A wear-resistant functional denture base material and its production process

Abstract

The present invention relates to the technical field of denture base materials, and discloses a wear-resistant functional denture base material and a production process thereof. The denture base material comprises the following raw materials: polymethyl methacrylate, denture water, an initiator, an accelerator, a wear-resistant additive, and a functional composite. By adding the wear-resistant additive, a diffusion enhancement effect can be achieved in the denture base material, thereby reducing the wear rate of the denture base material, improving the hardness and wear resistance of the denture base material, and helping to reduce the replacement frequency of the denture base; by adding the functional composite, a toughening effect can be achieved, the bending strength of the denture base material can be improved, the fracture of the denture base material can be avoided, and the denture base material can be given long-lasting antibacterial properties, thereby reducing the erosion of the denture base material by microorganisms and extending the service life of the denture base.

Description

Technical Field

[0001] The present invention relates to the technical field of denture base materials, and in particular to a wear-resistant functional denture base material and a production process thereof. Background Art

[0002] With the continuous improvement of living standards and the intensification of population aging, people pay more attention to oral health, and the demand for dentures is also increasing. Dentures, also known as false teeth, have the functions of helping to chew food, maintain facial contours, prevent tooth displacement, prevent oral diseases, improve pronunciation, etc., which are of great significance to improving the quality of life. Denture base is an important component of full dentures, providing support and attachment basis for artificial teeth, reducing pressure and discomfort on oral tissues, and preventing dentures from moving or falling off in the mouth. Denture base materials are usually made of resin materials or metal materials. Denture bases made of metal materials may cause allergies and are heavy and expensive. Therefore, research on resin materials as denture base materials is very necessary.

[0003] Polymethyl methacrylate (PMMA) is a medical polymer material, also known as organic glass. It has the advantages of stable chemical properties, excellent transparency and gloss, non-toxic and environmentally friendly, light weight, easy processing, good biocompatibility, and not easy to cause allergies. It is a good material for preparing denture bases. However, polymethyl methacrylate also has shortcomings. The surface hardness of polymethyl methacrylate is not high and it is not scratch-resistant. During use, the surface is prone to wear and scratching, causing the denture base to break and be damaged. In addition, polymethyl methacrylate does not have antibacterial properties. Microorganisms can easily grow on the surface of the denture base to form plaque, causing the denture base material to be eroded, shortening the service life of the denture base, and causing oral diseases, which is not conducive to oral health. Therefore, it is very necessary to improve the wear resistance and antibacterial properties of polymethyl methacrylate materials. Patent publication number CN108743403B discloses a composite material for denture bases that can continuously release negative ions. By in-situ generating nano-silica particles on the surface of hokutolite and then grafting acrylic monomers on the surface of the nano-silica, a composite material with the same chemical structure as the denture base material polymethyl methacrylate is obtained. This promotes the dispersion of hokutolite, optimizes the compatibility between the two, and improves the mechanical properties of the denture base material. At the same time, the addition of nano-silica makes the material exhibit better physical and mechanical properties. However, this patent does not take into account the important role of the wear resistance and antibacterial properties of the denture base material in actual applications. Therefore, the present invention provides a denture base material with excellent wear resistance and antibacterial properties, and can also increase the service life of the denture base material. Summary of the Invention

[0004] In order to solve the problems mentioned in the background technology, the purpose of the present invention is to provide a wear-resistant functional denture base material and a production process thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A wear-resistant functional denture base material comprises the following raw materials in parts by weight: 85-100 parts of polymethyl methacrylate, 80-90 parts of denture water, 1-3 parts of initiator, 0.2-0.5 parts of accelerator, 3-6 parts of wear-resistant additive, and 2.5-5.5 parts of functional compound.

[0007] Furthermore, the dental tray water is methyl methacrylate; the initiator is di-tert-butyl peroxide or benzoyl peroxide; and the accelerator is sodium p-toluenesulfinate.

[0008] Furthermore, the preparation method of the wear-resistant additive comprises the following steps:

[0009] Step S1: adding nanohydroxyapatite to deionized water and dispersing it ultrasonically to form a nanohydroxyapatite suspension; adding sepiolite fiber to deionized water and dispersing it ultrasonically to form a sepiolite fiber suspension; and mixing the two suspensions to obtain a mixed suspension;

[0010] Step S2: Take liquid carboxyl-terminated fluororubber and add it to N,N-dimethylformamide, add the mixed suspension, stir evenly, increase the temperature to 80-90°C, add the catalyst, stir and react for 4-6 hours, separate the product, wash, and dry to obtain a wear-resistant additive.

[0011] By adopting the above technical solution, the hydroxyl groups on the surface of nanohydroxyapatite and the hydroxyl groups on the surface of sepiolite fiber can undergo esterification reaction with the carboxyl groups in the liquid carboxyl-terminated fluororubber structure under the action of a catalyst, organically combining the nanohydroxyapatite and sepiolite fiber to obtain a wear-resistant additive. The wear-resistant additive prepared by the present invention takes nano-hydroxyapatite and sepiolite fibers as a matrix and is organically modified by liquid end-carboxyl fluororubber, which effectively improves the compatibility of nano-hydroxyapatite and sepiolite fibers with the matrix and avoids the agglomeration of nano-hydroxyapatite and sepiolite fibers in the matrix material. The wear-resistant additive can be evenly dispersed in the matrix material to play a dispersion enhancement role, and effectively bears the load as a rigid support point, improves the hardness, reduces the cutting effect of abrasive particles, reduces the wear rate of the matrix material, and improves the wear resistance. At the same time, the combination of the two can produce a ball effect, changing the friction form from sliding friction to a mixed form of sliding and rolling friction, effectively slowing down crack propagation and reducing wear. In addition, the fluorine-containing molecular chain can reduce the surface energy of nano-hydroxyapatite and sepiolite fibers, helps to maintain a low friction coefficient of the matrix material, and can also inhibit severe abrasive wear caused by agglomeration, playing a synergistic wear-resistant role, thereby effectively improving the wear resistance of the denture base material, reducing the probability of wear and abrasion, and reducing the replacement frequency of the denture base.

[0012] Furthermore, in step S1, the mass fraction of the nano-hydroxyapatite suspension is 1-3%; the mass fraction of the sepiolite fiber suspension is 2-5%.

[0013] Furthermore, in step S2, the catalyst is p-toluenesulfonic acid or calcium methanesulfonate.

[0014] Furthermore, the preparation method of the functional complex comprises the following steps:

[0015] Step A: Sodium borohydride is added to dimethyl sulfoxide, nitrogen is introduced, the temperature is raised to 115-125°C, polyetheretherketone is added, and after 6-8 hours, the product is separated, washed, and dried to obtain hydroxylated polyetheretherketone;

[0016] Step B: adding hydroxylated polyetheretherketone to N,N-dimethylformamide, adding p-coumaric acid and p-toluenesulfonic acid, heating to react, separating the product, and cooling to room temperature to obtain a functional complex.

[0017] By adopting the above technical solution, the carbonyl group in the polyetheretherketone can be reduced to a hydroxyl group under the reducing action of sodium borohydride to obtain a hydroxylated polyetheretherketone. Under the action of p-toluenesulfonic acid, the hydroxyl group of the hydroxylated polyetheretherketone can undergo an esterification reaction with the carboxyl group in the p-coumaric acid structure to obtain a functional complex. The polyetheretherketone in the functional composite structure prepared by the present invention has good mechanical properties and biosafety, and can be applied to denture base materials. The functional composite structure contains introduced hydroxyl groups, which can produce hydrogen bonds with the ester groups in the polymethyl methacrylate matrix structure to form a semi-interpenetrating polymer network structure, which enhances the density and stability of the matrix material to a certain extent, can play a role in toughening the matrix material, improve the bending strength of the matrix material, and avoid the denture base from being easily broken. At the same time, the natural antibacterial substance p-coumaric acid is introduced into the structure, which has a broad-spectrum antibacterial effect, can exist in the matrix material for a long time, will not easily migrate or precipitate, and has a long-lasting antibacterial effect, which is beneficial to reducing oral diseases caused by microorganisms, reducing the probability of plaque generation, reducing the degree of damage to the denture base material, and extending the service life of the denture base.

[0018] Furthermore, in step B, the temperature of the temperature-raising reaction is set to 85-100° C. and the time is 6-8 hours.

[0019] A production process for a wear-resistant functional denture base material comprises the following steps:

[0020] Step 1: Stir and mix polymethyl methacrylate, initiator, wear-resistant additive, and functional compound to obtain a mixed base material;

[0021] Step 2: Add denture water and accelerator to the mixed base material, stir for 10-30 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 70-80℃ for 1-2 hours, then increase the temperature to 90-110℃ and heat at a constant temperature for 40-60 minutes to obtain the denture base material.

[0022] Beneficial effects of the present invention:

[0023] The present invention adds wear-resistant additives and functional complexes to the preparation process of denture base materials, so that the prepared denture base materials have the characteristics of high hardness, excellent wear resistance, good bending strength and excellent antibacterial properties. It can reduce the probability of wear and abrasion, reduce the replacement frequency of denture base materials, avoid the fracture of denture base materials, prevent microorganisms from eroding the denture base materials, resulting in a shortened service life and endangering oral health.

[0024] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 The scanning electron microscope images of the sepiolite fiber and the wear-resistant additive in the present invention, wherein (A) is the sepiolite fiber and (B) is the wear-resistant additive;

[0027] Figure 2 This is the infrared spectrum of the functional complex of the present invention. DETAILED DESCRIPTION

[0028] 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 any creative efforts shall fall within the scope of protection of the present invention.

[0029] The preparation methods of the wear-resistant additives and functional composites in the following examples and comparative examples are as follows:

[0030] 1. Preparation of wear-resistant additives

[0031] Step S1: adding nanohydroxyapatite to deionized water and dispersing it by ultrasonic to form a nanohydroxyapatite suspension with a mass fraction of 2%, adding sepiolite fiber to deionized water and dispersing it by ultrasonic to form a sepiolite fiber suspension with a mass fraction of 4%, and mixing the two suspensions to obtain a mixed suspension;

[0032] Step S2: Take 3 g of liquid carboxyl-terminated fluororubber and add it to N,N-dimethylformamide, add 250 mL of the mixed suspension, stir evenly, raise the temperature to 90°C, add 1.5 g of p-toluenesulfonic acid, stir and react for 6 hours, separate the product, wash, and dry to obtain a wear-resistant additive.

[0033] The morphology of sepiolite fibers and wear-resistant additives was observed using a Hitachi-S-2150 scanning electron microscope. Figure 1 As can be seen from the figure, (A) is the surface of the sepiolite fiber is smooth and has no attachments, (B) is the surface of the wear-resistant additive grafted with particles, which shows that the nano-hydroxyapatite and sepiolite fiber have achieved an organic combination.

[0034] 2. Preparation of functional complexes

[0035] Step A: Add 120 mg of sodium borohydride to dimethyl sulfoxide, introduce nitrogen, raise the temperature to 120°C, add 5.5 g of polyetheretherketone, and after 8 hours, separate the product, wash, and dry to obtain hydroxylated polyetheretherketone;

[0036] Step B: Add 5 g of hydroxylated polyetheretherketone to N,N-dimethylformamide, add 3.8 g of p-coumaric acid and 1.8 g of p-toluenesulfonic acid, heat to 95°C, react for 6 hours, separate the product, and cool to room temperature to obtain a functional complex.

[0037] The functional complex was tested by infrared spectroscopy using Nicolet iS10 Fourier transform infrared spectrometer. Figure 2 As shown in the figure, analysis shows that in the infrared spectrum of the functional complex, 3346cm -1 The absorption peak of hydroxyl group appeared at 3045cm -1 The absorption peak of the carbon-hydrogen bond in the benzene ring appears at 3018 cm -1 The absorption peak of the carbon-hydrogen bond in the carbon-carbon double bond appears at 1748 cm -1 The absorption peak of the carbon-oxygen double bond in the ester group appeared at 1713 cm -1 The absorption peak of the carbon-oxygen double bond in the carbonyl group appears at

[0038] Example 1

[0039] Production of denture base materials

[0040] Step 1: 85g of polymethyl methacrylate, 1g of benzoyl peroxide, 3g of wear-resistant additive, and 2.5g of functional compound are stirred and mixed to obtain a mixed base;

[0041] Step 2: Add 80g of methyl methacrylate and 0.2g of sodium p-toluenesulfinate to the mixed base material, stir for 10 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 70°C for 1 hour, then increase the temperature to 90°C and heat at a constant temperature for 40 minutes to obtain the denture base material.

[0042] Example 2

[0043] Production of denture base materials

[0044] Step 1: 90g of polymethyl methacrylate, 2g of benzoyl peroxide, 4g of wear-resistant additive, and 3.5g of functional compound are stirred and mixed to obtain a mixed base;

[0045] Step 2: Add 85g of methyl methacrylate and 0.3g of sodium p-toluenesulfinate to the mixed base material, stir for 20 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 100°C and heat at a constant temperature for 50 minutes to obtain the denture base material.

[0046] Example 3

[0047] Production of denture base materials

[0048] Step 1: 95g of polymethyl methacrylate, 2.5g of benzoyl peroxide, 5g of wear-resistant additive, and 4.5g of functional compound are stirred and mixed to obtain a mixed base;

[0049] Step 2: Add 85g of methyl methacrylate and 0.4g of sodium p-toluenesulfinate to the mixed base material, stir for 25 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 105°C and heat at a constant temperature for 55 minutes to obtain the denture base material.

[0050] Example 4

[0051] Production of denture base materials

[0052] Step 1: 100g of polymethyl methacrylate, 3g of benzoyl peroxide, 6g of wear-resistant additive, and 5.5g of functional compound are stirred and mixed to obtain a mixed base;

[0053] Step 2: Add 90g of methyl methacrylate and 0.5g of sodium p-toluenesulfinate to the mixed base material, stir for 30 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 80°C for 2 hours, then increase the temperature to 110°C and heat at a constant temperature for 60 minutes to obtain the denture base material.

[0054] Comparative Example 1

[0055] Production of denture base materials

[0056] Step 1: Stir and mix 90g of polymethyl methacrylate, 2g of benzoyl peroxide, and 4g of wear-resistant additive to obtain a mixed base;

[0057] Step 2: Add 85g of methyl methacrylate and 0.3g of sodium p-toluenesulfinate to the mixed base material, stir for 20 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 100°C and heat at a constant temperature for 50 minutes to obtain the denture base material.

[0058] Comparative Example 2

[0059] Production of denture base materials

[0060] Step 1: 90g of polymethyl methacrylate, 2g of benzoyl peroxide, and 3.5g of the functional compound are stirred and mixed to obtain a mixed base;

[0061] Step 2: Add 85g of methyl methacrylate and 0.3g of sodium p-toluenesulfinate to the mixed base material, stir for 20 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 100°C and heat at a constant temperature for 50 minutes to obtain the denture base material.

[0062] Comparative Example 3

[0063] Production of denture base materials

[0064] Step 1: 90g of polymethyl methacrylate, 2g of benzoyl peroxide, 2g of nanohydroxyapatite, 2g of sepiolite fiber, and 3.5g of the functional compound are stirred and mixed to obtain a mixed base;

[0065] Step 2: Add 85g of methyl methacrylate and 0.3g of sodium p-toluenesulfinate to the mixed base material, stir for 20 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 100°C and heat at a constant temperature for 50 minutes to obtain the denture base material.

[0066] Comparative Example 4

[0067] Production of denture base materials

[0068] Step 1: 90g of polymethyl methacrylate, 2g of benzoyl peroxide, 4g of wear-resistant additive, and 3.5g of p-coumaric acid were stirred and mixed to obtain a mixed base;

[0069] Step 2: Add 85g of methyl methacrylate and 0.3g of sodium p-toluenesulfinate to the mixed base material, stir for 20 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 75°C for 1.5 hours, then increase the temperature to 100°C and heat at a constant temperature for 50 minutes to obtain the denture base material.

[0070] Performance testing

[0071] The denture base materials prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were prepared into samples that met the test standards. The hardness of the samples was tested according to the standard GB / T 2411-2008; the wear resistance of the samples was tested according to the standard GB / T 5478-2008; and the bending strength of the samples was tested according to the standard GB / T 9341-2008. After the samples were placed for 60 days, the antibacterial properties of the samples were tested using the following method: 1 mL of a 10 -5 CFU / mL of Staphylococcus aureus liquid was added to the surface of the sterilized sample and incubated at 35°C for 6 hours. 20 μL of the liquid was evenly spread on the culture medium. After incubation at 35°C for 24 hours, the number of colonies in the culture medium was counted as W. A blank test was performed, and the number of colonies in the culture medium was counted as X. The antibacterial rate was calculated using the formula: Antibacterial rate (%) = [(XW) / X] × 100%. The test results are shown in the following table:

[0072] Hardness (HD) Wear rate (%) Flexural strength (MPa) Antibacterial rate (%) Example 1 60.9 0.16 117.6 99.6 Example 2 62.3 0.11 118.6 99.9 Example 3 61.5 0.14 117.9 99.7 Example 4 61.8 0.13 118.4 99.8 Comparative Example 1 60.1 0.21 65.8 56.3 Comparative Example 2 42.3 1.29 116.8 99.0 Comparative Example 3 51.5 0.86 117.1 99.4 Comparative Example 4 60.1 0.19 68.8 62.6

[0073] It can be seen from the above table that the denture base materials prepared in Examples 1 to 4 of the present invention have the characteristics of high hardness, excellent wear resistance, good bending strength, and excellent antibacterial properties. Comparative Example 1 added wear-resistant additives but no functional composites, and had excellent hardness and wear resistance, but poor bending strength and antibacterial properties; Comparative Example 2 added functional composites but no wear-resistant additives, and had excellent bending strength and antibacterial properties, but poor hardness and wear resistance; Comparative Example 3 added nanohydroxyapatite, sepiolite fiber and functional composites, and the unmodified nanohydroxyapatite and sepiolite fibers agglomerated in the matrix material, which had poor effect on improving hardness and wear resistance, and could not utilize fluorine-containing molecular chains to reduce surface energy, inhibit abrasive wear, and improve wear resistance, so the hardness and wear resistance were poor, but the bending strength and antibacterial properties were excellent; Comparative Example 4 added wear-resistant additives and p-coumaric acid, and had excellent hardness and wear resistance, but since p-coumaric acid is a small molecule natural antibacterial substance, it is easy to migrate or precipitate in the matrix, so the antibacterial properties are poor, and polyetheretherketone cannot be used to improve the bending strength of the matrix material, so the bending strength is poor.

[0074] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A wear-resistant functional denture base material, characterized in that: The invention comprises the following raw materials in parts by weight: 85-100 parts of polymethyl methacrylate, 80-90 parts of dental tray water, 1-3 parts of initiator, 0.2-0.5 parts of accelerator, 3-6 parts of wear-resistant additive, and 2.5-5.5 parts of functional compound; The wear-resistant additive is prepared by organically combining nano-hydroxyapatite and sepiolite fibers by utilizing the principle that the carboxyl groups in the liquid carboxyl-terminated fluororubber structure can undergo an esterification reaction with the hydroxyl groups on the surface of nano-hydroxyapatite and the hydroxyl groups on the surface of sepiolite fibers under the action of a catalyst; The catalyst is p-toluenesulfonic acid or calcium methanesulfonate; The functional compound is prepared by first using sodium borohydride as a reducing agent to reduce the carbonyl group in the polyetheretherketone to a hydroxyl group to prepare the hydroxylated polyetheretherketone, and then undergoing an esterification reaction with the carboxyl group in the coumaric acid structure.

2. The wear-resistant functional denture base material according to claim 1, characterized in that: The denture water is methyl methacrylate; the initiator is di-tert-butyl peroxide or benzoyl peroxide; and the accelerator is sodium p-toluenesulfinate.

3. The wear-resistant functional denture base material according to claim 1, characterized in that: The preparation method of the wear-resistant additive comprises the following steps: Step S1: adding nanohydroxyapatite to deionized water and dispersing it ultrasonically to form a nanohydroxyapatite suspension; adding sepiolite fiber to deionized water and dispersing it ultrasonically to form a sepiolite fiber suspension; and mixing the two suspensions to obtain a mixed suspension; Step S2: Take liquid carboxyl-terminated fluororubber and add it to N,N-dimethylformamide, add the mixed suspension, stir evenly, increase the temperature to 80-90°C, add the catalyst, stir and react for 4-6 hours, separate the product, wash, and dry to obtain a wear-resistant additive.

4. The wear-resistant functional denture base material according to claim 3, characterized in that: In step S1, the mass fraction of the nano-hydroxyapatite suspension is 1-3%; the mass fraction of the sepiolite fiber suspension is 2-5%.

5. The wear-resistant functional denture base material according to claim 1, characterized in that: The preparation method of the functional complex comprises the following steps: Step A: Sodium borohydride is added to dimethyl sulfoxide, nitrogen is introduced, the temperature is raised to 115-125°C, polyetheretherketone is added, and after 6-8 hours, the product is separated, washed, and dried to obtain hydroxylated polyetheretherketone; Step B: adding hydroxylated polyetheretherketone to N,N-dimethylformamide, adding p-coumaric acid and p-toluenesulfonic acid, heating to react, separating the product, and cooling to room temperature to obtain a functional complex.

6. The wear-resistant functional denture base material according to claim 5, characterized in that: In step B, the temperature of the temperature-raising reaction is set to 85-100° C. and the time is 6-8 hours.

7. A production process for the wear-resistant functional denture base material according to claim 1, characterized in that: The following steps are involved: Step 1: Stir and mix polymethyl methacrylate, initiator, wear-resistant additive, and functional compound to obtain a mixed base material; Step 2: Add denture water and accelerator to the mixed base material, stir for 10-30 minutes, and after it forms a mass, transfer it to a mold. Heat the mold in a constant temperature water bath at 70-80℃ for 1-2 hours, then increase the temperature to 90-110℃ and heat at a constant temperature for 40-60 minutes to obtain the denture base material.

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