Lithium disilicate ceramic-dental fluid resin composite material, preparation method and application thereof

Abstract

This invention relates to a lithium disilicate ceramic-dental fluid resin composite material and its preparation method. The composite material is prepared by 3D printing a lithium disilicate ceramic-photoinitiating resin composite slurry using a biomimetic dental crown model as a standard. The composite slurry, by weight, comprises: 65-75 parts lithium disilicate glass powder, 12.5-17.5 parts 1,6-hexanediol diacrylate, 2.5-7.5 parts pentaerythritol tetraacrylate containing the stabilizer MEHQ, 3-5 parts dispersant, 0.05-0.15 parts initiator, and 0.025-0.075 parts light absorber. The biomimetic crown model is a composite structure of concentric rings of glass sponge and wheel-shaped nodes resembling horsetail grass. This invention aims to construct a lithium disilicate ceramic framework with a radial-concentric multi-level structure through biomimetic structural design, and impregnate it with resin to form a composite material. This significantly improves the fracture toughness and energy absorption capacity of the material while maintaining sufficient strength, and makes its elastic modulus and density close to that of natural teeth, thus improving biomechanical compatibility.

Description

Technical Field

[0001] This invention relates to a lithium disilicate ceramic-dental fluid resin composite material, its preparation method and application, belonging to the field of oral restoration technology. Background Technology

[0002] All-ceramic restorations are widely used in clinical dentistry. However, most all-ceramic crowns used clinically are made of a single-component ZrO2 ceramic material. This leads to a mismatch between the mechanical properties of the restoration and natural teeth, easily causing uneven wear on opposing teeth. Lithium disilicate (Li2Si2O5) ceramics are widely used in dental restorations, such as crowns, veneers, and inlays, due to their excellent aesthetic properties and biocompatibility. However, while traditional lithium disilicate ceramic restorations have high strength and excellent aesthetic effects, their fracture toughness is low. In actual clinical applications and under the complex stress environment of the oral cavity, they are prone to brittle fracture and crack propagation due to occlusal forces, leading to restoration failure and affecting the long-term service life of the restoration.

[0003] To improve the toughness of ceramic materials, various ceramic-resin composite material solutions have been proposed in the prior art. For example, US Patent Document US20170239025A1 discloses a machinable ceramic-resin composite block (such as LAVA). TM This composite material (ULTIMATE) is made by mixing ceramic nanoparticles with a resin matrix and then processing them through pressure molding or computer-aided design (CAD) / computer-aided manufacturing (CAM), resulting in improved toughness compared to pure ceramics. However, the microstructure of this composite material is a uniformly distributed two-phase system, lacking macro-scale structural design. A typical trade-off exists between its strength and toughness, making it difficult to simultaneously meet the clinical requirements for high strength and excellent toughness.

[0004] Furthermore, existing methods for preparing ceramic-resin composites mostly employ injection molding or CAD / CAM subtractive manufacturing. These processes struggle to construct complex three-dimensional structures within the material, limiting the possibility of optimizing mechanical properties through structural design. 3D printing, however, allows for free design and precise fabrication of material structures, providing a new opportunity to optimize the mechanical properties of composite materials and holding immense promise for applications in dental restoration. Liu et al. prepared epoxy resin composites with high flexural strength by impregnating epoxy resin into pre-formed, porous, surface-functionalized three-dimensional alumina ceramic frameworks. This was due to the effective transfer of external stress by the interconnected isotropic 3D framework. Li et al. also fabricated glass / rubber interpenetrating phase composites with rationally designed structures using 3D printing technology, significantly enhancing their fracture toughness. Recently, this method has also been applied to the manufacture of dental composites.

[0005] Therefore, there is an urgent need to develop a lithium disilicate-resin composite material that combines high strength, high toughness, and excellent biomechanical compatibility. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a lithium disilicate ceramic-dental fluid resin composite material and its preparation method. This invention aims to construct a lithium disilicate ceramic framework with a radial-concentric multi-level structure through biomimetic structural design, and then impregnate it with resin to form a composite material. This significantly improves the material's fracture toughness and energy absorption capacity while maintaining sufficient strength, and makes its elastic modulus and density approach those of natural teeth, thus improving biomechanical compatibility.

[0007] The technical solution of the present invention is as follows:

[0008] A lithium disilicate ceramic-dental fluid resin composite material is prepared by 3D printing a lithium disilicate ceramic-photoinitiating resin composite slurry based on a biomimetic dental crown model.

[0009] The lithium disilicate ceramic-photoinitiating resin composite slurry comprises, by weight: 65-75 parts lithium disilicate glass powder, 12.5-17.5 parts 1,6-hexanediol diacrylate, 2.5-7.5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 3-5 parts dispersant, 0.05-0.15 parts initiator, and 0.025-0.075 parts light absorber;

[0010] The biomimetic crown model is a composite structure of concentric rings of glass sponge and wheel-shaped nodes of horsetail grass.

[0011] According to a preferred embodiment of the present invention, the lithium disilicate ceramic-photoinitiator resin composite slurry comprises, by weight, 70 parts of lithium disilicate glass powder, 15 parts of 1,6-hexanediol diacrylate, 5 parts of pentaerythritol tetraacrylate containing stabilizer MEHQ, 4 parts of dispersant, 0.1 parts of initiator, and 0.05 parts of light absorber.

[0012] According to a preferred embodiment of the present invention, the lithium disilicate glass powder has a D50 of 1.5 μm.

[0013] According to a preferred embodiment of the present invention, the dispersant is Lubrizol Solpus D540 dispersant.

[0014] According to a preferred embodiment of the present invention, the initiator is a photoinitiator TPO.

[0015] According to a preferred embodiment of the present invention, the light absorber is 1-phenylazo-2-naphthol (Sudan I).

[0016] According to a preferred embodiment of the present invention, the lithium disilicate ceramic-dental fluid resin composite slurry is prepared according to the following method:

[0017] According to the formula, lithium disilicate glass powder and dispersant are mixed and stirred in a magnetic water bath at 45~75℃ for 0.5~1.5h, and dried at 110~120℃ for 60~80min to obtain modified lithium disilicate powder; then 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate containing stabilizer MEHQ, initiator and light absorber are added to the modified lithium disilicate powder, and mixed at a speed of 90000~110000r / s for 4~5min, and then magnetically stirred at a speed of 450~550r / s for 20~30h to obtain lithium disilicate ceramic-photoinitiating resin composite slurry.

[0018] According to a preferred embodiment of the present invention, the glass sponge concentric ring-horsetail wheel-shaped node composite structure is composed of radial support arms and concentric rings; the radial support arms radiate outward from the center and number 4 to 8; the concentric rings are arranged in concentric circles around the center and number 2 to 4 layers.

[0019] More preferably, the radial support arms of the glass sponge concentric ring-horsetail wheel-shaped node composite structure are 7, the concentric rings are 3 layers, and the size is 10×10×5mm; the wall thickness of the glass sponge concentric ring-horsetail wheel-shaped node composite structure increases linearly and uniformly from 1.7mm to 2.3mm from bottom to top.

[0020] According to a preferred embodiment of the present invention, the ceramic volume fraction of the lithium disilicate ceramic-dental fluid resin composite material is 60-75 vol.

[0021] More preferably, the ceramic volume fraction of the lithium disilicate ceramic-dental fluid resin composite material is 65.24 vol.

[0022] In this invention, the ceramic volume fraction refers to the percentage of lithium disilicate ceramic relative to the total volume of the lithium disilicate ceramic-dental fluid resin composite material.

[0023] The preparation method of the above-mentioned lithium disilicate ceramic-dental fluid resin composite material specifically includes the following steps:

[0024] (1) The lithium disilicate ceramic-dental fluid resin composite slurry was deposited into the material tank of the 3D printer and 3D printed according to the bionic crown model to obtain the lithium disilicate ceramic scaffold.

[0025] (2) Separate the resin and lithium disilicate layer in the lithium disilicate ceramic framework obtained in step (1), cure it under a dental light curing lamp for 3-5 minutes, clean it and then degrease and sinter it; etch the degreased and sintered lithium disilicate ceramic framework in hydrofluoric acid solution for 25-35 seconds, clean it and then apply silane coupling agent to the surface of the etched lithium disilicate ceramic framework, then inject dental fluid resin into the pores under negative pressure, cure it under a light curing lamp for 9-13 minutes, and after polishing, obtain the lithium disilicate ceramic-dental fluid resin composite material.

[0026] According to a preferred embodiment of the present invention, in step (1), the 3D printing is performed in an AUTOCERA-R type DLP 3D printer; during the 3D printing process, the bottom of the forming stage is exposed to ultraviolet light to solidify it into the shape of a biomimetic crown model; the forming stage rises with a single layer thickness, allowing the lithium disilicate ceramic-dental fluid resin composite slurry to continue to flow in, submerging the area below the solidified layer, and the cycle continues until the entire lithium disilicate ceramic scaffold is formed;

[0027] The 3D printing parameters are 5s30mW, and the thickness of a single layer is 30μm.

[0028] According to a preferred embodiment of the present invention, in step (2), the degreasing and sintering process is carried out in a muffle furnace according to the following temperature parameters: degreasing: the temperature is uniformly increased from 20°C to 350°C within 600 min, held at 350°C for 2 h, and then uniformly increased from 350°C to 450°C within 600 min, held at 450°C for 2 h; sintering: the temperature is uniformly increased from 450°C to 850°C within 400 min, held at 850°C for 2 h, and then uniformly decreased from 850°C to 20°C within 85 min.

[0029] According to a preferred embodiment of the present invention, in step (2), the silane coupling agent is silane coupling agent KH-570; and the dental fluid resin is Te-Econom Flow resin.

[0030] The application of the above-mentioned lithium disilicate ceramic-dental fluid resin composite material in the preparation of dental restorations.

[0031] According to a preferred embodiment of the present invention, the dental restoration includes, but is not limited to, crowns, veneers, inlays, high-mounted inlays, and bridges. In practical applications, 3D printing technology can be used to precisely manufacture personalized restorations with complex shapes.

[0032] Technical features of the present invention:

[0033] Firstly, this invention is the first to combine the concentric cylindrical frame structure of glass sponge with the spoke-like radial structure of horsetail grass, constructing a multi-level porous ceramic skeleton with radial support arms and concentric rings. The radial support arms (4-8 in number) are responsible for distributing the load from the center outwards, alleviating local stress concentration; the concentric rings (2-4 layers) induce crack deflection and branching through multiple interfaces, consuming crack propagation energy. Furthermore, the interconnection of the radial support arms and concentric rings forms a three-dimensional continuous network, ensuring structural integrity. The wall thickness gradient design (1.7-2.3 mm gradient) simulates the stiffness gradient from enamel to dentin in natural teeth, achieving a smooth transition in mechanical properties.

[0034] Secondly, the lithium disilicate ceramic-dental fluid resin composite material and its preparation method provided by the present invention can achieve precise control of the ceramic volume fraction (60~75 vol%) by adjusting the number of radial support arms, the number of concentric ring layers and the wall thickness. This provides suitable pore space for resin impregnation while maintaining the continuity of the ceramic skeleton, so that the mechanical properties (strength, modulus and toughness) of the composite material can be adjusted as needed within a wide range.

[0035] Furthermore, this invention optimizes the ceramic slurry formulation to meet the requirements of DLP 3D printing: the solid content is controlled at 65~75wt% to ensure the density of the ceramic skeleton after sintering; by adding 3~8wt% polymeric dispersant (Lubrizol Solpus D540 dispersant), the slurry viscosity is reduced to 300-500 mPa•s, which is far below the recommended threshold of 5000 mPa•s for DLP printing, significantly improving printing accuracy and interlayer bonding quality;

[0036] Furthermore, the preparation method of the lithium disilicate ceramic-dental fluid resin composite material provided by this invention optimizes the segmented debinding and sintering process based on the thermogravimetric analysis results of lithium disilicate glass powder: holding at 350℃ can remove residual solvents and low molecular weight organic matter; slow heating from 350 to 450℃ can fully oxidize and decompose the photocurable resin network; holding at 440℃ can further remove residual carbides; holding at 850℃ for 2 hours can promote the nucleation and growth of Li2Si2O5 crystals, forming needle-like interlocking microstructures, while avoiding the formation of impurity phases such as Li2SiO3; and ventilation is maintained throughout the sintering process to promptly remove organic decomposition products and prevent carbon residue.

[0037] Finally, the lithium disilicate ceramic-dental fluid resin composite material provided by this invention exhibits excellent properties. Among them,

[0038] The material's elastic modulus (8~9 GPa) falls within the range of natural dentin (1.6~11.7 GPa), reducing stress shielding; the material density (2.0~2.1 g / cm³) 3It closely resembles natural teeth (1.96~2.78 g / cm³). 3 To avoid patient discomfort; the material's coefficient of friction (0.55~0.70) is moderately increased to enhance occlusal stability, while the wear rate only increases slightly (8-12×10). -5 mm 3 ( / N•m), ensuring a long service life.

[0039] The beneficial effects of this invention are as follows:

[0040] 1. This invention employs a comprehensive biomimetic strategy to design a biomimetic crown model with a glass sponge concentric ring-horsetail wheel-shaped node composite structure, and for the first time uses this composite structure to prepare lithium disilicate ceramic-dental fluid resin composite materials. This lithium disilicate ceramic-dental fluid resin composite material, through its biomimetic radial-concentric multi-level structural design, significantly improves the material's toughness (compressive toughness increased by more than 20%, flexural energy absorption increased by more than 30%) while maintaining sufficient strength (compressive strength ≥ 700 MPa, flexural strength ≥ 400 MPa), overcoming the technical challenge of balancing strength and toughness in traditional ceramic-resin composite materials.

[0041] 2. The lithium disilicate ceramic-dental fluid resin composite material provided by this invention has an elastic modulus (8~9 GPa) and density (2.0~2.1 g / cm³) close to that of natural teeth, which can effectively reduce the stress shielding effect, reduce excessive wear of opposing teeth, effectively improve the biomechanical compatibility of dental restorations, and have excellent biomechanical compatibility.

[0042] 3. The lithium disilicate ceramic-dental fluid resin composite material structure provided by the present invention has strong design flexibility. By adjusting structural parameters such as the number of radial support arms, the number of concentric rings, and the wall thickness, the mechanical properties of the composite material can be controlled as needed to meet the needs of different clinical scenarios.

[0043] 4. This invention provides a lithium disilicate ceramic-photoinitiating resin composite slurry. The slurry prepared using the composite slurry components and method provided by this invention significantly improves model printing accuracy, and the model exhibits no cracks after debinding and sintering, demonstrating excellent mechanical properties. Furthermore, by further combining the lithium disilicate ceramic-photoinitiating resin composite slurry with 3D printing technology, it is possible to precisely manufacture ceramic frameworks with complex internal structures, achieving high dimensional accuracy and good repeatability, thus providing a feasible solution for the efficient fabrication of personalized dental restorations.

[0044] 5. In the lithium disilicate ceramic-dental fluid resin composite material provided by the present invention, chemical bonding and mechanical interlocking are formed between the ceramic skeleton and the resin matrix through acid etching treatment and surface modification with silane coupling agent. The interface bonding strength is high, which is beneficial to stress transmission and crack deflection, further enhancing the toughness of the composite material and making the interface bonding more solid. Attached Figure Description

[0045] Figure 1 A flowchart illustrating the overall design process of a biomimetic crown model with a composite structure of concentric rings of glass sponge and wheel-shaped nodes of horsetail grass.

[0046] In the figure, a) shows the biomimetic strategy of immersing dental fluid resin in a lithium disilicate biomimetic crown model with a glass sponge concentric ring-horsetail wheel-shaped node composite structure to form a lithium disilicate ceramic-dental fluid resin composite material; b) is a schematic diagram of the stress on the lithium disilicate biomimetic crown model under the action of food of different sizes during application; c) is a radar chart comparing the performance of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2, the lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3, and commercial ceramics and dental fluid resin; d) is a sample photograph of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3, with a size of 8.0 × 8.0 × 4.0 mm. 3 e is a scanning electron microscope image of the interface between lithium disilicate ceramic and dental fluid resin in the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2.

[0047] Figure 2 The overall design process and manufacturing precision diagram of the lithium disilicate gradient biomimetic crown model with a glass sponge concentric ring-horsetail wheel-shaped node composite structure;

[0048] In the figure, a is a schematic diagram of the different lithium disilicate gradient biomimetic structure models prepared in Example 2, which are used for subsequent mechanical testing; b is the ceramic volume fraction analysis result of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2; c is a schematic diagram and photograph of the lithium disilicate ceramic-dental fluid resin composite material from the model to the sintered ceramic frame and then to the resin impregnation; d is the three-dimensional deviation analysis result of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2.

[0049] Figure 3 Figure showing the optimized printing and sintering results of lithium disilicate ceramic / photoinitiator resin composite slurry;

[0050] In the figures, a is a green image of the standard model prepared according to the printing parameters of Example 2 and Comparative Example 4; b is a scanning electron microscope image of the lithium disilicate ceramic scaffold prepared in Example 2 and the lithium disilicate ceramic scaffold prepared in Comparative Example 5; c is the particle size distribution of lithium disilicate glass powder; d is the viscosity of the lithium disilicate ceramic-dental fluid resin composite slurry prepared in Example 2 and the lithium disilicate ceramic-dental fluid resin composite slurry prepared in Comparative Example 8; e is the thermogravimetric analysis curve of the green body of the lithium disilicate ceramic scaffold prepared in Example 2 and the green body of the lithium disilicate ceramic scaffold prepared in Comparative Example 7; f is the sintering curve optimized based on the thermogravimetric analysis curve; g is the phase transformation analysis results of the lithium disilicate ceramic scaffold and lithium disilicate glass powder after debinding and sintering prepared in Example 2; h is a SEM image of lithium disilicate in the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the grain size distribution diagram derived therefrom.

[0051] Figure 4 A comparison of the mechanical properties of lithium disilicate ceramic scaffolds with different axis numbers prepared in Comparative Example 1 and lithium disilicate ceramic-dental fluid resin composite materials;

[0052] In the figure, a represents the compressive stress-strain curve of the lithium disilicate ceramic scaffolds with different numbers of axes prepared in Comparative Example 1; b represents the compressive stress-strain curve of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; c represents the compressive strength of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; d represents the Young's modulus of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; e represents the compressive toughness of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; f represents the flexural strength of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; g represents the flexural load-displacement curve of the lithium disilicate ceramic scaffolds with different numbers of axes prepared in Comparative Example 1; h represents the flexural load-displacement curve of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1; and i represents the flexural specific energy absorption of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of axes prepared in Comparative Example 1.

[0053] Figure 5 A comparison of the mechanical properties of lithium disilicate ceramic scaffolds with different numbers of rings and lithium disilicate ceramic-dental fluid resin composite materials prepared in Comparative Example 2.

[0054] In the figure, a represents the compressive stress-strain curve of the lithium disilicate ceramic scaffold with different numbers of wheels prepared in Comparative Example 2; b represents the compressive stress-strain curve of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; c represents the compressive strength of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; d represents the Young's modulus of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; e represents the compressive toughness of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; f represents the flexural strength of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; g represents the flexural load-displacement curve of the lithium disilicate ceramic scaffold with different numbers of wheels prepared in Comparative Example 2; h represents the flexural load-displacement curve of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2; and i represents the flexural specific energy absorption of the lithium disilicate ceramic-dental fluid resin composite material with different numbers of wheels prepared in Comparative Example 2.

[0055] Figure 6 Comparison of the mechanical properties of uniform lithium disilicate ceramic scaffolds with different wall thicknesses prepared in Comparative Example 3 and lithium disilicate ceramic-dental fluid resin composite materials.

[0056] In the figure, a is the compressive stress-strain curve of the lithium disilicate ceramic scaffold with different wall thicknesses prepared in Comparative Example 3; b is the compressive stress-strain curve of the lithium disilicate ceramic-dental fluid resin composite material with different wall thicknesses prepared in Comparative Example 3; c is the compressive strength of the lithium disilicate ceramic-dental fluid resin composite material with different wall thicknesses prepared in Comparative Example 3; d is the Young's modulus of the lithium disilicate ceramic-dental fluid resin composite material with different wall thicknesses prepared in Comparative Example 3; e is the compressive toughness of the lithium disilicate ceramic-dental fluid resin composite material with different wall thicknesses prepared in Comparative Example 3; f is the flexural strength of the lithium disilicate ceramic-dental fluid resin composite material with different wall thicknesses prepared in Comparative Example 3; g is the bending load-displacement curve of the lithium disilicate ceramic scaffold prepared in Comparative Example 3; h is the bending load-displacement curve of the lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3; and i is the flexural specific energy absorption of the lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3.

[0057] Figure 7 The graph shows a comparison of the mechanical properties of the gradient lithium disilicate ceramic scaffold with a wall thickness gradually increasing from 1.7 mm to 2.3 mm prepared in Example 2, and the lithium disilicate ceramic-dental fluid resin composite material with a wall thickness of 2.0 mm prepared in Comparative Example 3.

[0058] In the figure, a represents the compressive stress-strain curves of the graded lithium disilicate ceramic scaffold prepared in Example 2 and the homogeneous lithium disilicate ceramic scaffold prepared in Comparative Example 3; b represents the compressive stress-strain curves of the graded lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3; c represents the compressive strength of the graded lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3; d represents the Young's modulus of the graded lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3; e represents the compressive stress-strain curves of the graded lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3. The compressive toughness of the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Example 3 is given by f, the flexural strength of the gradient lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3 is given by g, the flexural load-displacement curve of the gradient lithium disilicate ceramic framework prepared in Example 2 and the homogeneous lithium disilicate ceramic framework prepared in Comparative Example 3 is given by h, the flexural load-displacement curve of the gradient lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3 is given by i, and the flexural specific energy absorption of the gradient lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the homogeneous lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3 is given by i.

[0059] Figure 8 The results are a comparison of the performance of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 with other composite materials reported in existing literature, as well as natural teeth and clinically used restorative materials.

[0060] In the figure, a is a schematic diagram of the model, stress distribution and strain distribution of different materials, b is the compressive strength of different materials, c is the elastic modulus of different materials, d is the compressive toughness of different materials, e is the Ashby diagram of different materials, and f is the Ashby diagram of flexural strength-density of different materials.

[0061] Figure 9 Friction and wear diagrams of pure lithium disilicate ceramic block, lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2, and pure dental fluid resin.

[0062] In the figure, a is the friction coefficient curve, b is the average friction coefficient, c is the macroscopic morphology of the worn surface, and d is the specific wear rate.

[0063] Figure 10 This is a diagram showing the biocompatibility results of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2.

[0064] In the figure, a shows the CCK-8 assay results of cells co-cultured with a blank control, pure lithium disilicate ceramic block, lithium disilicate ceramic frame prepared in Example 2, and lithium disilicate ceramic-dental fluid resin composite material; b shows the live / dead staining images of cells co-cultured with the blank control group on day 3; c shows the live / dead staining images of cells co-cultured with commercially available lithium disilicate blocks on day 3; d shows the live / dead staining images of cells co-cultured with the lithium disilicate ceramic frame prepared in Example 2 on day 3; and e shows the live / dead staining images of cells co-cultured with the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 on day 3. Detailed Implementation

[0065] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0066] The raw materials and equipment used in this embodiment are all commercially available products: lithium disilicate glass powder, D50=1.5um (e.g., Figure 3 (See c) is available from Shenzhen Aierchuang Co., Ltd., China; 1,6-hexanediol diacrylate (HDDA) and pentaerythritol tetraacrylate (PETA) containing stabilizer MEHQ are available from Shanghai Aladdin Technology Co., Ltd., China; photoinitiator TPO is available from Shanghai Aladdin Technology Co., Ltd., China; photoinitiator (2,4,6-trimethylbenzoyl) diphenylphosphine oxide is available from Geretsried GmbH, Germany; Lubrizol Solpus D540 dispersant (polyester solution) is available from Lubrizol GmbH, Germany.

[0067] In this invention, the ceramic volume fraction refers to the percentage of lithium disilicate ceramic relative to the total volume of the lithium disilicate ceramic-dental fluid resin composite material.

[0068] Example 1

[0069] like Figure 1 As shown in a, this invention utilizes the toughness of tooth enamel and the gradient changes between tooth enamel and dentin, and adopts a comprehensive biomimetic strategy to design a biomimetic crown model with a composite structure of glass sponge concentric rings and horsetail grass wheel-shaped nodes.

[0070] The glass sponge concentric ring-horsetail wheel-shaped node composite structure consists of radial support arms and concentric rings; the radial support arms radiate outward from the center, with a number of 4 to 8 (axis number); the concentric rings are arranged in concentric circles around the center, with a number of 2 to 4 layers (wheel number).

[0071] A biomimetic crown model of lithium disilicate with a concentric ring structure of glass sponge and a wheel-shaped node of horsetail grass was constructed using the 3D computer graphics software 3DMax (Autodesk, Inc., USA). The model had a wall thickness ranging from 1.0 mm to 3.0 mm. Each lithium disilicate biomimetic crown model measures 30 × 30 × 15 mm. The stress distribution of this lithium disilicate biomimetic crown model under the influence of food of different sizes during application is as follows: Figure 1 As shown in b.

[0072] However, during the design of the lithium disilicate biomimetic crown model, the inventors discovered that a 1.0mm thick support was too thin, leading to printing failure, while a 3.0mm thick support had too small pores, making it difficult for dental resin to penetrate. Therefore, the wall thickness of the lithium disilicate biomimetic crown model with a glass sponge concentric ring-horsetail wheel-shaped node composite structure was designed as a gradient biomimetic crown model, linearly and uniformly increasing from 1.7mm to 2.3mm from bottom to top, rather than a uniform biomimetic crown model with a single thickness. Specifically, as shown below... Figure 2 As shown in a.

[0073] Furthermore, since the size of 30×30×15mm was too large and not conducive to printing, the inventors performed Boolean operations on the gradient bionic crown model and the ordinary dental crown model, and finally the size of the lithium disilicate bionic crown model was adjusted to 10×10×5mm.

[0074] Example 2

[0075] A lithium disilicate ceramic-dental fluid resin composite slurry, by weight, comprises: 70 parts lithium disilicate glass powder, 15 parts 1,6-hexanediol diacrylate, 5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 4 parts Lubrizol Solpus D540 dispersant, 0.1 parts photoinitiator TPO, and 0.05 parts 1-phenylazo-2-naphthol.

[0076] The preparation method of the above-mentioned lithium disilicate ceramic-dental fluid resin composite slurry includes the following steps:

[0077] According to the formula, lithium disilicate glass powder was mixed with Lubrizol Solpus D540 dispersant and stirred in a magnetic water bath at 60°C for 1 hour. After stirring, it was dried at 130°C for 90 minutes to obtain modified lithium disilicate powder. Then, 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate containing stabilizer MEHQ and photoinitiator TPO were added to the modified lithium disilicate powder. The mixture was vigorously mixed at 100,000 r / s using a planetary degassing mixer BHJ-3 (Henan Beihong Industrial Co., Ltd., Henan, China) for 4.5 minutes, and then magnetically stirred at 500 r / s for 24 hours to obtain a stable and uniform lithium disilicate ceramic-dental fluid resin composite slurry.

[0078] A method for preparing a lithium disilicate ceramic-dental fluid resin composite material specifically includes the following steps:

[0079] (1) Lithium disilicate ceramic-dental fluid resin composite slurry was deposited into the slurry tank of a DLP 3D printer (AUTOCERA-R, Beijing Tenway Technology Co., Ltd., China) and the lithium disilicate bionic crown model constructed according to Example 1 was 3D printed. During the printing process, the bottom of the forming stage was exposed to ultraviolet light to solidify it into the shape of the lithium disilicate bionic crown model. The forming stage rose with a single layer thickness, allowing the lithium disilicate ceramic-dental fluid resin composite slurry to continue to flow in and submerge the area below the solidified layer. The cycle continued until the entire blank was formed. The 3D printing parameters were 5s 30mW and the single layer thickness was 30μm. A lithium disilicate ceramic support was obtained with 7 axes (number of radial support arms), 3 wheels (number of concentric ring layers), and a size of 10×10×5mm. The wall thickness increased linearly and uniformly (gradiently) from 1.7mm to 2.3mm from bottom to top.

[0080] (2) After the lithium disilicate ceramic scaffold obtained in step (1) is formed, its resin and lithium disilicate layer are separated, and the lithium disilicate ceramic scaffold is cured in a dental light curing lamp for 4 min. Then, the cured lithium disilicate ceramic scaffold is cleaned in an anhydrous ethanol bath, and any residual non-cured slurry is removed by ultrasonic stirring. Then, degreasing and sintering are performed, and the degreased and sintered lithium disilicate ceramic scaffold is acid-etched in a 5 vol% hydrofluoric acid solution for 30 s. The acid-etched lithium disilicate ceramic scaffold is ultrasonically treated in anhydrous ethanol for 10 min and dried. 0.2 g of silane coupling agent KH-570 (Beijing Medion Co., Ltd., China) is coated on the surface of the acid-etched lithium disilicate ceramic scaffold to form interfacial bonds. Then, 0.5 g of Te-Econom Flow resin is injected into the pores under vacuum negative pressure. The Flow resin is slowly impregnated to prevent air bubbles from being trapped. After the infusion is completed, it is cured under a light curing lamp for 10 minutes to ensure complete polymerization. Finally, it is polished with SiC sandpaper to obtain a lithium disilicate ceramic-dental fluid resin composite material.

[0081] The degreasing and sintering process is carried out in a muffle furnace according to the following temperature parameters: Degreasing: the temperature is uniformly increased from 20°C to 350°C within 600 min, held at 350°C for 2 h, and then uniformly increased from 350°C to 450°C within 600 min, held at 450°C for 2 h; Sintering: the temperature is uniformly increased from 450°C to 850°C within 400 min, held at 850°C for 2 h, and then uniformly decreased from 850°C to 20°C within 85 min.

[0082] The three-dimensional model and photographs of the lithium disilicate ceramic-dental fluid resin composite material prepared in this embodiment, from the model to the sintered ceramic framework and then to the resin impregnation, are as follows: Figure 2 As shown in c. Then, ceramic volume fraction analysis was performed, and the optimal ceramic volume fraction was found to be 65.24 vol%. Specifically, as shown in... Figure 2 As shown in b.

[0083] Example 3

[0084] A lithium disilicate ceramic-dental fluid resin composite slurry, by weight comprising: 65 parts lithium disilicate glass powder, 12.5 parts 1,6-hexanediol diacrylate, 2.5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 3 parts dispersant, 0.05 parts initiator, and 0.025 parts light absorber.

[0085] The preparation method of the lithium disilicate ceramic-dental fluid resin composite slurry is the same as in Example 2.

[0086] Then, using lithium disilicate ceramic-dental fluid resin composite slurry as raw material, a lithium disilicate ceramic scaffold with a volume fraction of 65.24% and a lithium disilicate ceramic-dental fluid resin composite material were prepared according to the method in Example 2.

[0087] Example 4

[0088] A lithium disilicate ceramic-dental fluid resin composite slurry, by weight, comprises: 75 parts lithium disilicate glass powder, 17.5 parts 1,6-hexanediol diacrylate, 7.5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 5 parts dispersant, 0.15 parts initiator, and 0.075 parts light absorber.

[0089] The preparation method of the lithium disilicate ceramic-dental fluid resin composite slurry is the same as in Example 2.

[0090] Then, using lithium disilicate ceramic-dental fluid resin composite slurry as raw material, a lithium disilicate ceramic scaffold with a volume fraction of 65.24% and a lithium disilicate ceramic-dental fluid resin composite material were prepared according to the method in Example 2.

[0091] Comparative Example 1

[0092] A lithium disilicate ceramic-dental fluid resin composite material (ceramic volume fraction 65.24%) is described in Example 2, with the only difference being the number of axes of the lithium disilicate biomimetic crown model in step (1). The products in this comparative example are lithium disilicate ceramic frameworks with different numbers of axes and lithium disilicate ceramic-dental fluid resin composite materials, namely 4, 5, 6, and 8 axes.

[0093] Comparative Example 2

[0094] A lithium disilicate ceramic-dental fluid resin composite material (ceramic volume fraction 65.24%) is described in Example 2, with the only difference being the number of wheels in step (1) of the lithium disilicate biomimetic crown model. The comparative examples are lithium disilicate ceramic scaffolds with different numbers of wheels and lithium disilicate ceramic-dental fluid resin composite materials, specifically 2 and 4 wheels respectively.

[0095] Comparative Example 3

[0096] A lithium disilicate ceramic-dental fluid resin composite material has the structure described in Example 1, and the composition and preparation method of the lithium disilicate ceramic-dental fluid resin composite slurry are as described in Example 2. The only difference is that the wall thickness of the lithium disilicate ceramic scaffold is different in step (1). The products of this comparative example are uniform lithium disilicate ceramic scaffolds and lithium disilicate ceramic-dental fluid resin composite materials with different wall thicknesses, namely 1.7 mm, 1.9 mm, 2.0 mm, 2.1 mm, and 2.3 mm.

[0097] Comparative Example 4

[0098] A lithium disilicate ceramic-dental fluid resin composite material is described in Example 2, with the same composition and preparation method as in step (2), except that the printing parameters are different. The products of this comparative example were prepared under the conditions of 7s 30mW, 3s 30mW, 5s 32mW, and 5s 28mW, respectively.

[0099] Comparative Example 5

[0100] A lithium disilicate ceramic-dental fluid resin composite material has the structure described in Example 1, and the composition and preparation method of the lithium disilicate ceramic-dental fluid resin composite slurry are as described in Example 2, except that in step (1), the lithium disilicate ceramic framework is not cured by a dental light-curing lamp. The product of this comparative example is an uncured lithium disilicate ceramic framework, and a lithium disilicate ceramic-dental fluid resin composite material using the framework.

[0101] Comparative Example 6

[0102] A lithium disilicate ceramic-dental fluid resin composite material, with the structure described in Example 1 and the preparation method described in Example 2, differs only in that: in step (1), the mass of lithium disilicate in the lithium disilicate ceramic-dental fluid resin composite slurry is different; the weight parts of lithium disilicate glass powder in the lithium disilicate ceramic-dental fluid resin composite slurry used in this comparative example product are 40 parts, 50 parts, 60 parts, and 70 parts, respectively. This comparative example product is a lithium disilicate ceramic scaffold with different amounts of lithium disilicate glass powder, and a lithium disilicate ceramic-dental fluid resin composite material using this scaffold.

[0103] Comparative Example 7

[0104] A lithium disilicate ceramic-dental fluid resin composite material has the structure described in Example 1 and the composition of the lithium disilicate ceramic-dental fluid resin composite slurry is described in Example 2. The only difference is that the degreasing and sintering parameters are different in step (2). The degreasing and sintering process of the product in this comparative example is as follows: the temperature is uniformly increased from 20°C to 300°C within 300 min, held at 300°C for 2 h, uniformly increased from 300°C to 400°C within 300 min, held at 400°C for 2 h, uniformly increased from 400°C to 600°C within 200 min, held at 600°C for 2 h, and uniformly decreased from 600°C to 20°C within 40 min.

[0105] Comparative Example 8

[0106] A lithium disilicate ceramic-dental fluid resin composite slurry, with the specific composition as described in Example 2, differing only in that the weight parts of Lubrizol Solpus D540 dispersant are adjusted to 1 part, 2 parts and 3 parts respectively.

[0107] The products in this comparative example are lithium disilicate ceramic-dental fluid resin composite slurries with different amounts of dispersant.

[0108] Experimental Example 1

[0109] 1. The performance of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2, the lithium disilicate-dental fluid resin composite material prepared in Comparative Example 3, and commercial ceramics and dental fluid resins were compared. The results are as follows: Figure 1 As shown in c.

[0110] Depend on Figure 1As can be seen from c, although the strength of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 is slightly lower than that of pure ceramic, its toughness is significantly improved, proving that the composite material has significantly improved mechanical properties compared to the single material. Furthermore, the mechanical properties of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 are enhanced compared to the lithium disilicate-dental fluid resin composite material prepared in Comparative Example 3, indicating that the gradient design has certain advantages.

[0111] The graded lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 and the lithium disilicate ceramic-dental fluid resin composite material prepared in Comparative Example 3 were photographed and displayed. The results are as follows: Figure 1 As shown in d.

[0112] Depend on Figure 1 As can be seen from d, although the biomimetic structural design of the lithium disilicate ceramic-dental fluid resin composite material provided by the present invention is complex, it can be accurately manufactured by DLP technology.

[0113] The surface morphology of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 was examined using a field emission scanning electron microscope (G300 FE-SEM, Carl Zeiss, Germany). The results are as follows: Figure 1 As shown in e.

[0114] Depend on Figure 1 As can be seen from e, the lithium disilicate in the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 has a tight bond with the dental fluid resin.

[0115] 2. Acquired using an intraoral scanner (Aoralscan 3, China Ruiteng 3D Technology Co., Ltd.) Figure 2 A three-dimensional model of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2, shown in Figure c, was exported in STL file format. This scanned model was then aligned and compared with a reference crown design (the patient's untreated crown model) in Geomagic Wrap software (3D Systems, USA) to conduct a comprehensive three-dimensional deviation analysis. The results are as follows: Figure 2 As shown in d.

[0116] Depend on Figure 2 As can be seen from d, although the biomimetic structural design of the lithium disilicate ceramic-dental fluid resin composite material prepared by the present invention is complex, it can be accurately manufactured by DLP technology.

[0117] 3. Using the lithium disilicate ceramic-photoinitiating resin composite slurry from Example 2 and Comparative Example 4, and following its printing parameters, the standard model provided with the DLP printer was printed. The results are as follows: Figure 3 As shown in a.

[0118] Depend on Figure 3 It can be seen that printing with a power of 5s 30mW followed by immediate curing yields the best printing precision. However, at power levels of 7s 30mW and 5s 32mW, excessive growth of fine pores occurs. At power levels of 3s 30mW and 5s 28mW, the lithium disilicate layer and resin layer fracture, with the lithium disilicate layer adhering to the substrate film. Furthermore, the lithium disilicate ceramic-dental fluid resin composite material printed at the 5s 30mW parameter exhibits stronger interlayer bonding, making it the optimal printing parameter.

[0119] 4. Electron microscopy was performed on the lithium disilicate ceramic scaffold prepared in Example 2 (which had been cured) and the lithium disilicate ceramic scaffold prepared in Comparative Example 5 (which had not been cured). The results are as follows: Figure 3 As shown in b.

[0120] Depend on Figure 3 As can be seen from b, curing treatment can greatly enhance the tightness of the interlayer bonding of the lithium disilicate ceramic support after sintering and reduce the generation of cracks.

[0121] 5. Rheological analysis was performed on the lithium disilicate ceramic-dental fluid resin composite slurry prepared in Example 2 and the lithium disilicate ceramic-dental fluid resin composite slurry prepared in Comparative Example 8 using a digital viscometer (NDJ-5SE, China Shangyi Instrument Co., Ltd.). The results are as follows: Figure 3 As shown in d.

[0122] Depend on Figure 3 As can be seen from d, after increasing the amount of dispersant added from 1 part to 4 parts, the viscosity of the lithium disilicate ceramic-dental fluid resin composite slurry decreased by 83.3%, from 2250.6 mP·s to 330.7 mP·s, which is far below the 5000 mP·s threshold recommended for digital light processing (DLP) printing.

[0123] 6. Thermogravimetric analysis (TGA) was performed on the green bodies of the lithium disilicate ceramic scaffolds prepared in Example 2 and Comparative Example 7. The results are as follows: Figure 3 As shown in e.

[0124] Depend on Figure 3As shown in the data, below 270℃, the weight loss rate was 2.11% due to the evaporation of residual solvent and moisture; between 270 and 440℃, the main loss was 22.8%, peaking at 352.8℃, corresponding to the oxidative decomposition of the photopolymer network; the final loss between 440 and 600℃ was 4.48% (peaking at 454.7℃), related to the removal of residual carbonaceous matter. No further mass change occurred above 600℃, confirming complete removal of the binder. Based on the TGA results, thermal debinding temperatures of 350℃ and 450℃ were selected, followed by sintering at 850℃, which is a common crystallization temperature for lithium disilicate ceramics.

[0125] Then, based on the thermogravimetric analysis (TGA) results, the following optimization was obtained: Figure 3 Based on the sintering curve parameters of f, the optimal debinding sintering process was determined as follows: uniformly increase the temperature from 20℃ to 350℃ within 600 min, hold at 350℃ for 2 h, uniformly increase the temperature from 350℃ to 450℃ within 600 min, hold at 450℃ for 2 h; uniformly increase the temperature from 450℃ to 850℃ within 400 min, hold at 850℃ for 2 h, and uniformly decrease the temperature from 850℃ to 20℃ within 85 min.

[0126] 7. Within the 2θ range of 20° to 90°, Cu Kα radiation of 40 mA and 45 kV was used to perform phase transition analysis on the degreased and sintered lithium disilicate ceramic scaffold and lithium disilicate glass powder prepared in Example 2 by X-ray diffraction (XRD, Ultima IV, Rigaku, Tokyo, Japan). The results are as follows: Figure 3 As shown in g.

[0127] Depend on Figure 3 As can be seen from g, the lithium disilicate ceramic scaffold prepared in Example 2 after degreasing and sintering has a good crystallinity of 71.3±0.5%.

[0128] 8. The microstructure of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 was imaged using a field emission scanning electron microscope (G300 FE-SEM, Carl Zeiss, Germany), and grain size analysis was performed using ImageJ software (National Institutes of Health, USA). The results are as follows: Figure 3 As shown in h.

[0129] Depend on Figure 3 As can be seen from h, the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 has a microstructure composed of interlaced needle-like Li2Si2O5 crystals, with an average grain size of 2.25±0.06μm.

[0130] Experimental Example 2

[0131] 1. Using a microcomputer-controlled electronic universal testing machine (SUST Ltd., Zhuhai, China), compression tests and three-point bending tests were conducted on the following samples prepared in Comparative Example 1: lithium disilicate ceramic scaffolds with different numbers of axial members and lithium disilicate ceramic-dental fluid resin composites; Comparative Example 2: lithium disilicate ceramic scaffolds with different numbers of axial members and lithium disilicate ceramic-dental fluid resin composites; Comparative Example 3: lithium disilicate ceramic scaffolds with different wall thicknesses (1.7~2.3 mm) and lithium disilicate ceramic-dental fluid resin composites; and the gradient lithium disilicate ceramic-dental fluid resin composites prepared in Example 2, at a loading rate of 0.5 mm / min. Five tests were performed on each sample group, and the standard deviation was reported to obtain the stress-strain curves. Young's modulus, toughness, flexural strength, and compressive strength were derived from the stress-strain curves, and the toughness was calculated. The results are as follows: Figures 4-7 As shown.

[0132] First, we explored the effect of shape factors (number of axes, number of wheels) on mechanical properties.

[0133] Depend on Figure 4 and Figure 5 It is observed that, with the increase in the number of axes, the mechanical properties of both the lithium disilicate ceramic scaffold and the lithium disilicate ceramic-dental fluid resin composite initially improve (from 4 axes to 7 axes), then decrease (from 7 axes to 8 axes). Similarly, with the increase in the number of rings, the performance of the lithium disilicate ceramic scaffold and the lithium disilicate ceramic-dental fluid resin composite improves from 2 rings to 3 rings, but decreases at 4 rings. Based on these results, the shape and structure designs with 7 axes and 3 rings exhibit the optimal mechanical properties. Specifically, the lithium disilicate ceramic-dental fluid resin composite with this configuration has a compressive strength of 600.84±42.20 MPa, a Young's modulus of 7.89±0.11 GPa, a compressive toughness of 24.53±0.63 MJ / m³, a flexural strength of 423.75±25.59 MPa, and a flexural specific energy absorption (SEA) of 356.50±14.79 J / kg.

[0134] Secondly, we explored the effect of wall thickness (ceramic volume fraction) on mechanical properties.

[0135] Depend on Figure 6It is evident that the mechanical properties of both the lithium disilicate ceramic scaffold and the lithium disilicate ceramic-dental fluid resin composite material improve with increasing wall width. For example, the lithium disilicate ceramic-dental fluid resin composite material with a wall width of 2.3 mm (CVF=74.26%) prepared in Comparative Example 3 achieved a compressive strength of 810.99±20.78 MPa, a Young's modulus of 8.94±0.17 GPa, a compressive toughness of 37.91±0.69 MJ / m³, a flexural strength of 473.08±17.13 MPa, and a flexural specific energy absorption of 506.47±18.88 J / kg. These values ​​represent increases of 1.68 times, 1.16 times, 2.34 times, 1.51 times, and 2.05 times, respectively, compared to the 1.7 mm wall width design (CVF=60.22%). This indicates that increasing CVF can improve modulus, strength, and toughness.

[0136] Finally, the impact of gradient design on mechanical properties is explored.

[0137] Depend on Figure 7 It can be seen that the gradient lithium disilicate ceramic-dental fluid resin composite material with a wall thickness gradually changing from 1.7 mm to 2.3 mm prepared in Example 2 has a compressive strength of 761.58±19.46 MPa, an elastic modulus of 8.38±0.13 GPa, a compressive toughness of 35.74±1.34 MJ / m³, a flexural strength of 424.25±18.40 MPa, and a flexural fracture energy absorption rate (SEA) of 421.16±14.42 J / kg. Compared with the homogeneous lithium disilicate ceramic-dental fluid resin composite material with a wall thickness of 2.0 mm prepared in Comparative Example 3, these values ​​are increased by 16.1%, 3.9%, 29.9%, 6.2%, and 12.7%, respectively. Similarly, the gradient lithium disilicate ceramic scaffold prepared in Example 2 is also superior to the uniform lithium disilicate ceramic scaffold prepared in Comparative Example 3. The compressive strength, elastic modulus, compressive toughness, flexural strength, and flexural fracture energy absorption rate are increased by 7.7%, 3.3%, 17.0%, 5.6%, and 8.7%, respectively. This fully demonstrates that, at a comparable ceramic volume fraction (CVF), gradient design can further improve compressive strength and toughness.

[0138] 4. Finite element simulation tests were performed on the lithium disilicate ceramic-dental fluid resin composite material (Li2Si2O5) prepared in Example 2, and on other composite materials reported in existing literature (such as [1-5] 3YSZ-resin composite material, ZrO2-resin composite material, Al2O3-resin composite material, ZrO2-SiO2-resin composite material), as well as natural teeth (such as [2, 6] enamel, dentin) and clinically used restorative materials (such as [7-8] commercial lithium disilicate, dental resin), to compare the performance of different materials. The results are as follows: Figure 8 As shown.

[0139] The specific method is as follows: Using an ABAQUS instrument (Dassault Systemes Simulia Corp., USA), a stress of 800N was applied along the Z-axis of different materials to simulate the maximum biting force. Completely fixed boundary conditions were carefully applied to the bottom surface to anchor it, while compressing the top surface. Finite element analysis was then used to carefully examine the stress distribution at different locations.

[0140] [1] Published in the article "W. Li, Z. Zhang, K. Zhang, Y. Feng, C. Wan, High strength and damage tolerance in lightweight 3D-architectured ceramic / polymercomposites with varied periodical topology, Additive Manufacturing 97 (2025)104605, https: / / doi.org / 10.1016 / j.addma.2024.104605."

[0141] [2] In the article "J. Sun, S. Yu, J. Wade-Zhu, Y. Wang, H. Qu, S. Zhao, R. Zhang, J. Yang, J. Binner, J. Bai, 3D printing of ceramic composite with biomimetic toughening design, Additive Manufacturing 58 (2022) 103027, https: / / doi.org / 10.1016 / j.addma.2022.103027." Published.

[0142] [3] In the article "Q. Li, Y. Liu, D. Zhao, Y. Yang, Q. Liu, Y. Zhang, J. Wu, Z. Dong, Digital light printing of zirconia / resin composite material with biomimetic graded design for dental application, Dental Materials 41(1)(2025) 16-27, http: / / doi.org / https: / / doi.org / 10.1016 / j.dental.2024.10.010.It was made public in China.

[0143] [4] Published in the article “S. Al-Jawoosh, A. Ireland, B. Su, Fabrication and characterisation of a novel biomimetic anisotropic ceramic / polymer-infiltrated composite material, Dental Materials 34(7) (2018) 994-1002, https: / / doi.org / 10.1016 / j.dental.2018.03.008.”

[0144] [5] Published in the article “X. Cui, X. Zhang, L. Hu, Z. Zhao, K. Tang, Z. Yang, F. Wang, J. Chen, L. Niu, Mechanical properties of polymer-infiltrated ZrO2ceramic network improved by incorporation of SiO2 component, Materials & Design 252 (2025) 113739, https: / / doi.org / 10.1016 / j.matdes.2025.113739.”

[0145] [6] Published in the article “SM Weidmann, JA Weatherell, SM Hamm, Variations of enamel density in sections of human teeth, Archives of Oral Biology 12(1)(1967) 85-97, https: / / doi.org / 10.1016 / 0003-9969(67)90145-8.”

[0146] [7]Published in the article “A. Muhetaer, C. Tang, A. Anniwaer, H. Yang, C. Huang, Advances in ceramics for tooth repair: From bench to chairside, Journal of Dentistry 146 (2024) 105053, https: / / doi.org / 10.1016 / j.jdent.2024.105053.”

[0147] [8] In the article "RS Saini, RIH Binduhayyim, V. Gurumurthy, AAF Alshadidi, LIN Aldosari, A. Okshah, MS Kuruniyan, D. Dermawan, A. Avetisyan, SA Mosaddad, A. Heboyan, Dental biomaterials redefined: molecular docking and dynamics-driven dental resin composite optimization, BMC oral health 24(1) (2024) 557, http: / / doi.org / 10.1186 / s12903-024-04343-1."

[0148] Depend on Figure 8 It is evident that the compressive strength, toughness, flexural strength, and density of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 exceed those of other composite material designs reported in the literature [1-5], as well as the performance of natural teeth [2, 6] and clinically used restorative materials [7, 8].

[0149] Test Example 3: Friction and Wear Test

[0150] Friction and wear tests were conducted using a multifunctional tribolab (UMT-5, Bruker Nano GmbH, Germany) tribolab. Three groups of materials were tested: pure lithium disilicate ceramic block (Li2Si2O5, Creamic), lithium disilicate ceramic-dental fluid resin composite material (Composite) prepared in Example 2, and pure dental fluid resin (Resin). The sample dimensions for testing were 12mm × 12mm × 5mm (n=5).

[0151] The specific method is as follows: The sample is immersed in artificial saliva at 37℃, with a normal load of 5N, a friction frequency of 2Hz, a single stroke of 5mm, and a 4mm diameter Si3N4 friction ball. 3600 linear reciprocating friction cycles are performed. The average friction coefficient is the average value of the stable friction coefficients in the friction curve. The surface morphology of the sample after friction is scanned using a white light interferometer (Contour GT-K, Bruker technology, Beijing, China) to obtain the wear volume loss. The results are as follows: Figure 9 As shown.

[0152] Depend on Figure 9 It can be seen that the average friction coefficient of the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 increased by 179.5%, and the specific wear rate increased by 26.1% (1.08 × 10⁻⁶). -6 mm 3 / N·m). Compared with pure lithium disilicate ceramics. Compared with pure dental fluid resin, the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2 showed a 18.2% reduction in the coefficient of friction and a 75.0% reduction in the specific wear rate. These results indicate that although the addition of the dental fluid resin phase inevitably reduces wear resistance compared with lithium disilicate ceramics, the degradation of wear performance is relatively mild, and the wear resistance of the composite material is much superior to that of the pure resin.

[0153] Experimental Example 3: Cytotoxicity Test

[0154] 1. Cell proliferation test

[0155] Human gingival fibroblasts (HGF, Procell, China) were cultured in complete medium (89% DMEM high-glucose medium, 10% fetal bovine serum, and 1% penicillin / streptomycin) at 37°C, 5% CO2, and 95% air. Before testing, the test materials in four groups were washed sequentially with deionized water, PBS buffer, and 75% ethanol, and then sterilized under UV light for 2 hours. The four groups were as follows: Group 1 was the blank control group, with HGF cells cultured for 1, 3, and 7 days; Group 2 was pure lithium disilicate ceramic blocks (Commercial ceramic), co-cultured with HGF cells for 1, 3, and 7 days; Group 3 was the lithium disilicate ceramic scaffold prepared in Example 2, co-cultured with HGF cells for 1, 3, and 7 days; and Group 4 was the lithium disilicate ceramic-dental fluid resin composite material prepared in Example 2, co-cultured with HGF cells for 1, 3, and 7 days.

[0156] According to the manufacturer's instructions, the cytotoxicity of the four cell groups was determined using the Cell Counting Kit-8 assay kit. Specifically, after 1, 3, and 7 days of cell culture, the culture medium was completely replaced with 1 ml of DMEM containing 10% CCK-8 reagent. Absorbance was measured at 450 nm using a microplate reader (SPECTRO star Nano, BMG Labtech, Offenburg, Germany). After a 2-hour co-culture period, absorbance was measured again at 450 nm using a microplate reader (SPECTRO star Nano, BMG Labtech, Offenburg, Germany). The results are as follows: Figure 10 As shown in a.

[0157] Depend on Figure 10 As can be seen from this, the lithium disilicate ceramic frame and the lithium disilicate ceramic-dental fluid resin composite material prepared in this invention are both non-cytotoxic.

[0158] 2. Cell live / dead staining

[0159] After a 3-day co-culture period, groups 1-4 were first stained for cell viability using a live / dead cell viability kit, and then fluorescent images were captured in a dark room using a scanning microscope (D-35578, Leica, Wetzlar, Germany). The results are as follows. Figure 10 As shown in b~e.

[0160] Depend on Figure 10 As can be seen from b~e, the lithium disilicate ceramic-dental fluid resin composite material prepared in this invention has good biocompatibility for clinical applications.

[0161] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A lithium disilicate ceramic-dental fluid resin composite material, characterized in that, It is prepared by 3D printing of lithium disilicate ceramic-photoinitiating resin composite slurry based on a biomimetic dental crown model; The lithium disilicate ceramic-photoinitiating resin composite slurry comprises, by weight: 65-75 parts lithium disilicate glass powder, 12.5-17.5 parts 1,6-hexanediol diacrylate, 2.5-7.5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 3-5 parts dispersant, 0.05-0.15 parts initiator, and 0.025-0.075 parts light absorber; The biomimetic crown model is a composite structure of concentric rings of glass sponge and wheel-shaped nodes of horsetail grass.

2. The lithium disilicate ceramic-dental fluid resin composite material as described in claim 1, characterized in that, The lithium disilicate ceramic-photoinitiator resin composite slurry comprises, by weight: 70 parts lithium disilicate glass powder, 15 parts 1,6-hexanediol diacrylate, 5 parts pentaerythritol tetraacrylate containing stabilizer MEHQ, 4 parts dispersant, 0.1 parts initiator, and 0.05 parts light absorber.

3. The lithium disilicate ceramic-dental fluid resin composite material as described in claim 1, characterized in that, The lithium disilicate glass powder has a D50 of 1.5 μm; the dispersant is Lubrizol Solpus D540 dispersant; the initiator is photoinitiator TPO; and the light absorber is 1-phenylazo-2-naphthol.

4. The lithium disilicate ceramic-dental fluid resin composite material as described in claim 1, characterized in that, The lithium disilicate ceramic-dental fluid resin composite slurry is prepared according to the following method: According to the formula, lithium disilicate glass powder and dispersant are mixed and stirred in a magnetic water bath at 45~75℃ for 0.5~1.5h, and dried at 110~120℃ for 60~80min to obtain modified lithium disilicate powder; then 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate containing stabilizer MEHQ, initiator and light absorber are added to the modified lithium disilicate powder, and mixed at a speed of 90000~110000r / s for 4~5min, and then magnetically stirred at a speed of 450~550r / s for 20~30h to obtain lithium disilicate ceramic-photoinitiating resin composite slurry.

5. The lithium disilicate ceramic-dental fluid resin composite material as described in claim 1, characterized in that, The glass sponge concentric ring-horsetail wheel-shaped node composite structure consists of radial support arms and concentric rings; the radial support arms radiate outward from the center and number 4 to 8; the concentric rings are arranged in concentric circles around the center and number 2 to 4 layers. More preferably, the radial support arms of the glass sponge concentric ring-horsetail wheel-shaped node composite structure are 7, the concentric rings are 3 layers, and the size is 10×10×5mm; the wall thickness of the glass sponge concentric ring-horsetail wheel-shaped node composite structure increases linearly and uniformly from 1.7mm to 2.3mm from bottom to top.

6. The lithium disilicate ceramic-dental fluid resin composite material as described in claim 1, characterized in that, The ceramic volume fraction of the lithium disilicate ceramic-dental fluid resin composite material is 60-75 vol%. More preferably, the ceramic volume fraction of the lithium disilicate ceramic-dental fluid resin composite material is 65.24 vol.

7. The method for preparing the lithium disilicate ceramic-dental fluid resin composite material according to claim 1, characterized in that, Specifically, the following steps are included: (1) The lithium disilicate ceramic-dental fluid resin composite slurry was deposited into the material tank of the 3D printer and 3D printed according to the bionic crown model to obtain the lithium disilicate ceramic scaffold. (2) Separate the resin and lithium disilicate layer in the lithium disilicate ceramic framework obtained in step (1), cure it under a dental light curing lamp for 3-5 minutes, clean it and then degrease and sinter it; etch the degreased and sintered lithium disilicate ceramic framework in hydrofluoric acid solution for 25-35 seconds, clean it and then apply silane coupling agent to the surface of the etched lithium disilicate ceramic framework, then inject dental fluid resin into the pores under negative pressure, cure it under a light curing lamp for 9-13 minutes, and after polishing, obtain the lithium disilicate ceramic-dental fluid resin composite material.

8. The preparation method according to claim 7, characterized in that, In step (1), the 3D printing is performed in an AUTOCERA-R type DLP3D printer. During the 3D printing process, the bottom of the forming stage is exposed to ultraviolet light to solidify it into the shape of a biomimetic crown model. The forming stage rises with a single layer thickness, allowing the lithium disilicate ceramic-dental fluid resin composite slurry to continue to flow in, flooding the area below the solidified layer. The cycle continues until the entire lithium disilicate ceramic scaffold is formed. The 3D printing parameters are 5s30mW, and the thickness of a single layer is 30μm.

9. The preparation method according to claim 7, characterized in that, In step (2), the degreasing and sintering process is carried out in a muffle furnace according to the following temperature parameters: degreasing: the temperature is raised from 20°C to 350°C at a constant rate within 600 min, and held at 350°C for 2 h; the temperature is raised from 350°C to 450°C at a constant rate within 600 min, and held at 450°C for 2 h. Sintering: The temperature is raised from 450℃ to 850℃ at a constant rate within 400 min, held at 850℃ for 2 h, and then lowered from 850℃ to 20℃ at a constant rate within 85 min. The silane coupling agent is silane coupling agent KH-570; the dental fluid resin is Te-Econom Flow resin.

10. The application of the lithium disilicate ceramic-dental fluid resin composite material of claim 1 in the preparation of dental restorations.

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