Method for 3D printing of gradient bionic tooth structure based on composite ceramic repair material

Abstract

The invention relates to the technical field of bionic teeth, in particular to a method for 3D printing of a gradient bionic tooth structure based on a composite ceramic repair material, and the method comprises the following steps: S1, adopting lithium aluminum silicate series biological ceramic as a base material, and carrying out plasma ball milling treatment to obtain uniform powder; preparing slurry from the powder and polyethylene glycol diacrylate resin containing 3wt% of a photoinitiator according to a powder-water ratio of 42%-46%; s2, performing three-stage treatment on the slurry by using a vacuum defoaming unit; s3, constructing a gradient stress distribution model based on CT scanning data, and dividing an enamel layer, a dentin layer and a dental pulp cavity transition layer; s4, performing lamination forming on the slurry at the speed of 50 + / -5mm / s through a piezoelectric microdroplet injection system; and S5, carrying out sintering molding on the printed bionic tooth body structure by adopting a gradient sintering process. The problems that an interface between a restoration body and surrounding tissues is unstable and inflammatory reaction and rejection reaction easily occur due to the fact that a traditional restoration material is often difficult to accurately simulate the gradient structure of teeth are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of bionic teeth, and in particular to a method for 3D printing a gradient bionic tooth structure based on a composite ceramic restorative material. Background Art

[0002] In the field of stomatology, the design and manufacture of gradient bionic tooth tissue has always been a hot topic and a difficult point of research. Traditional dental restoration materials and methods often fail to accurately imitate the gradient structure and function of natural teeth, resulting in unsatisfactory restoration results. The emergence of 3D printing provides a new way to solve this problem.

[0003] Natural teeth have a complex gradient structure, from enamel to dentin to pulp, with different tissue compositions, mechanical properties and biological characteristics in different areas. This gradient structure gives teeth excellent mechanical properties and biocompatibility. However, traditional restorative materials often find it difficult to accurately mimic this gradient structure, resulting in an unstable interface between the restoration and surrounding tissues, which is prone to inflammatory and rejection reactions. Summary of the invention

[0004] The purpose of the present invention is to provide a method for 3D printing gradient bionic tooth structure based on composite ceramic restorative materials, so as to solve the problem that traditional restorative materials are often difficult to accurately imitate the gradient structure of teeth, resulting in an unstable interface between the restoration and the surrounding tissue, and prone to inflammatory and rejection reactions.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for 3D printing a gradient bionic tooth structure based on a composite ceramic restorative material comprises the following steps: step S1, using lithium aluminum silicate bioceramics as a basic material, plasma ball milling to obtain a uniform powder, preparing a slurry with a polyethylene glycol diacrylate resin containing 3wt% of a photoinitiator at a powder-water ratio of 42%-46%, and adding 0.5-1.2wt% of nano zirconium oxide whiskers as a reinforcing phase; step S2, subjecting the slurry to a three-stage treatment by a vacuum degassing unit; step S3, based on CT scanning data, using a finite element analysis method to construct a gradient stress distribution model, dividing the enamel layer, the dentin layer and the pulp cavity transition layer; step S4, in a nitrogen protection environment, using a piezoelectric droplet injection system to perform layered molding of the slurry at a speed of 50±5mm / s, the curing energy density of each layer is 35-45mJ / cm², and the interlayer misalignment angle is set to 67°; step S5, sintering the printed bionic tooth structure using a gradient sintering process.

[0006] A further technical solution is that the composition of the lithium aluminum silicate bioceramic in step S1 is: Li 2O is 6-8wt%, Al 2 O3 is 55-60wt%, SiO 2 30-35wt%, P 2 O 5 It is 2-3wt%.

[0007] A further technical solution is that in step S1, uniform powder with D50≤5 μm is obtained after plasma ball milling for 8-12 hours.

[0008] A further technical solution is that the gradient sintering process is to sinter at 600°C for 2h, 850°C for 1.5h, and 1150°C for 0.5h in sequence.

[0009] A further technical solution is that in step S3, the vacuum degassing unit is used for three-stage treatment, which is respectively -0.095MPa for 30min, -0.1MPa for 20min, and -0.098MPa for 15min, and the viscosity is controlled at 800-1200mPa·s.

[0010] A further technical solution is that the elastic modulus of the enamel layer is 70-90 GPa, the elastic modulus of the dentin layer is 15-25 GPa, and the elastic modulus of the pulp cavity transition layer is 3-5 GPa.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 3D printing technology can accurately control the distribution and morphology of materials and realize the precise manufacture of gradient bionic tooth structures. By optimizing the design software, the gradient structure of natural teeth can be accurately simulated, including the tissue composition, mechanical properties and biological characteristics of different regions. Then, the composite ceramic material (slurry) is added layer by layer using a 3D printer to form a restoration with a gradient structure. This restoration can better integrate with the surrounding tissue, reduce inflammatory reactions and rejection reactions, and improve the repair effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the 3D printing process of the present invention.

[0013] Figure 2 This is a schematic diagram of the slurry of the present invention.

[0014] Figure 3 This is a partial electron microscope enlarged schematic diagram of the bionic tooth structure in Example 2 of the present invention.

[0015] Figure 4 This is the water contact angle test in Example 2 of the present invention.

[0016] Figure 5 This is the result of the cell CCK-8 experiment in Example 2 of the present invention.

[0017] Figure 6 This is the result of cell live and dead staining in Example 2 of the present invention.

[0018] Figure 7 The three-point bending test results in Example 2 of the present invention are shown.

[0019] Figure 8 This is the elastic modulus result in Example 2 of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] Embodiment 1: A method for 3D printing a gradient bionic tooth structure based on a composite ceramic restorative material comprises the following steps: step S1, using lithium aluminum silicate bioceramics as a basic material, plasma ball milling to obtain a uniform powder, preparing a slurry with a polyethylene glycol diacrylate resin containing 3wt% of a photoinitiator at a powder-water ratio of 42%-46%, and adding 0.5-1.2wt% of nano zirconium oxide whiskers as a reinforcing phase; step S2, subjecting the slurry to a three-stage treatment by a vacuum degassing unit; step S3, based on CT scanning data, using a finite element analysis method to construct a gradient stress distribution model, dividing the enamel layer, the dentin layer and the pulp cavity transition layer; step S4, in a nitrogen protection environment, using a piezoelectric droplet injection system to perform layered molding of the slurry at a speed of 50±5mm / s, the curing energy density of each layer is 35-45mJ / cm², and the interlayer misalignment angle is set to 67°; step S5, sintering the printed bionic tooth structure using a gradient sintering process.

[0022] The composition of the lithium aluminum silicate bioceramic in step S1 is: 6-8wt% Li2O, 55-60wt% Al2O3, 30-35wt% SiO2, and 2-3wt% P2O5.

[0023] In the step S1, after the plasma ball milling treatment for 8-12 hours, a uniform powder with a D50 of ≤5 μm is obtained.

[0024] The gradient sintering process is to sinter at 600°C for 2h, 850°C for 1.5h, and 1150°C for 0.5h. The sintering process introduces atmosphere gradient control: N2 / H2 mixed gas (95:5) is introduced in the 600-800°C stage, and Ar gas is switched above 800°C.

[0025] In step S3, the vacuum degassing unit is used for three-stage treatment, which is respectively -0.095MPa for 30min, -0.1MPa for 20min, and -0.098MPa for 15min, and the viscosity is controlled at 800-1200mPa·s.

[0026] The elastic modulus of the enamel layer is 70-90 GPa, the elastic modulus of the dentin layer is 15-25 GPa, and the elastic modulus of the pulp cavity transition layer is 3-5 GPa.

[0027] 3D printed composite ceramic restoration materials with gradient bionic tooth structures can further improve the biocompatibility of restorations. By accurately imitating the gradient structure and function of natural teeth, the restoration can better integrate with the surrounding tissues to form a stable interface. At the same time, the composite ceramic material itself has excellent biocompatibility and can reduce the occurrence of inflammatory reactions and rejection reactions. This improved biocompatibility helps to ensure the long-term stability and durability of the restoration and improve the quality of life of patients.

[0028] Gradient bionic design: This invention achieves precise manufacturing of gradient bionic dental tissue by precisely controlling the ratio of printing materials, which is more in line with the structure and functional characteristics of natural teeth.

[0029] High biocompatibility: The selected bioceramic materials have high biocompatibility, which can reduce the rejection reaction of the patient's oral tissue and improve the safety and effectiveness of the restoration.

[0030] Embodiment 2: According to the method in Example 1, in step S1, the powder-water ratio was controlled at 42%, 44%, and 46% respectively when preparing the slurry, and a control test was carried out. Figure 3-8 Shown are the test results of the control test.

[0031] Figure 3 Schematic diagram of partial electron microscope magnification of bionic tooth structure with three powder-to-water ratios.

[0032] Figure 4 Water contact angle tests for three powder-to-water ratios.

[0033] Figure 5 The results of cell CCK-8 experiments with three powder-water ratios are shown.

[0034] Figure 6 The results of live and dead staining of cells with three powder-to-water ratios.

[0035] Figure 7 These are the results of three-point bending tests after sintering at three powder-to-water ratios.

[0036] Figure 8These are the results of three-point bending tests after sintering at three powder-to-water ratios.

[0037] Although the present invention is described herein with reference to a number of illustrative embodiments of the present invention, it will be appreciated that those skilled in the art may devise many other modifications and implementations that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, drawings, and claims, a variety of variations and modifications may be made to the components and / or layout of the subject combination layout. In addition to the variations and modifications made to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A method for 3D printing a gradient bionic tooth structure based on a composite ceramic restorative material, characterized in that: The method comprises the following steps: step S1, using lithium aluminum silicate bioceramics as a base material, subjecting the powder to plasma ball milling treatment to obtain a uniform powder, preparing a slurry with a polyethylene glycol diacrylate resin containing 3 wt % of a photoinitiator at a powder-water ratio of 42%-46%, and adding 0.5-1.2 wt % of nano zirconium oxide whiskers as a reinforcing phase; Step S2, subjecting the slurry to three-stage treatment in a vacuum degassing unit; Step S3, based on CT scanning data, using the finite element analysis method to construct a gradient stress distribution model to divide the enamel layer, dentin layer and pulp cavity transition layer; Step S4, in a nitrogen protection environment, using a piezoelectric droplet injection system to layer the slurry at a speed of 50±5mm / s, with a curing energy density of 35-45mJ / cm² per layer and an interlayer misalignment angle set to 67°; Step S5, sintering the printed bionic tooth structure using a gradient sintering process.

2. The method of 3D printing gradient bionic tooth structure based on composite ceramic restorative materials according to claim 1, characterized in that: The composition of the lithium aluminum silicate bioceramic in step S1 is: 6-8wt% Li2O, 55-60wt% Al2O3, 30-35wt% SiO2, and 2-3wt% P2O5.

3. The method for 3D printing gradient bionic tooth structure based on composite ceramic restorative materials according to claim 1, characterized in that: In the step S1, after the plasma ball milling treatment for 8-12 hours, a uniform powder with a D50 of ≤5 μm is obtained.

4. The method of 3D printing gradient bionic tooth structure based on composite ceramic restorative materials according to claim 1, characterized in that: The gradient sintering process is to sinter at 600° C. for 2 h, 850° C. for 1.5 h, and 1150° C. for 0.5 h in sequence.

5. The method for 3D printing gradient bionic tooth structure based on composite ceramic restorative materials according to claim 1, characterized in that: In step S3, the vacuum degassing unit is used for three-stage treatment, which is respectively -0.095MPa for 30min, -0.1MPa for 20min, and -0.098MPa for 15min, and the viscosity is controlled at 800-1200mPa·s.

6. The method for 3D printing gradient bionic tooth structure based on composite ceramic restorative materials according to claim 1, characterized in that: The elastic modulus of the enamel layer is 70-90 GPa, the elastic modulus of the dentin layer is 15-25 GPa, and the elastic modulus of the pulp cavity transition layer is 3-5 GPa.

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