CN111494218B - Bioactive glass - Google Patents

Abstract

The present invention relates to a bioactive glass, belonging to the field of materials. Compared with basic glass, the glass of the present invention further contains a certain amount of lithium oxide and calcium fluoride, the glass has a fast mineralization speed, can quickly form hydroxyapatite, has good biological activity, and can be used in teeth and the like.

Description

A bioactive glass

Technical Field

The invention relates to bioactive glass and belongs to the field of materials.

Background technique

Bioactive glass was developed by Professor Hench of the University of Florida in 1969. In addition to the 45S5 bioactive glass formula developed by Professor Hench, a variety of bioactive glasses have been continuously developed. Although these new bioactive glasses have improved their mechanical properties and biocompatibility to a certain extent, the 45S5 bioactive glass formula is still recognized as the formula with better bioactivity.

Bioactive glass is a type of glass with a special composition and structure. This special composition and structure give it good bioactivity and can be used as a bioactive material for the repair of human teeth, bones, skin, etc. The bioactivity of bioactive glass is the result of a series of complex physiological and chemical reactions on the glass surface under physiological conditions. When bioactive glass is applied to the human body, it can closely exchange ions with human body fluids, and eventually form a hydroxyapatite layer similar to the composition of teeth, bones, skin, etc. At present, bioactive glass has been successfully used in the treatment and repair of bone injuries and periodontal defects. In recent years, the use of bioactive glass with calcium, phosphorus, and silicon components to treat tooth sensitivity has become a research hotspot. When bioactive glass is applied to the exposed dentinal tubules, a layer of apatite gradually adheres to the dentinal tubules, and apatite crystals are formed in the tubules, thereby sealing the exposed dentinal tubules and effectively improving dentinal hypersensitivity.

Although 45S5 bioactive glass has a certain mineralization anti-allergic effect, it takes a long time to mineralize, that is, it takes a long time to take effect, and it cannot quickly and effectively solve the problem of dentin hypersensitivity. Therefore, it is necessary to further improve its bioactivity in order to obtain a bioactive glass with fast speed and lasting effect, which can prevent, relieve and/or cure a variety of symptoms including tooth hypersensitivity faster and better.

Summary of the invention

The present invention provides a bioactive glass with better bioactivity based on 45S5 bioactive glass. When the bioactive glass provided by the present invention is used, hydroxyapatite can be quickly formed. When used in oral teeth, it can quickly seal dentinal tubules, prevent, alleviate and/or cure tooth allergy symptoms, and has a significant anti-sensitivity effect. It also has the functions of preventing oral caries and repairing damaged tooth enamel.

The bioactive glass of the present invention can form a hydroxyapatite (HCA) layer in vitro when placed in a simulated body fluid (SBF). The formation of hydroxyapatite begins when the bioactive glass is in contact with the simulated body fluid. In the case of the present invention, if the bioactive glass is exposed to a simulated body fluid (SBF) and forms a HCA crystal layer within 24 hours, then the glass is considered to be bioactive.

The bioactive glass provided by the present invention comprises, by weight of oxides, the following:

The bioactive glass provided by the present invention contains _Li2O (lithium oxide). The radius of lithium ions is much smaller than that of sodium ions, so adding lithium ions can make the glass structure looser. In the present invention, adding 0.5% to 2.5% (by oxide mass) of _Li2O can make the glass structure loose, the glass network is easy to disintegrate, and the glass activity is greater, while not affecting the glass forming performance of the glass, which is beneficial to improving the anti-allergic speed and effect of the active glass.

The bioactive glass provided by the present invention contains an appropriate amount of _CaF2 (calcium fluoride), the appropriate amount being 2.0% to 9.0% (calculated by oxide mass). The appropriate amount of _CaF2 is beneficial to increasing the speed of the bioactive glass forming hydroxyapatite in the human body fluid environment, and is beneficial to increasing the anti-allergic speed and effect of the active glass.

The right amount of _CaF2 and _Li2O is conducive to increasing the speed of forming hydroxyapatite in the human body fluid environment of bioactive glass, while taking into account the glass forming performance. The inventors found that when the _CaF2 in the bioactive glass is 5.55% to 7.66%, the _Li2O is 0.84% to 1.25%, and the mass ratio of _Li2O to _CaF2 is 0.11 to 0.16, the activity of the bioactive glass is more significantly improved.

Adding barium to the glass will replace part of the Ca ²⁺ in the generated hydroxyapatite, thereby generating mixed Ba ²⁺ /Ca ²⁺ hydroxyapatite. Since the hydroxyapatite substituted with Ba ²⁺ has a lower solubility than the unsubstituted hydroxyapatite, the deposition rate of the generated hydroxyapatite increases, showing that the glass is more active. The bioactive glass provided by the present invention contains an appropriate amount of BaO (barium oxide), the appropriate amount is 1.0% to 3.0% (by oxide mass), and the appropriate amount of BaO is conducive to increasing the speed of hydroxyapatite formation of the bioactive glass in the human body fluid environment, and is also conducive to improving the acid corrosion resistance of the glass, thereby helping to increase the anti-allergic speed of the bioactive glass and making the effect more lasting.

Magnesium exists as a network modifier in glass. When added to bioactive glass, the glass structure will be distorted, the original structure of the bioactive glass will be destroyed, the glass will have a faster ion release rate, and the activity will be improved. The bioactive glass provided by the present invention contains an appropriate amount of MgO (magnesium oxide), the appropriate amount is 1.0% to 3.0% (by oxide mass), and the appropriate amount of MgO is conducive to improving the acid corrosion resistance of the bioactive glass, thereby helping to improve the anti-allergic speed of the bioactive glass and making the effect more lasting.

The bioactive glass provided by the present invention further contains SiO ₂ (silicon dioxide), P ₂ O ₅ (phosphorus pentoxide), Na ₂ O (sodium oxide), and CaO (calcium oxide) in terms of oxide mass.

SiO ₂ forms an amorphous network of bioactive glass, and the percentage of SiO ₂ affects its network connectivity. The bioactive glass provided by the present invention contains 35.0% to 40.0% SiO ₂ by oxide mass, which is beneficial to improve the activity of the bioactive glass when combined with other components.

The phosphate ions released from the surface of the bioactive glass are helpful for the formation of hydroxyapatite. Although hydroxyapatite can be formed without the bioactive glass providing phosphate ions, the phosphate ions provided by the bioactive glass can increase the formation speed of hydroxyapatite. The bioactive glass provided by the present invention contains 8.0% to 11.0% P ₂ O ₅ by weight of oxide, and is beneficial to improve the activity of the bioactive glass when combined with other components.

The release of calcium ions from the surface of the bioactive glass helps to form a layer rich in calcium phosphate on the glass surface. The bioactive glass provides calcium ions to increase the formation rate of the calcium phosphate-rich layer. The bioactive glass provided by the present invention contains 18.0% to 22.0% CaO by weight of oxide, and is combined with other components to improve the activity of the bioactive glass.

The bioactive glass provided by the present invention contains 18.0% to 22.0% Na ₂ O by weight of oxides, and is combined with other components to improve the activity of the bioactive glass.

The bioactive glass provided by the present invention can be used for purposes including but not limited to replenishing minerals to tooth structures, serving as a dentin sealant, replenishing minerals for enamel, replenishing minerals for early caries, replenishing minerals for carious dentin, preventing caries, resisting caries, repairing corrosion, and serving as a sealant for holes and cracks. It can also be included in toothpaste, mouthwash, gel, and restorative materials, or used to reduce dentin sensitivity, and/or enhance tissue bonding, etc.

The bioactive glass provided by the present invention can be introduced into toothpaste, mouthwash, dentifrice, chewing gum, gel, etc. and used in the oral cavity. The bioactive glass provided by the present invention can be used as a material, preparation or composition for repairing bones or skin and used for repairing bones or skin.

The bioactive glass provided by the present invention can be applied topically, such as being prepared into an emulsion, lotion, ointment, powder, gel or paste and applied to teeth or skin; for example, it can be prepared into a toothpaste containing bioactive glass and applied to the teeth of patients suffering from tooth decay, periodontal disease, hypersensitive teeth, etc.; it can be used to treat periodontal disease, to prevent and/or treat tooth decay; it can also increase the rate of hydroxyapatite deposition, so that the surface of dentinal tubules is closed, and is used to treat tooth hypersensitivity.

The bioactive glass of the present invention can be formulated with other necessary auxiliary agents to form a composition and used in the above-mentioned various preparations or uses. The auxiliary agent can be any component other than the bioactive glass, including but not limited to components added to prepare the composition into a form suitable for use, components to make the composition more stable for a long time, etc.

The bioactive glass of the present invention or the composition comprising the bioactive glass may further comprise one or more antibacterial agents, one or more tartar control agents, and one or more structure building agents.

In the composition, the bioactive glass may be present in an amount of 0.1% to 50.0% based on the total mass of the composition. In some embodiments, in the composition, the bioactive glass is present in an amount of 1.0% to 20.0% based on the total mass of the composition. In some embodiments, in the composition, the bioactive glass is present in an amount of 1.0% to 10.0% based on the total mass of the composition. The auxiliary agent may include a filler, a lubricant and/or a binder, etc.

In some embodiments, a composition comprising the aforementioned bioactive glass and adjuvants further comprises an antibacterial agent, a tartar control agent, a structure building agent, or a combination thereof; the bioactive glass is present in an amount of 0.1% to 50.0% based on the total mass of the composition; the composition is an emulsion, a lotion, an ointment, a powder, a gel or a paste.

The bioactive glass of the present invention or a composition comprising the bioactive glass of the present invention can be used in a method for preventing or treating tooth hypersensitivity, a method for partially or completely blocking dentinal tubules, a method for preventing incipient caries, a method for preventing or treating tooth decay, a method for remineralizing incipient caries, a method for remineralizing enamel, a method for sealing cracks in tooth structure, a method for sealing pits in tooth structure, a method for lining tooth structure, a method for covering a dental pulp, or/and a method for treating tooth structure after periodontal surgery. In some embodiments, the bioactive glass of the present invention or a composition comprising the bioactive glass of the present invention can be used in a method for preventing or treating tooth hypersensitivity, a method for partially or completely blocking dentinal tubules, a method for remineralizing incipient caries, a method for sealing cracks in tooth structure, or a method for sealing pits in tooth structure. In some embodiments, the bioactive glass of the present invention or a composition comprising the bioactive glass of the present invention can be used in a method for partially or completely blocking dentinal tubules, a method for sealing cracks in tooth structure, or a method for sealing pits in tooth structure.

The bioactive glass of the present invention or the composition comprising the bioactive glass of the present invention can be used in fields including but not limited to tooth repair, bone repair, skin repair and/or as a drug carrier.

A method for preventing or treating tooth decay comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for preventing incipient tooth decay comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for treating tooth hypersensitivity comprising contacting one or more hypersensitive teeth with an effective amount of said bioactive glass. A method for partially or completely sealing dentin tubules comprising contacting said tubules with an effective amount of a bioactive glass. A method for remineralizing enamel comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for remineralizing incipient tooth decay comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for sealing cracks in a tooth structure comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for sealing pits in a tooth structure comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for lining a tooth structure comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for covering a dental pulp comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for treating a tooth structure after periodontal surgery comprising contacting a tooth structure with an effective amount of a bioactive glass. A method for repairing bone or skin comprises contacting the bone or skin to be repaired with an effective amount of bioactive glass.

The bioactive glass provided by the present invention can be mineralized faster, and when applied to teeth, can better prevent, alleviate and/or cure symptoms such as tooth allergy and dental caries. The bioactive glass of the present invention has enhanced biological activity, and its hydroxyapatite deposition rate is accelerated, and its wound healing rate is accelerated. Its mineralization rate is faster than that of 45S5, and hydroxyapatite can be quickly formed, achieving the effects of quickly closing dentinal tubules, alleviating/curing tooth allergy symptoms, etc.

Remineralization refers to any substance that is capable of forming hydroxyapatite.

The term "tooth structure" refers to all parts of a tooth, including but not limited to enamel, dentin, pulp, root structure, cementum, root material, coronal material, all dental artifacts, etc.

For the purposes of the present invention, the tissue may be bone tissue, cartilage, soft tissue including connective tissue, and dental tissue including calcified dental tissue such as enamel and dentin.

The bioactive glass of the present invention can be prepared according to the following method, which comprises the following steps:

1) Weigh the raw materials of each component according to the formula ratio, mix them evenly, and put them into a crucible;

2) placing the crucible in an electric furnace, setting the heating rate of the electric furnace to 400° C. to 450° C. within 0.5 h to 1.5 h, then to 900° C. to 950° C. within 0.5 h to 1.5 h, then to 1300° C. to 1400° C. within 1.5 h to 2.5 h, and finally keeping the temperature at 1300° C. to 1400° C. for 1 h to 4 h to melt and clarify the glass liquid to obtain molten glass liquid;

3) quenching the molten glass to obtain bioactive glass; optionally including

4) The obtained bioactive glass is dried in an oven at 100°C to 120°C for 4h to 8h, then ball-milled with a planetary ball mill for 2h to 8h (the medium is anhydrous ethanol, and the rotation speed is 150r/min to 500r/min), passed through a 400-600 mesh standard sieve, and dried at 100°C to 120°C for 2h to 6h to obtain the bioactive glass.

In some embodiments, the bioactive glass of the present invention can be prepared according to the following method, which comprises the following steps:

1) Weigh the raw materials of each component according to the formula ratio, mix them evenly in a mortar, and put them into a corundum crucible;

2) placing the crucible in a high-temperature electric furnace at room temperature, setting the furnace heating rate to 400°C to 450°C in 1 hour, then setting the furnace heating rate to 900°C to 950°C in 1 hour, and then slowly heating to 1300°C to 1400°C in 2 hours to fully decompose and melt the component raw materials, and finally keeping the temperature at 1300°C to 1400°C for 2 hours to melt and clarify the glass liquid to obtain molten glass liquid;

3) directly quenching the molten glass liquid with water to obtain bioactive glass; optionally including

4) The obtained bioactive glass particles were dried in an oven at 110° C. for 6 h, then ball-milled using a planetary ball mill (the medium was anhydrous ethanol, the rotation speed was 300 r/min), passed through a 500-mesh standard sieve, and dried at 110° C. for 4 h to obtain bioactive glass.

The method for preparing bioactive glass provided by the present invention is easy to control and implement, and can obtain products that meet the requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an XRD (X-ray powder diffraction) spectrum of a bioactive glass powder sample after being cultured in a simulated body fluid for 24 hours, wherein the characteristic peak intensities from high to low are the detection patterns of Example 2, Example 3 and Comparative Example 1 and the standard pattern of hydroxyapatite.

FIG. 2 is a SEM (scanning electron microscope) image of the sample surface of a human tooth sample cultured in a simulated body fluid for 3 days, 7 days and 14 days after simulating tooth brushing in a 1% concentration of the bioactive glass pure water solution of Example 2.

FIG. 3 is a surface SEM image of a human tooth sample incubated in a 1% concentration of the bioactive glass pure water solution of Example 3 in a simulated body fluid for 3 days, 7 days and 14 days after simulating tooth brushing.

FIG. 4 is a surface SEM image of a human tooth sample incubated in a simulated body fluid for 3 days, 7 days and 14 days after simulating tooth brushing in a 1% concentration of the bioactive glass pure water solution of Comparative Example 1.

Figure 5 is SEM images of the sample surface of human tooth samples cultured in simulated body fluid for 3d, 7d and 14d.

Detailed ways

The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the table. The embodiments described below by reference to the table are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

Unless otherwise specified, all scientific and technological terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. All patents and publications to which the present invention relates are incorporated herein by reference in their entirety. The term "comprising" or "including" is an open expression, that is, including the contents specified in the present invention, but does not exclude the contents of other aspects. In the present invention, whether or not the words "about" or "approximately" are used, all the numbers disclosed herein are approximate values. The value of each number may vary within ±10% or less or reasonable differences considered by those skilled in the art, such as 1%, 2%, 3%, 4% or 5%.

If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

In the examples described below, unless otherwise specified, all temperatures are in degrees Celsius. The reagents used can be purchased from the market or prepared by the methods described in the present invention.

The following abbreviations are used throughout the present invention: wt.% means weight percent; °C means degrees Celsius, SEM means scanning electron microscopy, XRD means X-ray powder diffraction, μm means micrometer, ml means milliliter, and r/min means revolutions per minute;

When referring to time, d stands for day, h stands for hour, min stands for minute, and s stands for second.

In the present invention, room temperature refers to ambient temperature, which may be 0°C-45°C. In some embodiments, the room temperature is 10°C-30°C. In some embodiments, the room temperature is 20°C-35°C. In some embodiments, the room temperature is 20°C-30°C.

In the following examples, the pure water used therein was boiled.

Example 1: Test of crystallization amount:

Weigh 0.2 g of active glass powder and add it to 100 ml of simulated body fluid (SBF), place it in a constant temperature shaker at 37°C, start the reciprocating mode, and rotate at 120 r/min. After 24 hours, take it out, filter it, wash it, dry it, and mix it evenly. Use XRD to test the percentage of crystal content.

The composition of simulated body fluid is as follows:

Preparation of simulated body fluid: Prepare according to ISO/TR 10271 standard, adjust pH to 7.0 with NaOH (sodium hydroxide) aqueous solution; the pure water used is boiled and sterilized, all utensils are sterilized at 121℃, and the prepared simulated body fluid is sealed and stored for use within 1 week.

The inventors have found through experiments that the amount of crystallization can reflect to a certain extent the speed at which the glass used generates hydroxyapatite under the same conditions. A high amount of crystallization indicates that the glass has high biological activity. However, since XRD can only semi-quantitatively determine the amount of crystallization precipitated from the glass rather than accurately calculate it, the amount of crystallization calculated by XRD is not the only indicator of the reaction activity. The biological activity of the glass requires the comparison of the test results of XRD and SEM. In order to preliminarily screen glass components with good biological activity, based on the basic formula 45S5, the inventors changed the components and/or the content of the components through research, and then detected the amount of crystallization of the obtained glass. Through the changes in the components and the changes in the amount of crystallization, the important components and their content ranges were preliminarily determined, as shown in Tables 1 to 4 below, where each component is calculated by oxide mass (wt.%).

Table 1: Group A bioglass components and the amount of hydroxyapatite produced

Table 2: Group B bioglass components and the amount of hydroxyapatite produced

Table 3: Group C bioglass components and the amount of hydroxyapatite produced

Table 4: Composition of bioglass in group D and the amount of hydroxyapatite produced

According to the crystallization amount in Tables 1 to 4, it can be seen that different amounts of Li ₂ O and/or CaF ₂ are introduced into the base glass 45S5, and it is found that within a certain range, the crystallization amount after hydration can be increased, but after a certain range, the crystallization amount decreases again when it is increased. According to Tables 1 to 4, it can be concluded that when CaF ₂ in the bioactive glass is 5.55% to 7.66%, Li ₂ O is 0.84% to 1.25%, and the mass ratio of Li ₂ O to CaF ₂ is 0.11 to 0.16, the crystallization amount is higher, which is more beneficial to the improvement of the activity of the bioactive glass.

Example 2

According to the mass of the compound, chemically pure raw materials 28.4% SiO ₂ , 7.6% P ₂ O ₅ , 26.2% Na ₂ CO ₃ , 27.6% CaCO ₃ , 5.6% CaF ₂ , 1.5% Li ₂ CO ₃ , 2.1% MgO, and 1.0% BaCO ₃ are added to a mortar, mixed evenly, and loaded into a corundum crucible. The corundum crucible is placed in a high-temperature electric furnace at room temperature, and the electric furnace is set to heat up to 400° C. in 1 hour, then set to heat up to 900° C. in 1 hour, and then slowly heated to 1350° C. in 2 hours to fully decompose and melt each batch material, and finally kept at 1350° C. for 2 hours to fully melt and clarify the glass liquid; the molten glass liquid is directly quenched with water to obtain granular bioactive glass particles. The obtained bioactive glass particles were dried in an oven at 110°C for 6 hours, ball-milled for 4 hours using a planetary ball mill (the medium was anhydrous ethanol, the rotation speed was 300 r/min), and then passed through a 500-mesh standard sieve and dried at 110°C for 4 hours to obtain bioactive glass particles of a certain particle size.

Example 3

According to the mass of the compound, chemically pure raw materials 29.1% SiO ₂ , 8.0% P ₂ O ₅ , 27.5% Na ₂ CO ₃ , 28.9% CaCO ₃ , 2.5% CaF ₂ , 1.6% Li ₂ CO ₃ , 1.3% MgO, and 0.5% BaCO ₃ are added to a mortar, mixed evenly, and loaded into a corundum crucible. The corundum crucible is placed in a high-temperature electric furnace at room temperature, and the electric furnace is set to heat up to 400° C. in 1 hour, then set to heat up to 900° C. in 1 hour, and then slowly heated to 1350° C. in 2 hours to fully decompose and melt each batch material, and finally kept at 1350° C. for 2 hours to fully melt and clarify the glass liquid; the molten glass liquid is directly quenched with water to obtain granular bioactive glass particles. The obtained bioactive glass particles were dried in an oven at 110°C for 6 hours, ball-milled for 4 hours (the medium was anhydrous ethanol, the rotation speed was 300r/min), passed through a 500-mesh standard sieve, and dried at 110°C for 4 hours to obtain bioactive glass particles of a certain particle size.

Comparative Example 1 (i.e. 45S5 formulation):

According to the mass of the compound, chemically pure raw materials 33.01% SiO ₂ , 4.44% P ₂ O ₅ , 30.48% Na ₂ CO ₃ , and 32.07% CaCO ₃ are added to a mortar, mixed evenly, and loaded into a corundum crucible. The corundum crucible is placed in a high-temperature electric furnace at room temperature, and the electric furnace is set to heat up to 400°C in 1h, then set to heat up to 900°C in 1h, and then slowly heated to 1350°C in 2h to fully decompose and melt each batch material, and finally kept at 1350°C for 2h to fully melt and clarify the glass liquid; the molten glass liquid is directly quenched with water to obtain granular bioactive glass particles. The obtained bioactive glass particles are dried in an oven at 110°C for 6h, ball milled for 4h (the medium is anhydrous ethanol, the speed is 300r/min), and then passed through a 500-mesh standard sieve and dried for 4h to obtain bioactive glass particles of a certain particle size.

Example 4: Activity Test

1. XRD test

The obtained bioactive glass particles were ball-milled, sieved and dried, and the samples after 500 mesh sieve were measured by Malvern 2000 laser particle size analyzer to ensure that the particle size was within the same range. The particle size distribution of each sample is shown in Table 5. Then, the same amount of 0.2g was weighed and placed in 100ml SBF (simulated body fluid), and cultured at 37℃ for 24h in a constant temperature oscillating water bath. Then, the sample was transferred to filter paper for filtration, and the sample left on the filter paper was repeatedly rinsed with anhydrous ethanol. After filtration, the sample was placed in an oven at 110℃, dried for 4h, and then placed in a desiccator for cooling. The cooled sample was peeled off from the filter paper, ground in an agate mortar for 5min, and after sufficient mixing, characterized by XRD to determine whether the generated product was hydroxyapatite and the peak intensity of the characteristic peak.

Table 5: Particle size distribution of each sample

sample D10(μm) D50(μm) D90(μm) Example 2 3.452 7.137 14.419 Example 3 2.987 6.662 14.870 Comparative Example 1 2.942 6.539 13.957

The XRD test results are shown in Figure 1. The spectra show that the substances generated by Example 2, Example 3 and Comparative Example 1 are all hydroxyapatite crystal phases. And under the same conditions, the amount of hydroxyapatite crystallization contained in Example 2 and Example 3 is significantly higher than that of 45S5 in Comparative Example 1.

2. SEM test

The ex vivo human teeth were cut transversely into 2.5 mm thick slice samples. Each tooth sample was placed separately to avoid differences between different teeth. The samples were ground and polished with a precision grinding and polishing machine. They were first corroded with a 6% citric acid aqueous solution (mass concentration) to expose the dentinal tubules to obtain human tooth samples.

The human tooth samples were respectively simulated by brushing with 1% (mass concentration) water (pure water) solution of the bioactive glass of the embodiment and the comparative example, brushing each surface for 30 seconds, and after brushing, the teeth were placed in a beaker and rinsed with pure water for 3 times, and then immersed in 100 ml of SBF (simulated body fluid); the above steps were repeated once a day at an interval of 12 hours, and the simulated body fluid was replaced at the same time every day (e.g., the above steps were performed once at 8:00 a.m. and 20:00 p.m. every day, and the simulated body fluid was replaced at 8:00 a.m.); samples were taken at the same time after 3 days, 7 days, and 14 days (e.g., sampling at 8:00 a.m. after 3 days, sampling at 8:00 a.m. after 7 days, and sampling at 8:00 a.m. after 14 days), and the samples were ultrasonically treated with anhydrous ethanol for 15 minutes and dried in the shade before SEM testing.

The results of SEM testing are shown in Figures 2 to 5. According to the SEM images, under the same culture conditions, there is a tendency for hydroxyapatite to form around the dentin pores in Experimental Example 2 at 3 days, and most of the dentin pores have been closed at 7 days. The speed of repairing the dentin pores in Example 3 is slower than that in Example 2, but more dentin pores have been closed at 7 days. In Comparative Example 1, only some of the dentin pores were closed at 14 days.

The bioactive glasses of Comparative Example 1, Example 2 and Example 3 were tested by XRD. Under the same conditions, the amount of crystallization of Example 2 and Example 3 was greater than that of Comparative Example 1, that is, more hydroxyapatite crystals were generated. According to SEM testing, under the same conditions, the bioactive glasses of Example 2 and Example 3 sealed more dentinal tubules at 14 days than the bioactive glass of Comparative Example 1, that is, the dentinal tubules were repaired faster. Combining the XRD and SEM test results of Comparative Example 1, Example 2 and Example 3, under the same conditions, more hydroxyapatite crystals were generated and more dentinal tubules were sealed, that is, the activity of the bioactive glasses of Example 2 and Example 3 was significantly better than that of Comparative Example 1, and the symptoms of tooth allergy could be quickly relieved and cured with lasting effects.

The method of the present invention has been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein within the content, spirit and scope of the present invention to implement and apply the technology of the present invention. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention.

Claims (10)

1. A bioactive glass comprising the following components in terms of oxide mass:

Wherein the mass ratio of Li ₂ O to CaF ₂ is 0.11-0.16.

2. A bioactive glass comprises ：SiO₂37.4％、P₂O₅9.95％、Na₂O 20.36％、CaO 20.36％、CaF₂ 7.37％、Li₂O 0.81％、MgO 2.72％ and BaO 1.03% by weight of oxide; or SiO₂37.24％、P₂O₅9.92％、Na₂O 20.29％、CaO20.29％、CaF₂ 7.35％、Li₂O 1.21％、MgO 1.63％ and BaO 2.06%; or SiO₂37.43％、P₂O₅10.02％、Na₂O 20.19％、CaO 20.38％、CaF₂7.38％、Li₂O 0.80％、MgO 2.77％ and BaO 1.02%.

3. Use of the bioactive glass of claim 1 or 2 in the preparation of a toothpaste, mouthwash, dentifrice, chewing gum, gel, or pharmaceutical carrier.

4. Use of a bioactive glass as claimed in claim 1 or 2 in the preparation of a composition for use in a method of preventing or treating dental hypersensitivity, for partially or totally occluding dentinal tubules, for use in a method of preventing incipient caries, for use in a method of preventing or treating caries, for use in a method of incipient caries remineralization, for use in remineralizing enamel, for use in a method of occluding a crack in a tooth structure, for use in a method of occluding a point gap in a tooth structure, for use in a method of lining a tooth structure, for use in a method of covering dental pulp, or/and for use in a method of treating a tooth structure after periodontal surgery, or for use in skeletal repair.

5. A composition comprising the bioactive glass of claim 1 or 2 and an adjunct, wherein the composition is used in a method for preventing or treating dental hypersensitivity, a method for partially or totally occluding dentinal tubules, a method for preventing incipient caries, a method for preventing or treating caries, a method for incipient caries remineralization, a method for remineralizing enamel, a method for occluding a crack in a tooth structure, a method for occluding a point gap in a tooth structure, a method for lining a tooth structure, a method for covering dental pulp, or/and a method for treating a tooth structure after periodontal surgery.

6. The composition of claim 5 which is an emulsion, lotion, ointment, powder, gel or paste.

7. The composition of claim 5, wherein the bioactive glass is present in an amount of 0.1% to 50.0% based on the total mass of the composition.

8. The composition of claim 5, further comprising an antibacterial agent, a tartar control agent, a structure-building agent, or a combination thereof.

9. A method of making the bioactive glass of claim 1 or 2, comprising the steps of:

1) Weighing the raw materials of all the components according to the formula proportion, uniformly mixing, and filling into a crucible;

2) Placing the crucible in an electric furnace, setting the temperature rising speed of the electric furnace to be between 400 and 450 ℃ within 0.5 to 1.5 hours, then setting the temperature rising speed to be between 900 and 950 ℃ within 0.5 to 1.5 hours, then heating to be between 1300 and 1400 ℃ within 1.5 to 2.5 hours, and finally preserving the heat for 1 to 4 hours at the temperature of between 1300 and 1400 ℃ to melt and clarify the glass liquid to obtain molten glass liquid;

3) And (5) water quenching the molten glass liquid to obtain the bioactive glass.

10. The method of claim 9, further comprising:

4) Drying the obtained bioactive glass particles in an oven at 100-120 ℃ for 4-8 hours, and then ball milling for 2-8 hours by using a planetary ball mill, wherein the medium is absolute ethyl alcohol, and the rotating speed is 150-500 r/min; sieving with 400-600 target standard sieve, and baking at 100-120 deg.c for 2-6 hr to obtain bioactive glass.