Toothpaste composition capable of inhibiting bacteria and relieving gingival inflammation and preparation method thereof

Abstract

According to the toothpaste composition capable of inhibiting bacteria and relieving gingival inflammation and the preparation method of the toothpaste composition, the final morphology of cerium oxide is adjusted through hydrothermal temperature, alkaline conditions, monopotassium phosphate and sodium sulfite, the obtained cerium oxide is in a flower cluster sphere shape, the cerium oxide shows excellent biocompatibility, stability and antibacterial activity, and the toothpaste composition can be used for preparing the toothpaste composition for relieving gingival inflammation. The finally obtained toothpaste has the technical effects of inhibiting bacteria and relieving gingival inflammation.

Description

Technical Field

[0001] The invention relates to the field of daily necessities, and relates to a toothpaste composition having the functions of inhibiting bacteria and alleviating gingivitis and a preparation method thereof, and in particular to the application of cerium dioxide nanoparticles having the above functions in toothpaste daily chemical products. Background Art

[0002] Toothpaste is a necessity for people to assist in teeth cleaning in their daily lives. There are two types of toothpaste on the market: ordinary toothpaste and functional toothpaste. There are three main effects of toothpaste on the tooth surface: first, the mechanical cleaning effect of the toothbrush and the abrasive in the toothpaste, second, the chemical effects of emulsification, decomposition, neutralization and other effects on the tooth surface residues through the surfactant in the toothpaste, and third, the addition of some functional ingredients such as sodium fluoride, nano-hydroxyapatite, bioactive glass, arginine, etc., to promote the remineralization of demineralized enamel, relieve dentin sensitivity and inhibit dental plaque.

[0003] The main ingredients of toothpaste include water, moisturizers, surfactants, preservatives and flavors. Its two basic functions are to remove dental plaque and prevent tooth decay. Plaque removal is mainly achieved through abrasives, such as silica, aluminum hydroxide, calcium carbonate, etc. These abrasive particles are insoluble and usually dispersed in the soluble part of toothpaste. Prevention of tooth decay is achieved by adding fluorides such as sodium fluoride and other molecules. In addition, other functional ingredients can be added, such as anti-plaque, anti-gingivitis, anti-odor, anti-tartar, whitening and anti-erosion related ingredients. As the product with the highest popularity and direct contact with the oral cavity, the natural, safe and effective ingredients of toothpaste have attracted much attention. Surfactants are widely added to toothpaste, mainly for cleaning and foaming, and to evenly distribute the ingredients in toothpaste, but studies have shown that there are certain safety hazards.

[0004] Cerium (Ce) is one of the most abundant elements on Earth. It is not only the most abundant element among all rare earth elements, but also has a higher content in the Earth's crust (66.5ppm) than copper (60ppm). In addition, it also has [Xe]4f5d 1 6s 2The special external electron configuration makes cerium have unique physical and chemical properties, and it has a wide range of applications in the fields of alloys, catalysis, and antibacterial. Cerium dioxide (CeO2) is a light yellow / white powder, a very common and most stable cerium compound, and the only compound among rare earth elements that exhibits a stable +4 valence state. The present invention focuses on the application of cerium oxide in the field of toothpaste. For example, CN116553596A of Wuyi University discloses a cerium dioxide nanoparticle and its preparation method and application. The preparation method of the cerium dioxide nanoparticle comprises the following steps: dissolving cerium nitrate, stirring, adding concentrated ammonia water, continuing stirring, centrifuging, removing the supernatant, adding a washing solvent, and ultrasonically dispersing to obtain the cerium dioxide nanoparticle. The preparation method of the cerium dioxide nanoparticle is simple, the reaction conditions are mild, the preparation process is green and efficient, and the experiment has good repeatability. Compared with other antibacterial agents and anti-inflammatory agents, it has lower synthesis difficulty and cost. The cerium dioxide nanoparticles prepared at the same time have good antibacterial and biocompatible properties, can reduce tooth allergies by repairing and strengthening tooth enamel, and improve human oral health. Toothpaste containing CeO2 NPs has antibacterial, remineralizing and antioxidant properties. Saliva contains ions and proteins, which may form nanoparticle-ion-protein complexes with nanoparticles and precipitate on the tooth surface, thereby preventing the occurrence of caries and prolonging its action time, effectively overcoming the problems of other toothpastes in the prior art, such as short stay in the mouth, short action time for preventing and treating caries, and unclear effect. Summary of the invention

[0005] The present invention provides a toothpaste composition with antibacterial and gingivitis relief effects and a preparation method thereof, in particular, application of cerium dioxide nanoparticles with the above functions in toothpaste daily chemical products, wherein the cerium dioxide nanoparticles in the toothpaste are in the form of flower-clustered spheres, with a sphere size of 100-200nm, a cluster length of 10-20nm, a cluster diameter of 5-10nm, and a specific surface area of ​​≥359m 2 / g, which has good antibacterial and biocompatible properties, and especially has the technical effects of inhibiting bacteria and alleviating gingival inflammation.

[0006] A toothpaste composition having the functions of inhibiting bacteria and alleviating gingival inflammation, comprising the following raw materials in parts by weight: 68-70wt.% sorbitol, 45-47 parts of deionized water; Glycerin 20-21 parts; 8-11 parts of silicon dioxide xerogel; Hydrated silicon dioxide 6-7 parts 5-6 parts of polyethylene glycol; 3-5 parts of cerium oxide nanoparticles; 1.5-2 parts of mint essence; 1-2 parts of sodium lauryl sulfate; Sodium fluorophosphate 0.7-0.8 part; Hydroxymethyl cellulose 0.3-0.4 parts; 0.3-0.4 parts of edible coloring agent; Saccharin sodium 0.2-0.3 parts; Benzoic acid 0.06-0.1 parts.

[0007] The cerium oxide nanoparticles are cerium oxide materials synthesized under super-alkaline hydrothermal conditions. The material is in the shape of flower-bundled spheres with a sphere size of 100-200nm, a bundle length of 10-20nm, and a bundle diameter of 5-10nm.

[0008] The specific surface area of ​​flower-clustered spherical cerium oxide is ≥359m 2 / g.

[0009] The cerium oxide material is prepared by the following steps: (1) Diluting ethylene glycol by 10-12 times with deionized water to obtain a hydrothermal reaction solvent, then sequentially adding potassium hydroxide and potassium bicarbonate to the solvent and stirring thoroughly, adding sodium sulfite and stirring to dissolve after the mixture is cooled, then slowly adding potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, and transferring the mixed solution to a hydrothermal reactor and sealing the mixture; (2) Raise the temperature to 300-310°C at a rate of 4-5°C / min, keep the temperature constant for 24-36 hours, and take it out after it cools naturally; (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0010] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: (4-5) mol / L: (15-16) mol / L: (2-4) mol / L: (0.4-0.5) mol / L.

[0011] During the hydrothermal reaction, the duty ratio of the solution in the reactor is 75-90 vol.%.

[0012] A method for preparing a toothpaste composition having antibacterial and gingivitis-relieving effects, comprising the following steps: (1) Mix silica xerogel, cerium oxide nanoparticles, 4 / 5 of sorbitol deionized water and glycerol at 30-40° C. and stir for 20-30 min; (2) Mix hydrated silicon dioxide, polyethylene glycol, sodium fluorophosphate, hydroxymethyl cellulose and sodium saccharin to obtain a mixed powder, introduce the solution prepared in step (1) into the mixed powder, and stir thoroughly for 4-6 minutes; (3) Add sodium lauryl sulfate, mint flavor, edible colorant, benzoic acid and remaining sorbitol in deionized water, stir and mix thoroughly for 10-15 minutes to obtain a toothpaste composition.

[0013] 8. A method for preparing a toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 7, wherein the cerium oxide nanoparticles are prepared by the following steps: (1) Diluting ethylene glycol by 10-12 times with deionized water to obtain a hydrothermal reaction solvent, then sequentially adding potassium hydroxide and potassium bicarbonate to the solvent and stirring thoroughly, adding sodium sulfite and stirring to dissolve after the mixture is cooled, then slowly adding potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, and transferring the mixed solution to a hydrothermal reactor and sealing the mixture; (2) Raise the temperature to 300-310°C at a rate of 4-5°C / min, keep the temperature constant for 24-36 hours, and take it out after it cools naturally; (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0014] A method for applying cerium oxide nanoparticles, wherein the cerium oxide nanoparticles are used in a toothpaste composition, wherein the cerium oxide particles are cerium oxide synthesized under superalkaline hydrothermal conditions, wherein the cerium oxide is in the form of a flower-bundled sphere, wherein the sphere size is 100-200 nm, the bundle length is 10-20 nm, the bundle diameter is 5-10 nm, and the specific surface area of ​​the flower-bundled sphere-shaped cerium oxide is ≥359 m 2 / g.

[0015] Technical effect: (1) The present invention adjusts the final morphology of cerium oxide by hydrothermal temperature, alkaline conditions, potassium dihydrogen phosphate and sodium sulfite, and the obtained cerium oxide presents a flower-like clustered sphere shape with a sphere size of 100-200nm, a cluster length of 10-20nm, a cluster diameter of 5-10nm, and an extremely high specific surface area of ​​≥359m 2 / g, showing excellent biocompatibility, stability and antibacterial properties; (2) the toothpaste obtained by the above preparation has the technical effects of antibacterial and reducing gingival inflammation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 Morphology of cerium oxide in the toothpaste composition of Example 2.

[0017] Attached Figure 2 Comparative Example 1: Morphology of cerium oxide in the toothpaste composition.

[0018] Attached Figure 3 Morphology of cerium oxide in the toothpaste composition of Comparative Example 2.

[0019] Attached Figure 4 Morphology of cerium oxide in the toothpaste composition of Comparative Example 3.

[0020] Attached Figure 5 Example 2 shows the therapeutic effect of the toothpaste composition on gingivitis. DETAILED DESCRIPTION Example 1

[0021] A toothpaste composition having the functions of inhibiting bacteria and alleviating gingival inflammation, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 45 parts; Glycerin 20 parts; 8 parts of silica xerogel; 6 parts of hydrated silicon dioxide 5 parts of polyethylene glycol; 3 parts of cerium oxide nanoparticles; 1.5 parts of mint essence; 1 part of sodium lauryl sulfate; 0.7 part of sodium fluorophosphate; 0.3 parts of hydroxymethyl cellulose; 0.3 parts of edible coloring agent; 0.2 parts of saccharin sodium; 0.06 parts of benzoic acid.

[0022] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 10 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released, add sodium sulfite and stir to dissolve. Then slowly add potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0023] (2) Raise the temperature to 300°C at a rate of 4°C / min, maintain the temperature for 24 hours, and remove the sample after it cools naturally.

[0024] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0025] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: 4 mol / L: 15 mol / L: 2 mol / L: 0.4 mol / L. Example 2

[0026] A toothpaste composition having the functions of inhibiting bacteria and alleviating gingival inflammation, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 46 parts; Glycerin 20.5 parts; 9.5 parts of silicon dioxide xerogel; 6.5 parts of hydrated silicon dioxide 5.5 parts of polyethylene glycol; 4 parts of cerium oxide nanoparticles; 1.75 parts of mint essence; 1.5 parts of sodium lauryl sulfate; 0.75 part of sodium fluorophosphate; 0.35 parts of hydroxymethyl cellulose; 0.35 parts of edible coloring agent; 0.25 parts of saccharin sodium; 0.08 parts of benzoic acid.

[0027] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 11 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released, add sodium sulfite and stir to dissolve. Then slowly add potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0028] (2) Raise the temperature to 305°C at a rate of 4.5°C / min, maintain the temperature for 30 hours, and remove the sample after it cools naturally.

[0029] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0030] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: 4.5 mol / L: 15.5 mol / L: 3 mol / L: 0.45 mol / L. Example 3

[0031] A toothpaste composition having the functions of inhibiting bacteria and alleviating gingival inflammation, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 47 parts; Glycerin 21 parts; 11 parts of silica xerogel; 7 parts of hydrated silicon dioxide 56 parts of polyethylene glycol; 5 parts of cerium oxide nanoparticles; 2 parts mint essence; 2 parts of sodium lauryl sulfate; 0.8 part of sodium fluorophosphate; 0.4 part of hydroxymethyl cellulose; 0.4 parts of edible coloring agent; 0.3 parts of saccharin sodium; 0.1 part of benzoic acid.

[0032] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 12 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released, add sodium sulfite and stir to dissolve. Then slowly add potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0033] (2) Raise the temperature to 310°C at a rate of 5°C / min, maintain the temperature for 36 hours, and remove the sample after it cools naturally.

[0034] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0035] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: 5 mol / L: 16 mol / L: 4 mol / L: 0.5 mol / L.

[0036] Comparative Example 1 A toothpaste composition having the functions of inhibiting bacteria and reducing gingivitis, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 46 parts; Glycerin 20.5 parts; 9.5 parts of silicon dioxide xerogel; 6.5 parts of hydrated silicon dioxide 5.5 parts of polyethylene glycol; 4 parts of cerium oxide nanoparticles; 1.75 parts of mint essence; 1.5 parts of sodium lauryl sulfate; 0.75 part of sodium fluorophosphate; 0.35 parts of hydroxymethyl cellulose; 0.35 parts of edible coloring agent; 0.25 parts of saccharin sodium; 0.08 parts of benzoic acid.

[0037] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 11 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released, add sodium sulfite and stir to dissolve. Then slowly add potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0038] (2) Raise the temperature to 305°C at a rate of 4.5°C / min, maintain the temperature for 30 hours, and remove the sample after it cools naturally.

[0039] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0040] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: 4.5 mol / L: 0.1 mol / L: 3 mol / L: 0.45 mol / L.

[0041] Comparative Example 2 A toothpaste composition having the functions of inhibiting bacteria and alleviating gingivitis, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 46 parts; Glycerin 20.5 parts; 9.5 parts of silicon dioxide xerogel; 6.5 parts of hydrated silicon dioxide 5.5 parts of polyethylene glycol; 4 parts of cerium oxide nanoparticles; 1.75 parts of mint essence; 1.5 parts of sodium lauryl sulfate; 0.75 part of sodium fluorophosphate; 0.35 parts of hydroxymethyl cellulose; 0.35 parts of edible coloring agent; 0.25 parts of saccharin sodium; 0.08 parts of benzoic acid.

[0042] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 11 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released heat, add cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0043] (2) Raise the temperature to 305°C at a rate of 4.5°C / min, maintain the temperature for 30 hours, and remove the sample after it cools naturally.

[0044] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0045] The molar ratio of cerium nitrate:potassium hydroxide:potassium carbonate is 2 mol / L:15.5 mol / L:3 mol / L.

[0046] Comparative Example 3 A toothpaste composition having the functions of inhibiting bacteria and alleviating gingivitis, comprising the following raw materials in parts by weight: 70wt.% sorbitol deionized water 46 parts; Glycerin 20.5 parts; 9.5 parts of silicon dioxide xerogel; 6.5 parts of hydrated silicon dioxide 5.5 parts of polyethylene glycol; 4 parts of cerium oxide nanoparticles; 1.75 parts of mint essence; 1.5 parts of sodium lauryl sulfate; 0.75 part of sodium fluorophosphate; 0.35 parts of hydroxymethyl cellulose; 0.35 parts of edible coloring agent; 0.25 parts of saccharin sodium; 0.08 parts of benzoic acid.

[0047] The cerium oxide material is prepared by the following steps: (1) Dilute ethylene glycol 11 times with deionized water to obtain a hydrothermal reaction solvent, then add potassium hydroxide and potassium bicarbonate in sequence and stir thoroughly. After the mixture is cooled and released, add sodium sulfite and stir to dissolve. Then slowly add potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, transfer the mixed solution to a hydrothermal reactor, and seal it.

[0048] (2) Raise the temperature to 105°C at a rate of 4.5°C / min, maintain the temperature for 30 hours, and remove the sample after it cools naturally.

[0049] (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

[0050] The molar ratio of cerium nitrate: potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: 4.5 mol / L: 15.5 mol / L: 3 mol / L: 0.45 mol / L.

[0051] The cerium oxide prepared in Example 2 and Comparative Examples 1-3 was characterized, and the corresponding cerium oxide morphology is shown in the attached figure. Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 As shown, in comparative example 1, the amount of sodium hydroxide base is reduced, in comparative example 2, potassium dihydrogen phosphate and sodium sulfite are not used, and the temperature of comparative example 3 is lowered to the conventional hydrothermal temperature. The cerium oxide obtained in Example 2 is in the shape of a flower-like clustered sphere, with a sphere size of about 200 nm, a cluster length of about 12 nm, and a cluster diameter of about 7 nm. The specific surface area is tested, and the corresponding specific surface area is 359 m 2 / g, while the cerium oxide morphology obtained in Comparative Example 1 is as shown in the attached Figure 2 As shown in Figure 2, the lower alkalinity results in a conventional spherical structure of cerium oxide, with a corresponding specific surface area of ​​48.3 m 2 / g, similar to the cerium oxide morphology obtained under low temperature hydrothermal conditions in Comparative Example 3, as shown in the attached Figure 4 As shown, there is no substantial difference in the specific surface area between Comparative Example 1 and Comparative Example 3. Comparative Example 2 lacks potassium dihydrogen phosphate and sodium sulfite, which have a significant effect on the morphology of cerium oxide. Figure 3The overall morphology is messy, but there are fewer nanobeams formed. However, the overall morphology of the product is irregular. It can be clearly concluded that the specific surface area of ​​cerium oxide in comparative example 3 is 198.3 m 2 / g, hydrothermal temperature, alkaline conditions, potassium dihydrogen phosphate and sodium sulfite all directly affect the final morphology of cerium oxide. The antibacterial test was carried out on the toothpaste concentrates in Example 2 and Comparative Examples 1-3, and the antibacterial zones for Staphylococcus aureus were 28±1.2mm, 11.32±0.9mm, 23±2.3mm and 9.23±0.8mm respectively.

[0052] The toothpastes of Example 2 and Comparative Example 4 were selected for experimental testing. The experimental subjects were two people, myself and a volunteer. The test period was 21 days. The toothpaste was used twice a day, morning and evening. The plaque index of myself using the toothpaste of Example 2 was reduced from 2.03 to 0.25, and the gum index was reduced from 2.48 to 0.59. The plaque index of the volunteer was reduced from 1.73 to 0.78, and the gum index was reduced from 2.37 to 0.83. For details, see the attached Figure 5 The experimental figures show that the toothpaste prepared by the present invention has obvious effect of inhibiting or treating gingivitis, which is significantly better than that of comparative example 3.

[0053] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A toothpaste composition having antibacterial and gingivitis-relieving properties, characterized in that Including the following raw materials by weight: 68-70wt.% sorbitol, 45-47 parts of deionized water; Glycerin 20-21 parts; 8-11 parts of silicon dioxide xerogel; Hydrated silicon dioxide 6-7 parts 5-6 parts of polyethylene glycol; 3-5 parts of cerium oxide nanoparticles; 1.5-2 parts of mint essence; 1-2 parts of sodium lauryl sulfate; Sodium fluorophosphate 0.7-0.8 part; Hydroxymethyl cellulose 0.3-0.4 parts; 0.3-0.4 parts of edible coloring agent; Saccharin sodium 0.2-0.3 parts; Benzoic acid 0.06-0.1 parts.

2. A toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 1, characterized in that The cerium oxide nanoparticles are cerium oxide materials synthesized under super-alkaline hydrothermal conditions. The material is in the shape of flower-bundled spheres with a sphere size of 100-200nm, a bundle length of 10-20nm, and a bundle diameter of 5-10nm.

3. A toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 2, characterized in that The specific surface area of ​​flower-clustered spherical cerium oxide is ≥359m 2 / g.

4. A toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 1, characterized in that The cerium oxide material is prepared by the following steps: (1) Diluting ethylene glycol by 10-12 times with deionized water to obtain a hydrothermal reaction solvent, then sequentially adding potassium hydroxide and potassium bicarbonate to the solvent and stirring thoroughly, adding sodium sulfite and stirring to dissolve after the mixture is cooled, then slowly adding potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, and transferring the mixed solution to a hydrothermal reactor and sealing the mixture; (2) Raise the temperature to 300-310°C at a rate of 4-5°C / min, keep the temperature constant for 24-36 hours, and take it out after natural cooling; (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

5. The toothpaste composition having the functions of inhibiting bacteria and alleviating gingivitis as claimed in claim 1, characterized in that the cerium nitrate: The molar ratio of potassium dihydrogen phosphate:potassium hydroxide:potassium carbonate:sodium sulfite is 2 mol / L:(4-5) mol / L:(15-16) mol / L:(2-4) mol / L:(0.4-0.5) mol / L.

6. A toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 1, characterized in that During the hydrothermal reaction, the duty ratio of the solution in the reactor is 75-90 vol.%.

7. A method for preparing a toothpaste composition having antibacterial and gingivitis-relieving properties, characterized in that The steps include: (1) Mix silica xerogel, cerium oxide nanoparticles, 4 / 5 of sorbitol deionized water and glycerol at 30-40° C. and stir for 20-30 min; (2) Mix hydrated silicon dioxide, polyethylene glycol, sodium fluorophosphate, hydroxymethyl cellulose and sodium saccharin to obtain a mixed powder, introduce the solution prepared in step (1) into the mixed powder, and stir thoroughly for 4-6 minutes; (3) Add sodium lauryl sulfate, mint flavor, edible colorant, benzoic acid and remaining sorbitol in deionized water, stir and mix thoroughly for 10-15 minutes to obtain a toothpaste composition.

8. The method for preparing a toothpaste composition having antibacterial and gingivitis-relieving properties as claimed in claim 7, characterized in that Cerium oxide nanoparticles are prepared by the following steps: (1) Diluting ethylene glycol by 10-12 times with deionized water to obtain a hydrothermal reaction solvent, then sequentially adding potassium hydroxide and potassium bicarbonate to the solvent and stirring thoroughly, adding sodium sulfite and stirring to dissolve after the mixture is cooled, then slowly adding potassium dihydrogen phosphate and cerium nitrate to obtain a mixed solution, and transferring the mixed solution to a hydrothermal reactor and sealing the mixture; (2) Raise the temperature to 300-310°C at a rate of 4-5°C / min, keep the temperature constant for 24-36 hours, and take it out after natural cooling; (3) Filter, wash and dry to obtain flower-bundled spherical cerium oxide.

9. The method for preparing a toothpaste composition having antibacterial and gingivitis alleviating properties as claimed in claim 7, wherein the cerium nitrate is: The molar ratio of potassium dihydrogen phosphate: potassium hydroxide: potassium carbonate: sodium sulfite is 2 mol / L: (4-5) mol / L: (15-16) mol / L: (2-4) mol / L: (0.4-0.5) mol / L.

10. A method for applying cerium oxide nanoparticles, characterized in that The cerium oxide nanoparticles are used in a toothpaste composition. The cerium oxide particles are cerium oxide synthesized under super-strong alkaline hydrothermal conditions. The cerium oxide is in the form of a flower-bundled sphere with a sphere size of 100-200 nm, a bundle length of 10-20 nm, a bundle diameter of 5-10 nm, and a specific surface area of ​​the flower-bundled sphere-shaped cerium oxide of ≥359 m 2 / g.

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