Bacteriostatic and antibacterial lithium disilicate glass ceramic and preparation method thereof

Abstract

The invention discloses bacteriostatic and antibacterial lithium disilicate glass ceramic and a preparation method thereof. The bacteriostatic and antibacterial lithium disilicate glass ceramic comprises the following components in percentage by weight: 60-70% of lithium disilicate whiskers, 5-12% of a nucleating agent, 1-5% of aluminum oxide, 1-4% of calcium oxide, 5-10% of an antibacterial agent and 12-18% of fluorapatite, wherein the nucleating agent is formed by compounding phosphorus pentoxide and zirconium oxide, and the antibacterial agent is formed by compounding silver oxide and zinc oxide; the invention relates to the technical field of lithium disilicate glass ceramics. In the glass ceramic, silver ions can be combined with groups such as sulfydryl and amino in bacterial cells to interfere the metabolic process of bacteria and inactivate enzymes of the bacteria so as to inhibit growth and reproduction of the bacteria, and zinc ions can influence permeability of bacterial cell membranes and destroy physiological functions of the bacteria and cooperate with the silver ions to enhance the antibacterial effect of the glass ceramic.

Description

Technical Field

[0001] The invention relates to the technical field of lithium disilicate glass ceramics, in particular to antibacterial and antimicrobial lithium disilicate glass ceramics and a preparation method thereof. Background Art

[0002] Lithium disilicate glass-ceramic is a new type of inorganic non-metallic material primarily composed of silicon dioxide (SiO2) and lithium oxide (Li2O). Due to its excellent biocompatibility, aesthetics, and mechanical properties, it is widely used in dentistry for the production of restorations such as crowns, bridges, and veneers. It can match the color and transparency of natural teeth while possessing sufficient strength and wear resistance to withstand the forces of chewing and daily use in the mouth.

[0003] The Chinese patent with publication number CN109534681B discloses a method for preparing lithium disilicate composite bioglass ceramics, which includes the following steps: first, bioglass powder is prepared by a sol-gel method and a melting method, mixed in a certain proportion, and then ground, sieved, molded, and calcined to obtain lithium disilicate composite bioglass ceramics; this method has the advantages of simple process, cheap raw materials, and easy operation. The prepared lithium disilicate composite bioglass ceramics have good mechanical properties and biological activity, and can be applied to the repair of wound defects, controlled drug release, cell culture, etc. in the dental field, and have good application prospects. However, the antibacterial properties and corrosion resistance of the glass ceramics prepared by the above-mentioned prior art need to be improved; for this reason, the present invention proposes an antibacterial and antimicrobial lithium disilicate glass ceramic and a preparation method thereof to solve the above-mentioned problems. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In view of the deficiencies in the prior art, the present invention provides an antibacterial and antimicrobial lithium disilicate glass ceramic and a preparation method thereof, which solves the problems mentioned in the above background technology.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: an antibacterial and antimicrobial lithium disilicate glass ceramic, comprising the following components in weight percentage: 60%-70% lithium disilicate whiskers, 5%-12% nucleating agent, 1%-5% aluminum oxide, 1%-4% calcium oxide, 5%-10% antibacterial agent, and 12%-18% fluorapatite;

[0008] The nucleating agent is composed of a compound of phosphorus pentoxide and zirconium oxide, and the antibacterial agent is composed of a compound of silver oxide and zinc oxide.

[0009] Preferably, the preparation method of the lithium disilicate whiskers is:

[0010] S1. Dissolve lithium hydroxide in deionized water, and then slowly add silica sol dropwise under stirring;

[0011] S2. After mixing, first add lithium fluoride dropwise, stir and react for 40-60 minutes, then add hexadecyltrimethylammonium bromide dropwise to react;

[0012] S3. After the reaction is completed, cool naturally to room temperature, then centrifuge, wash and dry.

[0013] Preferably, in S1, the molar ratio of lithium hydroxide to silica sol is 2:1; and the stirring speed is 200-300 r / min.

[0014] Preferably, in S2, the added mass of lithium fluoride is 5%-8%; the added mass of hexadecyltrimethylammonium bromide is 1%-3%.

[0015] Preferably, during the preparation of the lithium disilicate whiskers, the reaction temperature is 200-220° C. and the reaction time is 36-48 hours.

[0016] Preferably, in S3, centrifugation is performed at a speed of 4000-6000 r / min for 10-15 min; ultrasonic cleaning is performed with deionized water for 3-5 times; and drying is performed at 80-100° C. for 18-24 h.

[0017] Preferably, the preparation method of the fluorapatite is: adding calcium nitrate tetrahydrate dropwise to ammonium phosphate trihydrate, mixing well, then adding ammonium fluoride, continuing to stir evenly, and then centrifuging the product. The precipitate is washed with deionized water 1-3 times and anhydrous ethanol 2-3 times, and then placed in a drying oven at 75-85°C for drying, and then placed in a resistance furnace at 1350-1400°C for calcination for 50-60 minutes to obtain fluorapatite.

[0018] Preferably, the molar ratio of calcium, phosphorus and fluorine in the calcium nitrate tetrahydrate, ammonium phosphate trihydrate and ammonium fluoride is 10:6:2.

[0019] A method for preparing antibacterial and antimicrobial lithium disilicate glass ceramics comprises the following steps:

[0020] Step 1: Weigh each raw material and grind and mix;

[0021] Step 2: Place the ground and mixed raw materials into a corundum crucible preheated in a muffle furnace, and place it in a high-temperature melting furnace to obtain a uniform and clear glass melt;

[0022] Step 3: Open the furnace door and pour the homogenized glass liquid into the preheated graphite mold;

[0023] Step 4: Place the mold in an annealing furnace preheated to 450-600°C and keep it warm for 45-60 minutes, then cool it to room temperature before taking it out.

[0024] Preferably, in step 2, the melting temperature is 1400-1550° C., the heating rate is 8-10° C. / min, and the melting time is 50-70 min.

[0025] (3) Beneficial effects

[0026] The present invention provides an antibacterial and antimicrobial lithium disilicate glass ceramic and a preparation method thereof. Compared with the prior art, it has the following advantages:

[0027] (1) In the present invention, silver ions can combine with sulfhydryl, amino and other groups in bacterial cells, interfere with the bacterial metabolic process, inactivate bacterial enzymes, and thus inhibit bacterial growth and reproduction. Zinc ions can affect the permeability of bacterial cell membranes, destroy the physiological functions of bacteria, and cooperate with silver ions to enhance the antibacterial effect of glass ceramics.

[0028] (2) In the present invention, lithium disilicate whiskers have a very high aspect ratio and excellent mechanical properties, and can play a role in bridging and hindering crack propagation in the glass ceramic matrix, thereby improving the strength and toughness of the material; alumina is a high-hardness, high-strength ceramic material, which can improve the overall hardness and strength of the glass ceramic. At the same time, lithium disilicate whiskers and alumina are distributed in the glass ceramic matrix, which can withstand friction stress and reduce wear on the surface of the material, thereby improving the wear resistance of the glass ceramic; calcium oxide can adjust the chemical composition of the glass ceramic, improve its structure, and improve the stability and mechanical properties of the material; the nucleating agents phosphorus pentoxide and zirconium oxide can promote the crystallization of the glass ceramic, forming fine and uniform grains, and improving the density and mechanical properties of the material.

[0029] (3) In the present invention, fluorapatite can fill the internal pores of glass ceramics, making the structure denser, thereby improving the overall strength and hardness of the material. At the same time, it interacts with components such as lithium disilicate whiskers and aluminum oxide to improve the toughness of the material and enhance the material's ability to resist crack propagation. The added fluorapatite can form a protective layer on the surface of the glass ceramics, thereby improving the material's ability to resist friction. At the same time, fluorapatite particles can be filled in the grain gaps and pores of the glass ceramics, reducing the channels for the corrosive medium to enter the interior of the material and reducing the contact area between the corrosive medium and the material. The addition of fluorapatite can also make the antibacterial agent more evenly distributed in the glass ceramics, thereby better exerting the antibacterial effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a comparison chart of the wear resistance test provided by the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Example 1

[0033] A method for preparing antibacterial and antimicrobial lithium disilicate glass ceramics comprises the following steps:

[0034] Step 1: Weigh the following raw materials: 70% lithium disilicate whiskers, 10% phosphorus pentoxide and zirconium oxide composite in a mass ratio of 1:1, 1.5% aluminum oxide, 1.5% calcium oxide, 5% silver oxide and zinc oxide composite in a mass ratio of 1:1, and 12% fluorapatite, and grind and mix them;

[0035] The preparation method of lithium disilicate whiskers is as follows: lithium hydroxide is dissolved in deionized water at 200°C, and then stirred at 200 r / min, and silica sol is slowly added dropwise, with the molar ratio of lithium hydroxide to silica sol being 2:1; after mixing, 5% lithium fluoride is first added dropwise, stirred and reacted for 40 minutes, and then 1% hexadecyltrimethylammonium bromide is added dropwise, reacted for 36 hours, and then naturally cooled to room temperature, and then centrifuged at 4000 r / min for 10 minutes, followed by ultrasonic cleaning with deionized water three times, and finally dried at 80°C for 18 hours;

[0036] The preparation method of fluorapatite is as follows: adding calcium nitrate tetrahydrate dropwise to ammonium phosphate trihydrate, mixing and then adding ammonium fluoride, wherein the molar ratio of calcium, phosphorus and fluorine is 10:6:2, continuing to stir evenly, and then centrifuging the product. The precipitate is washed once with deionized water and twice with anhydrous ethanol, and then dried in a drying oven at 75°C, and then calcined in a resistance furnace at 1350°C for 50 minutes to obtain fluorapatite.

[0037] Step 2: Place the ground and mixed raw materials into a corundum crucible preheated in a muffle furnace, place it in a high-temperature melting furnace, heat it to 14000°C at a heating rate of 8°C / min, and melt it for 50 minutes to obtain a uniform and clear glass melt;

[0038] Step 3: Open the furnace door and pour the homogenized glass liquid into the preheated graphite mold;

[0039] Step 4: Place the mold in an annealing furnace preheated to 450°C for 45 minutes, then cool it to room temperature before taking it out.

[0040] Example 2

[0041] A method for preparing antibacterial and antimicrobial lithium disilicate glass ceramics comprises the following steps:

[0042] Step 1: Weigh the following raw materials: 65% lithium disilicate whiskers, 10% phosphorus pentoxide and zirconium oxide composite with a mass ratio of 1:1.2, 3% aluminum oxide, 2% calcium oxide, 5% silver oxide and zinc oxide composite with a mass ratio of 1:1, and 15% fluorapatite, and grind and mix them;

[0043] The preparation method of lithium disilicate whiskers is as follows: lithium hydroxide is dissolved in deionized water at 210°C, and then stirred at a speed of 250 r / min, and silica sol is slowly added dropwise, with the molar ratio of lithium hydroxide to silica sol being 2:1; after mixing, 7% lithium fluoride is first added dropwise, and stirred for reaction for 50 minutes, and then 1%-3% hexadecyltrimethylammonium bromide is added dropwise, and after reaction for 42 hours, it is naturally cooled to room temperature, and then centrifuged at a speed of 5000 r / min for 12 minutes, followed by ultrasonic cleaning with deionized water four times, and finally dried at 90°C for 21 hours;

[0044] The preparation method of fluorapatite is as follows: adding calcium nitrate tetrahydrate dropwise to ammonium phosphate trihydrate, mixing and then adding ammonium fluoride, wherein the molar ratio of calcium, phosphorus and fluorine is 10:6:2, continuing to stir evenly, and then centrifuging the product. The precipitate is washed twice with deionized water and three times with anhydrous ethanol, and then dried in a drying oven at 80°C, and then calcined in a resistance furnace at 13800°C for 55 minutes to obtain fluorapatite.

[0045] Step 2: Place the ground and mixed raw materials into a corundum crucible preheated in a muffle furnace, place it in a high-temperature melting furnace, heat it to 15050°C at a heating rate of 9°C / min, and melt it for 60 minutes to obtain a uniform and clear glass melt;

[0046] Step 3: Open the furnace door and pour the homogenized glass liquid into the preheated graphite mold;

[0047] Step 4: Place the mold in an annealing furnace that has been preheated to 500°C and keep it warm for 50 minutes, then cool it to room temperature and take it out.

[0048] Example 3

[0049] A method for preparing antibacterial and antimicrobial lithium disilicate glass ceramics comprises the following steps:

[0050] Step 1: Weigh the following raw materials: 60% lithium disilicate whiskers, 10% phosphorus pentoxide and zirconium oxide composite with a mass ratio of 1:1.5, 3.5% aluminum oxide, 3.5% calcium oxide, 5% silver oxide and zinc oxide composite with a mass ratio of 1:1, and 18% fluorapatite, and grind and mix them;

[0051] The preparation method of lithium disilicate whiskers is as follows: lithium hydroxide is dissolved in deionized water at 220°C, and then stirred at a speed of 300 r / min, and silica sol is slowly added dropwise, with the molar ratio of lithium hydroxide to silica sol being 2:1; after mixing, 8% lithium fluoride is first added dropwise, stirred and reacted for 60 minutes, and then 3% hexadecyltrimethylammonium bromide is added dropwise, reacted for 48 hours, and then naturally cooled to room temperature, and then centrifuged at a speed of 6000 r / min for 15 minutes, followed by ultrasonic cleaning with deionized water for 5 times, and finally dried at 100°C for 24 hours;

[0052] The preparation method of fluorapatite is as follows: adding calcium nitrate tetrahydrate dropwise to ammonium phosphate trihydrate, mixing and then adding ammonium fluoride, wherein the molar ratio of calcium, phosphorus and fluorine is 10:6:2, continuing to stir evenly, and then centrifuging the product. The precipitate is washed with deionized water 3 times and anhydrous ethanol 2-3 times in sequence, and then dried in a drying oven at 85°C, and then calcined in a resistance furnace at 1400°C for 60 minutes to obtain fluorapatite.

[0053] Step 2: The ground and mixed raw materials are placed in a corundum crucible preheated in a muffle furnace, placed in a high-temperature melting furnace, heated to 1550°C at a heating rate of 10°C / min, and melted for 70 minutes to obtain a uniform and clear glass melt;

[0054] Step 3: Open the furnace door and pour the homogenized glass liquid into the preheated graphite mold;

[0055] Step 4: Place the mold in an annealing furnace preheated to 600°C and keep it warm for 60 minutes, then cool it to room temperature and take it out.

[0056] Comparative Example 1

[0057] Compared with Example 1, the difference is that the lithium disilicate whiskers are replaced with silicon dioxide and lithium oxide in a mass ratio of 1:1; the rest remain unchanged.

[0058] Comparative Example 2

[0059] Compared with Example 1, the difference is that the nucleating agent is replaced by phosphorus pentoxide; the rest remains unchanged.

[0060] Comparative Example 3

[0061] Compared with Example 1, the difference is that no fluorapatite is added; the rest remains unchanged.

[0062] Comparative Example 4

[0063] Compared with Example 1, the difference is that the antibacterial agent is replaced by silver oxide; the rest remains unchanged.

[0064] Acid etching of the specimens: Prepare a 1 mmol / L citric acid solution (pH 3.20) with deionized water. Measure 50 mL of the citric acid solution in a beaker, maintain a constant temperature at 37°C, and place the specimen with the jaw facing upwards. Stir slowly with a constant-temperature magnetic stirrer to simulate the saliva flow environment in the mouth. After the set acid etching time, remove the specimen, rinse repeatedly with deionized water, and dry naturally at room temperature. Observe its surface.

[0065] Bending strength test: Tested in accordance with IS0 6872 standard.

[0066] Hardness test: Test in accordance with GB / T 16534-2009.

[0067] Antibacterial performance test: Refer to GB / T 21866-2008 to test the antibacterial rate (using Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus as strains).

[0068] Table 1

[0069]

[0070]

[0071] Wear resistance test: The test was conducted using a friction and wear tester with a load of 5N and a friction cycle of 500,000 times. The results are as follows: Figure 1 As shown in FIG1 , the wear resistance of the glass ceramics of Examples 1-3 is significantly improved compared with that of Comparative Examples 1-3, and the wear resistance of the glass ceramics of Comparative Example 4 is slightly worse than that of Examples 1-3.

[0072] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0073] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0074] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An antibacterial and antimicrobial lithium disilicate glass ceramic, characterized in that: The invention comprises the following components in weight percentage: 60%-70% lithium disilicate whiskers, 5%-12% nucleating agent, 1%-5% aluminum oxide, 1%-4% calcium oxide, 5%-10% antibacterial agent, and 12%-18% fluorapatite; The nucleating agent is composed of a compound of phosphorus pentoxide and zirconium oxide, and the antibacterial agent is composed of a compound of silver oxide and zinc oxide.

2. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 1, characterized in that: The preparation method of the lithium disilicate whiskers is: S1. Dissolve lithium hydroxide in deionized water, and then slowly add silica sol dropwise under stirring; S2. After mixing, first add lithium fluoride dropwise, stir and react for 40-60 minutes, then add hexadecyltrimethylammonium bromide dropwise to react; S3. After the reaction is completed, cool naturally to room temperature, then centrifuge, wash and dry.

3. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 2, characterized in that: In S1, the molar ratio of lithium hydroxide to silica sol is 2:1; and the stirring speed is 200-300 r / min.

4. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 2, characterized in that: In the S2, the added mass of lithium fluoride is 5%-8%; the added mass of cetyltrimethylammonium bromide is 1%-3%.

5. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 2, characterized in that: During the preparation of the lithium disilicate whiskers, the reaction temperature is 200-220° C. and the reaction time is 36-48 hours.

6. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 2, characterized in that: In the S3, centrifuge at a speed of 4000-6000 r / min for 10-15 minutes; ultrasonically clean with deionized water for 3-5 times; and dry at 80-100° C. for 18-24 hours.

7. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 1, characterized in that: The fluorapatite preparation method comprises the following steps: adding calcium nitrate tetrahydrate dropwise to ammonium phosphate trihydrate, mixing thoroughly, then adding ammonium fluoride, continuing to stir uniformly, and then centrifuging the product. The precipitate is washed with deionized water 1-3 times, and then washed with anhydrous ethanol 2-3 times, and then dried in a drying oven at 75-85°C, and then calcined in a resistance furnace at 1350-1400°C for 50-60 minutes to obtain the fluorapatite.

8. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 7, characterized in that: In the calcium nitrate tetrahydrate, ammonium phosphate trihydrate and ammonium fluoride, the molar ratio of calcium, phosphorus and fluorine is 10:6:

2.

9. A method for preparing the antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 1, characterized in that: Specifically comprising the following preparation steps: Step 1: Weigh each raw material and grind and mix; Step 2: Place the ground and mixed raw materials into a corundum crucible preheated in a muffle furnace, and place it in a high-temperature melting furnace to obtain a uniform and clear glass melt; Step 3: Open the furnace door and pour the homogenized glass liquid into the preheated graphite mold; Step 4: Place the mold in an annealing furnace preheated to 450-600°C and keep it warm for 45-60 minutes, then cool it to room temperature before taking it out.

10. The antibacterial and antimicrobial lithium disilicate glass ceramic according to claim 9, characterized in that: In the step 2, the melting temperature is 1400-1550° C., the heating rate is 8-10° C. / min, and the melting time is 50-70 min.

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