阅读说明：本技术 一种高生物活性高力学强度的改性氧化锆陶瓷及其制备方法 (Modified zirconia ceramic with high bioactivity and high mechanical strength and preparation method thereof ) 是由 叶建东 张文民 秦艳萍 于 2021-07-31 设计创作，主要内容包括：本发明公开了一种高生物活性高力学强度的改性氧化锆陶瓷及其制备方法。该方法包括：制备钙镁硅或钙硅磷生物活性粉体；制备氧化锆悬浮液；制备具有多孔表面层的氧化锆陶瓷；通过负压渗透工艺,将具有多孔表面层的氧化锆陶瓷置于悬浮液中,使钙镁硅或钙硅磷生物活性粉体悬浮液渗透入多孔表面层中,经干燥后进行热处理,得到该陶瓷。本发明通过将钙镁硅或钙硅磷生物活性粉体附载在氧化锆孔道的多孔表面层中,赋予氧化锆陶瓷高生物活性,多孔表面层与氧化锆陶瓷基体结合并同步烧成,解决了表面活性层与氧化锆基体材料界面结合强度差的难题；而生物活性物质只是渗透进多孔表面层的孔道中,烧结后内部基体依然保持高致密,材料的力学性能不受到明显影响。(The invention discloses a modified zirconia ceramic with high bioactivity and high mechanical strength and a preparation method thereof. The method comprises the following steps: preparing calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder; preparing a zirconium oxide suspension; preparing a zirconia ceramic having a porous surface layer; putting the zirconia ceramic with the porous surface layer into the suspension by a negative pressure infiltration process, so that the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder suspension is infiltrated into the porous surface layer, and carrying out heat treatment after drying to obtain the ceramic. The invention endows the zirconia ceramics with high bioactivity by attaching the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder in the porous surface layer of the zirconia pore canal, and the porous surface layer is combined with the zirconia ceramics matrix and synchronously sintered, thereby solving the problem of poor interface bonding strength of the surface active layer and the zirconia matrix material; the bioactive substances only permeate into the pore channels of the porous surface layer, the internal matrix still keeps high compactness after sintering, and the mechanical property of the material is not obviously influenced.)

1. A preparation method of modified zirconia ceramics with high bioactivity and high mechanical strength is characterized by comprising the following steps:

(1) adding a silicon-containing compound, a calcium salt, a magnesium salt or a phosphorus salt into water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 6.0-8.0, and performing hydrolytic polycondensation reaction to obtain calcium-magnesium silica sol or calcium-silicon-phosphorus sol; standing and aging the calcium-magnesium-silicon sol or the calcium-silicon-phosphorus sol, drying, calcining and ball-milling to obtain calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder;

(2) pressing and molding zirconia powder, heating to perform presintering treatment to obtain a zirconia ceramic presintering body;

(3) adding a pore-forming agent, a stabilizing agent, a dispersing agent and zirconia powder into a solvent, and uniformly mixing to obtain a suspension 1; dipping or spraying the suspension 1 on the surface of the zirconia ceramic pre-sintered body in the step (2), drying to form a pore-forming surface layer, and heating for sintering treatment to obtain the zirconia ceramic with a porous surface layer;

(4) adding a stabilizer, a dispersant and the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder obtained in the step (1) into a solvent, and uniformly mixing to obtain a suspension 2; soaking the zirconia ceramic with the porous surface layer in the step (3) in the suspension 2 in a container, performing negative pressure infiltration treatment, taking out, and drying to obtain the zirconia ceramic with the compounded surface layer; and heating the compounded zirconia ceramic for heat treatment to obtain the modified zirconia ceramic with the surface compounded with the bioactive substances.

2. The method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the silicon-containing compound in the step (1) is at least one of tetraethoxysilane, silicon acetate and methyl silicate; the calcium salt in the step (1) is at least one of calcium nitrate, calcium chloride, calcium acetate and calcium citrate; the magnesium salt in the step (1) is at least one of magnesium nitrate, magnesium chloride, magnesium acetate and magnesium citrate; the phosphorus salt in the step (1) is at least one of sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, potassium hydrogen phosphate, potassium dihydrogen phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate.

3. The method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the mixed solution in the step (1) comprises the following components in parts by weight:

4. the method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength as claimed in claim 1, wherein the time of the hydrolytic polycondensation reaction in the step (1) is 6-48 h; the standing and aging time of the step (1) is 6-48 h; the drying temperature in the step (1) is 60-180 ℃, and the drying time is 12-72 h; the calcining temperature in the step (1) is 700-1400 ℃, and the calcining time is 6-48 h; the rotation speed of the ball milling is 400-2500 rpm, and the ball milling time is 12-48 h.

5. The method for preparing the modified zirconia ceramic with high bioactivity and mechanical strength as claimed in claim 1, wherein the pressure of the step (2) is 100-220MPa, and the time of the compression molding is 2-30 min; the temperature of the pre-sintering treatment is 500-1000 ℃, and the time of the pre-sintering treatment is 0.5-3 h; the rate of temperature rise is 2-10 ℃/min.

6. The method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the pore-forming agent in the step (3) is at least one of polyethylacrylate microspheres, polylactic acid-glycolic acid copolymer microspheres, polyacrylic acid microspheres and polystyrene microspheres, polymethyl methacrylate microspheres and graphite microspheres, and the particle size of the pore-forming agent is 1-20 μm; the stabilizer in the step (3) is at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl butyral and glycerol; the dispersant in the step (3) is at least one of polyethylene glycol, polyacrylic acid and polymethacrylate ammonia; the solvent in the step (3) is at least one of water and absolute ethyl alcohol;

the suspension 1 in the step (3) comprises the following components in parts by weight:

7. the method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the drying temperature in the step (3) is 60-100 ℃, and the drying time is 6-12 h; the thickness of the pore-forming surface layer in the step (3) is 10-80 μm; the temperature of the sintering treatment in the step (3) is 1350-.

8. The method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the median diameter of the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder in the step (4) is 0.1-30 μm; the stabilizer in the step (4) is at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl butyral and glycerol; the dispersant in the step (4) is at least one of polyethylene glycol, polyacrylic acid and polymethacrylate ammonia; the solvent in the step (4) is at least one of water and absolute ethyl alcohol; the suspension 2 in the step (4) comprises the following components in parts by weight:

9. the method for preparing the modified zirconia ceramic with high bioactivity and high mechanical strength according to claim 1, wherein the infiltration pressure of the negative pressure infiltration treatment in the step (4) is 0 to-0.2 MPa, and the time of the negative pressure infiltration treatment is 10s to 80 min; the drying temperature is 60-100 ℃, and the drying time is 6-12 h; the temperature of the heat treatment in the step (4) is 600-1300 ℃, the time of the heat treatment is 0.5-4h, and the heating rate is 2-10 ℃/min.

10. A method for preparing a modified zirconia ceramic with high bioactivity and high mechanical strength, which is prepared by the preparation method of any one of claims 1 to 9.

Technical Field

The invention relates to the field of dental restoration medical materials, in particular to a modified zirconia ceramic with high bioactivity and high mechanical strength and a preparation method thereof.

Background

The pure titanium or titanium alloy dental implant has wide application in clinical treatment of dentition deletion and defect caused by decayed tooth, periodontitis, dental trauma and the like. However, the blackening of titanium metal, which is a problem in that the gingiva is thin or recedes in the aesthetic region of the anterior teeth, has a high aesthetic risk and an inflammatory reaction due to the release of titanium ions, also affects the later stability of the implant. The zirconia ceramic has good biocompatibility, chemical stability, excellent mechanical property and unique aesthetic effect, and becomes a dental prosthetic material with good clinical application prospect. Zirconium oxide has no bioactivity as a biological inert material, and after being implanted into a body, the surrounding fibrous tissue (biomembrane) can prevent the integration of the implant and the surrounding bone tissue, thereby causing implantation failure, so that the development of the zirconium oxide dental repair material with high bioactivity and high mechanical strength has great significance.

In recent years, modified zirconia is mainly subjected to surface modification by a coating method and a sand blasting combined acid etching method, but the coating method generally has the problem of mismatch of thermal expansion coefficients, so that residual stress exists, the bonding degree of a substrate and a coating interface is weak, the coating can be dissolved and fall off in an oral environment for a long time, and the coating is not suitable for clinical application. The sand blasting and acid etching method influences the growth, proliferation and adhesion of cells and the expression of related genes by changing the surface topological structure of the material. However, in the sand blasting, hard particles such as alumina are used for impacting the surface of the material to generate depressions, so that the structure of the material is damaged in the process, mechanical stress is generated and exists in the structure of the material, and the mechanical property and the long-term stability of the performance of the material are influenced. The acid etching will destroy Zr-O bond of zirconia, greatly reducing the mechanical strength of zirconia ceramics. CN112028626A discloses a method for preparing zirconia bioactive ceramics, which shows poor bonding degree due to residual stress caused by mismatch of thermal expansion coefficients of the coating and the substrate, and may cause coating peeling in long-term application. CN106904962B discloses a method for preparing bioactive zirconia dental ceramic material, in which the presence of active substance in the zirconia grain boundary affects the mechanical properties of zirconia, and the addition amount of active substance is limited. CN109867520A discloses a zirconium oxide-based strontium, silicon and fluorine micro-doped hydroxyapatite zirconium oxide toughened composite coating, a preparation method and application thereof, and the problems that the thermal expansion coefficients of the coating and a substrate are mismatched, the bonding degree is not enough, and the coating is easy to fall off exist. CN110917394A discloses the application of ion modified zirconia surface in the preparation of zirconia abutment or implant, and also has the problem that the binding degree is not enough, which causes the coating to easily fall off. The silver ion modified zirconia has improved antibacterial performance, but has no effect of promoting cell proliferation and differentiation.

The calcium-magnesium-silicon or calcium-silicon-phosphorus compound has a stimulating effect on the gene expression of osteoblasts, can obviously promote bone regeneration in clinical application, has a stimulating effect on the gene expression of osteoblasts, and can obviously promote bone regeneration in clinical application. The calcium-magnesium-silicon or calcium-silicon-phosphorus compound has good biological activity, biocompatibility, biodegradability and mechanical property, releases active ions such as calcium, magnesium, silicon, phosphorus and the like, can induce the formation of a apatite layer, and is beneficial to the combination of materials and bone tissues. Research shows that wollastonite deposited on the porous alumina ceramic can obviously improve the biological activity of the porous alumina ceramic and mineralize the apatite; diopside scaffolds induce apatite production, supporting human osteoblast adhesion, growth and alkaline phosphatase (ALP) content. Therefore, the research of the zirconia dental ceramic which has high bioactivity and high strength and has high bonding strength between the surface modification layer and the matrix has important significance.

Disclosure of Invention

In order to overcome the defects that the conventional biological modified zirconia dental ceramic in the prior art cannot simultaneously have excellent biological activity and high mechanical strength, the invention aims to provide a modified zirconia ceramic with a surface compounded with a biological active substance and a preparation method thereof. The zirconia ceramic material has good biological activity, high mechanical property and simple preparation process.

The purpose of the invention is realized by at least one of the following technical solutions.

According to the preparation method provided by the invention, the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive substances are loaded in the porous surface layer of the zirconia pore channel, so that the zirconia ceramic is endowed with high bioactivity, and the porous surface layer is combined with the zirconia ceramic matrix and synchronously sintered, so that the problem of poor interface bonding strength of the surface active layer and the zirconia matrix material is solved; the bioactive substances only permeate into the porous surface layer, the internal matrix still keeps high compactness after heat treatment, the mechanical property of the material is not obviously influenced, and the problem that the conventional biological modified zirconia dental ceramic cannot have good bioactivity and high mechanical strength at the same time can be solved.

The preparation method of the modified zirconia ceramic with the surface compounded with the bioactive substances, provided by the invention, comprises the following steps:

(1) preparing calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder: adding a hydrolyzable silicon-containing compound, a water-soluble calcium salt, a water-soluble magnesium salt or a water-soluble phosphorus salt into deionized water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 6.0-8.0, and carrying out hydrolytic polycondensation reaction to obtain calcium-magnesium silica sol or calcium-silicon-phosphorus sol; standing and aging the calcium-magnesium-silicon sol or the calcium-silicon-phosphorus sol, drying, calcining and ball-milling to obtain calcium-magnesium-silicon bioactive powder or calcium-silicon-phosphorus bioactive powder;

(2) pressing and molding zirconia powder to prepare a zirconia ceramic green body, and heating for pre-sintering treatment to obtain a zirconia ceramic pre-sintered body;

(3) preparation of zirconia suspension: adding a pore-forming agent, a stabilizing agent, a dispersing agent and zirconia powder into a solvent, and uniformly mixing to obtain a suspension 1 (a zirconia suspension with high stability and high dispersibility); dipping (dip-coating process) or spraying the suspension 1 on the surface of the zirconia ceramic pre-sintered body in the step (2) (the suspension is permeated and adsorbed on the surface of the pre-sintered body), drying and sintering to obtain the zirconia ceramic with a porous surface layer;

(4) adding a stabilizer, a dispersing agent and the calcium-magnesium-silicon bioactive powder or the calcium-silicon-phosphorus bioactive powder obtained in the step (1) into a solvent, and uniformly mixing to obtain a suspension 2 (high-stability and high-dispersity calcium-magnesium-silicon or calcium-silicon-phosphorus nano powder suspension); soaking the zirconia ceramic with the porous surface layer in the step (3) in the suspension 2 in a container, performing negative pressure infiltration treatment (enabling the calcium-magnesium-silicon or calcium-silicon-phosphorus nano powder suspension to penetrate into the porous surface layer of the zirconia ceramic through the negative pressure infiltration treatment), taking out, and drying to obtain the zirconia ceramic with the composite surface layer; and heating the compounded zirconia ceramic for heat treatment to obtain the modified zirconia ceramic (zirconia dental ceramic with high bioactivity and high strength) with the surface compounded with the bioactive substances.

Further, the silicon-containing compound in the step (1) is at least one of ethyl orthosilicate, silicon acetate and methyl silicate;

further, the calcium salt in the step (1) is at least one of calcium nitrate, calcium chloride, calcium acetate and calcium citrate;

further, the magnesium salt in the step (1) is at least one of magnesium nitrate, magnesium chloride, magnesium acetate and magnesium citrate;

further, the phosphorus salt in step (1) is at least one of sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, potassium hydrogen phosphate, potassium dihydrogen phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate.

Further, the mixed solution in the step (1) comprises the following components in parts by weight:

further, the time of the hydrolytic polycondensation reaction in the step (1) is 6-48 h;

further, the standing and aging time of the step (1) is 6-48 h;

further, the drying temperature in the step (1) is 60-180 ℃, and the drying time is 12-72 h;

further, the calcining temperature in the step (1) is 700-;

further, the rotation speed of the ball milling in the step (1) is 500-.

Preferably, the ball milling in the step (1) is carried out by a sand mill.

Preferably, after the calcium-magnesium-silica sol or the calcium-silicon-phosphorus sol in the step (1) is kept stand and aged, the calcium-magnesium-silica sol or the calcium-silicon-phosphorus sol is centrifugally washed for 2 to 3 times by deionized water and then dried.

Further, the pressure of the compression molding in the step (2) is 100-220MPa, and the time of the compression molding is 2-30 min;

preferably, the press-forming of step (2) comprises: filling zirconia powder into a plastic mould, sealing and molding by using an isostatic press.

Further, the temperature of the pre-sintering treatment in the step (2) is 500-; the rate of temperature rise is 2-10 ℃/min.

Further, the pore-forming agent in the step (3) is at least one of a polyethylacrylate microsphere, a polylactic acid-glycolic acid copolymer microsphere, a polyacrylic acid microsphere and a polystyrene microsphere, a polymethyl methacrylate microsphere and a graphite microsphere, and the particle size of the pore-forming agent is 1-20 μm;

further, the stabilizer in the step (3) is at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl butyral and glycerol;

further, the dispersant in the step (3) is at least one of polyethylene glycol, polyacrylic acid and polymethacrylate ammonia;

further, the solvent in the step (3) is at least one of water and absolute ethyl alcohol;

further, the suspension 1 in the step (3) comprises the following components in parts by weight:

further, the drying temperature in the step (3) is 60-100 ℃, and the drying time is 6-12 h;

further, the thickness of the pore-forming surface layer in the step (3) is 10-80 μm;

preferably, the thickness of the pore-forming surface layer in the step (3) is 20-80 μm.

Preferably, the average pore diameter in the pore-forming surface layer in the step (3) is 0.1-50 μm, and the porosity is 20% -70%.

Further, the temperature of the sintering treatment in the step (3) is 1350-.

Preferably, the impregnating of step (3) comprises: and (2) soaking the zirconia ceramic pre-sintered body in zirconia suspension (suspension 1) for 10s-2min, and quickly pulling out the zirconia ceramic pre-sintered body from the suspension 1 after soaking.

Preferably, the spraying of step (3) comprises: and spraying the suspension 1 on the zirconia ceramic pre-sintered body, wherein the spraying pressure is 0.2MPa, and the spraying time is 0.5-4 min.

Preferably, the zirconia powder in the step (2) and the step (3) is Y₂O₃、MgO、CaO、La₂O₃Any one or more of these as a partially stabilized tetragonal zirconia powder that is a stabilizer.

Further preferably, the zirconia powder in step (2) and step (3) is yttria-stabilized zirconia powder.

Further, the particle size of the calcium-magnesium-silicon or calcium-phosphorus-silicon bioactive powder in the step (4) is 0.1-30 μm;

further, the stabilizer in the step (4) is at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl butyral and glycerol;

further, the dispersant in the step (4) is at least one of polyethylene glycol, polyacrylic acid and polymethacrylate ammonia;

further, the solvent in the step (4) is at least one of water and absolute ethyl alcohol;

further, the suspension 2 in the step (4) comprises the following components in parts by mass:

further, the infiltration pressure of the negative pressure infiltration treatment in the step (4) is 0-0.2 MPa, and the time of the negative pressure infiltration treatment is 10s-80 min;

further, the drying temperature in the step (4) is 60-100 ℃, and the drying time is 6-12 h;

further, the temperature of the heat treatment in the step (4) is 600-.

The invention provides a modified zirconia ceramic with a surface compounded with bioactive substances, which is prepared by the preparation method.

According to the invention, the nano calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder is loaded inside the zirconia pore canal with a porous surface layer structure, and is sintered at high temperature to generate partial liquid phase or solid phase diffusion, so that a certain bonding strength is ensured between the nano calcium-magnesium-silicon bioactive powder and the zirconia and the nano calcium-magnesium-silicon bioactive powder is embedded inside the non-directional pore canal, the bioactive substance is ensured not to fall off from the pore canal, and the zirconia is endowed with high bioactivity.

In the preparation method provided by the invention, the sol is aged, dried at low temperature and thermally treated at high temperature to generate the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder, the composition and the thermal treatment system of the sol are controlled to generate one or more of calcium-magnesium-silicon bioactive substances or calcium-silicon-phosphorus bioactive substances such as wollastonite, akermanite, diopside, whitlayite, wainesilicite and the like, the zirconia ceramic is endowed with high bioactivity, the porous surface layer structure and the zirconia ceramic matrix are synchronously sintered to realize integration, the problem of poor bonding strength of the surface active layer and the zirconia matrix material interface is solved, and the porosity, the pore size and the thickness of the porous structure can be regulated and controlled. The porous surface layer structure can permeate various active powder bodies without being limited by the types of the active powder bodies, improves the dental ceramic restoration effect, promotes wider clinical application of the dental ceramic, and has certain social and economic values.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the preparation method provided by the invention, the porous zirconia layer is constructed on the surface of the zirconia ceramic with the compact structure for the first time, the thickness, the pore diameter and the porosity of the porous zirconia layer are randomly adjustable, and the zirconia ceramic with the compact structure ensures that the dental ceramic has excellent mechanical strength. Through improving the powder ball milling process, the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder is ball milled to a micron or submicron level, the powder is prevented from being blocked on the surface of the porous layer, the filling density of the pore passage of the porous layer is ensured through negative pressure permeation, the calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder loaded on the pore passage of the porous zirconia layer has a stimulating effect on the gene expression of osteoblasts, and the bone regeneration can be obviously promoted in clinical application. The calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder has good bioactivity, biocompatibility, biodegradability and mechanical properties, releases active ions such as calcium, magnesium, silicon, phosphorus and the like, can induce the formation of a apatite layer, and is beneficial to the combination of materials and bone tissues.

(2) After the high-bioactivity high-strength zirconia dental ceramic prepared by the invention is soaked in simulated body fluid for a period of time, weakly crystallized hydroxyapatite which is an inorganic substance in bone tissues can be mineralized on the surface, so that the bioactivity is obviously improved;

(3) the porous zirconia layer prepared by the invention can permeate various active powders, is not limited by components and is not limited to one or more bioactive powders. The infiltration capacity of the bioactive powder is not limited by regulating the thickness, the aperture and the porosity of the zirconia porous layer and the infiltration negative pressure, so that the bioactivity of the dental ceramic is improved;

(4) in the preparation method provided by the invention, the related zirconia ceramic surface modification treatment method is implemented on the zirconia ceramic molding pre-sintered body, so that the problem of high processing difficulty of the sintered zirconia ceramic due to high hardness and high density of the sintered zirconia ceramic is avoided, special equipment is not required, the preparation method is simple, the yield is high, and the cost is low;

(5) compared with the problems that the bioactive coating prepared on the surface of a zirconia ceramic compact sintered body in the prior art is easy to peel off and dissolve in a complex oral environment due to poor interface bonding, the bioactive surface layer prepared by the method is an integrated material with the zirconia ceramic, the problem of residual stress caused by mismatch of thermal expansion coefficients is avoided, the bioactive coating is more stably and firmly bonded with alveolar bone tissues, long-term stable bioactivity can be maintained, and the clinical long-term treatment effect is better.

Drawings

Fig. 1 is a graph showing the result of the porous surface microstructure of the modified zirconia ceramic with no bioactive substance compounded on the surface, prepared in example 1.

Fig. 2 is a result graph of the porous surface microstructure of the modified zirconia ceramic of example 2, the surface of which is not compounded with a bioactive substance.

FIG. 3 is a particle size distribution diagram of the bioactive powder infiltrated in example 1.

Fig. 4 is a graph showing the result of the microstructure of the modified zirconia ceramic with the surface compounded with bioactive substances of example 1 after 4 days of simulated body fluid mineralization by SBF.

Fig. 5 is a graph showing the result of the microstructure of the modified zirconia ceramic with the surface compounded with bioactive substances of example 2 after 4 days of simulated body fluid mineralization by SBF.

Fig. 6 is a graph showing the result of the microstructure of the modified zirconia ceramic with the surface compounded with bioactive substances of example 3 after the simulated body fluid mineralization by SBF for 12 days.

FIG. 7 is a graph showing the results of co-culturing the modified zirconia ceramics with bioactive substances compounded on the surfaces thereof in examples 1 to 3, zirconia ceramics without any modification treatment, and mouse bone marrow mesenchymal stem cells for 1 day and 3 days.

FIG. 8 is a graph showing ALP quantification results of co-culture of the modified zirconia ceramics with bioactive substances compounded on the surfaces, which are obtained in examples 1 to 3, and zirconia ceramics without any modification treatment with mouse bone marrow mesenchymal stem cells for 7 days and 14 days.

Detailed Description

The following examples are presented to further illustrate the practice of the invention, but the practice and protection of the invention is not limited thereto. It is noted that the processes described below, if not specifically described in detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are not indicated to the manufacturer, and are considered to be conventional products available by commercial purchase.

Example 1

(1) Preparing calcium magnesium silicon bioactive powder: adding 10g of ethyl orthosilicate, 20g of calcium nitrate and 30g of magnesium nitrate into 50g of deionized water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 8.0 to perform a hydrolysis polycondensation reaction (the reaction time is 12 hours) to form calcium-magnesium-silica sol, standing and aging the sol for 6 hours, drying the sol for 12 hours at the temperature of 60 ℃, calcining the sol for 48 hours at the high temperature of 1200 ℃, and performing ball milling (the rotating speed is 1000 revolutions per minute, and the time is 12 hours) to obtain calcium-magnesium-silica bioactive powder;

(2) pressing and molding yttria-stabilized zirconia powder at 220MPa for 2min to prepare a zirconia ceramic green body, and heating to 500 ℃ for presintering treatment at the speed of 10 ℃/min for 2h to obtain a zirconia ceramic presintering body;

(3) preparation of zirconia suspension: mixing the polyethylacrylate microspheres, polyvinyl alcohol, polyacrylic acid, deionized water and zirconia powder according to the mass ratio of 10:10:2:53:25, uniformly mixing and stirring to prepare a suspension 1 (high-stability and high-dispersity zirconia suspension);

(4) dipping the suspension 1 prepared in the step (3) on the surface of the zirconia ceramic pre-sintered body prepared in the step (2) by a dipping and pulling process, wherein the dipping time is 10s, the porous surface layer is dried for 12h at the temperature of 60 ℃ after the zirconia suspension is permeated and adsorbed, a pore-forming surface layer (the thickness is 10um) is formed, and then the sintering is carried out for 2h at the temperature of 1350 ℃ and the heating rate is 5 ℃/min, so as to obtain the zirconia ceramic with the porous surface layer;

(5) preparing calcium-magnesium-silicon bioactive powder suspension: mixing polyvinyl alcohol, polyacrylic acid, deionized water and calcium-magnesium-silicon bioactive powder according to the mass ratio of 10:10:2:43:35, and uniformly mixing to prepare a suspension 2 (high-stability and high-dispersity calcium-magnesium-silicon bioactive powder suspension);

(6) soaking and permeating the zirconia ceramic with the porous surface layer prepared in the step (5) in the suspension 2 prepared in the step (5) by a negative pressure permeation process, wherein the permeation pressure is 0.1MPa, the permeation time is 10s, so that the calcium-magnesium-silicon bioactive powder suspension is permeated into the porous surface layer of the zirconia ceramic, taking out the zirconia ceramic, and drying the zirconia ceramic at the temperature of 60 ℃ for 12h to obtain the zirconia ceramic with the porous surface layer compounded with the calcium-magnesium-silicon bioactive powder;

(7) and (3) heating the zirconia ceramic of the porous surface layer composite calcium-magnesium-silicon bioactive powder prepared in the step (6) to 1300 ℃ for heat treatment for 0.5h, wherein the heating rate is 10 ℃/min, and obtaining the modified zirconia ceramic (zirconia dental ceramic with high bioactivity and high strength) of the surface composite bioactive substance.

FIG. 1 is a graph showing the results of the surface microstructure of the modified zirconia ceramic surface-composited with bioactive substances prepared in example 1; as shown in fig. 1, the pore size distribution of the porous surface layer is relatively uniform and large, which is beneficial for the active powder to penetrate and fill into the pore channel under the negative pressure condition.

FIG. 3 is a particle size distribution diagram of the bioactive powder infiltrated in example 1. As can be seen from the figure, the particle size of the bioactive powder after ball milling is mainly concentrated between 0.1um and 3 um.

The modified zirconia ceramic with the surface compounded with the bioactive substances prepared in this example has high bioactivity, as shown in fig. 4, after the modified zirconia ceramic is soaked in 1.0 time of Simulated Body Fluid (SBF) for 4 days, abundant cluster-like crystals appear on the surface of the sample after the surface layer is permeated with the calcium-magnesium-silicon bioactive powder, which indicates that the bioactivity of the modified zirconia ceramic is significantly improved.

The bending strength of the modified zirconia ceramic with the surface compounded with the bioactive substances is 1100MPa after mechanical property tests (refer to national standard GB/T6569-86). The preparation method provided by the embodiment of the invention improves the bioactivity to a certain extent on the premise of ensuring the excellent mechanical property of the product.

Example 2

(1) Preparing calcium magnesium silicon bioactive powder: adding 10g of ethyl orthosilicate, 20g of calcium nitrate and 30g of magnesium citrate into 50g of deionized water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 8.0 to perform a hydrolytic polycondensation reaction (the reaction time is 24 hours) to form calcium-magnesium-silica sol, standing and aging the sol for 6 hours, drying the sol for 12 hours at the temperature of 60 ℃, calcining the sol for 48 hours at the high temperature of 1400 ℃, and performing ball milling (the rotating speed is 1000 revolutions per minute and the time is 12 hours) to obtain calcium-magnesium-silica bioactive powder;

(2) pressing and molding yttria-stabilized zirconia powder under the pressure of 100MPa for 30min to prepare a zirconia ceramic green body, and heating to 500 ℃ for presintering treatment, wherein the presintering treatment time is 2h and the heating rate is 2 ℃/min to obtain a zirconia ceramic presintering body;

(3) preparation of zirconia suspension: mixing graphite microspheres, polyvinyl alcohol, polyacrylic acid, deionized water and zirconia powder according to a mass ratio of 10:10:2:53:25, uniformly mixing and stirring to prepare a suspension 1 (high-stability and high-dispersity zirconia suspension);

(4) dipping the suspension 1 prepared in the step (3) on the surface of the zirconia ceramic pre-sintered body prepared in the step (2) by a dipping and pulling process for 20s, drying the suspension at 60 ℃ for 12h after the porous surface layer permeates and adsorbs the zirconia suspension to form a pore-forming surface layer (the thickness is 10 mu m), and then sintering the surface layer at 1350 ℃ for 2h, wherein the temperature rising rate is 5 ℃/min to obtain the zirconia ceramic with the porous surface layer;

(5) preparing calcium-magnesium-silicon bioactive powder suspension: mixing polyvinyl alcohol, polyacrylic acid, deionized water and calcium-magnesium-silicon bioactive powder according to the mass ratio of 10:10:2:43:35, and uniformly mixing to prepare a suspension 2 (high-stability and high-dispersity calcium-magnesium-silicon bioactive powder suspension);

(6) soaking and permeating the zirconia ceramic with the porous surface layer prepared in the step (5) in the suspension 2 prepared in the step (5) by a negative pressure permeation process, wherein the permeation pressure is 0.1MPa, the permeation time is 10s, so that the calcium-magnesium-silicon bioactive powder suspension is permeated into the porous surface layer of the zirconia ceramic, taking out the zirconia ceramic, and drying the zirconia ceramic at the temperature of 60 ℃ for 12h to obtain the zirconia ceramic with the porous surface layer compounded with the calcium-magnesium-silicon bioactive powder;

(7) and (3) heating the zirconia ceramic of the porous surface layer composite calcium-magnesium-silicon bioactive powder prepared in the step (6) to 1300 ℃ for heat treatment for 0.5h, wherein the heating rate is 10 ℃/min, and obtaining the modified zirconia ceramic (zirconia dental ceramic with high bioactivity and high strength) of the surface composite bioactive substance.

Fig. 2 is a surface microstructure result diagram of a modified zirconia ceramic with a bioactive substance compounded on the surface according to example 2. As shown in fig. 2, the pore size distribution of the porous surface layer is relatively uniform and large, which is beneficial for the active powder to penetrate and fill into the pore channel under the negative pressure condition.

The modified zirconia ceramic with the surface compounded with the bioactive substances prepared in this example has high bioactivity, as shown in fig. 5, after the modified zirconia ceramic is soaked in 1.0 time of Simulated Body Fluid (SBF) for 4 days, abundant cluster-like crystals appear on the surface of the sample after the surface layer is permeated with the calcium-magnesium-silicon bioactive powder, which indicates that the bioactivity of the modified zirconia ceramic is significantly improved.

The bending strength of the modified zirconia ceramic with the surface compounded with the bioactive substances is 1050MPa by mechanical property tests (refer to national standard GB/T6569-86). The preparation method provided by the embodiment of the invention improves the bioactivity to a certain extent on the premise of ensuring the excellent mechanical property of the product.

Example 3

(1) Preparing calcium-silicon-phosphorus bioactive powder: adding 31g of ethyl orthosilicate, 29g of calcium nitrate and 20g of sodium phosphate into 20g of deionized water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 8.0, carrying out a hydrolysis polycondensation reaction (the reaction time is 24 hours) to form calcium-silicon-phosphorus sol, standing and aging the sol for 6 hours, drying the sol for 12 hours at the temperature of 60 ℃, calcining the sol for 48 hours at the high temperature of 800 ℃, and carrying out ball milling (the rotating speed is 1000 revolutions per minute, and the time is 12 hours) to obtain calcium-silicon-phosphorus bioactive powder;

(2) pressing and molding yttria-stabilized zirconia powder at the pressure of 180MPa for 10min to prepare a zirconia ceramic green body, and heating to 500 ℃ for presintering treatment at the temperature of 2h and the heating rate of 5 ℃/min to obtain a zirconia ceramic presintering body;

(3) preparation of zirconia suspension: mixing the polyethylacrylate microspheres, polyvinyl alcohol, polyacrylic acid, deionized water and zirconia powder according to the mass ratio of 10:10:2:53:25, uniformly mixing and stirring to prepare a suspension 1 (high-stability and high-dispersity zirconia suspension);

(4) dipping the suspension 1 prepared in the step (3) on the surface of the zirconia ceramic pre-sintered body prepared in the step (2) by a dipping and pulling process for 20s, drying the porous surface layer at 60 ℃ for 12h after the porous surface layer permeates and adsorbs the zirconia suspension to form a pore-forming surface layer (the thickness is 10um), and sintering the pore-forming surface layer at 1350 ℃ for 2h, wherein the temperature rising rate is 5 ℃/min to obtain the zirconia ceramic with the porous surface layer;

(5) preparing calcium-magnesium-silicon bioactive powder suspension: mixing polyvinyl alcohol, polyacrylic acid, deionized water and calcium-magnesium-silicon bioactive powder according to the mass ratio of 10:10:2:43:35, and uniformly mixing to prepare a suspension 2 (high-stability and high-dispersity calcium-magnesium-silicon bioactive powder suspension);

(6) soaking and permeating the zirconia ceramic with the porous surface layer prepared in the step (5) in the suspension 2 prepared in the step (5) by a negative pressure permeation process, wherein the permeation pressure is 0.1MPa, the permeation time is 10s, so that the calcium-magnesium-silicon bioactive powder suspension is permeated into the porous surface layer of the zirconia ceramic, taking out the zirconia ceramic, and drying the zirconia ceramic at the temperature of 60 ℃ for 12h to obtain the zirconia ceramic with the porous surface layer compounded with the calcium-magnesium-silicon bioactive powder;

(7) and (3) heating the zirconia ceramic of the porous surface layer composite calcium-magnesium-silicon bioactive powder prepared in the step (6) to 800 ℃ for heat treatment for 0.5h, wherein the heating rate is 10 ℃/min, and obtaining the modified zirconia ceramic (zirconia dental ceramic with high bioactivity and high strength) of the surface composite bioactive substance.

The modified zirconia ceramic with the surface compounded with the bioactive substances prepared in this example has high bioactivity, as shown in fig. 6, after the modified zirconia ceramic is soaked in 1.0 time of Simulated Body Fluid (SBF) for 12 days, abundant cluster-like crystals appear on the surface of the sample after the calcium-magnesium-silicon bioactive powder is permeated into the surface layer, which indicates that the bioactivity of the modified zirconia ceramic is significantly improved, as shown in fig. 5.

The bending strength of the modified zirconia ceramic with the surface compounded with the bioactive substances is 1120MPa by a mechanical property test (refer to national standard GB/T6569-86). The preparation method provided by the embodiment of the invention improves the bioactivity to a certain extent on the premise of ensuring the excellent mechanical property of the product.

Example 4

(1) Preparing calcium-silicon-phosphorus bioactive powder: adding 31g of ethyl orthosilicate, 34g of calcium nitrate and 15g of sodium phosphate into 20g of deionized water, uniformly mixing to obtain a mixed solution, adjusting the pH of the mixed solution to 8.0, carrying out a hydrolysis polycondensation reaction (the reaction time is 24 hours) to form calcium-silicon-phosphorus sol, standing and aging the sol for 6 hours, drying the sol for 12 hours at the temperature of 60 ℃, calcining the sol for 48 hours at the high temperature of 850 ℃, and carrying out ball milling (the rotating speed is 1000 revolutions per minute and the time is 12 hours) to obtain calcium-silicon-phosphorus bioactive powder;

(2) pressing and molding yttria-stabilized zirconia powder at the pressure of 200MPa for 10min to prepare a zirconia ceramic green body, and heating to 500 ℃ for presintering treatment at the temperature of 2h and the heating rate of 5 ℃/min to obtain a zirconia ceramic presintering body;

(3) preparation of zirconia suspension: mixing the polyethylacrylate microspheres, polyvinyl alcohol, polyacrylic acid, deionized water and zirconia powder according to the mass ratio of 10:5:2:53:30, uniformly mixing and stirring to prepare a suspension 1 (high-stability and high-dispersity zirconia suspension);

(4) dipping the suspension 1 prepared in the step (3) on the surface of the zirconia ceramic pre-sintered body prepared in the step (2) by a dipping and pulling process for 20s, drying the porous surface layer at 60 ℃ for 12h after the porous surface layer permeates and adsorbs the zirconia suspension to form a pore-forming surface layer (the thickness is 10um), and sintering the pore-forming surface layer at 1350 ℃ for 2h, wherein the temperature rising rate is 5 ℃/min to obtain the zirconia ceramic with the porous surface layer;

(5) preparing calcium-magnesium-silicon bioactive powder suspension: mixing polyvinyl alcohol, polyacrylic acid, deionized water and calcium-magnesium-silicon bioactive powder according to the mass ratio of 10:10:2:43:35, and uniformly mixing to prepare a suspension 2 (high-stability and high-dispersity calcium-magnesium-silicon bioactive powder suspension);

(6) soaking and permeating the zirconia ceramic with the porous surface layer prepared in the step (5) in the suspension 2 prepared in the step (5) by a negative pressure permeation process, wherein the permeation pressure is 0.1MPa, the permeation time is 10s, so that the calcium-magnesium-silicon bioactive powder suspension is permeated into the porous surface layer of the zirconia ceramic, taking out the zirconia ceramic, and drying the zirconia ceramic at the temperature of 60 ℃ for 12h to obtain the zirconia ceramic with the porous surface layer compounded with the calcium-magnesium-silicon bioactive powder;

(7) and (3) heating the zirconia ceramic of the porous surface layer composite calcium-magnesium-silicon bioactive powder prepared in the step (6) to 900 ℃ for heat treatment for 0.5h, wherein the heating rate is 10 ℃/min, and obtaining the modified zirconia ceramic (zirconia dental ceramic with high bioactivity and high strength) of the surface composite bioactive substance.

The modified zirconia ceramic with the surface compounded with the bioactive substances prepared in this embodiment has high bioactivity, and after the modified zirconia ceramic is soaked in 1.0 time of Simulated Body Fluid (SBF) for 12 days, abundant cluster-shaped crystals appear on the surface of a sample with the surface layer permeated with the calcium-magnesium-silicon bioactive powder, which indicates that the bioactivity of the modified zirconia ceramic is significantly improved, as shown in fig. 5.

The bending strength of the modified zirconia ceramic with the surface compounded with the bioactive substances is 1150MPa by mechanical property tests (refer to national standard GB/T6569-86). The preparation method provided by the embodiment of the invention improves the bioactivity to a certain extent on the premise of ensuring the excellent mechanical property of the product.

Cell experiments

Measuring proliferation of cells: under aseptic conditions, the modified zirconia ceramics with the surface compounded with calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder prepared in the examples 1 to 3 and the zirconia ceramics without any modification treatment are sterilized at high temperature and high pressure and then dried to obtain zirconia ceramic samples (respectively marked as the sample in the example 1, the sample in the example 2, the sample in the example 3 and a blank group sample). Then putting each zirconia ceramic sample into a 48-pore plate respectively, soaking for 6h by using a complete culture medium, sucking away the complete culture medium, adding the mouse bone marrow mesenchymal stem cell suspension with the generation of 9 into the pore plate, wherein the number of cells in each pore is 10000, and the culture process is changed into the complete culture medium every other day. When the cells were cultured for 1 day and 3 days, the expression of the osteogenic differentiation alkaline phosphatase activity of the cells was measured.

Determination of alkaline phosphatase expression: under aseptic conditions, the modified zirconia ceramics with the surface compounded with calcium-magnesium-silicon or calcium-silicon-phosphorus bioactive powder prepared in the examples 1 to 3 and the zirconia ceramics without any modification treatment are sterilized at high temperature and high pressure and then dried to obtain zirconia ceramic samples (respectively marked as the sample in the example 1, the sample in the example 2, the sample in the example 3 and a blank group sample). Then respectively putting each zirconia ceramic sample into a 48-pore plate, soaking for 6h by using a complete culture medium, sucking away the complete culture medium, adding mouse bone marrow mesenchymal stem cell suspension with the generation of 9 into the pore plate, wherein the number of cells in each pore is 20000, and replacing osteogenic induction liquid every other day in the culture process. When the cells were cultured for 7 days and 14 days, the expression of the osteogenic differentiation alkaline phosphatase activity of the cells was measured.

The preparation of the zirconia ceramic without any modification treatment comprises the following steps: pre-sintering body of zirconia ceramic and calcining treatment. The zirconia ceramic pre-sintered body can be obtained by referring to step (2) of example 1, and then the zirconia ceramic pre-sintered body is subjected to a firing treatment, the firing treatment being: heating to 1300 deg.C for 0.5h at a heating rate of 10 deg.C/min.

FIG. 7 is a graph showing the results of co-culturing the modified zirconia ceramics with bioactive substances compounded on the surfaces thereof in examples 1 to 3, zirconia ceramics without any modification treatment, and mouse bone marrow mesenchymal stem cells for 1 day and 3 days.

As can be seen from fig. 7, the modified zirconia ceramic with the surface compounded with the bioactive substances prepared in the examples and the mouse bone marrow mesenchymal stem cells have better cell proliferation effects in 1 day and 3 days of co-culture than the zirconia ceramic without any modification treatment, and the cell proliferation condition is significantly improved.

At the time of 7 days and 14 days of co-culture, mouse bone marrow mesenchymal stem cells in each sample group were taken and detected using an ALP quantification kit. FIG. 8 is a graph showing ALP quantification results of co-culture of the modified zirconia ceramics with bioactive substances compounded on the surfaces, which are obtained in examples 1 to 3, and zirconia ceramics without any modification treatment with mouse bone marrow mesenchymal stem cells for 7 days and 14 days.

As can be seen from fig. 8, the osteogenic differentiation effect of the cells of the modified zirconia ceramic with the surface compounded with the bioactive substances and the mouse bone marrow mesenchymal stem cells cultured together for 7 days and 14 days is better than that of the zirconia ceramic without any modification treatment, and the osteogenic differentiation condition of the cells is remarkably improved. Blank groups in fig. 7 and 8 represent zirconia ceramics without any modification treatment, and 1, 2, and 3 represent example 1, example 2, and example 3, respectively.

The above examples are only preferred embodiments of the present invention, which are intended to be illustrative and not limiting, and those skilled in the art should understand that they can make various changes, substitutions and alterations without departing from the spirit and scope of the invention.