A piezoelectric base material with antibacterial and soft tissue healing promoting properties, and its preparation method and application

Abstract

The present invention discloses a piezoelectric base material with antibacterial and soft tissue healing promotion function, and a preparation method and application thereof. The piezoelectric base material with antibacterial and soft tissue healing promotion function provided by the present invention has strong operability in clinical application. During the application of the piezoelectric base material, it exhibits excellent piezoelectric responsiveness and electrical stability, and realizes synergistic toughening and strengthening of the material. While considering the promotion of soft tissue sealing and electrical properties, the mechanical properties of the material are also considered, ensuring the feasibility of clinical use of the material, and contributing to the clinical prevention of peri-implant disease and the long-term stability of the implant.

Description

Technical Field

[0001] The present invention relates to the field of material preparation, and in particular to a piezoelectric base material capable of resisting bacteria and promoting soft tissue healing, and a preparation method and application thereof. Background Art

[0002] Implant restoration is a common method of restoring missing teeth in oral clinics. It is achieved by implanting implants in the jawbone as a basis to support and retain the crown restoration on the upper part to repair the missing teeth. The current clinical dental implant restoration abutment materials do not have antibacterial ability and are easily invaded by oral bacteria to induce peri-implant disease and cause damage to the supporting bone tissue. The restoration will eventually fall off or break due to insufficient supporting bone tissue. Therefore, researchers hope to prevent the occurrence of peri-implant disease by using dental implant restoration abutment materials with self-antibacterial properties to prevent bacterial invasion. Existing research mainly uses abutment surface treatment to exert antibacterial effects, but surface treatment is easily affected by the oral environment and has poor long-term stability.

[0003] Therefore, it is necessary to prepare abutment materials with intrinsic antibacterial properties to prevent bacterial infection. In addition, how to better balance the strength, toughness and electrical properties while improving the mechanical strength of implant restorations is still a challenge for oral restorations.

[0004] The information in the background technology is only for illustrating the general background of the present invention and should not be regarded as admitting or suggesting in any form that such information constitutes the prior art known to a person skilled in the art. Summary of the invention

[0005] In order to solve at least some of the technical problems in the prior art, the present invention prepares an organic polymer material toughened and reinforced abutment material system, which is expected to achieve long-term intrinsic antibacterial properties of electrical signals while achieving higher mechanical strength, preventing the occurrence of peri-implant disease and improving the long-term stability of dental implant restorations. Specifically, the present invention includes the following contents.

[0006] A first aspect of the present invention provides a method for preparing an antibacterial piezoelectric substrate material that promotes soft tissue healing, which includes the step of selecting a sintering temperature for the piezoelectric material based on the electrical and mechanical properties of the piezoelectric substrate material.

[0007] In certain embodiments, the method for preparing the antibacterial and soft tissue healing-promoting piezoelectric abutment material according to the present invention comprises:

[0008] (1) compacting the inorganic piezoelectric material and then sintering it to obtain a porous green body, wherein the compacting process includes dry-pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa for 1-120 s to obtain a dense green body;

[0009] (2) placing the sintered porous substrate in a solution containing an organic polymer material, and obtaining the piezoelectric base material after solidification.

[0010] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing-promoting piezoelectric substrate material of the present invention, the method further comprises the step of treating the sintered porous substrate with a compound having the following structure:

[0011] X(CH 2 ) n S Y 3 Formula I,

[0012] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0013] In certain embodiments, according to the method for preparing the piezoelectric base material with antibacterial and soft tissue healing properties described in the present invention, the piezoelectric base material includes an organic polymer material and an inorganic piezoelectric material, and the organic polymer material and the inorganic piezoelectric material are respectively connected to form a three-dimensional network structure, and the antibacterial and soft tissue healing properties are achieved by controlling the sintering temperature during the preparation process and the amount of the organic polymer material and the inorganic piezoelectric material.

[0014] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing promoting piezoelectric base material of the present invention, the mass ratio of the organic polymer material to the inorganic piezoelectric material is in the range of 1:10 to 1:200.

[0015] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing-promoting piezoelectric base material of the present invention, the piezoelectric material includes barium titanate, strontium titanate, barium strontium titanate, lithium niobate, potassium niobate, sodium potassium niobate, bismuth ferrite, bismuth titanate, calcium bismuth niobate, bismuth iron titanate, sodium bismuth titanate, barium sodium bismuth titanate, zirconium oxide, lanthanum oxide, cerium oxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, calcium zirconate, barium calcium zirconate titanate, or at least one of the above-mentioned ternary or multi-component piezoelectric materials.

[0016] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing promoting piezoelectric base material of the present invention, the organic polymer material comprises an acrylic polymer.

[0017] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing promoting piezoelectric base material of the present invention, the sintering temperature is greater than 1000°C and less than 1300°C.

[0018] In certain embodiments, according to the method for preparing the antibacterial and soft tissue healing-promoting piezoelectric base material of the present invention, the method further comprises the step of polarizing the piezoelectric base material, with a polarization field strength of 0.1-5 kV / mm, a polarization temperature of 10-40°C, and a treatment time of 1-120 min.

[0019] The second aspect of the present invention provides a piezoelectric base material that is antibacterial and promotes soft tissue healing, which is obtained according to the preparation method of the present invention.

[0020] The third aspect of the present invention provides the use of the above-mentioned piezoelectric substrate material in the preparation of biomedical materials.

[0021] The present invention achieves toughening and strengthening of piezoelectric base materials by controlling the sintering temperature of piezoelectric materials and the ratio of piezoelectric materials to organic polymer materials. On this basis, the piezoelectric base material is subjected to spatial electric field functionalization treatment to form biomedical materials (including but not limited to oral prostheses) with different electrical strengths, while having piezoelectric responsiveness, electrical stability and mechanical properties, forming a long-term stable self-antibacterial electrical microenvironment. The piezoelectric base material prepared by the present invention is a non-degradable type, which can maintain long-term piezoelectric responsiveness and electrical stability, and can avoid potential problems of harming the body such as ion precipitation caused by material degradation and absorption by the human body.

[0022] In addition, due to its intrinsic ferroelectric properties, the piezoelectric base material of the present invention can have different piezoelectric responsiveness after spatial electric field functionalization treatment. The established spatial electrical microenvironment can achieve stable and controllable soft tissue cell attachment and antibacterial effects. The antibacterial effect of the electrical microenvironment can achieve the effect of preventing bacterial invasion by enhancing the surface soft tissue closure and inhibiting the activity of surrounding bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The results show the mass ratio of the organic polymer material to the piezoelectric material (barium titanate) in the material.

[0024] Figure 2 The flexural strength of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials is shown.

[0025] Figure 3 The elastic modulus of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials is shown.

[0026] Figure 4 The fracture toughness of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials is shown.

[0027] Figure 5 The XRD patterns of barium titanate substrates sintered at different temperatures are shown.

[0028] Figure 6 The flexural strength comparison between the barium titanate matrix sintered at 1200°C and the densely sintered barium titanate matrix before and after toughening with organic polymer materials is shown.

[0029] Figure 7 The elastic modulus comparison of the barium titanate matrix sintered at 1200°C before and after toughening with organic polymer materials and the densely sintered barium titanate matrix is ​​shown.

[0030] Figure 8 The fracture toughness comparison of the barium titanate matrix sintered at 1200°C before and after toughening and the densely sintered barium titanate matrix is ​​shown.

[0031] Fig. 9 The cracks in organic polymer material toughened barium titanate are observed under nanoindentation.

[0032] Fig.10 It shows that toughened barium titanate can effectively generate piezoelectric signals under pressure.

[0033] Fig.11 The three-dimensional structure image of the porous barium titanate matrix sintered at 1200°C is shown.

[0034] Fig.12 The electrical properties of toughened barium titanate after polarization treatment under different conditions are shown.

[0035] Fig.13 The electrical properties of toughened barium titanate sintered at different temperatures after polarization treatment (A) and the electrical properties of toughened barium titanate sintered at different raw material ratios after polarization treatment (B) are shown.

[0036] Fig.14 The results of measuring the cell spreading area and adhesion area on the surface of toughened barium titanate under pressure of different force values ​​are shown.

[0037] Fig.15 The results of cell proliferation and migration measurements on the surface of toughened barium titanate under pressure of different force values ​​are shown.

[0038] Fig.16The experimental results of the antibacterial effect of toughened barium titanate are shown. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that the upper and lower limits of the scope and each intermediate value therebetween are specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0041] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0042] Preparation method

[0043] One aspect of the present invention provides a method for preparing an antibacterial piezoelectric base material that promotes soft tissue healing, which includes the step of selecting a sintering temperature for the piezoelectric material based on the electrical properties (including the generated voltage, piezoelectric constant, etc.) and mechanical properties (including fracture toughness, elastic modulus, flexural strength, etc.) of the piezoelectric base material, thereby improving the mechanical strength of the piezoelectric base material while better balancing strength, toughness and electrical properties.

[0044] In a preferred embodiment, the preparation method of the present invention comprises:

[0045] (1) compacting the inorganic piezoelectric material and then sintering it to obtain a porous green body, wherein the compacting process includes dry-pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa for 1-120 s to obtain a dense green body;

[0046] (2) placing the sintered porous substrate in a solution containing an organic polymer material, and obtaining the piezoelectric base material after solidification.

[0047] In a preferred embodiment, the preparation method of the present invention comprises:

[0048] (1') compacting the inorganic piezoelectric material and then sintering it to obtain a porous green body, wherein the compacting process includes dry-pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa for 1-120 s to form a preliminary shape, and then compacting it with a pressure medium at 50-500 MPa for 1-120 s to obtain a dense green body;

[0049] (2') treating the sintered porous green body (also referred to as a porous piezoelectric material or a porous substrate) with a reagent, wherein the reagent is a compound having the following structure, and the organic polymer material and the inorganic piezoelectric material are coupled by the reaction of the compound:

[0050] X(CH 2 ) n S Y 3 Formula I,

[0051] wherein n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy;

[0052] (3') treating the treated piezoelectric material in a solution containing an organic polymer material to obtain the piezoelectric base material.

[0053] Those skilled in the art should understand that the purpose of the present invention can be achieved without the use of reagents for treatment, that is, without the presence of a unit promoting bonding in the three-dimensional structure. This can be achieved by directly mixing the sintered material with a solution containing an organic polymer material and obtaining a piezoelectric base material after curing.

[0054] In the present invention, the piezoelectric material first forms a porous matrix in the base material, and then the organic polymer material is fully filled in the pores. The present invention has found through extensive research that in such a three-dimensional network structure, the mass ratio of the organic polymer material to the piezoelectric material affects the mechanical properties of the piezoelectric base material, and further affects its electrical properties. The mass ratio of the organic polymer material to the piezoelectric material is too high. Although it can meet the toughness requirements, the elastic modulus and flexural strength are greatly reduced, and its electrical properties are greatly reduced. On the other hand, the mass ratio of the organic polymer material to the piezoelectric material is too low. Although it can improve the elastic modulus of the material, it will cause the toughness and flexural strength of the material to decrease, and thus it cannot be applied to oral clinical restoration applications.

[0055] In the present invention, the mass ratio of the organic polymer material to the piezoelectric material ranges from 1:10 to 1:200, preferably 1:10 to 1:150, further preferably 1:10 to 1:145, further preferably 1:10 to 1:100, further preferably 1:10 to 1:50, for example 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50.

[0056] In the present invention, the inorganic piezoelectric material examples include, but are not limited to, barium titanate, strontium titanate, barium strontium titanate, lithium niobate, potassium niobate, potassium sodium niobate, bismuth ferrite, bismuth titanate, calcium bismuth niobate, bismuth iron titanate, sodium bismuth titanate, sodium bismuth titanate, barium bismuth titanate, zirconium oxide, lanthanum oxide, cerium oxide, titanium dioxide, tantalum pentoxide, niobium pentoxide, calcium zirconate, barium calcium zirconate titanate, or at least one of the above-mentioned ternary or multi-element piezoelectric materials. Those skilled in the art should understand that only some of the inorganic piezoelectric materials are listed above, and any inorganic piezoelectric material that can be used as a filling matrix for organic polymer materials can be used in the present invention.

[0057] The form of the inorganic piezoelectric material of the present invention is not particularly limited, and can be powder, particles, or fibers. In the case of particles, the particle size is not particularly limited, and can be 10 nm-200 μm, for example, 100 nm-150 μm, 500 nm-150 μm, 1 μm-150 μm, 50 μm-150 μm. When the selected matrix material raw material is a porous barium titanate matrix and an organic polymer material is used as a filling material to prepare a piezoelectric base material having a connected three-dimensional network structure, the sintering temperature is determined to be greater than 1000°C and less than 1300°C.

[0058] Step (1') of the present invention is a compaction and sintering step, in which the piezoelectric material is first compacted, preferably including a first compaction and a second compaction step, wherein the first compaction includes dry-pressing the powder or particles of the piezoelectric material at 1-50 MPa, preferably 5-50 MPa, and preferably 10-50 MPa (for example, 10, 20, 30, 40, 50 MPa) and maintaining it for 1-120 s, preferably 5-100 s, and preferably 5-50 s, and further preferably 10-50 s (for example, 10, 15, 20, 25, 30, 35, 40, 45, 50 s) to initially shape the green body. The second compaction includes using 50-500 MPa, preferably 60-250 MPa, preferably 80-200 MPa, and further preferably 100-200 MPa (e.g., 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 MPa) after the first compaction. The pressure medium is compacted and maintained for 1-120 s, preferably 5-100 s, preferably 5-50 s, and further preferably 10-50 s (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50 s) to make the green compact dense and uniform. The pressure medium is not particularly limited and can be a liquid medium such as water. The compaction treatment temperature during the first compaction and the second compaction is not limited, preferably room temperature, and cold isostatic pressing is particularly preferred.

[0059] After compaction molding, further sintering treatment is performed. The inventors found that the sintering temperature affects the mechanical properties of the piezoelectric base material and further affects its electrical properties. If the sintering temperature is too low (for example, not higher than 1000°C), although it can meet the toughness requirements, the elastic modulus and flexural strength are greatly reduced, and its electrical properties are greatly reduced. The reduced mechanical and electrical properties make it impossible to apply it to oral clinical restoration applications. On the other hand, if the sintering temperature is too high (for example, not less than 1300°C), although it can increase the elastic modulus of the material, it will cause the toughness and flexural strength of the material to decrease, and thus it is also impossible to apply it to oral clinical restoration applications. In a preferred embodiment, the sintering temperature is in the range of 1000-1290°C, preferably 1050-1290°C, further preferably 1100-1280°C, further preferably 1150-1250°C, for example 1150, 1160, 1170, 1180, 1190, 1200, 1210, 1220, 1230, 1240, 1250°C.

[0060] The heating method in step (1') is not particularly limited, and gradient heating can be used for sintering, for example, gradient heating within the range of 50-200°C, 80-180°C, 80-150°C or 80-120°C to a suitable temperature and then sintering to obtain a porous matrix.

[0061] Step (2') of the present invention is a step of treating the sintered porous matrix with a reagent. In the three-dimensional network structure of the piezoelectric base material of the present invention, it further includes a promoting binding unit connecting the organic polymer material and the piezoelectric material, and the promoting binding unit is coupled with the organic polymer material and the inorganic piezoelectric material respectively. In a preferred embodiment, the promoting binding unit is coupled with the organic polymer material and the inorganic piezoelectric material by reacting with a compound having the following structure:

[0062] X(CH 2 ) n S Y 3 Formula I,

[0063] Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

[0064] In a specific embodiment, the compound used in the present invention is 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0065] Step (2') of the present invention comprises reacting the compound with water or a mixed solvent of water and alcohol under acidic conditions to obtain a coupling solution, and then keeping the substrate and the coupling solution under vacuum for a period of time, preferably 1-24 h, such as 1-12 h, 2-10 h, 2-8 h, 4-8 h, and vacuum drying at 40-90° C. (preferably 50-80° C., such as 50-70° C.) after the reaction.

[0066] When a mixed solvent of water and alcohol is used, the volume ratio of water, ethanol and the compound is 1-50:1-50:1, preferably 5-45:5-45:1, further preferably 5-30:5-30:1, further preferably 10-25:10-25:1, and more preferably 10-20:10-20:1.

[0067] In the present invention, the piezoelectric substrate material has a porosity of 0.1-50% before being filled with the organic polymer material, preferably 1-50%, further preferably 5-40%, further preferably 10-30%, and even more preferably 10-20%.

[0068] Step (3') of the present invention is an organic polymer material filling and heat curing step. In order to fully infiltrate the substrate, the substrate after coupling treatment is vacuum-assisted mixed and heat cured with the organic polymer material. The heat curing temperature and time are not particularly limited and can be adjusted according to the adaptability of the selected organic polymer material. In a preferred embodiment, the curing is carried out at 80-200°C, preferably 80-180°C, preferably 80-160°C, and more preferably 80-150°C for 0.1-24 h, preferably 1-12 h, and more preferably 5-12 h.

[0069] Not subject to any theoretical constraints, any organic polymer material that can be cured (such as but not limited to photocuring, thermal curing, etc.) in a porous inorganic piezoelectric material matrix can be used for the reinforced toughening composite material of the present invention, and its examples include but are not limited to acrylate polymers (copolymers), polyurethane polymers, organic polymer compounds containing two or more epoxy groups, and phenolic polymers. In the present invention, the organic polymer material includes acrylate polymers, and examples of acrylate polymers include but are not limited to methyl methacrylate, ethyl methyl acrylate, ethyl ethyl acrylate, and butyl acrylate, etc. A mixture of one acrylate polymer or two or more acrylate polymers can be used. When a mixture of two or more acrylate polymers is used, the ratio between the two or more acrylate polymers is not particularly limited and can be adjusted as needed. The molecular weight and viscosity of the acrylate polymer are not particularly limited, and those skilled in the art can select an acrylate polymer of suitable molecular weight and viscosity as needed.

[0070] In a preferred embodiment, the acrylic polymer used in the present invention is a methacrylic polymer, which includes but is not limited to methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate, and benzyl methacrylate. In a specific embodiment, the acrylic polymer used in the present invention is a mixture of bisphenol A glycerol dimethacrylate and triethylene glycol dimethacrylate.

[0071] The preparation method of the present invention comprises the step of performing optional corona poling treatment on the piezoelectric substrate material, wherein the parameters of the corona poling treatment include: the polarization field intensity is 0.1-5 kV / mm, for example, 0.1-4 kV / mm, 0.1-3 kV / mm, 0.1-2 kV / mm, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2 kV / mm, etc.

[0072] Piezoelectric Substrate Materials

[0073] One aspect of the present invention provides a piezoelectric base material that is antibacterial and promotes soft tissue healing, wherein the piezoelectric base material has significantly enhanced strength and toughness. The piezoelectric base material of the present invention comprises a piezoelectric material as a matrix and an organic polymer material filled in the matrix, and the organic polymer material and the piezoelectric material are each connected to form a three-dimensional network (mesh) structure, which gives the material high strength and toughness, can effectively disperse stress, reduce fatigue damage of the material during long-term use, extend the service life, and provide better processing performance.

[0074] The piezoelectric substrate material of the present invention has a broad-spectrum antibacterial property, and can be used to inhibit or kill various bacteria, including Gram-positive bacteria represented by Streptococcus mutans or Gram-negative bacteria represented by Escherichia coli.

[0075] application

[0076] One aspect of the present invention provides the use of piezoelectric base materials in the preparation of biomedical materials (including but not limited to oral prostheses, etc.) having both antibacterial properties and mechanical service properties. Oral prostheses include but are not limited to implant bases, inlays, crowns, artificial teeth, bases, etc.

[0077] Example 1

[0078] 1. Preparation method

[0079] The barium titanate particles with a particle size of 30-100 μm are compacted, compacted and formed, and then sintered at a temperature interval of 100°C in the temperature range of 1000-1300°C to obtain a porous matrix. The compaction process includes a first compaction step and a second compaction step. The first compaction step includes: subjecting the barium titanate powder to dry pressing at 30 MPa and holding for 25 seconds to initially form a green body. The second compaction step includes using 180 MPa cold isostatic pressing after the first compaction and holding for 35 seconds to make the green body dense and uniform.

[0080] The substrate is subjected to coupling treatment, and the specific treatment steps include: mixing 45% volume of water, 45% volume of ethanol and 3% volume of silane coupling agent KH570, and adding acetic acid to adjust the pH to 3-4 to prepare a silane coupling solution, and then half immersing the barium titanate substrate in the solution, allowing the solution to fully infiltrate the substrate under vacuum assistance, and then completely immersing the substrate in the solution for 6 hours, and then taking it out and vacuum drying it at 60°C.

[0081] The matrix after coupling treatment is filled with organic polymer material and thermally cured to achieve the reinforcement and toughening of the piezoelectric material to obtain the piezoelectric base material. The organic polymer material is a mixture of bisphenol A propylene glycol dimethacrylate and triethylene glycol dimethacrylate (Bis-GMA / TEGDMA), and the mass ratio of the organic polymer material to the piezoelectric material ranges from 1:10 to 1:200.

[0082] Control group 1 (marked as porous barium titanate in the figure): The material of control group 1 uses barium titanate particles with a particle size of 30-100 μm, and after cold isostatic pressing, it is sintered at a temperature interval of 100°C in the temperature range of 1000-1300°C to obtain a porous matrix. The cold isostatic pressing treatment steps include: the barium titanate powder is subjected to 30 MPa dry pressing and maintained for 25 seconds to form a green body, and then 180 MPa cold isostatic pressing is used and maintained for 35 seconds to make the green body dense and uniform.

[0083] Control group 2 (marked as dense barium titanate in the figure): The material of control group 2 uses barium titanate particles with a particle size of 30-100 μm, which are cold isostatically pressed and sintered at 1400°C to obtain a dense barium titanate matrix. The cold isostatic pressing treatment steps include: the barium titanate powder is subjected to 30 MPa dry pressing and maintained for 25 seconds to form a green body, and then 180 MPa cold isostatic pressing is used and maintained for 35 seconds to make the green body dense and uniform.

[0084] For the piezoelectric substrate material before and after toughening, the flexural strength and elastic modulus of the material were tested by three-point bending test, and the fracture toughness of the material was tested by single-sided V-groove beam method. In addition, X-ray diffraction was also performed on the barium titanate substrate sintered at different temperatures.

[0085] 2. Results

[0086] Figure 1 The mass ratio of the polymer to barium titanate in the piezoelectric base material is shown. The mass ratio of the polymer to barium titanate can vary in the range of 1:10 to 1:200, wherein when the sintering temperature is 1200°C, the mass ratio of the polymer to barium titanate is between 1:35 and 1:36.

[0087] Figure 2 The flexural strength of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials is shown. The results show that the flexural strength of the barium titanate matrix is ​​significantly enhanced after toughening and strengthening with organic polymer materials. Among them, the barium titanate matrix sintered at 1200°C has the highest flexural strength after filling with organic polymer materials.

[0088] Figure 3The elastic modulus of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials is shown. The results show that the barium titanate matrix sintered at 1200°C has an elastic modulus (16-20.3 GPa) closest to natural dentin after filling with organic polymer materials, which is beneficial to the downward transmission of occlusal force.

[0089] Figure 4 The fracture toughness data of the barium titanate matrix sintered at different temperatures before and after toughening with organic polymer materials are shown. The results show that the fracture toughness of the barium titanate matrix sintered at 1200℃ is higher after toughening. In summary, the barium titanate matrix sintered at 1200℃ has the best mechanical properties after toughening with organic polymer materials.

[0090] Figure 5 The XRD patterns of the barium titanate matrix sintered at different temperatures are shown. It can be seen that at the sintering temperature of the preparation method of the present invention, the crystal phase of the barium titanate matrix does not change, and the particles before sintering are all tetragonal.

[0091] Figure 6 The flexural strength comparison of the barium titanate matrix sintered at 1200°C before and after toughening and the densely sintered barium titanate matrix is ​​shown. The flexural strength of the barium titanate material toughened with organic polymer materials is significantly higher than that of the simple dense barium titanate matrix.

[0092] Figure 7 The elastic modulus of the barium titanate matrix sintered at 1200°C before and after toughening is compared with the densely sintered barium titanate matrix. The elastic modulus of the barium titanate material toughened with organic polymer materials is closer to natural dentin.

[0093] Figure 8 The fracture toughness comparison of the barium titanate matrix sintered at 1200°C before and after toughening and the densely sintered barium titanate matrix is ​​shown. The fracture toughness of the barium titanate material toughened by organic polymer materials is equivalent to that of the dense barium titanate matrix.

[0094] Fig. 9 The cracks of barium titanate materials toughened by organic polymer materials were observed under nanoindentation, and crack bridging phenomenon of organic polymer materials can be seen at the cracks, which further clarifies the toughening mechanism of organic polymer materials enhancing the mechanical strength of barium titanate through crack bridging.

[0095] Fig.10 It shows that after the barium titanate matrix is ​​toughened and strengthened by organic polymer materials, it can still effectively generate piezoelectric signals under pressure. The present invention further constructs a three-dimensional structural image of the porous barium titanate matrix sintered at 1200°C through high-precision CT scanning, as shown in the figure. Fig.11 As shown, it can be seen that the pores are basically evenly distributed.

[0096] In summary, the mechanical strength of piezoelectric materials can be enhanced by adding organic polymer materials without significantly affecting the piezoelectric properties of the material itself.

[0097] Example 2

[0098] The piezoelectric substrate material prepared in Example 1 was subjected to polarization treatment, and the polarization conditions were as follows: polarization time was 15-90 minutes, polarization field strength was 1 kV / mm, polarization medium was air, and polarization temperature was 25°C.

[0099] The results are as follows Fig.12 As shown in Figure A, the piezoelectric constant d of the piezoelectric substrate material after being polarized for different times 33 Figure B shows the surface potential data of the piezoelectric base material measured after polarization for different times. The above results show that the residual polarization performance of the material can be regulated by controlling the polarization time. Figure C shows the piezoelectric signal image of the piezoelectric base material after polarization for different times under a pressure of 200N. Figure D shows the piezoelectric strength data of the piezoelectric base material under a pressure of 200N with different polarization times. The results show that the piezoelectric strength is positively correlated with the polarization time. Figure E shows the piezoelectric signal graph of the piezoelectric base material under different pressures after 90 minutes of polarization. Figure F shows the piezoelectric strength data of the piezoelectric base material under different pressures after 90 minutes of polarization. The results show that the piezoelectric strength is positively correlated with the applied pressure value. In summary, the piezoelectric base material can achieve the desired piezoelectric strength under different pressure conditions by regulating the polarization time. The frequency of pressure applied to the material in this embodiment is 1.5 times / second, which is the normal physiological chewing frequency of a person.

[0100] This example further polarizes the barium titanate substrate sintered at different temperatures for 90 minutes after being filled with organic polymer materials, and tests the piezoelectric voltage strength data under a pressure of 200 N. The results are as follows: Fig.13 As shown in Figure 2, the barium titanate matrix sintered at 1200°C can significantly improve the piezoelectric voltage strength after toughening compared with other temperatures (such as Fig.13 (as shown in Figure A).

[0101] This example further polarizes the piezoelectric substrate materials with different raw material ratios for 90 minutes and tests the piezoelectric voltage strength data under a pressure of 200 N. The results are shown in FIG. Fig.13 As shown in B, different raw material ratios affect the piezoelectric properties of the piezoelectric substrate material. When the sintering temperature is 1200°C, the mass ratio of the organic polymer material to the piezoelectric material is 1:35 to 1:36, and the piezoelectric substrate material has a significantly improved piezoelectric voltage strength.

[0102] Example 3

[0103] 1. Effect of piezoelectric abutment materials on gingival fibroblasts

[0104] Gingival fibroblasts were inoculated on the surface of the piezoelectric base material after 90 minutes of polarization. The piezoelectric base material was subjected to pressure of different force values, and the pressure was applied 1200 times at a frequency of 1.5 times / second (half of the number of times a person chews daily). After 6 hours, the cell adhesion protein was immunofluorescently stained to measure the cell spreading area and adhesion area under pressure of different force values. The control group material was commercially available grade 4 pure titanium, and the size of the control group was consistent with the piezoelectric base material.

[0105] The results are as follows Fig.14 As shown in Figure 1, it can be seen that the cell spreading area and focal adhesion area are the largest at about 100 N pressure (about 4.5 V) (Figure AB), and Figure C shows the ratio of focal adhesion area to cell spreading area. It can be seen that the ratio reaches the maximum at 100 N pressure. Figure D shows the quantitative spreading area of ​​gingival fibroblasts, which can be seen to be the largest at 100 N pressure.

[0106] 2. CCK-8 experiment on the effect of piezoelectric substrate materials on cell proliferation

[0107] Gingival fibroblasts were inoculated on the surface of the piezoelectric base material after 90 minutes of polarization. The piezoelectric base material was subjected to pressure of different force values, 2400 times per day at a frequency of 1.5 times / second, and CCK-8 tests were performed at 1 day and 3 days. The control group material was commercially available grade 4 pure titanium, and the size of the control group was consistent with the piezoelectric base material.

[0108] The results are as follows Fig.15 As shown in Figure A, after 3 days, cell proliferation was significantly enhanced under 100 N pressure (about 4.5 V).

[0109] 3. Cell scratch test of piezoelectric substrate materials

[0110] Using the cell scratch healing plug-in, gingival fibroblasts were inoculated on the surface of the piezoelectric base material after 90 minutes of polarization. The piezoelectric base material was subjected to pressure of different force values, and the pressure was applied 2400 times at a frequency of 1.5 times / second every day. After 1 day, the cell nucleus was stained to observe the healing of the scratch. The control group material was commercially available grade 4 pure titanium, and the size of the control group was consistent with the piezoelectric base material.

[0111] The results are as follows Fig.15 As shown in Figure B, it can be seen that the migration activity of cells is significantly enhanced under 100 N pressure (about 4.5 V).

[0112] 4. Antibacterial experiment of piezoelectric base materials

[0113] The common oral pathogen Streptococcus mutans was inoculated on the surface of the piezoelectric abutment material after 90 minutes of polarization. The piezoelectric abutment material was subjected to pressure of different force values ​​at a frequency of 1.5 times / second per day. For the implant abutment, the marginal soft tissue sealing effect is more important than the antibacterial effect. In order not to affect the soft tissue integration effect of the material, the maximum force value was selected to be 100 N. The control group material was commercially available grade 4 pure titanium, and the size of the control group was consistent with the piezoelectric abutment material.

[0114] The results of the antibacterial effect experiment are as follows Fig.16 As shown in Figure A, the number of bacterial colonies decreased significantly under the pressure of 50 N. The quantitative statistical results of the number of bacteria are shown in Fig.16 As shown in Figure B.

[0115] Streptococcus mutans was inoculated on the surface of the piezoelectric base material after 90 minutes of polarization. After 12 hours of incubation, different forces were applied to the piezoelectric base material at a frequency of 1.5 times / second per day. The culture was continued for 12 hours, and crystal violet staining was used to quantify the formation of bacterial biofilm. The results were consistent with the antibacterial plate experiment. The bacterial biofilm was least formed under the pressure of 50 N (such as Fig.16 (as shown in Figure C).

[0116] After inoculating the common oral pathogen Streptococcus mutans on the surface of the piezoelectric base material after 90 minutes of polarization, the piezoelectric base material was subjected to pressure with different force values, and the pressure was applied at a frequency of 1.5 times / second every day. Live and dead bacteria were stained and images were taken for 24 hours. The results matched the previous antibacterial experimental results (such as Fig.16 (as shown in Figure D).

[0117] In summary, the piezoelectric signal of the piezoelectric base material has an obvious effect of promoting soft tissue attachment, and at the same time can ensure a certain antibacterial effect, which can prevent the occurrence of secondary caries, peri-implant disease, etc.

[0118] The piezoelectric base material provided by the present invention has strong operability in clinical applications. During the application of the piezoelectric base material, it exhibits excellent piezoelectric responsiveness and electrical stability, and realizes synergistic enhancement of mechanical reinforcement and toughening. While considering the electrical properties, the mechanical properties of the material are also considered, and the technical synergy of promoting cell adhesion, antibacterial and mechanical toughening is further realized, ensuring the feasibility of clinical use, and contributing to the development of biomedical materials, such as the clinical prevention of secondary caries, peri-implant disease, etc. and the long-term stability of implants.

[0119] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. Various adjustments or changes may be made to the exemplary embodiments of the present specification without departing from the scope or spirit of the present invention. The scope of the claims should be based on the broadest interpretation to cover all modifications and equivalent structures and functions.

Claims

1. A method for preparing a piezoelectric base material that is antibacterial and promotes soft tissue healing, characterized in that: include: (1) compacting the inorganic piezoelectric material and then further sintering it to obtain a porous green body, selecting a sintering temperature for the inorganic piezoelectric material according to the electrical and mechanical properties of the piezoelectric substrate, wherein the sintering temperature is greater than 1000° C. and less than 1300° C., and the inorganic piezoelectric material includes at least one of barium titanate, barium strontium titanate, lithium niobate, potassium niobate, sodium potassium niobate, calcium bismuth niobate, bismuth iron titanate, bismuth ferrite, bismuth titanate, sodium bismuth titanate, sodium barium bismuth titanate, and barium calcium zirconate titanate; (2) placing the sintered porous substrate in a solution containing an organic polymer material, and obtaining a piezoelectric base material in which the organic polymer material and the inorganic piezoelectric material are connected to form a three-dimensional network structure after curing, wherein the mass ratio of the organic polymer material to the inorganic piezoelectric material is in the range of 1:10 to 1:150, and the organic polymer material includes an acrylic polymer.

2. The method for preparing the antibacterial and soft tissue healing-promoting piezoelectric abutment material according to claim 1, characterized in that: The compaction treatment includes dry-pressing the powder or particles of the inorganic piezoelectric material at 1-50 MPa and maintaining it for 1-120 s for preliminary molding, and then compacting it using a pressure medium at 50-500 MPa and maintaining it for 1-120 s to obtain a dense green body.

3. The method for preparing the antibacterial and soft tissue healing-promoting piezoelectric base material according to claim 1, characterized in that: The method further comprises treating the sintered porous substrate with a compound having the following structure: X(CH2) n of the formula I, SiY3 Wherein, n=0-3, X is selected from at least one of vinyl, amino, epoxy, methacryloxy, mercapto and urea, and Y is selected from at least one of chloro, methoxy, ethoxy, methoxyethoxy and acetoxy.

4. The method for preparing the antibacterial and soft tissue healing-promoting piezoelectric base material according to claim 1, characterized in that: By controlling the sintering temperature during the preparation process and the amount of the organic polymer material and the inorganic piezoelectric material, antibacterial and soft tissue healing can be achieved.

5. The method for preparing the antibacterial and soft tissue healing-promoting piezoelectric abutment material according to claim 1, characterized in that The organic polymer material includes at least one of methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, butyl methacrylate and benzyl methacrylate.

6. The method for preparing the antibacterial and soft tissue healing-promoting piezoelectric abutment material according to claim 1, characterized in that: The method further comprises the step of polarizing the piezoelectric substrate material, wherein the polarization field strength is 0.1-5 kV / mm, the polarization temperature is 10-40° C., and the processing time is 1-120 min.

7. A piezoelectric base material that is antibacterial and promotes soft tissue healing, characterized in that: Obtained according to the preparation method according to any one of claims 1 to 6.

8. Use of the piezoelectric substrate material according to claim 7 in the preparation of biomedical materials.

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