A manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening and a method of preparing the same

Abstract

The present application relates to the technical field of oral products, and specifically discloses a manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening and a preparation method thereof. The preparation method comprises the following steps: preparing manganese tungstate nanoparticles, dispersing tungsten hexacarbonyl and a surfactant in a first organic solvent, adding an oleic acid / oleylamine ligand pair under first reaction conditions, then stirring and reacting under second reaction conditions, cooling, centrifuging, washing, and drying to obtain the manganese tungstate nanoparticles. The manganese tungstate nanoparticles / polyethylene glycol composite material is prepared by dispersing the manganese tungstate nanoparticles and a polyethylene glycol derivative in a second organic solvent, uniformly stirring, and nitrogen drying. The manganese tungstate nanoparticle / polyethylene glycol composite material is dissolved in artificial saliva, hydrogen peroxide solution is added and mixed to obtain the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening.

Description

Technical Field

[0001] This invention relates to the field of oral care products technology, specifically to a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening and its preparation method. Background Technology

[0002] In the field of dental aesthetics, the aesthetic value of tooth color is influenced not only by the inherent color of the teeth themselves but also by extrinsic stains accumulated on the tooth surface. These extrinsic stains mainly originate from environmental factors such as smoking habits, daily diet, and exposure to certain chemicals (such as cationic agents). To address this, most teeth whitening techniques rely on hydrogen peroxide and its derivatives (such as urea peroxide) as whitening agents. However, while these traditional whitening agents are effective in removing pigments, they have potential side effects—including enamel erosion, damage to oral soft tissues, and tooth sensitivity.

[0003] Sonodynamic therapy, as an emerging non-invasive treatment, utilizes a sonosensitive agent, aided by ultrasound, to induce the generation of highly reactive reactive oxygen species, thereby breaking down extrinsic pigments on the tooth surface to achieve tooth whitening. Among the key components of sonodynamic therapy, the selection and optimization of the sonosensitive agent plays a crucial role in improving treatment effectiveness.

[0004] Sound sensitizers are mainly divided into two categories: organic and inorganic. Organic sound sensitizers are chemically unstable and have potential biotoxicity, especially in the complex environment of the oral cavity, where they can easily cause tissue damage. Inorganic sound sensitizers, on the other hand, have excellent chemical stability and good biocompatibility.

[0005] How to obtain an inorganic sonosensitive agent for use in sonodynamic therapy to achieve better therapeutic effects is an urgent technical problem to be solved. Summary of the Invention

[0006] To address the aforementioned problems, one objective of this invention is to provide a method for preparing a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening. Manganese tungstate nanoparticles modified with polyethylene glycol derivatives, as an inorganic sonic sensitizer, not only exhibit good aqueous suspension stability and biocompatibility in aqueous solutions, but also demonstrate highly efficient reactive oxygen species (ROS) generation capacity under ultrasonic irradiation. Their anoxic structure provides ideal sites for electron capture, effectively inhibiting electron-hole pair recombination, thereby significantly improving the ROS yield. Furthermore, manganese tungstate nanoparticles also possess catalase-like activity, catalyzing the decomposition of hydrogen peroxide into more ROS. This synergistic effect of sonodynamics and chemokinetics achieves a more efficient, safe, and long-lasting teeth whitening effect.

[0007] A second objective of this invention is to provide a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening. Manganese tungstate nanoparticles with oxygen vacancies are prepared by a simple and effective method, hydrophilically modified to increase their water suspension stability, and combined with a hydrogen peroxide solution of appropriate concentration to achieve teeth whitening without damaging tooth enamel.

[0008] The first technical solution adopted in this invention is: a method for preparing a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening, comprising the following steps:

[0009] Step 1: Preparation of manganese tungstate nanoparticles. Tungsten hexacarbonyl and surfactant are dispersed in a first organic solvent. Oleic acid / oleylamine ligand pair is added under the first reaction conditions. The reaction is then stirred under the second reaction conditions. After cooling, centrifugation, washing, and drying, manganese tungstate nanoparticles are obtained.

[0010] Step 2: Prepare manganese tungstate nanoparticles / polyethylene glycol composite material. Disperse the manganese tungstate nanoparticles and polyethylene glycol derivatives in a second organic solvent, stir evenly, and dry with nitrogen to obtain manganese tungstate nanoparticles / polyethylene glycol composite material.

[0011] Step 3: Dissolve the manganese tungstate nanoparticle / polyethylene glycol composite material in artificial saliva, add hydrogen peroxide solution and mix to obtain a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening.

[0012] Preferably, the first organic solvent is a dibenzyl ether;

[0013] The second organic solvent is chloroform.

[0014] Preferably, the surfactant is 1,2-dodecanediol.

[0015] Preferably, the volume ratio of oleic acid to oleylamine in the oleic acid / oleylamine ligand pair is 1:1, and the amount of oleic acid / oleylamine ligand pair added is 1-2 mL.

[0016] Preferably, the polyethylene glycol derivative is distearylphosphatidylethanolamine-methoxy polyethylene glycol.

[0017] Preferably, the concentration of manganese tungstate nanoparticles / hydrogen peroxide in the composition is 150-200 μg / mL, and the concentration of hydrogen peroxide is 0.5-1 wt%.

[0018] Preferably, the washing conditions in step one are: washing with a cyclohexane-ethanol mixture, wherein the volume ratio of cyclohexane to ethanol in the cyclohexane-ethanol mixture is 1:(1.5-3).

[0019] Preferably, the first reaction conditions are: a nitrogen atmosphere and a reaction temperature of 110-130℃.

[0020] Preferably, the second reaction conditions are: heating the reaction temperature to 250-270°C, adding manganese acetylacetone, wherein the molar ratio of the hexacarbonyl tungsten to the manganese acetylacetone is 1:1, and the reaction time is 0.5-2 hours.

[0021] The second technical solution adopted in this invention is: a manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening.

[0022] The beneficial effects of the above technical solution are as follows:

[0023] (1) The preparation method of manganese tungstate nanoparticles / hydrogen peroxide composition provided by the present invention is simple and effective. The present invention can prepare manganese tungstate nanoparticles with uniform morphology and oxygen vacancies by high temperature organic phase synthesis. DSPE-PEG is coated on the surface of manganese tungstate nanoparticles and hydrophilic modification is performed to increase their water suspension stability. Then, it is combined with hydrogen peroxide to achieve the effect of whitening teeth without damaging tooth enamel.

[0024] (2) The manganese tungstate nanoparticle / hydrogen peroxide composition provided by the present invention can catalyze water and dissolved oxygen to generate active oxygen under the action of ultrasound and catalyze hydrogen peroxide to generate active oxygen, thereby achieving the effect of degrading pigments and whitening teeth. Attached Figure Description

[0025] Figure 1a This is a transmission electron microscope (TEM) image of manganese tungstate nanoparticles at 100 nm resolution.

[0026] Figure 1b This is a transmission electron microscope (TEM) image of manganese tungstate nanoparticles at a resolution of 20 nm.

[0027] Figure 2a The overall elemental distribution of manganese tungstate nanoparticles by energy dispersion (EDS);

[0028] Figure 2b Energy dispersive spectroscopy (EDS) oxygen distribution diagram of manganese tungstate nanoparticles;

[0029] Figure 2c Energy dispersive spectroscopy (EDS) distribution of manganese element in manganese tungstate nanoparticles;

[0030] Figure 2d Energy dispersive spectroscopy (EDS) distribution of tungsten in manganese tungstate nanoparticles;

[0031] Figure 3a The total X-ray photoelectron spectroscopy (XPS) spectrum of manganese tungstate nanoparticles;

[0032] Figure 3b The oxygen element spectrum of manganese tungstate nanoparticles is obtained from X-ray photoelectron spectroscopy (XPS).

[0033] Figure 3c The X-ray photoelectron spectroscopy (XPS) spectrum of tungsten in manganese tungstate nanoparticles;

[0034] Figure 3d The X-ray photoelectron spectroscopy (XPS) spectrum of manganese in manganese tungstate nanoparticles;

[0035] Figure 4 The image shows the X-ray diffraction (XRD) pattern of manganese tungstate nanoparticles.

[0036] Figure 5 Infrared spectrum of manganese tungstate nanoparticles / polyethylene glycol composite material;

[0037] Figure 6a A transmission electron microscope (TEM) image at 50 nm resolution of the manganese tungstate nanoparticle / hydrogen peroxide composition;

[0038] Figure 6b A transmission electron microscope (TEM) image of a manganese tungstate nanoparticle / hydrogen peroxide composition at 10 nm resolution;

[0039] Figure 7a Image showing tooth color;

[0040] Figure 7b A statistical graph of L values ​​measured by a tooth colorimeter;

[0041] Figure 8 Figure showing the survival rate of human gingival fibroblasts after treatment with different concentrations of manganese tungstate nanoparticles;

[0042] Figure 9a Photographs showing the color of tooth enamel after hydrogen peroxide treatment;

[0043] Figure 9b This is a scanning electron microscope (SEM) image of normal tooth enamel.

[0044] Figure 9c Scanning electron microscope (SEM) image of tooth enamel after treatment with manganese tungstate nanoparticles, hydrogen peroxide, and ultrasonication for 8 hours;

[0045] Figure 9d Scanning electron microscopy (SEM) image of tooth enamel treated with 20 wt% hydrogen peroxide for 30 minutes. Detailed Implementation

[0046] The embodiments of this application will be described in further detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0047] The terms “first,” “second,” etc. (if applicable) in the specification and claims are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data used in this way can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that comprises a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0048] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0049] Example 1

[0050] (1) Preparation of manganese tungstate nanoparticles

[0051] 352 mg of tungsten hexacarbonyl and 1.5 g of 1,2-dodecanediol were dispersed in 20 mL of dibenzyl ether. The mixture was heated to 120 °C under a nitrogen atmosphere, and then 1 mL of oleic acid and 1 mL of oleylamine were added. The mixture was then heated to 260 °C, and then 352 mg of manganese acetylacetone was added. The mixture was stirred continuously for 1 h. After cooling to room temperature, excess ethanol was added and the mixture was centrifuged (10 min, 10,000 rpm). The mixture was then dissolved in 10 mL of cyclohexane, and then 15 mL of ethanol was added and centrifuged (10 min, 10,000 rpm). This process was repeated three times. Finally, the mixture was dried in a 60 °C oven.

[0052] The prepared manganese tungstate nanoparticles were imaged using transmission electron microscopy (TEM), and the results are as follows: Figure 1a and 1b As shown, the size of the prepared manganese tungstate nanoparticles is approximately 4-8 nm. Energy dispersive spectrometry (EDS) elemental mapping was performed on the prepared manganese tungstate nanoparticles, and the results are as follows... Figures 2a-2dAs shown, the Mn, W, and O elements are uniformly distributed in the manganese tungstate nanoparticles. X-ray photoelectron spectroscopy (XPS) was performed on the prepared manganese tungstate nanoparticles, and the results are as follows. Figures 3a-3d As shown, peak fitting of oxygen element revealed the presence of oxygen vacancies, and W was also present in the material. 5+ and W 6+ The prepared manganese tungstate nanoparticles were analyzed by X-ray diffraction (XRD), and the results are as follows: Figure 4 As shown, the XRD pattern of manganese tungstate nanoparticles contains four characteristic diffraction peaks, which correspond to the lattice plane structures of (100), (001), (-111) and (002), respectively.

[0053] (2) Preparation of manganese tungstate nanoparticles / polyethylene glycol composite materials

[0054] 10 mg of manganese tungstate nanoparticles and 40 mg of DSPE-PEG were dispersed in 4 mL of chloroform and stirred for 1 h to obtain a mixed solution. The solution was then dried under nitrogen for 2 h using a nitrogen evaporator. After drying, a manganese tungstate nanoparticle / polyethylene glycol composite material was obtained.

[0055] Infrared spectroscopy was performed on the prepared manganese tungstate nanoparticle / polyethylene glycol composite material, and the results are as follows: Figure 5 As shown, the spectrum of the prepared manganese tungstate nanoparticle / polyethylene glycol composite material is visible at 3400 cm⁻¹. -1 A broad OH band was observed nearby at 1740 cm⁻¹. -1 A C=O stretching band was observed at 1740 cm⁻¹. -1 The image shows a stretching band of P=O and PO, which confirms that DSPE-PEG was successfully coated on the surface of manganese tungstate nanoparticles.

[0056] (3) Preparation of manganese tungstate / hydrogen peroxide composition

[0057] Artificial saliva was prepared according to ISO / TR10271, by dissolving 0.4g NaCl, 0.4g KCl, 0.795g CaCl2·2H2O, 0.78g NaH2PO4·2H2O, 0.05g Na2S·2H2O, and 1g urea in 1L of deionized water. The manganese tungstate nanoparticle / polyethylene glycol composite material was dissolved in 25mL of the artificial saliva, and then mixed with 25mL of 1wt% hydrogen peroxide solution to obtain 50mL of the manganese tungstate nanoparticle / hydrogen peroxide composition.

[0058] The prepared manganese tungstate nanoparticle / hydrogen peroxide composition was analyzed by transmission electron microscopy (TEM), and the results are as follows: Figure 6a and Figure 6bAs shown, manganese tungstate nanoparticles are uniformly dispersed in the solution in the form of small aggregates with a diameter of about 20-30 nm.

[0059] Example 2

[0060] (1) Preparation of manganese tungstate nanoparticles

[0061] 352 mg of tungsten hexacarbonyl and 1.5 g of 1,2-dodecanediol were dispersed in 20 mL of dibenzyl ether. The mixture was heated to 130 °C under a nitrogen atmosphere, and then 1.5 mL of oleic acid and 1.5 mL of oleylamine were added. The mixture was then heated to 270 °C, and 352 mg of manganese acetylacetone was added. The mixture was stirred continuously for 0.5 h. After cooling to room temperature, excess ethanol was added and the mixture was centrifuged (10 min, 10,000 rpm). The mixture was then dissolved in 10 mL of cyclohexane, and then 20 mL of ethanol was added and the mixture was centrifuged (10 min, 10,000 rpm). This process was repeated three times. Finally, the mixture was dried in a 60 °C oven.

[0062] (2) Preparation of manganese tungstate nanoparticles / polyethylene glycol composite materials

[0063] 10 mg of manganese tungstate nanoparticles and 50 mg of DSPE-PEG were dispersed in 4 mL of chloroform and stirred for 1 h to obtain a mixed solution. The solution was then dried under nitrogen for 2 h using a nitrogen evaporator. After drying, a manganese tungstate nanoparticle / polyethylene glycol composite material was obtained.

[0064] (3) Preparation of manganese tungstate / hydrogen peroxide composition

[0065] The manganese tungstate nanoparticle / polyethylene glycol composite material was dissolved in 25 mL of artificial saliva, and then mixed with 25 mL of 2 wt% hydrogen peroxide solution to finally obtain 50 mL of manganese tungstate nanoparticle / hydrogen peroxide composition.

[0066] Example 3

[0067] (1) Preparation of manganese tungstate nanoparticles

[0068] 352 mg of tungsten hexacarbonyl and 1.5 g of 1,2-dodecanediol were dispersed in 20 mL of dibenzyl ether. The mixture was heated to 110 °C under a nitrogen atmosphere, and then 1.5 mL of oleic acid and 1.5 mL of oleylamine were added. The mixture was then heated to 250 °C, and then 352 mg of manganese acetylacetone was added. The mixture was stirred continuously for 1.5 h. After cooling to room temperature, excess ethanol was added and the mixture was centrifuged (10 min, 10000 rpm). The mixture was then dissolved in 10 mL of cyclohexane, and then 30 mL of ethanol was added and the mixture was centrifuged (10 min, 10000 rpm). This process was repeated three times. Finally, the mixture was dried in a 60 °C oven.

[0069] (2) Preparation of manganese tungstate nanoparticles / polyethylene glycol composite materials

[0070] 10 mg of manganese tungstate nanoparticles and 30 mg of DSPE-PEG were dispersed in 3 mL of chloroform and stirred for 1 h to obtain a mixed solution. The solution was then dried under nitrogen for 2 h using a nitrogen evaporator. After drying, a manganese tungstate nanoparticle / polyethylene glycol composite material was obtained.

[0071] (3) Preparation of manganese tungstate / hydrogen peroxide composition

[0072] The manganese tungstate nanoparticle / polyethylene glycol composite material was dissolved in 25 mL of artificial saliva, and then mixed with 25 mL of 1 wt% hydrogen peroxide solution to finally obtain 50 mL of manganese tungstate nanoparticle / hydrogen peroxide composition.

[0073] Evaluation of the teeth whitening performance of manganese tungstate nanoparticles / hydrogen peroxide composition

[0074] (1) Establishment of a tooth staining model

[0075] The enamel of a fresh human tooth is cut in half, then soaked in a black tea solution for a week to color it. After that, it is rinsed with deionized water to remove surface dirt.

[0076] (2) Teeth whitening experiment

[0077] The stained teeth were divided into four groups: ultrasonic treatment only, hydrogen peroxide plus ultrasonic treatment, manganese tungstate nanoparticles plus ultrasonic treatment, and manganese tungstate nanoparticles plus hydrogen peroxide plus ultrasonic treatment. The ultrasonic treatment group was ultrasonicated in artificial saliva for 8 hours (15-20 kHz, 50% duty cycle); the manganese tungstate nanoparticles plus ultrasonic treatment group was ultrasonicated in a 200 μg / mL manganese tungstate nanoparticle suspension for 8 hours; the hydrogen peroxide plus ultrasonic treatment group was ultrasonicated in a 0.5 wt% hydrogen peroxide solution for 8 hours; and the manganese tungstate nanoparticles plus hydrogen peroxide plus ultrasonic treatment group was ultrasonicated in a suspension of both 0.5 wt% hydrogen peroxide and 200 μg / mL manganese tungstate nanoparticles for 8 hours. The suspensions were changed every hour.

[0078] (3) Evaluation of whitening effect

[0079] Take pictures of the appearance and measure its luminance (L) value using a colorimeter, such as Figure 7a and Figure 7b As shown, compared with the ultrasound group alone, the hydrogen peroxide plus ultrasound group, and the manganese tungstate nanoparticle plus ultrasound group, the whitening effect of the manganese tungstate nanoparticle plus hydrogen peroxide plus ultrasound group was more obvious, indicating that a better whitening effect can be achieved under the dual action of manganese tungstate nanoparticles and hydrogen peroxide.

[0080] Biocompatibility testing of manganese tungstate nanoparticles

[0081] (1) Cell recovery and passage

[0082] The cryovials containing human gingival fibroblasts (HGF-1) were rapidly thawed in a 37°C water bath. The thawed cell culture medium was then mixed with 9 mL of complete culture medium (DMEM containing 15% fetal bovine serum and 1% penicillin-streptomycin). After centrifugation at 1200 rpm for 5 min, the supernatant was discarded, and the cells were transferred to a T25 flask containing 5–6 mL of complete culture medium. The flasks were then incubated at 37°C, 5% CO2, and 95% relative humidity for 18 h. Successful thawing was indicated by observing elongated, spindle-shaped, irregularly edged adherent cells under a microscope. To ensure cell viability, the cells were passaged once the cell density reached at least 80%. For cell passage, discard the old culture medium, wash twice with PBS, add 1-2 mL of trypsin (0.25% Trypsin + 0.02% EDTA) and incubate at 37°C for 1-2 min to detach the cells. Then add 5-6 mL of complete culture medium to stop digestion and centrifuge again to remove the supernatant. After adding complete culture medium again, mix well by pipetting and aliquot the cell suspension into new culture dishes at a 1:2 ratio for continued culture.

[0083] (2) Cytotoxicity assay

[0084] HGF-1 cell viability was determined using the CCK-8 assay to evaluate the cytotoxicity of the material. Cells were seeded in 96-well plates at a density of 1 × 10⁶ cells per well. 4 Cells were incubated for 24 hours. The old culture medium was discarded, and 100 μL of fresh culture medium containing different concentrations of manganese tungstate nanoparticles (50–1500 μg / mL) in a manganese tungstate nanoparticle / polyethylene glycol composite material was added. The cells were then cultured at 37°C for another 24 hours. After incubation, 10 μL of CCK-8 reagent was added to each well, and incubation was continued for 1–2 hours. The absorbance at 450 nm was then measured. The HGF-1 cell viability was calculated using the formula: Cell viability = (A... s -A b ) / (A c -A b )×100%, where A s A b and A c The absorbance values ​​are for the sample group, blank group, and control group, respectively. Each sample group was tested in 5 parallel trials (n=5). Figure 8 As shown, when the concentration of manganese tungstate nanoparticles is above 200 μg / mL, the cell survival rate reaches more than 80%. Therefore, manganese tungstate nanoparticles at this concentration (and below) have good biocompatibility.

[0085] Testing of enamel surface damage in manganese tungstate nanoparticles / hydrogen peroxide composition

[0086] Teeth stained with 20 wt% hydrogen peroxide solution were soaked for 30 minutes and then removed, achieving a brightness (L) value similar to that of the manganese tungstate nanoparticle plus hydrogen peroxide plus ultrasonic treatment group. Then, scanning electron microscopy (SEM) images were taken of normal tooth enamel, tooth enamel treated with 20% hydrogen peroxide for 30 minutes, and tooth enamel treated with manganese tungstate nanoparticle plus hydrogen peroxide plus ultrasonic treatment for 8 hours. Figures 9a-9d As shown, the enamel surface of teeth treated with manganese tungstate nanoparticles, hydrogen peroxide, and ultrasound for 8 hours was smooth and almost indistinguishable from normal enamel, while the enamel surface of teeth treated with 20wt% hydrogen peroxide solution for 30 minutes showed obvious damage.

[0087] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for the preparation of a manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening, characterized in that, comprising the steps of: Step one: preparing manganese tungstate nanoparticles, dispersing tungsten hexacarbonyl and a surfactant in a first organic solvent, adding an oleic acid / oleylamine ligand pair under a first reaction condition, then stirring the reaction under a second reaction condition, cooling, centrifuging, washing, drying, and obtaining manganese tungstate nanoparticles; the second reaction condition is: heating the reaction temperature to 250-270℃, adding manganese acetylacetonate, the molar ratio of the tungsten hexacarbonyl to the manganese acetylacetonate is 1:1, and the reaction time is 0.5-2h; Step two: preparing manganese tungstate nanoparticle / polyethylene glycol composites, uniformly stirring the manganese tungstate nanoparticles and polyethylene glycol derivatives dispersed in a second organic solvent, and performing nitrogen drying to obtain manganese tungstate nanoparticle / polyethylene glycol composites; Step three: dissolving the manganese tungstate nanoparticle / polyethylene glycol composites in artificial saliva, adding hydrogen peroxide solution for mixing, and obtaining manganese tungstate nanoparticle / hydrogen peroxide compositions for tooth whitening.

2. The method for preparing the manganese tungstate nanoparticle / hydrogen peroxide composition for teeth whitening according to claim 1, characterized in that, The first organic solvent is dibenzyl ether. The second organic solvent is chloroform.

3. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The surfactant is 1,2-dodecanediol.

4. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The volume ratio of oleic acid to oleylamine in the oleic acid / oleylamine ligand pair is 1:1, and the addition amount of the oleic acid / oleylamine ligand pair is 1-2mL.

5. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The polyethylene glycol derivative is distearoylphosphatidylethanolamine-methoxypolyethylene glycol.

6. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The manganese tungstate nanoparticle / hydrogen peroxide composition has a manganese tungstate concentration of 150-200μg / mL and a hydrogen peroxide concentration of 0.5-1wt%.

7. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The washing condition in step one is: using a cyclohexane ethanol mixture for washing, and the volume ratio of cyclohexane to ethanol in the cyclohexane ethanol mixture is 1: (1.5-3).

8. The method of claim 1, wherein the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared by the steps of: The first reaction condition is: the reaction environment is a nitrogen atmosphere, and the reaction temperature is 110-130℃.

9. A manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening prepared by the preparation method of any one of claims 1-8.

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