A blue light-cured silicone hydrogel for oral bleaching and a method for preparing the same

Abstract

The application relates to a kind of blue light curing oral cavity whitening silicone hydrogel and its preparation method, and belongs to the technical field of oral cavity function materials.The silicone hydrogel is composed of 1.0-5.0 parts of silicone resin and 95.0-99.0 parts of deionized water, and the structure formula of the silicone resin is as follows: wherein x=66.0%-77.0%, y=18.0%-22.0%, z=5.0%-12.0%, and x+y+z=100%.The application further discloses a preparation method and application in oral cavity whitening toothpastes.The hydrogel is flexible, safe and non-irritating, and has no residue after peeling off, and the storage stability is more than 24 months after being cured by 450-470 nm blue light at room temperature.The preparation process is green, low-carbon, low-energy, and suitable for industrial production.

Description

Technical Field

[0001] This application relates to the field of oral functional materials technology, and in particular to a blue light-cured silicone hydrogel for oral whitening and its preparation method. Technical Background

[0002] Current teeth whitening strips mostly use traditional synthetic polymer materials as the base material and are manufactured using high-temperature heat drying molding processes. The overall technology still has room for improvement. Currently, the base materials for commercially available teeth whitening strips mainly include carbomer, polyacrylic acid, polyvinyl alcohol, and waterborne polyurethane, which generally suffer from the technical deficiency of being unable to achieve a balanced overall performance.

[0003] Specifically, carbomer and polyacrylic acid are high-carboxyl acid systems, and long-term use of dental veneers can easily cause problems such as gingival sensitivity and enamel micro-demineralization, resulting in poor biocompatibility. Polyvinyl alcohol has high film rigidity, poor light transmittance, and weak surface fit, making it difficult to adapt to the complex curved structure of tooth surfaces, leading to a poor user experience. Waterborne polyurethane materials are prone to oligomer residues, poor curing uniformity, and yellowing with long-term use, failing to meet the high stability and high safety requirements of high-end dental consumables. In summary, traditional synthetic polymer substrates cannot simultaneously achieve the requirements of high biocompatibility, high flexibility, and residue-free veneer removal.

[0004] Chinese patent CN115919684A discloses a silicone-modified acrylic resin whitening gel and its preparation method. This patent uses silicone-modified acrylic resin as the binder for the whitening gel, increasing the silicone segment content in the resin through unsaturated silicone monomers and a segmented polymerization process to impart certain hydrophobicity and sustained-release ability of the whitening ingredients to the gel. However, this technology still has the following shortcomings: its substrate is silicone-modified acrylic resin, and residual acrylate monomers may cause oral mucosal irritation; furthermore, its molding still relies on traditional high-temperature heat drying processes, resulting in high energy consumption, large residual heat, and potential damage to heat-sensitive whitening active ingredients.

[0005] In terms of molding process, the existing whitening strip production generally adopts high-temperature heat drying process, which not only has problems such as high energy consumption, organic waste gas emission, and large heat residue, resulting in poor green production, but also the high-temperature processing conditions will destroy the heat-sensitive whitening active ingredients, making it unsuitable for the processing requirements of low-temperature sensitive functional raw materials, which greatly limits the product formula upgrade and performance improvement. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical shortcomings of existing teeth whitening strip substrates, such as poor biocompatibility, poor adhesion to curved tooth surfaces, easy residue after use, high energy consumption, easy damage to heat-sensitive whitening active ingredients, and insufficient environmental friendliness of traditional high-temperature heat drying processes. This invention provides a blue light-cured silicone hydrogel for oral whitening and its preparation method. This silicone hydrogel possesses high flexibility, excellent biocompatibility, low irritation, no residue after peeling, and high storage stability. The accompanying teeth whitening strip preparation process is low-temperature non-destructive, green, and low-carbon, suitable for large-scale mass production, effectively solving many technical bottlenecks of existing technologies.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] A blue light-curable silicone hydrogel for oral whitening, characterized in that the silicone hydrogel is composed of the following components in parts by weight: 1.0 to 5.0 parts of silicone resin, 95.0 to 99.0 parts of deionized water, and the total weight of the two components is 100 parts.

[0009] The organosilicon resin is poly(dimethylsiloxane-co-3-methacryloyloxypropylmethylsiloxane-co-3-sulfopropylmethylsiloxane sodium), and its structural formula is as follows:

[0010]

[0011] Where x represents the molar percentage of the dimethylsiloxane segment, y represents the molar percentage of the sodium 3-sulfopropylmethylsiloxane segment, and z represents the molar percentage of the 3-methacryloyloxypropylmethylsiloxane segment.

[0012] Furthermore: where x = 66.0~77.0%, y = 18.0~22.0%, z = 5.0~12.0%, x+y+z = 00%.

[0013] Furthermore, the preparation method of the blue light-cured silicone hydrogel for oral whitening is characterized by comprising the following steps:

[0014] S1. Preparation of Organosilicon Resin: 100 mL of anhydrous methanol and 1.00 mol of 3-mercaptopropylmethyldimethoxysilane were added sequentially to a glass reactor equipped with a mechanical stirrer, a low-temperature controlled water bath, online pH monitoring, and a constant-pressure dropping device. The reactor was cooled to 0–5 °C at a cooling rate of 1 °C / min and kept at a constant temperature. The mechanical stirrer was set to 100 r / min and stirred at a constant temperature for 30 min to ensure complete dissolution of the raw materials. Then, 3.10 mol of a 30% hydrogen peroxide aqueous solution was measured and diluted with an equal volume of anhydrous methanol. The diluted hydrogen peroxide solution was then added dropwise to the reactor at a constant-pressure dropping device over a period of 60–90 min. During the dropwise addition, the pH value of the system was monitored in real time. When the pH value deviated from the range of 6.5 to 7.2, a small amount of saturated sodium carbonate aqueous solution was added for precise control to ensure that the pH value was maintained stably between 6.5 and 7.2 throughout the reaction. After the dropwise addition was completed, the system temperature was kept constant at 0 to 5 °C, and the reaction was continued for 5 to 6 hours before termination. All materials in the reactor were transferred to a vacuum distillation flask, and methanol was removed by vacuum distillation at 40 °C and a vacuum degree of -0.08 to -0.095 MPa to obtain the monomer sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate.

[0015] In a four-necked glass reactor equipped with mechanical stirring, a low-temperature controlled water bath, online pH monitoring, and a constant-pressure dropping device, dimethyldimethoxysilane (66%–77% molar), sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate (18%–22% molar), 3-[dimethoxymethylsilyl]propyl methacrylate (5%–12% molar), 500 mL of anhydrous methanol, and 2,6-di-tert-butyl-4-methylphenol (0.05% of the total monomer mass) were added sequentially, based on a total monomer mass of 1.00 mol. The reaction system was heated to 35–38 °C at a heating rate of 1 °C / min and kept at a constant temperature. The mechanical stirring speed was set to 200 r / min, and stirring was maintained at this temperature for 20 min. Glacial acetic acid was added dropwise to the reaction system at a constant-pressure dropping device at a uniform rate. During the addition, the pH value of the system was monitored in real time and adjusted to maintain a stable pH value within the range of 4.2–5.0. Subsequently, 1.10 mol of deionized water was added dropwise to the reaction system at a constant pressure dropping device, with the total dropping time controlled at 2.5 h. After the addition was completed, the system temperature was maintained at 35–38 ℃ and the pH value at 4.2–5.0, and the reaction was carried out at a constant temperature for 5–6 h. After the reaction was completed, heating was stopped, and the mixture was allowed to cool naturally to room temperature. All the material in the reaction vessel was transferred to a vacuum distillation flask, and vacuum distillation was carried out at 40 ℃ and a vacuum degree of -0.075 MPa to remove methanol, thereby obtaining the target product, poly(dimethylsiloxane-co-3-methacryloyloxypropylmethylsiloxane-co-3-sulfopropylmethylsiloxane sodium) organosilicon resin.

[0016] S2. Preparation of hydrogel: Add 1.0 to 5.0 parts of organosilicon resin to 95.0 to 99.0 parts of deionized water and stir at room temperature until completely dissolved to obtain organosilicon hydrogel.

[0017] Furthermore, the blue light-cured silicone hydrogel for oral whitening possesses photocrosslinking properties; a thin-film silicone hydrogel with a thickness not exceeding 2.0 cm, prepared using the aforementioned ratio, is then combined with sodium phenyl(2,4,6-trimethylbenzoyl)phosphonite photoinitiator at room temperature and exposed to light at a wavelength of 450–470 nm and an intensity of 20–80 mW / cm². 2 When exposed to light for more than 30 seconds, a three-dimensional cross-linked structure can be formed inside the film.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) This invention designs a ternary condensation polysilicon molecular structure. By precisely controlling the grafting ratio of hydrophilic sodium propyl sulfonate groups and photosensitive methacrylate groups, the material simultaneously possesses excellent water solubility, biocompatibility, and controllable photocrosslinking properties. It effectively avoids the acidic irritation problem of traditional carbomer and polyacrylic acid substrates, as well as the defects of polyvinyl alcohol film rigidity, poor tooth surface adhesion, and easy residue and yellowing of waterborne polyurethane. It achieves the comprehensive advantages of low oral irritation, high flexibility and adhesion, and no residue after peeling, making it suitable for long-term oral veneer application scenarios.

[0020] (2) This invention abandons the high-temperature heat drying molding process of traditional whitening strip production and adopts 450-470 nm room temperature blue light post-crosslinking modification technology. The entire process is carried out at low temperature without heat damage, which can perfectly adapt to various heat-sensitive whitening active ingredients and greatly broaden the product formulation compatibility range. At the same time, it eliminates the problems of high energy consumption, VOC emissions, and heat residue of traditional processes. The preparation process is green and environmentally friendly, with low energy consumption, and can meet the needs of industrial-scale production.

[0021] (3) This invention uses photocrosslinking reaction to stably bond oligomer molecules into a three-dimensional network structure, eliminating the problem of oligomer residue from the root. After crosslinking by room temperature light, a dense and stable three-dimensional network structure can be formed, which can significantly improve the structural stability and shape retention of whitening strips. The product can be stored at room temperature for more than 24 months. Its safety and durability are better than traditional oral hydrogel substrates, and it has extremely high oral care and cosmetic application value. Attached Figure Description

[0022] Figure 1 The proton nuclear magnetic resonance spectrum of the organosilicon resin 1 prepared in Example 1 of this invention (NMR spectrum). 1 (H NMR) image. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] In the following description, references to "some embodiments" describe a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this application pertain. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit the application.

[0025] In the following description of this embodiment, the terms "comprising," "including," "having," and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0026] It should be noted that all raw materials / reagents in the embodiments of this application can be purchased on the market or prepared according to conventional methods known to those skilled in the art; the term "and / or" in the embodiments of this application is only used to describe the relationship between related objects, indicating that there can be three relationships. For example, A and / or B means three cases: A exists alone, B exists alone, and A and B exist simultaneously. A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship.

[0027] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0028] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0029] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0030] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value and an intermediate value within the stated range, as well as any other stated value or an intermediate value within the stated range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art described herein. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in embodiments or test examples of this application. All references to this specification are generally incorporated herein by reference to disclose and describe methods and / or materials associated with said references. In the event of any conflict with any incorporated references, the content of this application shall prevail.

[0032] All embodiments of the present invention below adopt a unified preparation process, and the specific steps are as follows:

[0033] S1. Preparation of Organosilicon Resin: 100 mL of anhydrous methanol and 1.00 mol of 3-mercaptopropylmethyldimethoxysilane were added sequentially to a glass reactor equipped with a mechanical stirrer, a low-temperature controlled water bath, online pH monitoring, and a constant-pressure dropping device. The reactor was cooled to 0–5 °C at a cooling rate of 1 °C / min and kept at a constant temperature. The mechanical stirrer was set to 100 r / min and stirred at a constant temperature for 30 min to ensure complete dissolution of the raw materials. Then, 3.10 mol of a 30% hydrogen peroxide aqueous solution was measured and diluted with an equal volume of anhydrous methanol. The diluted hydrogen peroxide solution was then added dropwise to the reactor at a constant-pressure dropping device over a period of 60–90 min. During the dropwise addition, the pH value of the system was monitored in real time. When the pH value deviated from the range of 6.5 to 7.2, a small amount of saturated sodium carbonate aqueous solution was added for precise control to ensure that the pH value was maintained stably between 6.5 and 7.2 throughout the reaction. After the dropwise addition was completed, the system temperature was kept constant at 0 to 5 °C, and the reaction was continued for 5 to 6 hours before termination. All materials in the reactor were transferred to a vacuum distillation flask, and methanol was removed by vacuum distillation at 40 °C and a vacuum degree of -0.08 to -0.095 MPa to obtain the monomer sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate.

[0034] In a four-necked glass reactor equipped with mechanical stirring, a low-temperature controlled water bath, online pH monitoring, and a constant-pressure dropping device, dimethyldimethoxysilane (66%–77% molar), sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate (18%–22% molar), 3-[dimethoxymethylsilyl]propyl methacrylate (5%–12% molar), 500 mL of anhydrous methanol, and 2,6-di-tert-butyl-4-methylphenol (0.05% of the total monomer mass) were added sequentially, based on a total monomer mass of 1.00 mol. The reaction system was heated to 35–38 °C at a heating rate of 1 °C / min and kept at a constant temperature. The mechanical stirring speed was set to 200 r / min, and stirring was maintained at this temperature for 20 min. Glacial acetic acid was added dropwise to the reaction system at a constant-pressure dropping device at a uniform rate. During the addition, the pH value of the system was monitored in real time and adjusted to maintain a stable pH value within the range of 4.2–5.0. Subsequently, 1.10 mol of deionized water was added dropwise to the reaction system at a constant pressure dropping device, with the total dropping time controlled at 2.5 h. After the addition was completed, the system temperature was maintained at 35–38 ℃ and the pH value at 4.2–5.0, and the reaction was carried out at a constant temperature for 5–6 h. After the reaction was completed, heating was stopped, and the mixture was allowed to cool naturally to room temperature. All the material in the reaction vessel was transferred to a vacuum distillation flask, and vacuum distillation was carried out at 40 ℃ and a vacuum degree of -0.075 MPa to remove methanol, thereby obtaining the target product, poly(dimethylsiloxane-co-3-methacryloyloxypropylmethylsiloxane-co-3-sulfopropylmethylsiloxane sodium) organosilicon resin.

[0035] S2. Preparation of silicone hydrogel: According to the weight ratio, add the prepared silicone resin to deionized water and stir at room temperature until completely dissolved to obtain a uniform and transparent silicone hydrogel.

[0036] S3. Whitening Function Compounding and Coating Forming: Add oral whitening active ingredients and sodium phenyl (2,4,6-trimethylbenzoyl)phosphonite photoinitiator to the prepared homogeneous organosilicon hydrogel as needed, stir at low speed at room temperature to obtain a whitening organosilicon hydrogel coating solution; coat the coating solution evenly on the substrate surface, and prepare a thin film gel coating with a thickness ≤2.0 cm by controlling the coating thickness;

[0037] S4. Photocrosslinking and shaping: Under room temperature conditions, using a wavelength of 450–470 nm and a light intensity of 20–80 mW / cm². 2 Exposure to blue light for more than 30 seconds causes a stable and dense three-dimensional cross-linked structure to be built inside the gel film, ultimately producing silicone teeth whitening strips.

[0038] Example 1

[0039] This embodiment 1 provides a method for preparing silicone hydrogel 1 and the corresponding teeth whitening strip 1, the specific steps of which are as follows:

[0040] 1) Preparation of organosilicon resin 1: The molar ratio of the monomers of organosilicon resin 1 is: 66% dimethyldimethoxysilane, 22% sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate, and 12% 3-[dimethoxymethylsilyl]propyl methacrylate.

[0041] 2) Preparation of silicone hydrogel 1: By weight, silicone hydrogel 1 contains 1.0 parts of silicone resin 1 and 99.0 parts of deionized water.

[0042] 3) Whitening Function Compounding and Coating Forming: Add 2.0 parts polyvinylpyrrolidone K30, 0.5 parts glycerin, 1.0 part urea peroxide, 0.01 parts sodium tripolyphosphate, 0.01 parts sucralose, 0.01 parts citric acid, 0.01 parts potassium nitrate, 0.001 parts ethylenediaminetetraacetic acid, 0.05 parts menthol, and 0.05 parts sodium phenyl(2,4,6-trimethylbenzoyl)phosphonite to 1.0 part silicone hydrogel 1. Add the above mixture to a vacuum stirring emulsification pot and stir at low speed for 2.0 hours at room temperature (0.1 MPa) to obtain a whitening silicone hydrogel coating solution. Coat the coating solution uniformly onto the surface of a PET substrate. By controlling the coating thickness, a thin film gel coating with a thickness of 200 μm is prepared.

[0043] 4) Preparation of whitening strip 1: Under room temperature conditions, using an LED light source with a wavelength of 450–470 nm and a fixed operating condition of 20 mW / cm². 2 The gel coating was irradiated with light intensity for 30 seconds to obtain whitening strip 1.

[0044] Example 2

[0045] This embodiment 2 provides a method for preparing silicone hydrogel 2 and corresponding teeth whitening strips 2, the specific steps of which are as follows:

[0046] 1) Preparation of organosilicon resin 2: The molar ratio of the monomers of the organosilicon resin 2 is: 77% dimethyldimethoxysilane, 18% sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate, and 5% 3-[dimethoxymethylsilyl]propyl methacrylate.

[0047] 2) Preparation of silicone hydrogel 2: By weight, silicone hydrogel 2 contains 5.0 parts of silicone resin 2 and 95.0 parts of deionized water.

[0048] 3) Whitening Function Compounding and Coating Forming: Add 2.0 parts polyvinylpyrrolidone K30, 0.5 parts glycerin, 1.0 part urea peroxide, 0.01 parts sodium tripolyphosphate, 0.01 parts sucralose, 0.01 parts citric acid, 0.01 parts potassium nitrate, 0.001 parts ethylenediaminetetraacetic acid, 0.05 parts menthol, and 0.05 parts sodium phenyl(2,4,6-trimethylbenzoyl)phosphonite to 1.0 parts of silicone hydrogel 2. Add the above mixture to a vacuum stirring emulsification pot and stir at low speed for 2.0 hours at room temperature (0.1 MPa) to obtain a whitening silicone hydrogel coating solution. Coat the solution uniformly onto the surface of a PET substrate. By controlling the coating thickness, a thin film gel coating with a thickness of 200 μm is prepared.

[0049] 4) Preparation of whitening strip 2: Under room temperature conditions, using an LED light source with a wavelength of 450–470 nm and a fixed operating condition of 80 mW / cm². 2 The gel coating was irradiated with light intensity for 45 seconds to obtain whitening strip 2.

[0050] Comparative Example 1

[0051] Comparative Example 1 provides a method for preparing teeth whitening strip 3, the specific steps of which are as follows:

[0052] 1.0 part of polyvinyl alcohol with a viscosity of 70.0 MPa, 50.0 part of medical alcohol, 50.0 part of deionized water, 0.5 part of glycerin, 2.0 part of polyvinylpyrrolidone K30, 1.0 part of urea peroxide, 0.01 part of sodium tripolyphosphate, 0.01 part of sucralose, 0.01 part of citric acid, 0.01 part of potassium nitrate, 0.001 part of ethylenediaminetetraacetic acid, and 0.05 part of menthol were added to a vacuum stirring emulsification pot and stirred at low speed at 0.1 MPa for 2.0 hours at room temperature to obtain a gel coating solution. The gel was then uniformly coated onto a PET film substrate using a coating machine to a thickness of 200 μm. The composite was then baked in an 80 ℃ oven for 2.0 hours to obtain whitening teeth whitening strip 3.

[0053] Comparative Example 2

[0054] Comparative Example 2 provides a method for preparing whitening strip 4, the specific steps of which are as follows:

[0055] 1.0 part of carbomer U20, 90.0 part of deionized water, 0.5 part of glycerin, 2.0 part of polyvinylpyrrolidone K30, 1.0 part of urea peroxide, 0.01 part of sodium tripolyphosphate, 0.01 part of sucralose, 0.01 part of citric acid, 0.01 part of potassium nitrate, 0.001 part of ethylenediaminetetraacetic acid, and 0.05 part of menthol were added to a vacuum stirring emulsification pot and stirred at low speed at 0.1 MPa for 2.0 hours at room temperature to obtain a gel coating solution. The gel was then uniformly coated onto a PET film substrate using a coating machine to a thickness of 200 μm. The composite was then baked in an 80 ℃ oven for 2.0 hours to obtain whitening teeth strip 4.

[0056] Performance testing

[0057] Experiment 1: Structure Testing of Organosilicon Resin

[0058] The experimental conditions were as follows: A Bruker AVANCE NEO 400MHz nuclear magnetic resonance spectrometer was used, with heavy water as the solvent, to test the structure of organosilicon resin 1. The results are as follows. Figure 1 As shown.

[0059] Experiment 2: Molecular weight test of organosilicon resin

[0060] The experimental conditions were as follows: A Waterse 2695 gel permeation chromatograph was used, with Styragel HR3 and HR4 columns in tandem, deionized water as the mobile phase, a flow rate of 1.0 mL / min, a column temperature of 35 ℃, a sample concentration of 5 mg / mL, and an injection volume of 20 μL. The molecular weight and molecular weight distribution of organosilicon resin 1 were tested.

[0061] Experiment 3: Cytotoxicity Test of Whitening Strips

[0062] The experimental conditions were as follows: In accordance with ISO 10993-5, human gingival fibroblasts were cultured in vitro and detected by MTT assay; the material extraction conditions were 37 ℃ for 24 h, and the extraction medium was cell culture medium. The toxicity level was quantified by cell survival rate, and a survival rate ≥95% was judged as having no cytotoxicity and excellent biocompatibility.

[0063] Experiment 4: Oral Mucosal Irritation Test of Whitening Strips

[0064] The experimental conditions were as follows: In accordance with ISO 10993-10 and ISO 7405 standards for evaluating dental mucosal irritation, the Shandong Seret SRT-Z029 periodontal probe torque tester was used to test the gingival condition of 50 healthy gingival volunteers in each group after using the gingival whitening strips. The strips were used once a day from 9:00 to 9:30 and once a day from 15:00 to 15:30, for a total of 2 times a day. After 7 consecutive days of use, the periodontal probe was used for testing.

[0065] Experiment 5: Small molecule leaching residue test of whitening strips

[0066] The test conditions are as follows: According to the ISO 10993-18 standard for chemical characterization of materials, high performance liquid chromatography and gel permeation chromatography were used to detect the presence of unreacted monomers, oligomers, acidic small molecules and other precipitated impurities in the soaking solution after soaking in deionized water at room temperature for 24 hours. No detection means no small molecule leaching residue.

[0067] Experiment 6: Whitening strip peel residue test

[0068] The experimental conditions were as follows: 50 volunteers with healthy gums were uniformly treated at room temperature for 30 minutes and then peeled off at a constant speed. The residue on the substrate surface was observed visually and under a microscope to determine whether there was any residual adhesive or film.

[0069] Experiment 7: Storage stability test of whitening strips

[0070] The test conditions are as follows: Based on YY / T 0681.1-2018 and ASTM F1980-21 General Standards for Accelerated Aging of Medical Devices, the Q10 accelerated aging method based on the Arrhenius kinetic model was used to simulate 2 years of room temperature storage stability. The Q10 value was taken as the industry-standard conservative value of 2.0. The standard room temperature storage reference temperature was 25 ℃, the accelerated aging test temperature was set at 55 ℃, the relative humidity was 60%±10%, and the accelerated aging time was 42 days, simulating 24 months of room temperature storage. The appearance, flexibility, transparency, yellowing and cracking, gel cohesion, and residual use of the whitening strips were uniformly tested. No degradation in any performance characteristic was considered to meet the 24-month storage stability requirements.

[0071] Experiment 8: Whitening strip whitening effect test

[0072] The experimental conditions were as follows: Maxillary premolars extracted within 30 days for orthodontic purposes were selected, and the surface color difference (L value) of the teeth was measured using a spectral colorimeter. The teeth were then wrapped with whitening adhesive tape and immersed in a beaker containing 100 ml of deionized water at 37°C for 2.0 hours. After immersion, the teeth were removed, and the surface color difference (L* value) was measured again using a spectral colorimeter. The whitening effect was evaluated based on the change in L* value (ΔL) before and after the immersion treatment.

[0073] The test results are as follows:

[0074] 1. The ¹H NMR spectrum of organosilicon resin 1 is as follows: Figure 1 As shown.

[0075] 2. The number-average molecular weight of organosilicon resin 1 is Mn=12800 g / mol, the weight-average molecular weight is Mw=15400 g / mol, and the molecular weight distribution index (PDI) is 1.20.

[0076] 3. The test results for cytotoxicity, oral mucosal irritation, small molecule dissolution residue, peel residue, storage stability, and teeth whitening effect of the whitening strips are shown in the table below:

[0077]

[0078] The quantitative data in the table above clearly demonstrates that the blue-light-cured silicone hydrogel teeth whitening strips prepared in the two embodiments of this invention exhibit significantly superior core performance compared to the traditional substrate comparison. The cell survival rate of the materials in this invention is ≥95%, meeting high biocompatibility standards. They cause no oral mucosal irritation, no small molecule dissolution residue, and are extremely safe for oral use. After peeling, there is no residue, providing an excellent user experience. Furthermore, this invention employs a 450–470 nm room-temperature blue light curing process, which is fully compatible with heat-sensitive whitening active ingredients, eliminating the activity loss problem associated with high-temperature processes. The product maintains stability at room temperature for over 24 months, with no yellowing, cracking, or failure even after long-term use. Compared to traditional heat-drying processes, the preparation process of this invention is green and low-carbon, with no VOC emissions and low energy consumption, making it suitable for industrial-scale mass production and possessing extremely high application value and market potential in oral whitening.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A blue light-curable silicone hydrogel for oral whitening, characterized in that, The silicone hydrogel is composed of the following components in parts by weight: 1.0 to 5.0 parts silicone resin, 95.0 to 99.0 parts deionized water, and the total weight of the two components is 100 parts. The organosilicon resin is poly(dimethylsiloxane-co-3-methacryloyloxypropylmethylsiloxane-co-3-sulfopropylmethylsiloxane sodium), and its structural formula is as follows: Where x represents the molar percentage of the dimethylsiloxane segment, y represents the molar percentage of the sodium 3-sulfopropylmethylsiloxane segment, and z represents the molar percentage of the 3-methacryloyloxypropylmethylsiloxane segment; x = 66.0%~77.0%, y = 18.0%~22.0%, z = 5.0%~12.0%, and x+y+z=100%.

2. A method for preparing the blue light-cured silicone hydrogel for oral whitening as described in claim 1, characterized in that, Includes the following steps: S1. Preparation of organosilicon resin: (1) Add 100 mL of anhydrous methanol and 1.00 mol of 3-mercaptopropylmethyldimethoxysilane sequentially to a glass reactor equipped with a mechanical stirrer, a low-temperature programmable water bath, online pH monitoring, and a constant-pressure dropping device; cool the reactor to 0–5 °C at a cooling rate of 1 °C / min and maintain the temperature; set the mechanical stirrer speed to 100 r / min and stir at a constant temperature for 30 min; measure 3.10 mol of 30% hydrogen peroxide aqueous solution, dilute it with an equal volume of anhydrous methanol, and add it dropwise into the reactor at a constant-pressure dropping device at a uniform rate, with the dropping time controlled at 60–90 min; monitor the pH value of the system in real time during the dropping process, and add saturated sodium carbonate aqueous solution to adjust the pH value when it deviates from 6.5–7.2 to ensure that the pH is maintained at 6.5–7.2; after the dropping is completed, maintain the system temperature at 0–5 °C and continue the reaction for 5–6 h, then terminate the reaction; transfer the material in the reactor to a vacuum distillation flask and distill at a temperature of 40 °C. Methanol was removed by vacuum distillation under ℃ and vacuum conditions of -0.08 to -0.095 MPa to obtain sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate monomer; (2) In a four-necked glass reactor equipped with mechanical stirring, a low-temperature programmable water bath, online pH monitoring, and a constant-pressure dropping device, based on a total monomer content of 1.00 mol, add sequentially 66%–77% dimethyldimethoxysilane, 18%–22% sodium 3-(dimethoxymethylsilyl)-1-propanesulfonate, 5%–12% 3-[dimethoxymethylsilyl]propyl methacrylate, 500 mL anhydrous methanol, and 0.05% 2,6-di-tert-butyl-4-methylphenol; heat to 35–38 ℃ at a rate of 1 ℃ / min and maintain a constant temperature; set the mechanical stirring speed to 200 r / min and stir at a constant temperature for 20 min; add glacial acetic acid dropwise through the constant-pressure dropping device to adjust the pH of the system to maintain it at 4.2–5.0; then take 1.10 Deionized water was added dropwise to the reaction system at a constant pressure dropping device over a period of 2.5 h. After the addition was complete, the system temperature was maintained at 35–38 °C and the pH at 4.2–5.0 for 5–6 h. After the reaction was completed, heating was stopped and the mixture was allowed to cool naturally to room temperature. The material in the reactor was then transferred to a vacuum distillation flask, and methanol was removed by vacuum distillation at 40 °C and a vacuum of -0.075 MPa to obtain the target product, poly(dimethylsiloxane-co-3-methacryloyloxypropylmethylsiloxane-co-3-sulfopropylmethylsiloxane sodium) organosilicon resin. S2. Preparation of hydrogel: Add 1.0 to 5.0 parts of organosilicon resin to 95.0 to 99.0 parts of deionized water and stir at room temperature until completely dissolved to obtain organosilicon hydrogel.

3. The blue light-curable silicone hydrogel for oral whitening according to claim 1, characterized in that, The organosilicon hydrogel exhibits photocrosslinking properties. A thin-film organosilicon hydrogel with a thickness not exceeding 2.0 cm, prepared using the formulation of claim 1, is then combined with sodium phenyl(2,4,6-trimethylbenzoyl)phosphonite photoinitiator at room temperature and exposed to light at a wavelength of 450–470 nm and an irradiation intensity of 20–80 mW / cm². 2 When exposed to light for more than 30 seconds, a three-dimensional cross-linked structure can be formed inside the film.

4. The blue light-curable silicone hydrogel for oral whitening according to claim 1, characterized in that, The organosilicon resin has a number-average molecular weight of 12,000–14,000 g / mol, a weight-average molecular weight of 14,000–17,000 g / mol, and a molecular weight distribution index (PDI) of 1.1–1.

3.

5. A blue light-cured teeth whitening strip, characterized in that, The silicone hydrogel for oral whitening with blue light curing as described in claim 1 is prepared by coating and photocrosslinking; the thickness of the film after coating is not greater than 2.0 cm; the photocrosslinking is carried out at room temperature, in combination with sodium phenyl (2,4,6-trimethylbenzoyl)phosphonite photoinitiator, using a wavelength of 450-470 nm and a light intensity of 20-80 mW / cm. 2 When exposed to light for more than 30 seconds, a three-dimensional cross-linked structure is formed inside the film.

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