Wear-resistant low-shrinkage dental resin composite material and preparation method thereof

Abstract

The invention relates to the technical field of dental biomedical materials, in particular to a wear-resistant low-shrinkage dental resin composite material and a preparation method thereof. Comprising the following raw materials: bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets, modified Zr-MOF, benzoyl peroxide, a silane coupling agent, camphorquinone, hydroquinone, chlorhexidine and triethylene glycol dimethacrylate. The bisphenol A-glycidyl methacrylate, the modified black phosphorus nanosheet and the modified Zr-MOF play a role through a synergistic effect, the bisphenol A-glycidyl methacrylate provides a stable carrier supporting effect for the modified black phosphorus nanosheet and the modified Zr-MOF, and the modified black phosphorus nanosheet effectively reduces the friction coefficient; and the modified Zr-MOF improves the rigidity and the strength of the resin matrix, adsorbs free monomers in the resin matrix, delays the curing rate, reduces stress concentration, fills shrinkage gaps of the resin matrix, and ensures the long-term usability of the dental resin composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of dental biomedical materials, and particularly to a wear-resistant dental resin composite material with a low shrinkage rate and a preparation method thereof. Background Art

[0002] With the progress of dental restoration technology, dental resin composite materials have become the mainstream materials for tooth restoration. Due to their excellent aesthetic properties, good adhesion, and low invasiveness, resin composite materials are widely used in tooth restoration, inlay restoration, tooth whitening, etc. However, existing dental resin composite materials still have several deficiencies. Poor wear resistance and high shrinkage rate will directly affect the service life and restoration effect of the composite material. In the oral environment, due to the chewing force and friction of teeth, long-term use is likely to cause surface wear of the composite material, and even phenomena such as material peeling or cracking. Therefore, how to improve the wear resistance of resin composite materials while maintaining good aesthetic effects has become the key to improving their clinical application performance. Low shrinkage rate is another important factor affecting the long-term performance of dental resin composite materials. During the curing process of dental resin composite materials, due to their double bond polymerization reaction, a large volume shrinkage often occurs. This not only leads to gaps between the restoration site and the teeth, causing secondary dental caries or restoration detachment, but also affects the mechanical properties of the composite material, such as flexural strength and compressive strength. Therefore, reducing the curing shrinkage rate of dental resin composite materials has also become the key to improving the stability and long-term use performance of the composite material. In short, improving the wear resistance and low shrinkage rate of dental resin composite materials is the key to improving their clinical application effects. Therefore, it is very meaningful to develop a wear-resistant dental resin composite material with a low shrinkage rate. Summary of the Invention

[0003] (1) Technical Problems to be Solved The purpose of the present invention is to provide a wear-resistant dental resin composite material with a low shrinkage rate and a preparation method thereof. By optimizing the material formula of the dental resin composite material and combining modern nanotechnology to optimize the interfacial bonding and dispersion of the material, the wear resistance of the material is improved, and at the same time, the curing shrinkage of the material is controlled, so as to prepare a wear-resistant dental resin composite material with a low shrinkage rate and meet the performance requirements of high wear resistance and low shrinkage.

[0004] (2) Technical Solutions To achieve the above purpose, on the one hand, the present invention provides a wear-resistant dental resin composite material with a low shrinkage rate, which comprises the following raw materials in parts by weight: 45-55 parts of bisphenol A-glycidyl methacrylate, 1-2 parts of modified Zr-MOF, 1-3 parts of benzoyl peroxide, 1-3 parts of silane coupling agent, 0.1-0.5 part of camphorquinone, 0.1-0.2 part of hydroquinone, 0.1-0.5 part of chlorhexidine, and 15-25 parts of triethylene glycol dimethacrylate; The wear-resistant low-shrinkage dental resin composite further comprises: Modified black phosphorus nanosheets; The weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:(45-55); The modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets, and the lateral size of the modified black phosphorus nanosheets is 90 nm - 120 nm, the thickness is 5 nm - 8 nm, and the specific surface area is 160 - 200 m 2 / g; The preparation method of the modified black phosphorus nanosheets comprises: S11. Dispersing the bulk black phosphorus crystal in N-methylpyrrolidone and performing ultrasonic treatment with an ultrasonic frequency of 40 - 50 kHz. After ultrasonic treatment at room temperature for 0.5 - 1 h, a dispersion of black phosphorus nanosheets is obtained; S12. Performing high-speed centrifugal separation on the dispersion of black phosphorus nanosheets at a rotation speed of 6000 - 8000 rpm. After centrifugation for 5 - 10 min, collecting the upper-layer dispersion containing black phosphorus nanosheets and performing vacuum drying at a drying temperature of 50 - 60°C. After drying for 12 - 14 h, black phosphorus nanosheets are obtained and ground into a powder for standby; S13. Dissolving the black phosphorus nanosheet powder in purified water under nitrogen protection and stirring, while heating to 75 - 85°C. After stirring for 0.5 - 1 h, slowly adding a hydrogen peroxide solution and continuing to stir for 5 - 6 h to obtain a first mixed solution; S14. Performing high-speed centrifugal separation on the first mixed solution at a rotation speed of 10000 - 12000 rpm. After centrifugation for 15 - 20 min, washing the separated solid with purified water 5 times and then performing vacuum drying at a drying temperature of 55 - 65°C. After drying for 18 - 24 h, a black phosphorus nanosheet intermediate is obtained and ground into a powder for standby; S15. Dissolving the black phosphorus nanosheet intermediate powder in dimethyl sulfoxide under stirring. After stirring for 0.5 - 1 h, slowly adding triethylamine, and after stirring for 0.5 - 1 h, continuing to slowly add methacryloyl chloride. The mass ratio of methacryloyl chloride to black phosphorus nanosheets is (0.05 - 0.1):1. Continuing to stir for 1 - 2 h to obtain a second mixed solution; S16. Transferring the second mixed solution to a reaction kettle for reaction, setting the reaction temperature to 65 - 75°C. After reacting for 6 - 8 h, collecting the reaction solution and performing high-speed centrifugal separation at a rotation speed of 10000 - 12000 rpm. After centrifugation for 15 - 20 min, washing the separated solid with purified water 5 times and then performing vacuum drying at a drying temperature of 55 - 65°C. After drying for 18 - 24 h, modified black phosphorus nanosheets are obtained and ground into a powder for standby.

[0005] Furthermore, the preparation method of the modified Zr-MOF includes: S21. Dispersing Zr-MOF in absolute ethanol and performing ultrasonic treatment at an ultrasonic frequency of 40 - 50 kHz. After ultrasonic treatment at room temperature for 0.5 - 1 h, a Zr-MOF dispersion is obtained; S22. Adding 3-aminopropyltriethoxysilane to the Zr-MOF dispersion under stirring, and simultaneously heating to 75 - 85 °C. After stirring for 12 - 15 h, a third mixed solution is obtained; S23. Performing high-speed centrifugal separation on the third mixed solution at a rotation speed of 10000 - 12000 rpm for 10 - 15 min. The separated solid is washed 3 times with absolute ethanol and then vacuum dried at a drying temperature of 55 - 65 °C for 18 - 24 h to obtain a Zr-MOF intermediate, which is ground into a powder and reserved; S24. Dissolving aniline in a 0.1 mol / L hydrochloric acid solution under stirring, setting the ice bath temperature to 0 - 5 °C. After stirring for 0.5 - 1 h, the Zr-MOF intermediate powder is slowly added, and after continuing to stir for 0.5 - 1 h, ammonium persulfate is slowly added dropwise. Subsequently, stirring and reacting continue for 12 - 15 h to obtain a fourth mixed solution; S25. Performing high-speed centrifugal separation on the fourth mixed solution at a rotation speed of 10000 - 12000 rpm for 10 - 15 min. The separated solid is alternately washed 3 times with a 0.1 mol / L hydrochloric acid solution, absolute ethanol, and purified water and then vacuum dried at a drying temperature of 45 - 55 °C for 18 - 24 h to obtain the modified Zr-MOF, which is ground into a powder and reserved.

[0006] Furthermore, the modified Zr-MOF is prepared by in-situ growth of polyaniline nanorods on the surface of Zr-MOF, and the particle size of the modified Zr-MOF is 90 - 120 nm, and the specific surface area is 800 - 900 m 2 / g.

[0007] Furthermore, the silane coupling agent is a compound of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane, and 3-glycidyltrimethoxysilane, and the weight ratio of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane, and 3-glycidyltrimethoxysilane is (1 - 2):(1 - 1.5):(0.5 - 1).

[0008] On the other hand, based on the same inventive concept, the present invention also provides a preparation method of a wear-resistant and low shrinkage dental resin composite material, which is applied to the wear-resistant and low shrinkage dental resin composite material described above, and includes the following steps: S31. Disperse the modified black phosphorus nanosheets and modified Zr-MOF in absolute ethanol respectively and perform ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz. After ultrasonic treatment for 1 - 2 h, a modified black phosphorus nanosheet dispersion and a modified Zr-MOF dispersion are obtained; S32. Under stirring, mix bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate. After stirring for 1 - 2 h, sequentially add a silane coupling agent, the modified black phosphorus nanosheet dispersion, and the modified Zr-MOF dispersion and perform ultrasonic treatment. After ultrasonic treatment for 1 - 2 h, a fifth mixed solution is obtained; S33. Under stirring, sequentially add benzoyl peroxide, camphorquinone, hydroquinone, and chlorhexidine to the fifth mixed solution. Continue stirring for 2 - 3 h and then place it in a vacuum drying oven for degassing. The degassing temperature is 35 - 45 °C. After degassing for 0.5 - 1 h, curing is carried out; S34. Curing is carried out in a forced-air drying oven. Pour it into the corresponding mold as needed. Set the curing temperature to 65 - 80 °C and the curing time to 0.5 - 1 h to obtain a wear-resistant and low-shrinkage dental resin composite.

[0009] The action mechanisms of the above raw material components are as follows: In a wear-resistant and low-shrinkage dental resin composite, bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets, and modified Zr-MOF jointly enhance the wear resistance of the dental resin composite and reduce its shrinkage rate through synergistic effects. Bisphenol A-glycidyl methacrylate is a commonly used dental resin matrix material at present, which has high mechanical strength, good chemical stability, and low hydrolyzability. The rigid bisphenol A main chain in its molecular structure can be cross-linked through polymerization reactions to form a strong three-dimensional cross-linked network. To a certain extent, its three-dimensional cross-linked network provides the hardness and strength of the resin, enhancing the wear resistance of the composite material. However, due to its relatively fragile nature, its wear resistance is poor and its shrinkage rate is high when used alone, affecting the overall stability of the material. In addition, as a matrix material, bisphenol A-glycidyl methacrylate can provide a stable carrier support for modified black phosphorus nanosheets and modified Zr-MOF, enabling the two to be evenly dispersed in the matrix material. Black phosphorus nanosheets are a new type of two-dimensional material with a high specific surface area, excellent mechanical properties, and good electrical conductivity. Their nanosheet structure can significantly enhance the mechanical properties of dental resin composites. However, due to their layered structure, they are prone to agglomeration, which in turn affects their dispersibility in the resin matrix. By introducing methacryloyl groups on the surface of black phosphorus nanosheets, modified black phosphorus nanosheets can further undergo a copolymerization reaction with the bisphenol A-glycidyl methacrylate matrix, enhancing the chemical binding force between the two, enabling the modified black phosphorus nanosheets to be more evenly dispersed in the bisphenol A-glycidyl methacrylate matrix. The layered structure of the modified black phosphorus nanosheets can effectively reduce the friction coefficient and the wear rate. At the same time, its staggered distribution with the three-dimensional cross-linked network structure of the bisphenol A-glycidyl methacrylate matrix can further enhance the shear resistance, making the material less likely to peel off during the friction process, improving the wear resistance, and also helping the resin matrix to maintain a better cured network structure. Its layered structure can hinder the free movement of molecular segments in the resin matrix, thereby reducing the volume shrinkage during the curing process. At the same time, the flexible characteristics of the modified black phosphorus nanosheets can further absorb part of the internal stress generated during the curing shrinkage process, slowing down the shrinkage effect of the material and improving the dimensional stability of the material.The modified Zr-MOF was prepared by in-situ growth of polyaniline nanorods on the surface of Zr-MOF. The modified Zr-MOF has a highly rigid nano-framework structure. Its porous and orderly arranged structure can form a strong support skeleton in the resin matrix, providing additional mechanical support, enhancing the overall rigidity of the material. At the same time, groups such as -NH and -N= on the surface of the modified Zr-MOF form hydrogen bonds and π-π interactions with the bisphenol A-glycidyl methacrylate matrix, further improving the interfacial binding force between the two, forming a more stable nano-network structure in the resin matrix, and then increasing the rigidity and strength of the resin matrix. The polyaniline nanorods on the surface of the modified Zr-MOF have good lubricity. Their flexible polymer chain structure can form a protective film during the friction process. The polyaniline nanorods are filled in the pores and on the surface of the modified Zr-MOF, further forming a microscopic lubricating layer, making the composite material show better wear resistance and fatigue resistance during use. At the same time, Zr-MOF and polyaniline nanorods form a rigid-flexible combined structure. While Zr-MOF provides rigid support, the polyaniline nanorods buffer the polymerization shrinkage stress, thus reducing the overall volume shrinkage rate. In addition, the modified Zr-MOF has a high specific surface area and a nano-porous structure. During the curing process, it can adsorb free monomers in the resin matrix, disperse the shrinkage stress during the resin curing process, delay the curing rate, reduce stress concentration. At the same time, the porous network of the modified Zr-MOF can further fill the shrinkage voids of the resin matrix, reduce volume changes, and make the composite material more stable. In short, bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets and modified Zr-MOF act together to synergistically improve the wear resistance of dental resin composites, reduce the shrinkage rate of dental resin composites, and ultimately improve the stability of dental resin composites, ensuring their long-term usability.

[0010] Benzoyl peroxide is a commonly used free radical initiator. It decomposes to generate free radicals under light or heating conditions, initiating the polymerization reaction of the resin matrix. The decomposition rate and initiation efficiency of benzoyl peroxide directly affect the curing process and final properties of the resin. At the same time, benzoyl peroxide ensures the full curing of the resin matrix, forming a dense cross-linked network structure, thereby improving the mechanical properties and wear resistance of the material.

[0011] Silane coupling agents are usually used to improve the interfacial bonding force between inorganic fillers and organic resin matrices. By means of chemical reactions, an organosilane layer is formed on the surface of the fillers, thereby enhancing the compatibility and interfacial bonding force between the fillers and the resin matrix, and further improving the mechanical properties and wear resistance of the materials. The silane coupling agent of the present invention is a compound of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane and 3-glycidyltrimethoxysilane. The molecule of 3-aminopropyltriethoxysilane contains an amino group and a silyl group. 3-vinylpropyltriethoxysilane contains a vinyl group and a silyl group. 3-glycidyltrimethoxysilane has an epoxy group and a silyl group. These groups can all form covalent bonds with the surface of the inorganic fillers, enhancing the chemical bonding and cross-linking reaction between the inorganic fillers and the resin, and thus improving the mechanical properties of the composite material.

[0012] Camphorquinone is a photoinitiator, often used together with amine compounds, to play a photosensitive curing role in dental composite materials. When the composite material is exposed to ultraviolet light or blue light, camphorquinone can absorb light energy and be converted into free radicals, initiating the polymerization of acrylate monomers in the resin matrix, thereby achieving curing. Camphorquinone ensures the rapid curing of the resin matrix, forming a dense cross-linked network structure, thus improving the mechanical properties and wear resistance of the material.

[0013] Hydroquinone is a commonly used antioxidant, used to control the polymerization reaction rate of the resin matrix and prevent premature curing. During the production process of resin materials, hydroquinone avoids the polymerization reaction of the resin matrix before use by inhibiting the generation of free radicals, thereby maintaining its good fluidity and processing performance.

[0014] Chlorhexidine is a broad-spectrum antibacterial agent, which can inhibit the growth and reproduction of bacteria in the oral environment, increase the antibacterial performance in dental composite materials, reduce the erosion and deterioration of the material by bacteria, and thus extend the service life of the material. At the same time, the addition of chlorhexidine also helps to enhance the biocompatibility of the material and reduce the irritation of bacteria in the oral cavity to teeth and gums.

[0015] Triethylene glycol dimethacrylate is a low-viscosity monomer, usually used as a diluent for bisphenol A-glycidyl methacrylate. The introduction of triethylene glycol dimethacrylate can reduce the viscosity of the resin matrix, improve the fluidity and processing performance of the material, and at the same time participate in the polymerization reaction of the resin matrix to form a cross-linked network structure, improving the mechanical properties and wear resistance of the material.

[0016] (3) Beneficial effects Compared with the prior art, the beneficial effects of the present invention are: 1. Bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets, and modified Zr-MOF act through a synergistic effect. Bisphenol A-glycidyl methacrylate provides a stable carrier support for the modified black phosphorus nanosheets and modified Zr-MOF, enabling the two to be uniformly dispersed in the matrix material. 2. The modified black phosphorus nanosheets undergo a copolymerization reaction with the bisphenol A-glycidyl methacrylate matrix, enhancing the chemical bonding force between the two. Its layered structure effectively reduces the friction coefficient, decreases the wear rate, improves the wear resistance of the material, and at the same time helps the resin matrix maintain a better cured network structure and mitigate the material shrinkage effect. 3. The modified Zr-MOF forms a more stable nano-network structure in the resin matrix, increasing the rigidity and strength of the resin matrix and forming a micro-lubricating layer, so that the composite material exhibits better wear resistance and fatigue resistance during use. 4. The rigid-flexible combined structure of the modified Zr-MOF further buffers the polymerization shrinkage stress. Its high specific surface area and nano-porous structure can adsorb free monomers in the resin matrix, delay the curing rate, reduce stress concentration, and at the same time further fill the shrinkage voids of the resin matrix, making the composite material more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the SEM image of the modified black phosphorus nanosheets in Example 1 of the present invention. Figure 2 It is the SEM image of the modified Zr-MOF in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] The test equipment and preparations in the following embodiments are as follows: electronic balance (Sartorius, Germany), electrothermal constant temperature water bath (Kedao, Jiangsu), magnetic stirrer (Meiyingpu, Shanghai), ultrasonic instrument (Yixin, Shanghai), high-speed centrifuge (Jidi, Guangzhou), vacuum drying oven (Jiecheng, Shanghai), pH meter (Yidian, Shanghai), scanning electron microscope (Zeiss, Germany), specific surface area analyzer (Beijing Beishide Instrument Technology), universal material testing machine (Jianzhuo, Suzhou), bending tester (Xinghuo, Jinan), sliding wear tester (Huahui, Lanzhou), optical microscope (Keyence); chemical drugs and reagents are purchased from Sigma-Aldrich.

[0020] Embodiment 1: This embodiment discloses a wear-resistant and low-shrinkage dental resin composite material, comprising the following raw materials in parts by weight: 50 parts of bisphenol A-glycidyl methacrylate, 1.5 parts of modified Zr-MOF, 2 parts of benzoyl peroxide, 2 parts of silane coupling agent, 0.3 parts of camphorquinone, 0.15 parts of hydroquinone, 0.3 parts of chlorhexidine, and 20 parts of triethylene glycol dimethacrylate. The wear-resistant and low-shrinkage dental resin composite material also includes modified black phosphorus nanosheets, wherein the weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:50, and the modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of the black phosphorus nanosheets, and the lateral size of the modified black phosphorus nanosheets is 90 nm~120 nm, the thickness is 5 nm~8 nm, and the specific surface area is 160~200 m 2 / g.

[0021] In the wear-resistant and low-shrinkage dental resin composite, bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets and modified Zr-MOF work together to improve the wear resistance of the dental resin composite and reduce its shrinkage through synergistic effects. Bisphenol A-glycidyl methacrylate is a commonly used dental resin matrix material with high mechanical strength, good chemical stability and low hydrolysis. The acrylate group (-C=CH2) in its molecular structure can be cross-linked through polymerization reaction under ultraviolet irradiation to form a strong three-dimensional cross-linked network. Its three-dimensional cross-linked network provides the hardness and strength of the resin to a certain extent, improving the wear resistance of the composite. However, due to its inherent fragility, it is easy to break or crack when it is impacted or pressed when used alone. It has poor wear resistance and high shrinkage. Especially when subjected to long-term wear and chewing stress, it will cause the resin material to wear and crack, affecting the overall stability of the material. In addition, bisphenol A-glycidyl methacrylate as a matrix material can provide a stable carrier support for modified black phosphorus nanosheets and modified Zr-MOF, so that both can be evenly dispersed in the matrix material to exert their reinforcing effect. Black phosphorus nanosheets are a new type of two-dimensional material with a high specific surface area, excellent mechanical properties and good electrical conductivity. Its nanosheet structure can significantly enhance the mechanical properties of dental resin composites, but due to its layered structure, it is easy to agglomerate, which in turn affects its dispersibility in the resin matrix. Modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets. Figure 1SEM image of the modified black phosphorus nanosheets shows that the modified black phosphorus nanosheets have a very obvious layered structure. Its large specific surface area can effectively increase the contact area with the resin matrix. The surface of the modified black phosphorus nanosheets contains methacryloyl groups, which can further undergo free radical copolymerization reaction with the bisphenol A-glycidyl methacrylate matrix, firmly embedding the modified black phosphorus nanosheets into the crosslinked network of the matrix material, enhancing the chemical interfacial bonding force between the two, making the modified black phosphorus nanosheets disperse more uniformly in the bisphenol A-glycidyl methacrylate matrix. The layered structure of the modified black phosphorus nanosheets can effectively reduce the friction coefficient and the wear rate. At the same time, its three-dimensional crosslinked network structure with the bisphenol A-glycidyl methacrylate matrix is interlaced, which can further improve the shear resistance, making the material not easy to peel off during the friction process, enhancing the wear resistance. It also helps the resin matrix maintain a better cured network structure. Its layered structure can hinder the free movement of molecular chain segments in the resin matrix, thereby reducing the volume shrinkage during the curing process. At the same time, the flexible characteristics of the modified black phosphorus nanosheets can further absorb part of the internal stress generated during the curing shrinkage process, slow down the shrinkage effect of the material, and improve the dimensional stability of the material. The modified Zr-MOF is prepared by in-situ growth of polyaniline nanorods on the surface of Zr-MOF. The modified Zr-MOF has a high-rigidity nano-framework structure, Figure 2SEM image of modified Zr-MOF shows that modified Zr-MOF has a high specific surface area and rich pore structure. Its porous ordered arrangement can form a strong support framework in the resin matrix, providing additional mechanical support, enhancing the overall rigidity of the material. At the same time, groups such as -NH and -N= on the surface of modified Zr-MOF form hydrogen bonds and π-π interactions with the bisphenol A-glycidyl methacrylate matrix, further improving the chemical interfacial bonding force between the two, forming a more stable nano-network structure in the resin matrix, and then increasing the rigidity and strength of the resin matrix. The polyaniline nanorods on the surface of modified Zr-MOF have good lubricity, and their flexible polymer chain structure can form a protective film during the friction process. The polyaniline nanorods are filled in the pores and on the surface of modified Zr-MOF, further forming a microscopic lubricating layer, making the composite material show better wear resistance and fatigue resistance during use. At the same time, Zr-MOF and polyaniline nanorods form a rigid-flexible combined structure. While Zr-MOF provides rigid support, polyaniline nanorods buffer the polymerization shrinkage stress, thereby reducing the overall volume shrinkage rate. In addition, modified Zr-MOF has a high specific surface area and nano-porous structure, which can adsorb free monomers in the resin matrix during the curing process, disperse the shrinkage stress during resin curing, delay the curing rate, reduce stress concentration, and at the same time, the porous network of modified Zr-MOF can further fill the shrinkage voids of the resin matrix, reduce volume changes, and make the composite material more stable. In short, bisphenol A-glycidyl methacrylate, modified black phosphorus nanosheets and modified Zr-MOF act together synergistically to improve the wear resistance of dental resin composites, reduce the shrinkage rate of dental resin composites, and ultimately improve the stability of dental resin composites, ensuring their long-term usability.

[0022] The preparation method of the modified black phosphorus nanosheets includes: S11. Dispersing the bulk black phosphorus crystal in N-methylpyrrolidone and performing ultrasonic treatment at an ultrasonic frequency of 40 - 50 kHz. After ultrasonic treatment at room temperature for 0.5 - 1 h, a black phosphorus nanosheet dispersion is obtained; S12. Performing high-speed centrifugal separation on the black phosphorus nanosheet dispersion at a rotation speed of 6000 - 8000 rpm. After centrifugation for 5 - 10 min, the upper layer of the dispersion containing black phosphorus nanosheets is collected and vacuum dried at a drying temperature of 50 - 60 °C. After drying for 12 - 14 h, black phosphorus nanosheets are obtained and ground into a powder for standby; S13. Dissolving the black phosphorus nanosheet powder in purified water under nitrogen protection and stirring, while heating to 75 - 85 °C. After stirring for 0.5 - 1 h, a hydrogen peroxide solution is slowly added, and stirring is continued for 5 - 6 h to obtain a first mixed solution; S14. Centrifuge the first mixed solution at a high speed at a rotation speed of 10,000 - 12,000 rpm for 15 - 20 min. Wash the separated solid with purified water 5 times and then conduct vacuum drying at a drying temperature of 55 - 65 °C for 18 - 24 h to obtain an intermediate of black phosphorus nanosheets, which is ground into a powder for standby; S15. Dissolve the intermediate powder of black phosphorus nanosheets in dimethyl sulfoxide under stirring. After stirring for 0.5 - 1 h, slowly add triethylamine. After stirring for 0.5 - 1 h, continue to slowly add methacryloyl chloride. The mass ratio of methacryloyl chloride to black phosphorus nanosheets is (0.05 - 0.1):1. Continue to stir for 1 - 2 h to obtain a second mixed solution; S16. Transfer the second mixed solution to a reaction kettle for reaction. Set the reaction temperature at 65 - 75 °C. After reacting for 6 - 8 h, collect the reaction solution and conduct high-speed centrifugation at a rotation speed of 10,000 - 12,000 rpm for 15 - 20 min. Wash the separated solid with purified water 5 times and then conduct vacuum drying at a drying temperature of 55 - 65 °C for 18 - 24 h to obtain modified black phosphorus nanosheets, which are ground into a powder for standby.

[0023] The preparation method of the modified Zr-MOF includes: S21. Disperse Zr-MOF in absolute ethanol and conduct ultrasonic treatment at an ultrasonic frequency of 40 - 50 kHz. After ultrasonic treatment at room temperature for 0.5 - 1 h, obtain a Zr-MOF dispersion; S22. Add 3-aminopropyltriethoxysilane to the Zr-MOF dispersion under stirring and simultaneously raise the temperature to 75 - 85 °C. After stirring for 12 - 15 h, obtain a third mixed solution; S23. Centrifuge the third mixed solution at a high speed at a rotation speed of 10,000 - 12,000 rpm for 10 - 15 min. Wash the separated solid with absolute ethanol 3 times and then conduct vacuum drying at a drying temperature of 55 - 65 °C for 18 - 24 h to obtain an intermediate of Zr-MOF, which is ground into a powder for standby; S24. Dissolve aniline in 0.1 mol / L hydrochloric acid solution under stirring. Set the ice bath temperature at 0 - 5 °C. After stirring for 0.5 - 1 h, slowly add the intermediate powder of Zr-MOF. After continuing to stir for 0.5 - 1 h, slowly dropwise add ammonium persulfate, and then continue to stir and react for 12 - 15 h to obtain a fourth mixed solution; S25. Centrifuge the fourth mixed solution at a high speed at a rotation speed of 10,000 - 12,000 rpm for 10 - 15 minutes. Wash the separated solid alternately with 0.1 mol / L hydrochloric acid solution, absolute ethanol, and purified water three times, and then perform vacuum drying. The drying temperature is 45 - 55 °C. After drying for 18 - 24 hours, the modified Zr-MOF is obtained and ground into a powder for standby.

[0024] The modified Zr-MOF is prepared by in-situ growth of polyaniline nanorods on the surface of Zr-MOF, and the particle size of the modified Zr-MOF is 90 - 120 nm, and the specific surface area is 800 - 900 m 2 / g.

[0025] The silane coupling agent is a compound of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane, and 3-glycidyltrimethoxysilane. The weight ratio of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane, and 3-glycidyltrimethoxysilane is (1 - 2):(1 - 1.5):(0.5 - 1).

[0026] A preparation method of a wear-resistant low-shrinkage dental resin composite material, which is applied to the wear-resistant low-shrinkage dental resin composite material described above, includes the following steps: S31. Disperse the modified black phosphorus nanosheets and the modified Zr-MOF in absolute ethanol respectively and perform ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz. After ultrasonic treatment for 1 - 2 hours, a modified black phosphorus nanosheet dispersion and a modified Zr-MOF dispersion are obtained; S32. Under the stirring state, mix bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate. After stirring for 1 - 2 hours, sequentially add the silane coupling agent, the modified black phosphorus nanosheet dispersion, and the modified Zr-MOF dispersion and perform ultrasonic treatment. After ultrasonic treatment for 1 - 2 hours, a fifth mixed solution is obtained; S33. Under the stirring state, sequentially add benzoyl peroxide, camphorquinone, hydroquinone, and chlorhexidine to the fifth mixed solution. Continue stirring for 2 - 3 hours, then place it in a vacuum drying oven for degassing. The degassing temperature is 35 - 45 °C. After degassing for 0.5 - 1 hour, curing is carried out; S34. The curing is carried out in a forced-air drying oven. Pour it into the corresponding mold as needed, set the curing temperature to 65 - 80 °C, and after curing for 0.5 - 1 hour, the wear-resistant low-shrinkage dental resin composite material is obtained.

[0027] Example 2: This example discloses a wear-resistant and low-shrinkage dental resin composite material, which includes the following raw materials in parts by weight: 45 parts of bisphenol A-glycidyl methacrylate, 1 part of modified Zr-MOF, 1 part of benzoyl peroxide, 1 part of silane coupling agent, 0.1 part of camphorquinone, 0.1 part of hydroquinone, 0.1 part of chlorhexidine, and 15 parts of triethylene glycol dimethacrylate. The wear-resistant and low-shrinkage dental resin composite material also includes modified black phosphorus nanosheets. The weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:45. The modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets. The lateral size of the modified black phosphorus nanosheets is 90 nm - 120 nm, the thickness is 5 nm - 8 nm, and the specific surface area is 160 - 200 m 2 / g. The preparation methods of the modified black phosphorus nanosheets and modified Zr-MOF in this example are the same as those in Example 1. The preparation method of a wear-resistant and low-shrinkage dental resin composite material in this example is the same as that in Example 1.

[0028] Example 3: This example discloses a wear-resistant and low-shrinkage dental resin composite material, which includes the following raw materials in parts by weight: 55 parts of bisphenol A-glycidyl methacrylate, 2 parts of modified Zr-MOF, 3 parts of benzoyl peroxide, 3 parts of silane coupling agent, 0.5 part of camphorquinone, 0.2 part of hydroquinone, 0.5 part of chlorhexidine, and 25 parts of triethylene glycol dimethacrylate. The wear-resistant and low-shrinkage dental resin composite material also includes modified black phosphorus nanosheets. The weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:55. The modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets. The lateral size of the modified black phosphorus nanosheets is 90 nm - 120 nm, the thickness is 5 nm - 8 nm, and the specific surface area is 160 - 200 m 2 / g. The preparation methods of the modified black phosphorus nanosheets and modified Zr-MOF in this example are the same as those in Example 1. The preparation method of a wear-resistant and low-shrinkage dental resin composite material in this example is the same as that in Example 1.

[0029] Control Group 1: The difference between this example and Example 1 is that it does not contain modified black phosphorus nanosheets. This example discloses a wear-resistant and low-shrinkage dental resin composite material, which includes the following raw materials in parts by weight: 50 parts of bisphenol A-glycidyl methacrylate, 1.5 parts of modified Zr-MOF, 2 parts of benzoyl peroxide, 2 parts of silane coupling agent, 0.3 part of camphorquinone, 0.15 part of hydroquinone, 0.3 part of chlorhexidine, and 20 parts of triethylene glycol dimethacrylate. The preparation method of the modified Zr-MOF in this example is the same as that in Example 1. The preparation method of a wear-resistant and low-shrinkage dental resin composite material in this example is the same as that in Example 1.

[0030] Control Group 2: The difference between this example and Example 1 is that it does not contain modified Zr-MOF. This example discloses a wear-resistant dental resin composite with low shrinkage rate, which comprises the following raw materials in parts by weight: 50 parts of bisphenol A-glycidyl methacrylate, 2 parts of benzoyl peroxide, 2 parts of silane coupling agent, 0.3 part of camphorquinone, 0.15 part of hydroquinone, 0.3 part of chlorhexidine, and 20 parts of triethylene glycol dimethacrylate. The wear-resistant dental resin composite with low shrinkage rate further comprises modified black phosphorus nanosheets, and the weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:50. The modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets, and the lateral size of the modified black phosphorus nanosheets is 90 nm - 120 nm, the thickness is 5 nm - 8 nm, and the specific surface area is 160 - 200 m 2 / g. The preparation method of the modified black phosphorus nanosheets in this example is the same as that in Example 1. The preparation method of a wear-resistant dental resin composite with low shrinkage rate in this example is the same as that in Example 1.

[0031] Control Group 3: The difference between this example and Example 1 is that it does not contain modified black phosphorus nanosheets and modified Zr-MOF. This example discloses a wear-resistant dental resin composite with low shrinkage rate, which comprises the following raw materials in parts by weight: 50 parts of bisphenol A-glycidyl methacrylate, 2 parts of benzoyl peroxide, 2 parts of silane coupling agent, 0.3 part of camphorquinone, 0.15 part of hydroquinone, 0.3 part of chlorhexidine, and 20 parts of triethylene glycol dimethacrylate. The preparation method of a wear-resistant dental resin composite with low shrinkage rate in this example is the same as that in Example 1.

[0032] Effect evaluation: Performance determination of dental resin composite: (1) Compressive strength test: Use a universal material testing machine for testing. Place the specimen under the indenter of the material testing machine, ensure its vertical alignment, apply pressure, and record the compressive strength of the materials in each experimental group; (2) Flexural strength test: Use a flexural testing machine, ensure that the center of the sample is located between the support points for flexural testing, and calculate the flexural strength according to the maximum load and the geometric dimensions of the specimen; (3) Friction and wear test: Use a sliding wear testing machine, set the abrasive as 60# sandpaper to simulate the friction between food and teeth in the oral cavity, fix the sample on the support disk of the wear testing machine, record the mass change of the sample after wear during the test process and calculate the wear rate; (4) Curing shrinkage rate test: Use a digital vernier caliper and an optical microscope to measure the volume change of the sample before and after curing. Each experimental group is set with three parallel tests, and the experimental results are averaged.

[0033] Table 1 Performance determination results of dental resin composites obtained in each experimental group

[0034] Table 1 shows the results of the performance determination of dental resin composites obtained in each experimental group. It can be seen from Table 1 that there are significant differences in the performance of the dental resin composites prepared in each experimental group. By comparing the performance of the dental resin composites prepared in Examples 1-3 with those in Control Groups 1-3, it can be found that, generally speaking, the dental resin composites prepared in Examples 1-3 have better performance. Moreover, the dental resin composite in Example 1 shows excellent performance, with a compressive strength of 242.5 MPa. Compressive strength is used to evaluate the strength of a material under compression, and the higher it is, the more capable it is of ensuring that it can withstand a high chewing force in the oral cavity. The flexural strength is 158 MPa, indicating that the composite material performs excellently during chewing. The wear rate is as low as 0.11 mg / cycle, and the volume shrinkage rate is as low as 2.5%, showing excellent wear resistance and low shrinkage rate. By comparing Example 1 with Control Groups 1-3 again, it can be found that when both modified black phosphorus nanosheets and modified Zr-MOF are added during the preparation of dental resin composites, the wear resistance of the material can be significantly improved, the shrinkage rate of the material can be reduced, and the overall performance of the dental resin composite can be enhanced.

[0035] Through the above limited experiments, the application effect of the wear-resistant and low-shrinkage dental resin composite in Example 1 of the present invention is remarkable. By optimizing the formula of the dental resin composite and combining modern nanotechnology, both modified black phosphorus nanosheets and modified Zr-MOF are added during the production process to optimize the interfacial bonding and dispersibility of the material. The modified black phosphorus nanosheets effectively reduce the friction coefficient and help the resin matrix maintain a better cured network structure. The modified Zr-MOF increases the rigidity and strength of the resin matrix, adsorbs the free monomers in the resin matrix, delays the curing rate, reduces stress concentration, fills the shrinkage voids in the resin matrix, and ensures the long-term usability of the dental resin composite.

[0036] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wear-resistant dental resin composite with low shrinkage rate, characterized in that, It includes the following raw materials in parts by weight: 45-55 parts of bisphenol A-glycidyl methacrylate, 1-2 parts of modified Zr-MOF, 1-3 parts of benzoyl peroxide, 1-3 parts of silane coupling agent, 0.1-0.5 parts of camphorquinone, 0.1-0.2 parts of hydroquinone, 0.1-0.5 parts of chlorhexidine, and 15-25 parts of triethylene glycol dimethacrylate; The wear-resistant low-shrinkage dental resin composite further includes: Modified black phosphorus nanosheets; The weight ratio of the modified black phosphorus nanosheets to bisphenol A-glycidyl methacrylate is 1:(45-55); The modified black phosphorus nanosheets are prepared by introducing methacryloyl groups on the surface of black phosphorus nanosheets, and the modified black phosphorus nanosheets have a lateral size of 90 nm to 120 nm, a thickness of 5 nm to 8 nm, and a specific surface area of 160 to 200 m 2 / g; The preparation method of the modified black phosphorus nanosheets includes: S11. Dispersing massive black phosphorus crystals in N-methylpyrrolidone and performing ultrasonic treatment. The ultrasonic frequency is 40-50 kHz. After ultrasonic treatment at room temperature for 0.5-1 h, a black phosphorus nanosheet dispersion is obtained; S12. Performing high-speed centrifugal separation on the black phosphorus nanosheet dispersion. The rotation speed is 6000-8000 rpm. After centrifugation for 5-10 min, the upper-layer dispersion containing black phosphorus nanosheets is collected and vacuum dried. The drying temperature is 50-60 °C. After drying for 12-14 h, black phosphorus nanosheets are obtained and ground into a powder for standby; S13. Dissolving the black phosphorus nanosheet powder in purified water under nitrogen protection and stirring, while heating to 75-85 °C. After stirring for 0.5-1 h, a hydrogen peroxide solution is slowly added, and stirring is continued for 5-6 h to obtain a first mixed solution; S14. Performing high-speed centrifugal separation on the first mixed solution. The rotation speed is 10000-12000 rpm. After centrifugation for 15-20 min, the separated solid is washed 5 times with purified water and then vacuum dried. The drying temperature is 55-65 °C. After drying for 18-24 h, a black phosphorus nanosheet intermediate is obtained and ground into a powder for standby; S15. Dissolving the black phosphorus nanosheet intermediate powder in dimethyl sulfoxide under stirring. After stirring for 0.5-1 h, triethylamine is slowly added. After stirring for 0.5-1 h, methacryloyl chloride is slowly added continuously. The mass ratio of methacryloyl chloride to black phosphorus nanosheets is (0.05-0.1):

1. Stirring is continued for 1-2 h to obtain a second mixed solution; S16. Transferring the second mixed solution to a reaction kettle for reaction. The reaction temperature is set at 65-75 °C. After reaction for 6-8 h, the reaction solution is collected and subjected to high-speed centrifugal separation. The rotation speed is 10000-12000 rpm. After centrifugation for 15-20 min, the separated solid is washed 5 times with purified water and then vacuum dried. The drying temperature is 55-65 °C. After drying for 18-24 h, modified black phosphorus nanosheets are obtained and ground into a powder for standby.

2. The wear-resistant and low shrinkage dental resin composite according to claim 1, characterized in that The preparation method of the modified Zr-MOF includes: S21. Dispersing Zr-MOF in absolute ethanol and performing ultrasonic treatment. The ultrasonic frequency is 40-50 kHz. After ultrasonic treatment at room temperature for 0.5-1 h, a Zr-MOF dispersion is obtained; S22. Add 3-aminopropyltriethoxysilane to the Zr-MOF dispersion under stirring, while heating up to 75 - 85 °C. After stirring for 12 - 15 h, a third mixed solution is obtained; S23. Centrifuge the third mixed solution at a high speed, with a rotation speed of 10000 - 12000 rpm and centrifuge for 10 - 15 min. The separated solid is washed 3 times with absolute ethanol and then dried in vacuum. The drying temperature is 55 - 65 °C. After drying for 18 - 24 h, a Zr-MOF intermediate is obtained and ground into a powder for standby; S24. Dissolve aniline in 0.1 mol / L hydrochloric acid solution under stirring, set the ice bath temperature to 0 - 5 °C. After stirring for 0.5 - 1 h, slowly add the Zr-MOF intermediate powder. After continuing to stir for 0.5 - 1 h, slowly dropwise add ammonium persulfate, and then continue to stir and react for 12 - 15 h to obtain a fourth mixed solution; S25. Centrifuge the fourth mixed solution at a high speed, with a rotation speed of 10000 - 12000 rpm and centrifuge for 10 - 15 min. The separated solid is washed 3 times alternately with 0.1 mol / L hydrochloric acid solution, absolute ethanol and purified water and then dried in vacuum. The drying temperature is 45 - 55 °C. After drying for 18 - 24 h, a modified Zr-MOF is obtained and ground into a powder for standby.

3. The wear-resistant and low shrinkage dental resin composite according to claim 2, wherein, The modified Zr-MOF is prepared by in-situ growth of polyaniline nanorods on the surface of Zr-MOF, and the particle size of the modified Zr-MOF is 90-120 nm, and the specific surface area is 800-900 m 2 / g.

4. A wear-resistant dental resin composite material with a low shrinkage rate according to claim 1, characterized in that The silane coupling agent is a compound of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane and 3-glycidyltrimethoxysilane. The weight ratio of 3-aminopropyltriethoxysilane, 3-vinylpropyltriethoxysilane and 3-glycidyltrimethoxysilane is (1 - 2):(1 - 1.5):(0.5 - 1).

5. A preparation method of a wear-resistant and low-shrinkage dental resin composite material, which is applied to prepare a wear-resistant and low-shrinkage dental resin composite material as described in any one of claims 1 to 4, and is characterized in that, The method includes the following steps: S31. Disperse the modified black phosphorus nanosheets and the modified Zr-MOF in absolute ethanol respectively and carry out ultrasonic treatment. The ultrasonic frequency is 40 - 50 kHz. After ultrasonic treatment for 1 - 2 h, a modified black phosphorus nanosheet dispersion and a modified Zr-MOF dispersion are obtained; S32. Mix bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate under stirring. After stirring for 1 - 2 h, sequentially add the silane coupling agent, the modified black phosphorus nanosheet dispersion and the modified Zr-MOF dispersion and carry out ultrasonic treatment. After ultrasonic treatment for 1 - 2 h, a fifth mixed solution is obtained; S33. Sequentially add benzoyl peroxide, camphorquinone, hydroquinone and chlorhexidine to the fifth mixed solution under stirring. Continue to stir for 2 - 3 h and then place it in a vacuum drying oven for degassing. The degassing temperature is 35 - 45 °C. After degassing for 0.5 - 1 h, curing is carried out; S34. Curing is carried out in a forced air drying oven. Pour it into the corresponding mold as needed. Set the curing temperature to 65 - 80 °C. After curing for 0.5 - 1 h, a wear-resistant low shrinkage dental resin composite is obtained.

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