in color transition, two adjacent layers are mutually fused, the resin can be used for manufacturing a whole false tooth and a complete false tooth, and the manufactured false tooth has the effect of gradually changing light transmittance and color and can better simulate the aesthetic effect of the cutting end and neck of a natural tooth.

Description

Technical Field

[0001] The invention belongs to the technical field of dental materials, and particularly relates to a resin with gradient color and light transmittance, a preparation method and application thereof, and a denture simulating natural teeth. Background Art

[0002] At present, with the improvement of people's living standards and the progress of science and technology, people have higher and higher requirements for aesthetic restoration of teeth. People want to achieve better aesthetic effects of simulating the incisal and neck of natural teeth. Therefore, there are higher requirements for the transparency and color of teeth, especially the current widespread use of resin teeth in partial and full dentures.

[0003] The composite materials used to prepare dentures in the prior art mainly include: composite resin materials, resin-infiltrated ceramic composite materials, polyetheretherketone materials, etc. These composite materials can meet the requirements of the dental field for precision manufacturing and efficiency of dentures. However, most of the existing composite materials are single-color and single-transmittance materials. The color and transmittance of the dentures produced are the same. Compared with natural teeth, there is a disadvantage that the transmittance and color are not similar enough, and they cannot meet the aesthetic effect of natural teeth's transmittance and color gradient.

[0004] A Chinese patent with publication number CN112206170A discloses a gradient resin and its preparation method and application. The gradient resin disclosed in the patent is formed by the fusion of different layers with transitional color changes, and the transmittance of different layers is not controlled. Therefore, it fails to show the characteristic of the gradient transmittance of natural teeth. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a resin with gradient color and light transmittance, a preparation method and application thereof, and a denture simulating natural teeth. The resin with gradient color and light transmittance provided by the present invention has a light transmittance and color similar to those of natural teeth, so as to achieve the aesthetic effect of full dentures.

[0006] The present invention provides a resin with a gradual change in color and light transmittance, wherein the resin is formed by hot pressing multiple layers of materials; the materials include raw material resin and colorant;

[0007] Each layer of the multi-layer material has different light transmittance and chromaticity;

[0008] The absolute value of the difference in light transmittance between two adjacent layers of the multilayer material is 1-7%, and the absolute value of the difference in light transmittance between the first layer and the last layer is greater than 20%;

[0009] The color difference between two adjacent layers of the multi-layer material is less than 1, and the color difference between the first layer and the last layer is greater than 4.

[0010] Preferably, the material comprises the following raw materials in percentage by weight:

[0011] Resin 99-99.99%, colorant 0.01-1%.

[0012] Preferably, the resin comprises a polymer and / or a monomer; the polymer comprises one or more of polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyn-butyl methacrylate, polyisobutyl methacrylate and polyhexyl methacrylate; the monomer comprises one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-phenoxyethyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate; 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane; 2,2-bis[4-(acryloxy-ethoxy)phenyl]propane; 2,2-bis[4-(methacryloxy-ethoxy)phenyl]propane; carbamate di(meth)acrylate; 4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diol dimethacrylate.

[0013] Preferably, the colorant includes one or more of zirconium vanadium yellow, cerium praseodymium yellow, lemon yellow, iron oxide yellow, chrome yellow, iron oxide red, erbium oxide, titanium dioxide, cobalt oxide, chromium oxide, iron oxide brown, iron oxide black and carbon black.

[0014] The present invention also provides a method for preparing the resin with gradient color and light transmittance described in the above technical solution, comprising the following steps:

[0015] The resin and the colorant are mixed according to the transmittance and chromaticity to obtain each layer of material;

[0016] The materials of each layer are laid in order of light transmittance from low to high or from high to low, and then hot pressed to obtain the resin with gradient color and light transmittance.

[0017] Preferably, the temperature of the hot pressing is 108-180°C.

[0018] Preferably, the hot pressing pressure is ≤20Mpa.

[0019] Preferably, the heat pressing time is ≥15 minutes.

[0020] The present invention also provides the use of the resin with gradient color and light transmittance described in the above technical solution or the resin with gradient color and light transmittance prepared by the preparation method in the production of dentures.

[0021] The present invention also provides a denture simulating natural teeth, wherein the denture presents a transparency and color gradient effect from one end to the other; the denture is made of the resin with a gradient color and transmittance described in the above technical solution or the resin with a gradient color and transmittance prepared by the preparation method.

[0022] The present invention provides a resin with a gradual change in color and light transmittance, wherein the resin is formed by hot pressing of multiple layers of materials; the materials include raw material resin and colorant; each layer of the multiple layers of materials has different light transmittance and chromaticity; the absolute value of the difference in light transmittance between two adjacent layers of materials in the multiple layers of materials is 1-7%, and the absolute value of the difference in light transmittance between the first layer and the last layer is greater than 20%; the color difference value between two adjacent layers of materials in the multiple layers of materials is less than 1, and the color difference value between the first layer and the last layer is greater than 4.

[0023] The resin with gradient color and light transmittance provided by the present invention strictly controls the light transmittance and chromaticity of each layer of material, so that the absolute value of the difference in light transmittance between two adjacent layers of material is 1-7%; the resin with gradient color and light transmittance provided by the present invention has a natural color transition, and two adjacent layers are integrated with each other, the color difference value between two adjacent layers of material is less than 1, and the color difference value between the first layer and the last layer is limited to >4, and can be used to make entire dentures and full-mouth dentures. The dentures made have the effects of light transmittance and color gradient, and can better simulate the aesthetic effects of the incisal end and neck of natural teeth.

[0024] The results of the examples show that the color difference between two adjacent layers of the resin with gradient color and light transmittance provided by the present invention is 0.24-0.99, both less than 1, and the color transition is natural, which fully meets the index requirements for simulating natural teeth.

[0025] The present invention also provides a method for preparing the resin with gradient color and transmittance described in the above technical solution, comprising the following steps: mixing the resin and the colorant according to the transmittance and chromaticity to obtain each layer of material; arranging each layer of material in order of transmittance from low to high or from high to low and then hot pressing to obtain the resin with gradient color and transmittance.

[0026] The color and light transmittance gradient resin prepared by the preparation method provided by the present invention has a natural color transition, two adjacent layers are integrated with each other, and the light transmittance and color meet the index requirements of simulating natural teeth. The preparation method provided by the present invention has simple steps, does not need to add multiple additives, has low cost, is easy to carry out industrial production, and has considerable market application prospects.

[0027] The present invention also provides the use of the resin with gradient color and light transmittance described in the above technical solution or the resin with gradient color and light transmittance prepared by the preparation method in making dentures. The denture simulating natural teeth provided by the present invention presents a gradual effect of transparency and color from one end to the other. The color and light transmittance of the denture made by using the resin with gradient color and light transmittance provided by the present invention are similar to those of natural teeth, and have good aesthetic effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the interlayer diagram of the color and light transmittance gradient resin prepared in Example 1;

[0029] Figure 2 This is the interlayer diagram of the resin prepared in Comparative Example 2;

[0030] Figure 3 This is a rendering of the denture prepared in Application Example 1;

[0031] Figure 4 This is the rendering of the complete denture prepared in Application Example 1. DETAILED DESCRIPTION

[0032] The present invention provides a resin with a gradual change in color and light transmittance, wherein the resin is formed by hot pressing multiple layers of materials; the materials include raw material resin and colorant;

[0033] Each layer of the multi-layer material has different light transmittance and chromaticity;

[0034] The absolute value of the difference in light transmittance between two adjacent layers of the multilayer material is 1-7%, and the absolute value of the difference in light transmittance between the first layer and the last layer is greater than 20%;

[0035] The color difference between two adjacent layers of the multi-layer material is less than 1, and the color difference between the first layer and the last layer is greater than 4.

[0036] In the present invention, unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0037] In the present invention, the material preferably includes the following raw materials in percentage by weight:

[0038] Resin 99-99.99%, colorant 0.01-1%.

[0039] In the present invention, the resin preferably includes a polymer and / or a monomer. In the present invention, the polymer preferably includes one or more of polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyn-butyl methacrylate, polyisobutyl methacrylate and polyhexyl methacrylate, more preferably polymethyl methacrylate and / or polyethyl methacrylate. In the present invention, the weight average molecular weight of the polymer is preferably 100,000 to 1,000,000.

[0040] In the present invention, the monomer preferably includes one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-phenoxyethyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate; 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane; 2,2-bis[4-(acryloxy-ethoxy)phenyl]propane; 2,2-bis[4-(methacryloxy-ethoxy)phenyl]propane; carbamate di(meth)acrylate; 4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diol dimethacrylate, more preferably methyl methacrylate and / or butyl methacrylate.

[0041] In the present invention, the mass ratio of polymer to monomer in the resin is preferably 0.1-1:0.9-0, more preferably 0.3-1:0.7-0. In a specific embodiment of the present invention, the resin can be a composition of polymethyl methacrylate and methyl methacrylate or a composition of polyethyl methacrylate and butyl methacrylate.

[0042] In the present invention, the colorant preferably includes one or more of zirconium vanadium yellow, cerium praseodymium yellow, lemon yellow, iron oxide yellow, chrome yellow, iron oxide red, erbium oxide, titanium dioxide, cobalt oxide, chromium oxide, iron oxide brown, iron oxide black and carbon black.

[0043] In the present invention, the multilayer materials are arranged in order of transmittance from low to high or from high to low. In the present invention, each layer of the multilayer materials has different transmittance and chromaticity. In the present invention, the absolute value of the difference in transmittance between two adjacent layers of materials in the multilayer materials is 1-7%, and the absolute value of the difference in transmittance between the first layer and the last layer is >20%; in the present invention, the color difference between two adjacent layers of materials in the multilayer materials is <1, preferably 0.24-0.99, and the color difference between the first layer and the last layer is >4. In the present invention, when preparing a resin with a gradient color and transmittance, the types of colorants used in the multilayer materials are the same.

[0044] In the specific embodiment 1 of the present invention, when the resin with gradient color and transmittance is prepared from 8 layers of materials, the measured values ​​of transmittance and chromaticity of each layer of materials are: the transmittance of the first layer is 42.01%, the L* value is 68.89, the a* value is 5.17, and the b* value is 22.27; the transmittance of the second layer is 48.48%, the L* value is 69.50, the a* value is 4.78, and the b* value is 21.61; the transmittance of the third layer is 54.49%, the L* value is 70.09, the a* value is 4.41, and the b* value is 20.99; the transmittance of the fourth layer is 59.68%, the L* value is 69.50, the a* value is 4.78, and the b* value is 21.61. * value is 70.67, a* value is 4.05, and b* value is 20.43; the fifth layer has a transmittance of 63.92%, L* value is 71.19, a* value is 3.80, and b* value is 20.02; the sixth layer has a transmittance of 66.93%, L* value is 71.63, a* value is 3.59, and b* value is 19.77; the seventh layer has a transmittance of 68.91%, L* value is 71.97, a* value is 3.45, and b* value is 19.57; the eighth layer has a transmittance of 69.93%, L* value is 72.22, a* value is 3.38, and b* value is 19.47.

[0045] The present invention also provides a method for preparing the resin with gradient color and light transmittance described in the above technical solution, comprising the following steps:

[0046] The resin and the colorant are mixed according to the transmittance and chromaticity to obtain each layer of material;

[0047] The materials of each layer are arranged in the order of light transmittance from low to high or from high to low and then hot pressed to obtain the resin with gradient color and light transmittance.

[0048] The present invention mixes resin and colorant according to light transmittance and chromaticity to obtain each layer of material.

[0049] After obtaining each layer of material, the present invention arranges each layer of material in the order of light transmittance from low to high or from high to low and then performs hot pressing to obtain the resin with gradient color and light transmittance.

[0050] In the present invention, the materials in each layer do not need to be sorted in the order of chromaticity.

[0051] In the present invention, the temperature of the hot pressing is preferably 108-180°C, more preferably 120-180°C, specifically 135°C, 145°C, 155°C or 160°C. In the present invention, the pressure of the hot pressing is preferably ≤20Mpa, more preferably <15Mpa. In the present invention, the time of the hot pressing is ≥15 minutes, preferably >20 minutes.

[0052] The present invention also provides the use of the resin with gradient color and light transmittance described in the above technical solution or the resin with gradient color and light transmittance prepared by the preparation method in the production of dentures.

[0053] The present invention also provides a denture simulating natural teeth, wherein the denture presents a transparency and color gradient effect from one end to the other; the denture is made of the resin with a gradient color and transmittance described in the above technical solution or the resin with a gradient color and transmittance prepared by the preparation method.

[0054] The technical solution of the present invention is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0055] Example 1

[0056] Example 1 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 1:

[0057] Table 1 Composition of each layer of material in Example 1

[0058] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.931032 0.056608 0.003195 0.009014 0.000151 Second floor 99.935334 0.053326 0.002943 0.008255 0.000142 Third floor 99.939636 0.050044 0.002690 0.007496 0.000134 Fourth floor 99.943939 0.046762 0.002438 0.006736 0.000125 Fifth floor 99.948241 0.043480 0.002186 0.005977 0.000116 Sixth floor 99.952543 0.040199 0.001933 0.005218 0.000107 Seventh floor 99.956846 0.036917 0.001681 0.004458 0.000098 Eighth Floor 99.961148 0.033635 0.001428 0.003699 0.000090

[0059] The resin in Table 1 is polymethyl methacrylate (weight average molecular weight of 550,000). The resin and the colorant are mixed evenly according to the percentage in Table 1 to make each layer of material with different transmittance and chromaticity; each layer of material is put into the mold in order from low to high transmittance to obtain a multi-layer material; the mold is heated to 160°C, and the obtained multi-layer material is hot-pressed at a pressure of 10MPa for 1.5 hours. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0060] Example 2

[0061] Example 2 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 2:

[0062] Table 2 Composition of each layer of material in Example 2

[0063] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.928757 0.058306 0.003323 0.009465 0.000149 Second floor 99.933204 0.054926 0.003060 0.008668 0.000142 Third floor 99.937660 0.051545 0.002798 0.007870 0.000127 Fourth floor 99.942107 0.048165 0.002536 0.007073 0.000119 Fifth floor 99.946554 0.044785 0.002273 0.006276 0.000112 Sixth floor 99.951002 0.041405 0.002011 0.005478 0.000104 Seventh floor 99.955446 0.038024 0.001748 0.004681 0.000101 Eighth Floor 99.959889 0.034644 0.001486 0.003884 0.000097

[0064] The resin in Table 2 is a composition of polymethyl methacrylate (weight average molecular weight of 500,000) and methyl methacrylate, and the mass ratio of polymethyl methacrylate to methyl methacrylate in the resin is 0.67:0.33. The resin and the colorant are mixed evenly according to the percentage content in Table 2 to prepare each layer of material with different transmittance and chromaticity; each layer of material is molded in order from low to high transmittance to obtain a multilayer material; the mold is heated to 135°C, and the obtained multilayer material is hot-pressed at a pressure of 2.5MPa for a holding time of 20min. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0065] Example 3

[0066] Example 3 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 3:

[0067] Table 3 Composition of each layer of material in Example 3

[0068] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.930309 0.057174 0.003259 0.009105 0.000153 Second floor 99.934657 0.053859 0.003002 0.008338 0.000144 Third floor 99.939005 0.050545 0.002744 0.007571 0.000135 Fourth floor 99.943353 0.047230 0.002487 0.006804 0.000126 Fifth floor 99.947702 0.043915 0.002229 0.006037 0.000117 Sixth floor 99.952049 0.040601 0.001972 0.005270 0.000108 Seventh floor 99.956398 0.037286 0.001714 0.004503 0.000099 Eighth Floor 99.960744 0.033972 0.001457 0.003736 0.000091

[0069] The resin in Table 3 is a composition of polyethyl methacrylate (weight average molecular weight of 300,000) and butyl methacrylate, and the mass ratio of polyethyl methacrylate to butyl methacrylate in the resin is 0.75:0.25. The resin and the colorant are mixed evenly according to the percentage content in Table 3 to prepare each layer of material with different transmittance and chromaticity; each layer of material is put into the mold in order from low to high transmittance to obtain a multi-layer material; the mold is heated to 145°C, and the obtained multi-layer material is hot-pressed at a pressure of 5MPa for a holding time of 30min. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0070] Comparative Example 1

[0071] Comparative Example 1 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 4:

[0072] Table 4 Composition of each layer of material in Comparative Example 1

[0073] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.936423 0.059965 0.000942 0.002623 0.000047 Second floor 99.936780 0.059965 0.000853 0.002358 0.000044 Third floor 99.937092 0.059965 0.000810 0.002092 0.000041 Fourth floor 99.937403 0.059965 0.000768 0.001826 0.000038 Fifth floor 99.933217 0.059965 0.000725 0.005977 0.000116 Sixth floor 99.934028 0.059965 0.000682 0.005218 0.000107 Seventh floor 99.934839 0.059965 0.000640 0.004458 0.000098 Eighth Floor 99.935649 0.059965 0.000597 0.003699 0.000090

[0074] The resin in Table 4 is polymethyl methacrylate (weight average molecular weight of 300,000). The resin and the colorant are mixed evenly according to the percentage in Table 4 to make each layer of material with different transmittance and chromaticity; each layer of material is put into the mold in order from low to high transmittance to obtain a multi-layer material; the mold is heated to 155°C, and the obtained multi-layer material is hot-pressed at a pressure of 5MPa for 2h. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0075] Comparative Example 2

[0076] Comparative Example 2 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 5:

[0077] Table 5 Composition of each layer of material in Comparative Example 2

[0078] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.932063 0.055911 0.006390 0.005409 0.000227 Second floor 99.937781 0.051997 0.004793 0.004057 0.000170 Third floor 99.941863 0.050320 0.003834 0.003245 0.000136 Fourth floor 99.945904 0.048083 0.003195 0.002705 0.000114 Fifth floor 99.949860 0.044729 0.002876 0.002434 0.000102 Sixth floor 99.953858 0.041933 0.002237 0.001893 0.000079 Seventh floor 99.957255 0.039138 0.001917 0.001623 0.000068 Eighth Floor 99.960651 0.036342 0.001598 0.001352 0.000057

[0079] The resin in Table 5 is a composition of polymethyl methacrylate (weight average molecular weight of 550,000) and methyl methacrylate, and the mass ratio of polymethyl methacrylate to methyl methacrylate in the resin is 0.69:0.31. The resin and the colorant are mixed evenly according to the percentage content in Table 5 to prepare each layer of material with different transmittance and chromaticity; each layer of material is sequentially molded from low to high transmittance to obtain a multilayer material; the mold is heated to 135°C, and the obtained multilayer material is hot-pressed at a pressure of 2.5MPa for a holding time of 30min. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0080] Comparative Example 3

[0081] Comparative Example 3 is prepared from 8 layers of materials, and the composition of each component in each layer of materials is shown in Table 6:

[0082] Table 6 Composition of each layer of material in Comparative Example 3

[0083] Number of layers Resin, % Titanium dioxide, % Red iron oxide, % Iron oxide yellow, % Iron oxide black, % First floor 99.933918 0.054515 0.003002 0.008420 0.000145 Second floor 99.937961 0.050699 0.002943 0.008255 0.000142 Third floor 99.939823 0.049064 0.002884 0.008090 0.000139 Fourth floor 99.942117 0.046883 0.002855 0.008007 0.000138 Fifth floor 99.945502 0.043612 0.002825 0.007925 0.000136 Sixth floor 99.948341 0.040886 0.002796 0.007842 0.000135 Seventh floor 99.951180 0.038161 0.002766 0.007760 0.000133 Eighth Floor 99.954019 0.035435 0.002737 0.007677 0.000132

[0084] The resin in Table 6 is polymethyl methacrylate (weight average molecular weight of 700,000). The resin and the colorant are mixed evenly according to the percentage in Table 6 to make each layer of material with different transmittance and chromaticity; each layer of material is put into the mold in order from low to high transmittance to obtain a multi-layer material; the mold is heated to 155°C, and the obtained multi-layer material is hot-pressed at a pressure of 5MPa for 1.5h. After cooling, the mold is removed to obtain a resin with a gradient color and transmittance.

[0085] Analytical Testing

[0086] The resins with gradient colors and light transmittance prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested, and the test methods and standards were as follows:

[0087] The transmittance is tested according to the standard GB / T2410-2008, and a haze meter is used for testing. The sample size is required to be 30×30×1mm.

[0088] The chromaticity value is tested by a spectrophotometer, the light source is "D65", the measurement mode is "reflection" and "SCI", and the chromaticity measurement value is obtained, and the chromaticity measurement value includes L*, a* and b* values. The calculation formula for the chromaticity difference between two adjacent layers (referred to as "color difference value") is:

[0089]

[0090] Wherein L*, a* and b* values ​​are the measured values ​​of chromaticity, and n is the material of the nth layer; the specific results are shown in Table 7;

[0091] The obtained resin with gradient color and light transmittance is cut into pieces with the size of The sample is (22±0.1)mm*(2.1±0.01)mm, and is polished with 400-grit sandpaper to remove the cutting marks, and then water-grinded with 2000-grit sandpaper to a sample thickness of 2.00±0.01mm.

[0092] The test results are summarized in Table 7.

[0093] Table 7 Test results of Examples 1 to 3 and Comparative Examples 1 to 3

[0094]

[0095]

[0096] It can be seen from Table 7 that the absolute value of the difference in light transmittance between two adjacent layers of materials in Examples 1 to 3 is 1.02% to 6.70%, and the range of the color difference between two adjacent layers is 0.24% to 0.99, both of which are less than 1.0, so that the light transmittance and color transition of the resins prepared in Examples 1 to 3 are natural, and the cut teeth also have the effect of light transmittance and color gradient, which can better simulate natural teeth and have a higher aesthetic effect.

[0097] In comparative example 1, the light transmittance variation between different layers is small, and the light transmittance variation from one end of the tooth to the other cannot be achieved.

[0098] In comparative example 2, the colors are stratified, and the color difference values ​​range from 0.67 to 1.17. The color difference between the first layer and the second layer is 1.17, and the color difference between the second layer and the third layer is 1.10, resulting in color stratification between layers and unnatural color transition.

[0099] In comparative example 3, the color difference between the first layer and the last layer is small, which is 3.3269, and the color gradient effect is poor.

[0100] Application Example 1

[0101] The denture is prepared by using the resin with gradient color and light transmittance prepared in Example 1. Figure 3 shown.

[0102] from Figure 3 It can be seen that the denture has a very high aesthetic effect, with a gradual change in color and transparency from the neck to the cutting end.

[0103] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A resin with a gradient color and light transmittance, characterized in that: The resin is formed by hot pressing multiple layers of materials; the materials include raw material resin and colorant; Each layer of the multi-layer material has different light transmittance and chromaticity; The absolute value of the difference in light transmittance between two adjacent layers of the multilayer material is 1-7%, and the absolute value of the difference in light transmittance between the first layer and the last layer is greater than 20%; The color difference between two adjacent layers of the multi-layer material is less than 1, and the color difference between the first layer and the last layer is greater than 4.

2. The resin with gradient color and light transmittance according to claim 1, characterized in that: The materials include the following raw materials in percentage by weight: Resin 99-99.99%, colorant 0.01-1%.

3. The resin with gradient color and light transmittance according to claim 1 or 2, characterized in that: The resin includes polymers and / or monomers; The polymer includes one or more of polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polyn-butyl methacrylate, polyisobutyl methacrylate and polyhexyl methacrylate; The monomers include one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-phenoxyethyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate; 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane; 2,2-bis[4-(acryloxy-ethoxy)phenyl]propane; 2,2-bis[4-(methacryloxy-ethoxy)phenyl]propane; carbamate di(meth)acrylate; and 4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diol dimethacrylate.

4. The resin with gradient color and light transmittance according to claim 1 or 2, characterized in that: The colorant includes one or more of zirconium vanadium yellow, cerium praseodymium yellow, lemon yellow, iron oxide yellow, chrome yellow, iron oxide red, erbium oxide, titanium dioxide, cobalt oxide, chromium oxide, iron oxide brown, iron oxide black and carbon black.

5. The method for preparing the resin with gradual color and light transmittance change according to any one of claims 1 to 4, characterized in that: The following steps are involved: The resin and the colorant are mixed according to the transmittance and chromaticity to obtain each layer of material; The materials of each layer are laid in order of light transmittance from low to high or from high to low, and then hot pressed to obtain the resin with gradient color and light transmittance.

6. The preparation method according to claim 5, characterized in that: The temperature of the hot pressing is 108-180°C.

7. The preparation method according to claim 5, characterized in that: The hot pressing pressure is ≤20Mpa.

8. The preparation method according to claim 5, characterized in that: The heat pressing time is ≥15 minutes.

9. Use of the resin with gradient color and light transmittance as described in any one of claims 1 to 4 or the resin with gradient color and light transmittance prepared by the preparation method as described in any one of claims 5 to 8 in the production of dentures.

10. A denture simulating natural teeth, characterized in that: The denture presents a gradual effect of transparency and color from one end to the other; the denture is made of the resin with gradual color and transmittance as described in any one of claims 1 to 4 or the resin with gradual color and transmittance prepared by the preparation method described in any one of claims 5 to 8.

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