Preparation method of a composite ceramic material for a teaching model tooth

Abstract

The application relates to the technical field of model tooth material, and particularly discloses a preparation method of a teaching model tooth composite ceramic material, which comprises the following steps: stirring pentaerythritol tetra(3-mercaptopropionate) and triallyl isocyanurate in a water bath to obtain a mixture; adding zinc polyacrylate into propylene glycol methyl ether acetate to uniformly disperse the zinc polyacrylate, then mixing the zinc polyacrylate with the mixture, adding benzoin dimethyl ether to stir, continuously adding a solvent until the solid content reaches 40%, and then carrying out water bath stirring and reaction; vacuum deaeration to form a base slurry; adding nano-hydroxyapatite and a photoinitiator into the vacuum-deaerated base slurry to prepare an inner layer slurry, and adding nano-silicon dioxide, a photoinitiator and a fluorescent whitening agent to prepare an outer layer slurry; layer-by-layer solidification of the slurry to construct a model; and low-temperature solidification. The model tooth can be used for classroom teaching and has the advantages of high hardness and good durability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of model tooth material, more particularly, it relates to a preparation method of a model tooth composite ceramic material for teaching. BACKGROUND

[0002] In the process of medical education and oral clinical teaching practice, model teeth, as a key teaching tool for simulating real tooth structure and operation environment, play a crucial role in many teaching links such as tooth morphology cognition, restoration body manufacturing, tooth preparation, root canal treatment, etc.

[0003] However, the current model teeth for teaching face many problems in practical application that need to be solved urgently, which seriously restricts the improvement of teaching quality and the optimization of teaching cost.

[0004] From the perspective of material performance, the materials used in traditional model teeth for teaching have obvious defects. Some materials have insufficient wear resistance, and are prone to wear or debris during frequent drilling, grinding and cutting operations. This not only shortens the service life of the model teeth and increases the teaching cost, but also affects the correct understanding of the tooth structure by students due to the change of the surface morphology. Some materials have high brittleness and lack of toughness, which are prone to breakage when subjected to external impact, posing a safety hazard of flying debris, limiting the use of some high-intensity operations in teaching, and being not conducive to students' comprehensive mastery of clinical skills.

[0005] In terms of long-term use performance, traditional model teeth are prone to mechanical property degradation during repeated use. Due to material aging or interfacial adhesion loss, the model teeth may experience interlayer cracking and strength reduction after experiencing multiple thermal and cold cycles or humid heat environments, which cannot meet the long-term teaching needs. This not only increases the waste of teaching resources, but also may affect the teaching progress and quality due to unstable performance of the model teeth.

[0006] In terms of teaching function expansion, traditional model teeth have single function and lack intelligent response characteristics. For example, they do not have self-repairing function and can only be replaced after damage, which increases the teaching cost.

[0007] Therefore, a new model tooth composite ceramic material for teaching is developed. SUMMARY

[0008] In order to improve the wear resistance and durability of the model teeth, the present application provides a preparation method of a model tooth composite ceramic material for teaching.

[0009] The present application provides a preparation method of a model tooth composite ceramic material for teaching, which adopts the following technical scheme:

[0010] A preparation method of a teaching model tooth composite ceramic material, comprising the following steps:

[0011] (1) preparing a base slurry: mixing tetra (3-mercaptopropionic acid) pentaerythritol ester and triallyl isocyanurate, stirring at 200-300 rpm in a 55-65°C water bath for 20-30 min to obtain a mixture; adding zinc polyacrylate into propylene glycol methyl ether acetate solvent, stirring and dispersing uniformly, then mixing with the mixture, adding benzoin dimethyl ether and stirring uniformly, adding propylene glycol methyl ether acetate solvent to a solid content of 40%, stirring at 200-300 rpm in a 55-65°C water bath for 2-3 hours, and forming the base slurry after vacuum degassing treatment;

[0012] (2) preparing a layered slurry:

[0013] the inner layer slurry: adding the base slurry after vacuum degassing treatment, nano-hydroxyapatite and a photoinitiator successively, and stirring uniformly to obtain the inner layer slurry;

[0014] the outer layer slurry: adding the base slurry after vacuum degassing treatment, nano-silicon dioxide, a photoinitiator and a fluorescent whitening agent successively, and stirring uniformly to obtain the outer layer slurry;

[0015] (3) adopting a light-curing 3D printing technology to form and cure the slurry layer by layer to build a model;

[0016] (4) low-temperature curing: 50-70°C heat-assisted curing under ultraviolet light for 2-3 hours.

[0017] By adopting the technical scheme, the mercapto group (-SH) in tetra (3-mercaptopropionic acid) pentaerythritol ester and the carbon-carbon double bond (C=C) in triallyl isocyanurate react under the action of the photoinitiator benzoin dimethyl ether to form a mercapto-ene dynamic covalent bond network, and the dynamic covalent bond has unique reversibility, and when the material is damaged, the mercapto-ene bond can be broken and recombined under the condition of 60°C heat treatment to quickly repair the hidden cracks of the material and realize self-repair of the material. At the same time, the zinc ion coordination bond network also plays a role, and Zn 2+ migrates to the damage site and recoordinates with the carboxyl group / phosphate group to enhance the toughness recovery of the material.

[0018] Optionally, the base slurry comprises the following raw materials in parts by weight: tetra (3-mercaptopropionic acid) pentaerythritol ester 40-60 parts, triallyl isocyanurate 20-30 parts, benzoin dimethyl ether 0.2-0.5 parts and zinc polyacrylate 15-25 parts.

[0019] By adopting the technical scheme, the base paste prepared by reasonably proportioning the raw materials through a specific process lays a foundation for subsequent formation of a gradient structure and improvement of wear resistance, and effectively solves the problems of easy damage and difficult maintenance of the teaching model.

[0020] Optionally, the inner layer paste comprises the following raw materials in parts by weight: base paste 90-110 parts, nano-hydroxyapatite 55-65 parts, and photoinitiator 1-2 parts.

[0021] The outer layer paste comprises the following raw materials in parts by weight: base paste 90-110 parts, nano-silicon dioxide 35-45 parts, photoinitiator 0.4-0.6 parts, and fluorescent whitening agent 0.1-0.3 parts.

[0022] By adopting the technical scheme, in the inner layer paste, nano-hydroxyapatite and photoinitiator are added in specific parts by weight based on the base paste. The photoinitiator can assist subsequent photocuring molding, the nano-hydroxyapatite can interact with the components in the base paste, and it can ion exchange with Zn²⁺ in the base paste to enhance the combination with the base paste, form a structure similar to dentin, and endow the material with good biocompatibility and mechanical properties. In the outer layer paste, nano-silicon dioxide and fluorescent whitening agent are added based on the base paste. The nano-silicon dioxide can improve the hardness of the outer layer to form a hard surface layer similar to enamel, and the fluorescent whitening agent makes the appearance of the model tooth closer to the color of real teeth. After the paste with different compositions in the inner and outer layers is layered and photocured, a bionic tooth gradient structure is constructed, the model tooth has the characteristics of flexibility in the inner layer and hardness in the outer layer, the overall wear resistance and strength are improved, the appearance is realistic, the teaching needs are better met, and the problems of poor performance and appearance of traditional teaching models are solved.

[0023] Optionally, the nano-hydroxyapatite is pretreated before being added, and the pretreatment operation is as follows: the nano-hydroxyapatite is ultrasonically treated in a 5wt% γ-(methacryloyloxy)propyltrimethoxysilane ethanol solution for 30 minutes.

[0024] The nano-silicon dioxide is pretreated before being added, and the pretreatment operation is as follows: the nano-silicon dioxide and isopropyl tri(dioctyl pyrophosphoryloxy) titanate are mixed and ball milled at a mass ratio of 96-98:2 for 10-15 minutes.

[0025] By adopting the technical scheme, the nanometer hydroxyapatite is ultrasonically treated for 30 min by using 5wt% of a gamma-(methacryloxy) propyl trimethoxysilane ethanol solution, a siloxane group at one end of the silane coupling agent reacts with a hydroxyl group on the surface of the nanometer hydroxyapatite to form a chemical bond, and a methacryloxy group at the other end can react with a photocuring resin system in the matrix slurry to crosslink, thereby enhancing the interface bonding force between the nanometer hydroxyapatite and the matrix, making the inner layer structure more stable, improving the mechanical properties of the material, promoting ion exchange between Zn²⁺ and Ca²⁺ in the nanometer hydroxyapatite, and optimizing the inner layer performance; the nanometer silicon dioxide and isopropyl tri(dioctyl pyrophosphoric acyloxy) titanate are mixed at a mass ratio of 96-98:2 and ball milled for 10-15 min, a long-chain alkyl group in the titanate coupling agent molecule physically adsorbs on the surface of the nanometer silicon dioxide, and the polar group can interact with the components in the matrix slurry, thereby improving the dispersibility of the nanometer silicon dioxide in the matrix, reducing the agglomeration phenomenon, making the outer layer structure more uniform and dense, improving the hardness and wear resistance of the outer layer, and further improving the performance of the entire model tooth composite ceramic material, so that the model tooth composite ceramic material is more suitable for teaching requirements.

[0026] Optionally, after low-temperature curing, a nanometer silicon sol-polyurethane composite coating is sprayed on the surface, and the coating includes the following raw materials in parts by weight: nanometer silicon dioxide sol 40-60 parts, polyurethane acrylate 30-50 parts, and photoinitiator 1-5 parts.

[0027] Optionally, the preparation of the nanometer silicon sol-polyurethane composite coating includes the following steps:

[0028] The nanometer silicon dioxide sol and the polyurethane acrylate are mixed, the photoinitiator is added, and after being fully mixed and uniformly stirred at 500-800 rpm in a 40-50°C water bath for 30-60 min, the nanometer silicon sol-polyurethane composite coating is obtained.

[0029] By adopting the technical scheme, the nanometer silicon dioxide particles in the nanometer silicon dioxide sol have a large number of hydroxyl groups on the surface, and the polyurethane acrylate contains a polymerizable carbon-carbon double bond, which undergoes photopolymerization under the action of the photoinitiator to form a high-molecular network structure, and at the same time, the silicon dioxide particles in the nanometer silicon dioxide sol are embedded in the network structure through physical adsorption and chemical bonding to form a tightly combined composite coating. The nanometer silicon sol-polyurethane composite coating has the beneficial effects that the addition of the nanometer silicon dioxide sol improves the hardness and wear resistance of the coating, so that the coating can better resist external forces such as drilling and grinding; the polyurethane acrylate endows the coating with good flexibility and adhesion, so that the coating is tightly combined with the model tooth matrix and is not easy to fall off; the synergistic effect of the two greatly improves the wear resistance of the model tooth, and the coating also has a certain antibacterial effect, improves the appearance and touch of the model tooth, prolongs the service life of the teaching model, and reduces the teaching cost.

[0030] Optionally, the spraying amount of the composite coating on the model tooth surface is 5 mg / cm 2 .

[0031] By adopting the above technical scheme, the control of the spraying amount can ensure that the composite coating formed by the nano-silica sol and the polyurethane acrylate uniformly covers the model tooth surface, and in the drilling and grinding operations, the coating is neither too thick to easily peel off nor too thin to effectively resist wear, effectively improving the wear resistance of the model tooth and greatly prolonging the service life of the model tooth. In terms of adhesion, the spraying amount can form a good bonding interface between the coating and the model tooth substrate, the flexibility and adhesion characteristics of the polyurethane acrylate can be fully utilized, and the coating can be tightly attached and not easily peeled off due to external force. In terms of antibacterial property, the appropriate amount of coating can uniformly distribute the antibacterial components, and the synergistic effect of the components such as nano-silica can make the antibacterial rate reach a high level, effectively inhibit the growth of bacteria, and ensure the health and safety of teaching use. At the same time, the appropriate spraying amount can also ensure that the model tooth has a good appearance and touch, is closer to real teeth, meets the teaching needs, and reasonably controls the cost on the premise of ensuring the performance, thereby reducing the teaching expenses.

[0032] Optionally, 0.5-1.5 parts of yttrium fluoride is further added to the outer layer slurry.

[0033] By adopting the above technical scheme, the addition of yttrium fluoride can further improve the hardness and wear resistance of the outer layer material of the model tooth, so that it is closer to the properties of natural tooth enamel, thereby improving the overall performance of the model tooth.

[0034] In summary, the present application has the following beneficial effects:

[0035] 1. The present application uses a layered slurry design of adding nano-hydroxyapatite in the inner layer and nano-silica in the outer layer, combined with light-cured 3D printing technology, to construct a biomimetic tooth gradient structure. The inner layer simulates the flexibility and biocompatibility of dentin, and the outer layer simulates the hardness and wear resistance of enamel, so that the model tooth has high strength and high toughness, significantly improves the wear resistance, and meets the teaching needs.

[0036] 2. In the present application, a dynamic covalent bond network is formed by the thiol-ene click reaction of tetra(3-mercaptopropionic acid) pentaerythritol ester and triallyl isocyanurate, combined with a zinc ion coordination bond network, to realize the self-repairing ability of the material under the condition of 60℃ heat treatment. The dynamic covalent bond can reversibly break and recombine to quickly repair surface cracks, and the zinc ion migrates to the damage site to enhance the toughness and restore it, so that the hidden cracks caused during use can be repaired by placing it in a incubator after teaching, thereby prolonging the service life of the model tooth and reducing the teaching cost.

[0037] 3、The application significantly improves the wear resistance, antibacterial property and appearance and touch of the model tooth by spraying 5 mg / cm2 of nano-silica sol-polyurethane composite coating combined with the rheological regulation effect of yttrium fluoride. The nano-silica in the composite coating enhances the hardness, the polyurethane acrylate provides flexibility and adhesion, and the yttrium fluoride optimizes the gradient layer structure, and the synergistic effect of the three makes the model tooth more similar to the real tooth, ensures the safety of teaching and health, and reasonably controls the cost. DETAILED DESCRIPTION

[0038] The application will be further described in detail below with reference to the examples. It is particularly pointed out that: in the following examples, the specific conditions not specified are carried out according to the conventional conditions or the conditions recommended by the manufacturer, and the raw materials used in the following examples can be obtained from ordinary market sales unless otherwise specified.

[0039] The polyurethane acrylate was purchased from Yinhang (Shanghai) Industry Co., Ltd., model number EB8413; the zinc polyacrylate was CAS number 25916-47-6; the nano-silica sol was purchased from Hangzhou Jili Biological Material Co., Ltd., model number JL-SO1, particle size of 10 nm; the polyurethane acrylate was purchased from Yinhang (Shanghai) Industry Co., Ltd., part number EB4491, model number EBECRYL 4491.

[0040] Preparation examples of raw materials and / or intermediates

[0041] Preparation examples of nano-silica sol-polyurethane composite coating

[0042] Preparation example 1

[0043] The nano-silica sol-polyurethane composite coating was prepared by the following steps:

[0044] 50 kg of nano-silica sol was added to 40 kg of polyurethane acrylate while stirring, after the addition was completed, stirring at 500 rpm for 10 min, 2 kg of 2-hydroxy-2-methyl-1-phenylpropanone (a photoinitiator) was added and mixed uniformly, and then stirring at 655 rpm in a 40°C water bath for 40 min to obtain a mixture.

[0045] Preparation example 2

[0046] The nano-silica sol-polyurethane composite coating was prepared by the following steps:

[0047] 40 kg of nano-silica sol was added to 50 kg of polyurethane acrylate while stirring, after the addition was completed, stirring at 500 rpm for 10 min, 4 kg of 2-hydroxy-2-methyl-1-phenylpropanone (a photoinitiator) was added and mixed uniformly, and then stirring at 500 rpm in a 45°C water bath for 60 min to obtain a mixture.

[0048] Preparation Example 3

[0049] A nano-silica sol-polyurethane composite coating is prepared including the following steps:

[0050] 60 kg of nano-silica sol is added to 30 kg of polyurethane acrylate while stirring, after the addition is complete, stirring at 500 rpm for 10 min, and 1 kg of 2-hydroxy-2-methyl-1-phenylpropanone (a photoinitiator) is added and mixed uniformly, stirring at 800 rpm in a 50°C water bath for 30 min to mix uniformly, and then 0.1 kg of a fluorescent brightener CBS-X is added and mixed uniformly to obtain a mixture.

[0051] Example

[0052] Example 1

[0053] A composite ceramic material for a teaching model tooth is prepared including the following steps:

[0054] (1) Preparation of base slurry: 50 kg of pentaerythritol tetra(3-mercaptopropionate) is mixed with 25 kg of triallyl isocyanurate, stirring at 300 rpm in a 60°C water bath for 25 min, and the reaction container is kept closed during stirring to obtain a mixture;

[0055] 20 kg of polyacrylic zinc is added to pre-cooled propylene glycol methyl ether acetate solvent at 10°C, sheared at 8000 rpm for 15 min, and then mixed with the mixture cooled to 30°C, stirred at 300 rpm for 60 min, 0.35 kg of benzoine dimethyl ether is added, the amount of propylene glycol methyl ether acetate is added to a solid content of 40%, stirred at 300 rpm for 10 min, and then vacuum degassing treatment is performed at 0.1 MPa for 15-20 min to form a base slurry with a viscosity of 1200 mPa·s;

[0056] (2) Layered slurry preparation:

[0057] Inner layer slurry: 10 kg of the base slurry after vacuum degassing treatment is sequentially mixed with 6 kg of nano-hydroxyapatite and 0.15 kg of phosphonated diphenyl phosphine oxide (a photoinitiator) to obtain an inner layer slurry;

[0058] Outer layer slurry: 10 kg of the base slurry after vacuum degassing treatment is sequentially mixed with 4 kg of nano-silica, 0.05 kg of bis(2,4,6-trimethylbenzoyl) phenyl phosphine oxide (a photoinitiator), and 0.02 kg of fluorescent brightener CBS-X to obtain an outer layer slurry;

[0059] (3) The inner layer slurry and the outer layer slurry are respectively loaded into the corresponding troughs of the 3D printer, and the model tooth structure is constructed by layer-by-layer printing and curing the slurry according to the three-dimensional design data of the model tooth. During the printing process, the printing layer thickness is controlled to be 0.2 mm, the inner layer curing energy density is 40 mJ / cm2, and the outer layer curing energy density is 22 mJ / cm2;

[0060] (4) Low-temperature curing: the printed model tooth is placed in a UV curing box and cured at 55°C for 2.5 hours under the condition of heat synergy. The curing degree of the model tooth is checked regularly during the curing process to ensure complete curing. The surface of the model tooth is sprayed with the nano-silica sol-polyurethane composite coating prepared in Preparation Example 1, and the spraying amount is 5 mg / cm2. 2 The particle size of the nano-hydroxyapatite is 50-70 nm, and the particle size of the silicon dioxide is 15-25 nm.

[0061] Example 2

[0062] A kind of model tooth composite ceramic material for teaching, preparation includes the following steps:

[0063] (1) Preparation of base slurry: 40 kg of pentaerythritol tetra (3-mercaptopropionic acid) is mixed with 30 kg of triallyl isocyanurate, stirred at 200 rpm in a 55°C water bath for 30 min, and the reaction container is kept closed during stirring. A mixture is obtained.

[0064] Take 15 kg of zinc polyacrylate and add it to the pre-cooled propylene glycol methyl ether acetate solvent at 8000 rpm. Shear for 15 min, then mix with the mixture cooled to 30°C. Stir at 300 rpm for 60 min. Add 0.2 kg of benzylic dimethyl ether. Add propylene glycol methyl ether acetate to a solid content of 40%. Stir at 300 rpm for 10 min, then vacuum degassing at 0.1 MPa for 20 min to form a base slurry with a viscosity of 1200 Pa·s.

[0065] (2) Layered slurry preparation:

[0066] Inner layer slurry: 9 kg of base slurry after vacuum degassing is added to 6.5 kg of nano-hydroxyapatite and 0.1 kg of phosphonate diphenyl phosphine oxide (photoinitiator) in sequence, and stirred uniformly to obtain the inner layer slurry.

[0067] Outer layer slurry: 11 kg of base slurry after vacuum degassing is added to 4.5 kg of nano-silicon dioxide, 0.04 kg of bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide (photoinitiator) and 0.01 kg of fluorescent whitening agent CBS-X in sequence, and stirred uniformly to obtain the outer layer slurry.

[0068] (3) The inner layer slurry and the outer layer slurry are respectively loaded into the corresponding troughs of the 3D printer, and the model tooth structure is constructed by layer-by-layer printing and curing the slurry according to the three-dimensional design data of the model tooth. During the printing process, the printing layer thickness is controlled to be 0.2 mm, the inner layer curing energy density is 40 mJ / cm2, and the outer layer curing energy density is 22 mJ / cm2;

[0069] (4) Low-temperature curing: the printed model tooth is placed in a UV curing box and cured at 60°C for 2 hours under the condition of heat synergy. The curing degree of the model tooth is checked regularly during the curing process to ensure complete curing. The surface of the model tooth is sprayed with the nano-silica sol-polyurethane composite coating prepared in Preparation Example 2, and the spraying amount is 5 mg / cm2. 2 The particle size of the nano-hydroxyapatite is 50-70 nm, and the particle size of the silicon dioxide is 15-25 nm.

[0070] Example 3

[0071] A kind of teaching model tooth composite ceramic material, preparation includes the following steps:

[0072] (1) Preparation of base slurry: 60 kg of pentaerythritol tetra (3-mercaptopropionate) is mixed with 20 kg of triallyl isocyanurate, stirred at 65°C in water bath for 20 min at 250 rpm, and the reaction container is kept closed during stirring. A mixture is obtained.

[0073] Take 25 kg of zinc polyacrylate and stir it into the pre-cooled propylene glycol methyl ether acetate solvent at 8000 rpm for 15 min. Then mix it with the mixture cooled to 30°C. Stir at 300 rpm for 60 min. Add 0.5 kg of benzoin dimethyl ether. Add propylene glycol methyl ether acetate to a solid content of 40%. Stir at 300 rpm for 10 min. Then vacuum degassing at 0.1 MPa for 20 min to form a base slurry with a viscosity of 1200 mPa·s.

[0074] (2) Layered slurry preparation:

[0075] Inner layer slurry: take 11 kg of base slurry after vacuum degassing and add 5.5 kg of nano-hydroxyapatite and 0.2 kg of phosphonate diphenyl phosphine oxide (photoinitiator) in sequence. Stir well to get the inner layer slurry.

[0076] Outer layer slurry: take 9 kg of base slurry after vacuum degassing and add 3.5 kg of nano-silicon dioxide, 0.06 kg of bis (2,4,6-trimethyl benzoyl) phenyl phosphine oxide (photoinitiator) and 0.03 kg of fluorescent whitening agent CBS-X in sequence. Stir well to get the outer layer slurry.

[0077] (3) The inner layer slurry and the outer layer slurry are respectively loaded into the corresponding grooves of the 3D printer, and the model tooth structure is constructed by layer-by-layer printing and curing the slurry according to the three-dimensional design data of the model tooth in the process of light-cured 3D printing; in the printing process, the printing layer thickness is controlled to be 0.2 mm, the inner layer curing energy density is 40 mJ / cm2, and the outer layer curing energy density is 22 mJ / cm2;

[0078] (4) Low-temperature curing: the printed model tooth is placed in a UV curing box and cured at 50°C for 3 hours under the condition of heat synergy, the curing degree of the model tooth is checked regularly during the curing process to ensure complete curing, and a nano-silica sol-polyurethane composite coating prepared in Preparation Example 3 is sprayed on the surface of the model tooth, and the spraying amount is 5 mg / cm2. 2 The particle size of the nano-hydroxyapatite is 50-70 nm, and the particle size of the nano-silica is 15-25 nm.

[0079] Example 4

[0080] A composite ceramic material for a teaching model tooth, which is different from Example 1 in that the nano-hydroxyapatite and the nano-silica added in this example are pretreated:

[0081] 7 kg of nano-hydroxyapatite is added to 20 kg of 5 wt% γ-(methacryloyloxy)propyltrimethoxysilane ethanol solution, ultrasonic treatment is performed at 300 W for 30 min, and the pretreated nano-hydroxyapatite is obtained by filtering and drying at 60°C for 5 h;

[0082] 9.8 kg of nano-silica and 0.2 kg of isopropyl tri(dioctyl pyrophosphoryl) titanate are added to a ball mill tank, and a proper amount of zirconia grinding balls are pre-loaded, and the mass ratio of the grinding balls to the powder is 4:1; the pretreated nano-silica is obtained by mixing and ball milling at 300 rpm for 10 min; and the remaining steps are the same as those in Example 1.

[0083] Example 5

[0084] A composite ceramic material for a teaching model tooth, which is different from Example 1 in that 1 kg of yttrium fluoride is further added to the outer layer slurry in this example:

[0085] The outer layer slurry: 10 kg of the base slurry after vacuum debubbling treatment is sequentially mixed with 4 kg of nano-silica, 1 kg of yttrium fluoride, 0.05 kg of bis(2,4,6-trimethylbenzoyl) phenyl phosphine oxide (a photoinitiator), and 0.02 kg of fluorescent whitening agent CBS-X to obtain the outer layer slurry; and the remaining steps are the same as those in Example 1.

[0086] Example 6

[0087] A composite ceramic material for teaching model teeth, which differs from Example 5 in that 0.5 kg of yttrium fluoride is added to the outer layer slurry of the present example.

[0088] Example 7

[0089] A composite ceramic material for teaching model teeth, which differs from Example 5 in that 1.5 kg of yttrium fluoride is added to the outer layer slurry of the present example.

[0090] Example 8

[0091] A composite ceramic material for teaching model teeth, which differs from Example 1 in that the surface of the model teeth of the present example is not sprayed with a nano-silica sol-polyurethane composite coating.

[0092] Example 9

[0093] A composite ceramic material for teaching model teeth, which differs from Example 1 in that the amount of the nano-silica sol-polyurethane composite coating sprayed on the surface of the model teeth of the present example is 6 mg / cm 2 .

[0094] Example 10

[0095] A composite ceramic material for teaching model teeth, which differs from Example 1 in that the amount of the nano-silica sol-polyurethane composite coating sprayed on the surface of the model teeth of the present example is 4 mg / cm 2 .

[0096] Comparative Example

[0097] Comparative Example 1

[0098] A composite ceramic material for teaching model teeth, which differs from Example 1 in that a single layer of homogeneous slurry is used in the present comparative example, and the preparation includes the following steps:

[0099] (1) Preparation of the base slurry: 50 kg of pentaerythritol tetra(3-mercaptopropionate) is mixed with 25 kg of triallyl isocyanurate, stirred at 300 rpm in a 60°C water bath for 25 min, and the reaction vessel is kept closed during the stirring process to obtain a mixture;

[0100] 20 kg of zinc polyacrylate is added to the pre-cooled to 10°C propylene glycol methyl ether acetate solvent, sheared at 8000 rpm for 15 min, and then mixed with the mixture cooled to 30°C, stirred at 300 rpm for 60 min, 0.35 kg of benzoin dimethyl ether is added, the amount of propylene glycol methyl ether acetate is added to a solid content of 40%, and after stirring at 300 rpm for 10 min, the slurry is vacuum degassed at 0.1 MPa for 15-20 min to form a base slurry with a viscosity of 1200 mPa·s;

[0101] (2) Slurry preparation:

[0102] After vacuum defoaming treatment, 20 kg of base slurry was added with 6 kg of nano-hydroxyapatite, 4 kg of nano-silicon dioxide, 0.02 kg of fluorescent whitening agent CBS-X, and 0.15 kg of phosphonate diphenyl phosphine oxide (photoinitiator) to mix and stir uniformly to obtain the slurry;

[0103] (3) Layered photocuring forming was performed by using the photocuring 3D printing technology, the slurry was loaded into the corresponding trough of the 3D printer, and the model tooth structure was printed and cured according to the three-dimensional design data of the model tooth. During the printing process, the curing energy density was 40 mJ / cm2.

[0104] (4) Low-temperature curing: the printed model tooth was placed in a UV curing box and cured at 55°C for 2.5 hours under heat synergistic conditions. The curing degree of the model tooth was checked regularly during the curing process to ensure complete curing.

[0105] Comparative Example 2

[0106] A teaching model tooth composite ceramic material, which is different from Example 1 in that a modified epoxy acrylate resin is used as the base resin in the comparative example, as follows:

[0107] (1) Preparation of base slurry: 20 kg of zinc polyacrylate was added to pre-cooled propylene glycol methyl ether acetate solvent at 8000 rpm for 15 min, then mixed with 75 kg of modified epoxy acrylate resin, stirred at 300 rpm for 60 min, added with 0.35 kg of benzyldimethyl ether, and the amount of propylene glycol methyl ether acetate was added to 40% solid content. After stirring at 300 rpm for 10 min, vacuum defoaming treatment was performed at 0.1 MPa for 15-20 min to form a base slurry with a viscosity of 1200 mPa·s.

[0108] The remaining steps are the same as in Example 1.

[0109] Comparative Example 3

[0110] A teaching model tooth composite ceramic material, which is different from Example 1 in that in the low-temperature curing process of step (4) in the comparative example, the printed model tooth was placed in a UV curing box and cured at 80°C for 2.5 h.

[0111] Performance test

[0112] Wear resistance: after being drilled and ground 50 times by a dental teaching tungsten carbide needle (diameter 1.6 mm) at a pressure of 3N and a speed of 20000 rpm, the surface Vickers hardness retention rate was detected.

[0113] Color fastness: soak in 1% sodium hypochlorite solution for 100 times (10 minutes each time) for disinfection, and use a spectrophotometer to measure the color difference;

[0114] Self-repairing: use a Vickers indenter of an indentation machine to simulate local impact on the surface of the model tooth, with a load of 100 g and a holding time of 15 s, to form a scratch with a length of 10 mm and a depth of 20±2 μm, and then place the model tooth in a 60℃ oven for 2 h, and then detect the scratch repair rate;

[0115] Bending strength: the bending strength of the model tooth is detected by a three-point bending method.

[0116] Table 1: Test data

[0117]

[0118] It can be seen from the data of Examples 1-3 and Comparative Example 1 in combination with Table 1 that the experimental data of Examples 1-3 are all better than those of Comparative Example 1, which indicates that the layered slurry design is adopted, the inner layer simulates the flexibility and biocompatibility of dentin, and the outer layer simulates the hardness and wear resistance of enamel, so that the gradient structure of the bionic tooth is constructed, and the model tooth has high strength and high toughness. However, the single-layer homogeneous slurry adopted in Comparative Example 1 cannot form such a gradient structure, resulting in poor performance of the model tooth in wear resistance, color fastness and self-repairing.

[0119] It can be seen from the data of Examples 1-3 and Comparative Example 2 in combination with Table 1 that the experimental data of Examples 1-3 are all better than those of Comparative Example 2, which indicates that the matrix system formed by tetra(3-mercaptopropionic acid) pentaerythritol ester and triallyl isocyanurate has advantages in wear resistance and self-repairing, and the application of the matrix system in the preparation process of the model tooth can obtain a model tooth with good wear resistance and high self-repairing ability.

[0120] It can be seen from the data of Examples 1-3 and Comparative Example 3 in combination with Table 1 that the experimental data of Examples 1-3 are all better than those of Comparative Example 3, which indicates that a suitable curing temperature also affects the performance of the model tooth, and maintaining the curing temperature at 50-70℃ is conducive to the formation of covalent bond network and zinc ion coordination bond network, and the stable construction of the gradient structure, thereby improving the performance of the model tooth.

[0121] It can be seen from the data of Example 1 and Example 4 in combination with Table 1 that the experimental data of Example 4 are all better than those of Example 1, which indicates that the further treatment of the nano-hydroxyapatite and nano-silicon dioxide can strengthen the bonding force with the matrix and improve the dispersibility, thereby improving the wear resistance, color fastness and self-repairing of the model tooth.

[0122] It can be seen from the data of Example 1 and Example 5-7 and Table 1 that the experimental data of Example 5-7 are all better than that of Example 1, which shows that the addition of yttrium fluoride has a positive effect on the performance of the model tooth.

[0123] It can be seen from the data of Example 1 and Example 8 and Table 1 that the experimental data of Example 1 are all better than that of Example 8, which shows that the coating of the nano-silica sol-polyurethane composite coating can further form a protective film layer on the surface of the model tooth, thereby improving the hardness and wear resistance of the model tooth.

[0124] It can be seen from the data of Example 1 and Example 9-10 and Table 1 that the experimental data of Example 1 are all better than that of Example 9-10, which shows that the spraying amount of the nano-silica sol-polyurethane composite coating is best at 5 mg / cm 2 , which can form a good bonding interface and further improve the performance of the model tooth.

[0125] The model tooth prepared in the present application can be replaced once every two semesters instead of once every semester, thereby greatly reducing the teaching cost.

[0126] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, as long as the modifications are within the scope of the claims of the present application.

Claims

1. A method for preparing a model tooth composite ceramic material for teaching, characterized by, It comprises the following steps: (1) Preparation of matrix slurry: After mixing tetra (3-mercapto propionic acid) pentaerythritol ester and triallyl isocyanurate, stirring at 200-300 rpm in 55-65℃ water bath for 20-30 min, the mixture is obtained; Take the zinc polyacrylate and disperse it uniformly in propylene glycol methyl ether acetate solvent, then mix it with the mixture, add benzoin dimethyl ether and stir uniformly, add propylene glycol methyl ether acetate solvent to 40%, stir at 200-300 rpm in 55-65℃ water bath for 2-3 hours, vacuum degassing treatment to form the matrix slurry; (2) Layered slurry preparation: Inner layer slurry: the vacuum degassing treated matrix slurry is mixed with nano hydroxyapatite and photoinitiator to obtain the inner layer slurry; Outer layer slurry: the vacuum degassing treated matrix slurry is mixed with nano silica, photoinitiator and fluorescent whitening agent to obtain the outer layer slurry; (3) Layered photocuring forming by using photocuring 3D printing technology, layer by layer curing slurry to build the model; (4) Low temperature curing: 50-70℃ heat synergistic curing under ultraviolet light for 2-3 hours.

2. The method for preparing a composite ceramic material for teaching model teeth according to claim 1, characterized in that: The matrix slurry comprises the following raw materials by weight: tetra (3-mercapto propionic acid) pentaerythritol ester 40-60 parts, triallyl isocyanurate 20-30 parts, benzoin dimethyl ether 0.2-0.5 parts and zinc polyacrylate 15-25 parts.

3. The preparation method of the model tooth composite ceramic material for teaching according to claim 1, characterized in that: The inner layer slurry comprises the following raw materials by weight: matrix slurry 90-110 parts, nano hydroxyapatite 55-65 parts, and photoinitiator 1-2 parts; The outer layer slurry comprises the following raw materials by weight: matrix slurry 90-110 parts, nano silica 35-45 parts, photoinitiator 0.4-0.6 parts, and fluorescent whitening agent 0.1-0.3 parts.

4. The method for preparing a composite ceramic material for teaching model teeth according to claim 1, characterized in that: The nano hydroxyapatite is pretreated before being added, specifically as follows: the nano hydroxyapatite is ultrasonically treated in 5wt% γ-(methacryloyloxy) propyl trimethoxysilane ethanol solution for 20-30 min, then taken out and dried to obtain the pretreated nano hydroxyapatite; The nano silica is pretreated before being added, specifically as follows: the nano silica is mixed with isopropyl tri (dioctyl pyrophosphoric acyloxy) titanate at a mass ratio of 96-98:2, and ball milled for 10-15 min to obtain the pretreated nano silica.

5. The method for preparing a composite ceramic material for teaching model teeth according to claim 1, characterized in that: After low temperature curing, a nano silicon sol-polyurethane composite coating is sprayed on the surface, which comprises the following raw materials by weight: nano silica sol 40-60 parts, polyurethane acrylate 30-50 parts, and photoinitiator 1-4 parts.

6. The method for preparing a composite ceramic material for teaching model teeth according to claim 5, characterized in that: The preparation of the nano silicon sol-polyurethane composite coating comprises the following steps: Mix the nano silica sol with the polyurethane acrylate, add the photoinitiator, and mix uniformly at 500-800 rpm in a 40-50℃ water bath for 30-60 min to obtain the mixture.

7. The method for preparing a composite ceramic material for teaching model teeth according to claim 5, characterized in that: The composite coating is applied to the model tooth surface at a spray amount of 5 mg / cm 2 .

8. The method for preparing a composite ceramic material for teaching model teeth according to claim 1, characterized in that: 0.5-1.5 parts of yttrium fluoride is also added to the outer layer slurry.

Images