High-strength nano-modified dental restoration material and preparation method thereof

Abstract

The invention provides a high-strength nano-modified dental restoration material and a preparation method thereof.The high-strength nano-modified dental restoration material is prepared from, by mass, 35-70 g of polyformaldehyde resin, 20-50 g of nano-zirconia ceramic, 2-5 g of coupling agent, 1-5 g of adhesive and 2-8 g of inorganic filler, the adhesive is phosphoric acid derivative modified polyvinyl alcohol. Polyformaldehyde resin is adopted as a resin base material, and nano zirconia ceramic is added as a ceramic phase, so that the resin-permeable ceramic network composite material is formed, and the mechanical property is enhanced; the adhesive is phosphoric acid derivative modified polyvinyl alcohol, so that the permeability of the resin is promoted, the adhesion among the components is enhanced, the mechanical property of the resin permeating ceramic network composite material is further improved, and the application of the resin in dental restoration is widened.

Description

Technical Field

[0001] The invention belongs to the field of tooth restoration materials, and in particular relates to a high-strength nano-modified tooth restoration material and a preparation method thereof. Background Art

[0002] Dental restoration materials can be divided into metal materials, all-ceramic materials and resin materials according to their components. Traditional metal materials have good compressive strength, can withstand chewing pressure, are low in cost, and can be treated in one visit, but have poor aesthetics and may require more tooth tissue to be removed, and are gradually being replaced by other new materials. All-ceramic materials have become a common restoration material on the market due to their good aesthetics and biocompatibility, but they are brittle, require sintering for crystallization glazing, require special treatment for bonding, and have significant wear on teeth. Resin materials have good aesthetics and processing properties, especially their good bonding and physical properties close to those of the tooth body, which have attracted much attention. However, defects such as polymerization shrinkage and poor wear resistance limit the further application of resin materials in dental restorations.

[0003] Resin-infiltrated ceramic network composites are composite materials obtained by infiltrating a pre-sintered ceramic scaffold network with organic monomers and then polymerizing at high temperature. They exhibit mechanical properties superior to those of traditional composite resins, and the elastic modulus of resin-infiltrated ceramic network composites is closer to that of dentin, which has significant advantages as a dental restoration material. Zirconia-based ceramics have been considered as a promising scaffold material for polymer-infiltrated ceramic networks in recent years. Zirconia-based resin-infiltrated ceramic network composites exhibit higher flexural modulus and Vickers hardness, but there is a problem of insufficient interfacial bonding between the ceramic phase and the infiltrated resin phase, resulting in lower flexural strength and fracture toughness for such zirconia-based resin-infiltrated ceramic network composites. How to enhance the interfacial cross-linking ability between the various components in such materials, and then develop zirconia-based resin-infiltrated ceramic network composites with better mechanical properties, and broaden their application in dental restorations is a problem that needs to be solved urgently. Summary of the invention

[0004] The object of the present invention is to provide a high-strength nano-modified tooth restoration material and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: On the one hand, the present invention provides a high-strength nano-modified tooth restoration material, wherein the raw materials for preparing the high-strength nano-modified tooth restoration material include 35-70g of polyformaldehyde resin, 20-50g of nano-zirconia ceramics, 2-5g of coupling agent, 1-5g of adhesive and 2-8g of inorganic filler by weight, and the adhesive is polyvinyl alcohol modified by a phosphoric acid derivative.

[0006] As a further improvement, the raw materials for preparing the polyvinyl alcohol modified with the phosphoric acid derivative include polyvinyl alcohol and 2-phosphinobutane-1,2,4-tricarboxylic acid, and the mass ratio of the polyvinyl alcohol to 2-phosphinobutane-1,2,4-tricarboxylic acid is 1:(2-6).

[0007] As a further improvement, the preparation method of polyvinyl alcohol modified by phosphoric acid derivatives comprises the following steps: dissolving polyvinyl alcohol in deionized water, stirring at 90-100° C. for 1-2 hours to obtain a reaction solution, adjusting the pH of the reaction solution to 1-3, then adding 2-phosphinobutane-1,2,4-tricarboxylic acid to the reaction solution, stirring at 45-50° C. for 1-5 hours, and post-treating to obtain polyvinyl alcohol modified by phosphoric acid derivatives, wherein the CAS number of 2-phosphinobutane-1,2,4-tricarboxylic acid is 37971-36-1.

[0008] As a further improvement, the raw materials for preparing the nano zirconium oxide ceramics include zirconium oxychloride, yttrium oxide, aluminum nitrate and sodium hydroxide.

[0009] As a further improvement, the preparation method of the nano zirconium oxide ceramic comprises the following steps:

[0010] S5-1, using anhydrous ethanol as a solvent, preparing a zirconium oxychloride solution with a concentration of 0.1-0.4 mol / L, and then adding yttrium oxide and aluminum nitrate to form a reaction solution A; using deionized water as a solvent, preparing a sodium hydroxide solution, and adding a dispersant to form a reaction solution B;

[0011] S5-2, placing the reaction solution B in a constant temperature heating magnetic stirrer, controlling the temperature at 50-60°C, and the stirring rate at 500-800 r / min, and uniformly adding the reaction solution A to the reaction solution B, and after the reaction is completed, standing and aging for 30-60 minutes, and washing the obtained precipitate with deionized water and ethanol for 5-10 times;

[0012] S5-3, placing the washed precipitate obtained in step S5-2 in an oven at 80-100°C and drying it for 8-12 hours to obtain a zirconium oxide precursor, and then grinding and calcining the zirconium oxide precursor to obtain nano zirconium oxide ceramics.

[0013] As a further improvement, the concentration of the sodium hydroxide solution in step S5-1 is 0.2-0.8 mol / L, and the dispersant comprises one or more of PEG400, PEG1000 and PEG2000.

[0014] As a further improvement, the calcination temperature in step S5-3 is 300-500°C, and the calcination time is 1-5h.

[0015] As a further improvement, the coupling agent comprises a silane coupling agent, a titanate coupling agent and a phosphate coupling agent, and the silane coupling agent comprises one or more of KH550, KH560 and KH570.

[0016] As a further improvement, the inorganic filler comprises one or more of nano zirconium oxide particles, nano aluminum oxide particles and sodium aluminum silicate.

[0017] In another aspect, the present invention provides a method for preparing a high-strength nano-modified tooth restoration material, comprising the following steps:

[0018] S10-1, weighing an adhesive and acetone, adding them into a beaker and mixing them, continuing to heat and stir at 40-50° C. until the adhesive is completely dissolved, and cooling to room temperature to obtain an adhesive solution with a concentration of 0.1-0.5 mol / L;

[0019] S10-2, mixing deionized water, ethanol and a coupling agent to form a modified solution and adjusting the pH of the modified solution to 3-4, immersing the nano-zirconia ceramic in the modified solution, and vacuum drying for 3-4 hours after immersing for 5-6 hours under vacuum assistance to obtain a modified nano-zirconia ceramic;

[0020] S10-3, placing the adhesive solution obtained in step S10-1 and the modified nano-zirconia ceramic obtained in step S10-2 in a vacuum dryer, adding polyoxymethylene resin and inorganic filler at the same time, repeatedly evacuating the vacuum to obtain the resin-infiltrated ceramic, and then thermally curing the resin-infiltrated ceramic at 80-100°C for 8-12h to obtain a high-strength nano-modified tooth restoration material.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a high-strength nano-modified tooth restoration material, which uses polyvinyl alcohol modified by a phosphoric acid derivative as an adhesive. This type of adhesive has both a carboxylic acid functional group and a phosphoric acid functional group, which can form a covalent bond with the ceramic phase and undergo a polymerization reaction with the resin phase, thereby promoting the adhesion between the various components and further enhancing the mechanical properties of the resin-permeable ceramic composed of polyoxymethylene resin as the resin phase and nano-zirconia ceramic as the ceramic phase. DETAILED DESCRIPTION

[0022] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0023] In the following examples, the compound monomers and related reagents used can be purchased from the market, among which polyoxymethylene resin was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.; PEG400 was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; polyvinyl alcohol was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.; commercially available nano-zirconia ceramics were purchased from Shanghai Liantian Materials Technology Co., Ltd., with the product number LT-ZrO 2 -006-2.

[0024] The following examples and comparative examples all comprise the following steps:

[0025] Preparation of adhesive:

[0026] Weigh each component and content according to Table 1, dissolve polyvinyl alcohol in deionized water, stir at 90°C for 2 hours to obtain a reaction solution, adjust the pH of the reaction solution to 1, then add 2-phosphinobutane-1,2,4-tricarboxylic acid to the reaction solution, stir at 45°C for 3 hours, evaporate the solvent, and obtain polyvinyl alcohol modified with a phosphoric acid derivative.

[0027] The combinations and contents of the adhesives used in Examples 1-5 and Comparative Examples 1-2 are shown in Table 1.

[0028] Table 1

[0029]

[0030]

[0031] Preparation of nano-zirconia ceramics:

[0032] Step S5-1, using anhydrous ethanol as a solvent, adding zirconium oxychloride to anhydrous ethanol to prepare 5 mL of a zirconium oxychloride solution with a concentration of 0.2 mol / L, and then adding 50 mg of yttrium oxide and 50 mg of aluminum nitrate to form a reaction solution A; using deionized water as a solvent, preparing 5 mL of a sodium hydroxide solution with a concentration of 0.4 mol / L, and adding 10 mg of a PEG400 dispersant to form a reaction solution B;

[0033] Step S5-2, placing the reaction solution B in a constant temperature heating magnetic stirrer, the temperature is controlled at 55°C, the stirring rate is controlled at 600r / min, and the reaction solution A is uniformly added dropwise to the reaction solution B. After the reaction is completed, the reaction solution is allowed to stand for 60 minutes, and the obtained precipitate is washed 5 times with deionized water and ethanol respectively;

[0034] Step S5-3, placing the washed precipitate obtained in step S5-2 in an oven at 85°C for 8 hours to obtain a zirconium oxide precursor, then grinding the zirconium oxide precursor and calcining it at 500°C for 4 hours to obtain nano zirconium oxide ceramics.

[0035] The preparation method of the high-strength nano-modified tooth restoration material of Examples 1-7 and Comparative Example 1 comprises the following steps:

[0036] Step S10-1, adding weighed acetone and adhesive into a beaker, mixing and stirring, continuing heating and stirring at 45° C. until the adhesive is completely dissolved, and cooling to room temperature to obtain an adhesive solution with a concentration of 0.2 mol / L;

[0037] Step S10-2, mixing deionized water, ethanol and a coupling agent in a mass ratio of 15:15:1 to form a modified solution, adjusting the pH of the modified solution to 3, immersing the nano-zirconia ceramic in the modified solution, and vacuum drying for 3 hours after immersion for 5 hours to obtain a modified nano-zirconia ceramic;

[0038] Step S10-3, placing the adhesive solution obtained in step S10-1 and the modified nano-zirconia ceramic obtained in step S10-2 in a vacuum dryer, adding polyformaldehyde resin and inorganic filler at the same time, repeatedly evacuating the vacuum for 3 times to obtain the ceramic infiltrated with the resin, and then thermally curing the ceramic infiltrated with the resin at 100°C for 8 hours to obtain a high-strength nano-modified tooth restoration material.

[0039] Example 1 provides a high-strength nano-modified tooth restoration material, comprising 50 g of polyoxymethylene resin, 50 g of nano-zirconia ceramics, 2 g of coupling agent (KH550 silane coupling agent), 2 g of adhesive (adhesive A) and 2 g of inorganic filler (nano-zirconia particles).

[0040] Example 2 provides a high-strength nano-modified tooth restoration material, comprising 65 g of polyoxymethylene resin, 40 g of nano-zirconia ceramics, 5 g of coupling agent (KH560 silane coupling agent), 5 g of adhesive (adhesive B) and 5 g of inorganic filler (sodium aluminum silicate).

[0041] Example 3 provides a high-strength nano-modified tooth restoration material, comprising 70 g of polyoxymethylene resin, 30 g of nano-zirconia ceramics, 5 g of coupling agent (KH570 silane coupling agent), 4 g of adhesive (adhesive C) and 8 g of inorganic filler (nano-alumina particles).

[0042] The components of a high-strength nano-modified tooth restoration material provided in Example 4 are basically the same as those in Example 1, except that 2 g of adhesive A is replaced by 2 g of adhesive D.

[0043] The components of a high-strength nano-modified tooth restoration material provided in Example 5 are basically the same as those in Example 1, except that 2 g of adhesive A is replaced by 2 g of adhesive E.

[0044] The components and mass of a high-strength nano-modified tooth restoration material provided in Comparative Example 1 are substantially the same as those in Example 1, except that 2 g of adhesive A is replaced with 10 g of adhesive A.

[0045] The components and mass of a high-strength nano-modified tooth restoration material provided in Comparative Example 2 are substantially the same as those in Example 1, except that 2 g of adhesive A is replaced with 0.5 g of adhesive A.

[0046] The components of a high-strength nano-modified tooth restoration material provided in Comparative Example 3 are basically the same as those in Example 1, except that 2 g of adhesive A is replaced by 2 g of polyvinyl alcohol.

[0047] The components of a high-strength nano-modified tooth restoration material provided in Comparative Example 4 are basically the same as those in Example 1, except that 50 g of nano-zirconia ceramic is replaced with 50 g of commercially available nano-zirconia ceramic.

[0048] The test method is as follows:

[0049] According to the standard of GB 30367-2013 dental ceramic materials, the high-strength nano-modified tooth restoration materials prepared in Examples 1-5 and Comparative Examples 1-4 were prepared into 35 mm×4 mm×3 mm specimens, chamfered and polished, and then the flexural strength and flexural modulus were tested according to the three-point bending test.

[0050] The high-strength nano-modified tooth restoration materials prepared in Examples 1-5 and Comparative Examples 1-4 were prepared into samples with a size of 2 mm×2 mm×2 mm and a smooth surface, and the hardness of the samples was measured by a Vickers hardness tester.

[0051] The high-strength nano-modified tooth restoration materials prepared in Examples 1-5 and Comparative Examples 1-4 were made into 44mm×4mm×3mm strips, and after polishing and cutting to form V-grooves with a depth of 1mm and a width of 2mm, the fracture toughness of the samples was tested using a universal tensile testing machine.

[0052] The test results are shown in Table 2, as follows:

[0053] Table 2

[0054]

[0055]

[0056] As can be seen from Examples 1-3, the high-strength nano-modified tooth restoration material provided by the present invention is composed of polyoxymethylene resin, nano-zirconia ceramics, coupling agents, adhesives and inorganic fillers, and has excellent flexural strength, bending modulus, hardness and fracture toughness. The polyoxymethylene resin is used as the resin phase, the nano-zirconia ceramics are used as the ceramic phase, and the polyvinyl alcohol modified by the phosphoric acid derivative provided by the present invention is used as the adhesive to form a resin-infiltrated ceramic network, thereby improving the mechanical properties of this type of tooth restoration material.

[0057] By comparing Examples 4-5 with Example 1, it can be seen that the high-strength nano-modified tooth restoration material provided by the present invention has better flexural strength, bending modulus, hardness and fracture toughness when the mass ratio of polyvinyl alcohol to the phosphoric acid derivative is within an appropriate range.

[0058] Comparison of Comparative Examples 1-2 and Example 1 shows that when the binder content is within an appropriate range, the high-strength nano-modified tooth restoration material prepared by the preparation method provided by the present invention has superior flexural strength, bending modulus, hardness and fracture toughness.

[0059] Comparison of Comparative Examples 3-4 and Example 1 shows that the polyvinyl alcohol modified with the phosphoric acid derivative provided by the present invention is used as an adhesive, and the nano-zirconia ceramic provided by the present invention is used at the same time, so that this type of adhesive has a carboxylic acid functional group and a phosphoric acid functional group, which can not only combine with the oxygen atoms on the surface of the nano-zirconia ceramic to remove water molecules to form a covalent bond, but also react with the resin phase to further enhance the bonding effect, promote the interface compatibility of each component, and enhance the flexural strength, bending modulus, hardness and fracture toughness of the overall tooth restoration material.

[0060] In summary, the present invention provides a high-strength nano-modified tooth restoration material, which is prepared by using polyformaldehyde resin as the resin phase, nano-zirconia ceramic as the ceramic phase, polyvinyl alcohol modified by a phosphoric acid derivative as the adhesive and adding a small amount of inorganic filler and coupling agent. The polyvinyl alcohol modified by the phosphoric acid derivative can not only form a covalent bond with the ceramic phase, but also undergo polymerization reaction with the resin phase, thereby further improving the adhesion between the various components, thereby enhancing the flexural strength, bending modulus, hardness and fracture toughness of the tooth restoration material.

[0061] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength nano-modified tooth restoration material, characterized in that: The raw materials for preparing the high-strength nano-modified tooth restoration material include 35-70g of polyoxymethylene resin, 20-50g of nano-zirconia ceramics, 2-5g of coupling agent, 1-5g of adhesive and 2-8g of inorganic filler by weight, and the adhesive is polyvinyl alcohol modified by phosphoric acid derivatives.

2. A high-strength nano-modified tooth restoration material according to claim 1, characterized in that: The raw materials for preparing the polyvinyl alcohol modified with the phosphoric acid derivative include polyvinyl alcohol and 2-phosphinobutane-1,2,4-tricarboxylic acid, and the mass ratio of the polyvinyl alcohol to the 2-phosphinobutane-1,2,4-tricarboxylic acid is 1:(2-6).

3. A high-strength nano-modified tooth restoration material according to claim 2, characterized in that: The preparation method of the polyvinyl alcohol modified by the phosphoric acid derivative comprises the following steps: dissolving the polyvinyl alcohol in deionized water, stirring at 90-100° C. for 1-2 hours to obtain a reaction solution, adjusting the pH of the reaction solution to 1-3, then adding 2-phosphinobutane-1,2,4-tricarboxylic acid to the reaction solution, stirring at 45-50° C. for 1-5 hours, and post-treating to obtain the polyvinyl alcohol modified by the phosphoric acid derivative.

4. The high-strength nano-modified tooth restoration material according to claim 1, characterized in that: The raw materials for preparing the nano zirconium oxide ceramics include zirconium oxychloride, yttrium oxide, aluminum nitrate and sodium hydroxide.

5. A high-strength nano-modified tooth restoration material according to claim 4, characterized in that: The preparation method of the nano zirconium oxide ceramic comprises the following steps: S5-1, using anhydrous ethanol as a solvent, preparing a zirconium oxychloride solution with a concentration of 0.1-0.4 mol / L, and then adding yttrium oxide and aluminum nitrate to form a reaction solution A; using deionized water as a solvent, preparing a sodium hydroxide solution, and adding a dispersant to form a reaction solution B; S5-2, placing the reaction solution B in a constant temperature heating magnetic stirrer, controlling the temperature at 50-60°C, and the stirring rate at 500-800 r / min, and uniformly adding the reaction solution A to the reaction solution B, and after the reaction is completed, standing and aging for 30-60 minutes, and washing the obtained precipitate with deionized water and ethanol for 5-10 times; S5-3, placing the washed precipitate obtained in step S5-2 in an oven at 80-100°C and drying it for 8-12 hours to obtain a zirconium oxide precursor, and then grinding and calcining the zirconium oxide precursor to obtain nano zirconium oxide ceramics.

6. A high-strength nano-modified tooth restoration material according to claim 5, characterized in that: In the step S5-1, the concentration of the sodium hydroxide solution is 0.2-0.8 mol / L, and the dispersant comprises one or more of PEG400, PEG1000 and PEG2000.

7. The high-strength nano-modified tooth restoration material according to claim 5, characterized in that: The calcination temperature in step S5-3 is 300-500°C, and the calcination time is 1-5h.

8. The high-strength nano-modified tooth restoration material according to claim 1, characterized in that: The coupling agent comprises a silane coupling agent, a titanate coupling agent and a phosphate coupling agent, and the silane coupling agent comprises one or more of KH550, KH560 and KH570.

9. The high-strength nano-modified tooth restoration material according to claim 1, characterized in that: The inorganic filler comprises one or more of nano zirconium oxide particles, nano aluminum oxide particles and sodium aluminum silicate.

10. A method for preparing a high-strength nano-modified tooth restoration material according to any one of claims 1 to 9, characterized in that: The following steps are involved: S10-1, weighing an adhesive and acetone, adding them into a beaker and mixing them, continuing to heat and stir at 40-50° C. until the adhesive is completely dissolved, and cooling to room temperature to obtain an adhesive solution with a concentration of 0.1-0.5 mol / L; S10-2, mixing deionized water, ethanol and a coupling agent to form a modified solution and adjusting the pH of the modified solution to 3-4, immersing the nano-zirconia ceramic in the modified solution, and vacuum drying for 3-4 hours after immersing for 5-6 hours under vacuum assistance to obtain a modified nano-zirconia ceramic; S10-3, placing the adhesive solution obtained in step S10-1 and the modified nano-zirconia ceramic obtained in step S10-2 in a vacuum dryer, adding polyformaldehyde resin and inorganic filler at the same time, repeatedly evacuating the vacuum to obtain the resin-infiltrated ceramic, and then thermally curing the resin-infiltrated ceramic at 80-100°C for 8-12h to obtain a high-strength nano-modified tooth restoration material.

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