Oral mucosa protection patch for preventing orthodontic traumatic ulcer and preparation method thereof

Abstract

The invention relates to an oral mucosa protection patch for preventing orthodontic traumatic ulcer and a preparation method thereof, the protection patch comprises a double-layer structure of a protection layer and an adhesion layer, each part of raw material of the protection layer comprises a PDMS prepolymer and a cross-linking agent in a mass ratio of 10: 1-33: 1; the adhesive layer is prepared from the following raw materials in each part: 6.3 to 7.7 g of acrylic acid, 0.67 to 0.80 g of polyvinyl alcohol, 0.036 to 0.044 g of alpha-ketoglutaric acid, 0.52 to 0.64 g of N-hydroxysuccinimide acrylate and 9.0 to 11.0 mu L of polyethylene glycol diacrylate; the preparation method comprises the following steps: respectively preparing the protective layer and the adhesion layer, and then combining the protective layer with the adhesion layer; the PDMS prepolymer and the cross-linking agent are mixed according to different proportions, so that PDMS elastomers with different elastic moduli can be prepared, the modulus can be adjusted in a personalized manner, the PDMS elastomers are matched with mechanical properties of mucous membrane tissues at corresponding parts, and friction and compression are reduced to the greatest extent; the adhesive layer hydrogel material has a good hydration effect, is firmly adhered to the oral mucosa, and can be used as a physical barrier to protect the oral mucosa and provide a moderate moist environment at the same time, so that the comfort level of a user is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedical polymer materials, and in particular relates to an oral mucosa protective patch for preventing orthodontic traumatic ulcers and a preparation method thereof. Background Art

[0002] Malocclusion generally refers to the deformities of teeth, jaws and craniofacial structures caused by genetic and environmental factors during the growth and development process. It can also be caused by trauma, periodontal disease and other reasons after the growth and development is completed. It manifests as uneven teeth and abnormal relationship between the upper and lower dental arches. It affects the development of the maxillofacial area, oral health, oral function and facial aesthetics. The correction methods for malocclusion include preventive correction, blocking correction, general correction and orthodontic and orthognathic combined treatment. Among them, the general correction of malocclusion is the most common in orthodontic clinics. The types of appliances used mainly include fixed appliances, removable appliances and functional appliances.

[0003] The most widely used square wire and straight wire fixed appliances in the world usually use adhesives to bond brackets and other correction devices to the tooth surface, install the archwire in the bracket groove by ligation or self-locking, and apply force through the archwire or elastic accessories to move the teeth to correct malocclusion. However, in the prior art, brackets are mainly bonded to the lip and cheek surfaces of the teeth, directly contacting the oral mucosa. Repeated friction stimulation may damage the oral mucosa and even cause oral ulcers. In addition, during the process of tooth alignment, the orthodontic archwire will gradually become longer relative to the patient's dental arch, causing the end to slip out of the buccal tube. Since the end of the orthodontic archwire is relatively sharp, it may damage the oral mucosa, causing pain and discomfort to the patient, affecting patient compliance and orthodontic treatment results.

[0004] The general solution at present is to place orthodontic protective wax kneaded into a ball on the bracket surface of the grinding mouth or the end of the orthodontic arch wire. However, this method only relies on mechanical retention force to combine with the correction device, and the adhesion effect is poor and easy to fall off, which inevitably leads to the problem of frequent replacement. On the other hand, the sharp end of the arch wire can easily pierce the wax block, affecting its protective effect.

[0005] A Chinese patent application with application number 202322007950.4 discloses an orthodontic mucosal protective cover. The design uses elastic silicone to form an arc-shaped diaphragm structure that matches the curvature of the teeth. By wearing front and rear protective diaphragms, the tooth surface lock is blocked to prevent direct contact with the oral mucosa. However, this device cannot effectively protect the oral mucosa that is in contact with the end of the arch wire. The elastic connecting piece connecting the front and rear diaphragms has limited effect, and the overall volume of the protective cover is large, which may cause obvious foreign body sensation and difficulty in cleaning oral hygiene.

[0006] At present, there is an urgent need in clinical practice for a new mucosal protective patch that can protect the oral mucosa and prevent traumatic oral ulcers caused by orthodontic treatment, especially the dislocation of the sharp end archwire. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide an oral mucosa protective patch for preventing orthodontic traumatic ulcers and a preparation method thereof. The double-layer structure is adopted, in which the protective layer adopts PDMS and the adhesive layer adopts polyacrylic acid hydrogel. Through the innovative preparation process and interlayer bonding method, the protective patch has a simple structure, is easy to prepare and use, has excellent comfort, adjustability and long-term effective protection effect, and can minimize the damage to the patient's oral mucosa and the discomfort caused by the corrective device during the orthodontic process; the patch of the present invention has strong adhesion, low swelling, and strong mechanical properties, and promotes the repair of oral ulcer wounds.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] Disclosed is an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the protective patch comprising a double-layer structure of a protective layer and an adhesive layer, wherein the raw materials of the protective layer comprise a PDMS prepolymer and a cross-linking agent in a mass ratio of 10:1 to 33:1; each portion of the raw materials of the adhesive layer contains 6.3 to 7.7 g of acrylic acid, 0.67 to 0.80 g of polyvinyl alcohol, 0.036 to 0.044 g of α-ketoglutaric acid, 0.52 to 0.64 g of N-hydroxysuccinimide acrylate, and 9.0 to 11.0 μL of polyethylene glycol diacrylate.

[0010] The protective layer covers the surface of the adhesive layer to isolate the friction of the correction device. The thickness of the protective layer is 0.5 to 1 mm, and the Young's modulus of the protective layer is 33.4 to 37.7 kPa.

[0011] The adhesive layer is in direct contact with the oral mucosa, the thickness of the adhesive layer is 240-480 μm, and the Young's modulus of the adhesive layer is 12.20-14.90 kPa.

[0012] The protective layer has the same bottom area as the adhesive layer, and the protective layer has the same shape as the base surface of the orthodontic correction device to be isolated, and the area of ​​the protective layer is greater than or equal to the base surface of the orthodontic correction device.

[0013] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0014] Step 1. Preparation of protective layer: weigh PDMS prepolymer and cross-linking agent in a mass ratio of 10:1 to 33:1, stir thoroughly until mixed evenly, and then evacuate for 20 to 40 minutes to remove bubbles to obtain a mixture of PDMS prepolymer and cross-linking agent; evenly apply the mixture of PDMS prepolymer and cross-linking agent on the surface of a culture dish, spin-coat at 250 to 350 rpm for 60 to 120 seconds, and then dry it at 55 to 65° C. for 24 to 30 hours, and take it out after the PDMS is completely cured;

[0015] Step 2. Preparation of adhesive layer: Weigh 6.3-7.7 g acrylic acid, 0.67-0.80 g polyvinyl alcohol, 0.036-0.044 g α-ketoglutaric acid, 0.52-0.64 g N-hydroxysuccinimide acrylate and 9.0-11.0 μL polyethylene glycol diacrylate are set aside; first, 10.4-12.7 mL of deionized water is placed in a container, and then the weighed acrylic acid is slowly added into the deionized water while stirring with a glass rod, a rotor is placed in the container, and the container is placed on a magnetic stirrer, and the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate are slowly added in sequence while stirring at a speed of 450-550 rpm, and stirred at 55-65° C. for 1-2 hours, and polyethylene glycol diacrylate is added to the above solution and continued to stir at a speed of 450-550 rpm at room temperature for 4-6 minutes to obtain an initial adhesion layer hydrogel precursor solution; then, 0.52-0.64 g of N-hydroxysuccinimide acrylate is added, and the final adhesion layer hydrogel precursor solution is obtained after complete dissolution by oscillation, and an appropriate amount of this solution is injected into a customized mold, and an adhesive hydrogel is formed by UV crosslinking;

[0016] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 10:1 to 33:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 30 to 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with "+" facing up in a mixed solution of 0.5wt% to 1.5wt% 3-aminopropyltriethoxysilane, 49.25wt% to 49.75wt% ethanol and 49.25wt% to 49.75wt% deionized water for 1 to 4 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 1.5 to 3 hours until the protective layer and the adhesion layer are firmly bonded.

[0017] In the step 2, the light source power of the ultraviolet cross-linking instrument for ultraviolet cross-linking is 7.2-8.8W, the wavelength is 229-279nm, and the cross-linking time is 900-1200s.

[0018] The PDMS prepolymer and cross-linking agent are commercially available products, such as Dow Corning DC184.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The purpose of the present invention is to provide an oral mucosa protective patch for preventing orthodontic traumatic ulcers, which adopts a double-layer structure, in which the protective layer adopts PDMS and the adhesive layer adopts polyacrylic acid hydrogel. Through innovative preparation technology and interlayer bonding method, the protective patch has a simple structure, is easy to prepare and use, has excellent comfort, adjustability and long-term effective protection effect, and can minimize the damage to the patient's oral mucosa and the discomfort caused by the corrective device during orthodontic treatment.

[0021] 2. The protective layer is made of PDMS material, which has good biocompatibility, low toxicity and low irritation, and has been approved by the U.S. Food and Drug Administration (FDA) for use in food, drugs and medical devices. PDMS material has excellent flexibility and elasticity, which can effectively alleviate the friction between orthodontic devices and oral mucosa, reduce damage to oral mucosa, and prevent the occurrence of traumatic ulcers. PDMS matrix and curing agent are mixed in different proportions to prepare PDMS elastomers with different elastic moduli. The modulus can be adjusted individually to match the mechanical properties of the mucosal tissue in the corresponding part, reduce the adverse consequences caused by mechanical mismatch, and can perfectly fit the morphology of different parts in the mouth to minimize friction and pressure.

[0022] 3. The adhesive layer hydrogel has good hydration, adheres firmly to the oral mucosa, and can act as a physical barrier to protect the oral mucosa while providing a moderately moist environment, thereby improving the comfort of the user.

[0023] 4. Both the protective layer and the adhesive layer can be prepared in any shape and size according to actual needs and application scenarios. When orthodontic brackets or other accessory devices are used to grind the mouth, protective patches of corresponding sizes and shapes can be prepared according to their sizes, which can effectively protect the friction areas of the mucosa while minimizing the volume of the protective patch, which is beneficial to oral hygiene and reduces the foreign body sensation, further improving patient comfort.

[0024] 5. The protective patch adheres to the oral mucosa with strong adhesion, and its protective effect will not be affected by falling off or loosening. It can also be used in a wide range of scenarios. It can not only prevent orthodontic brackets or other anterior oral accessory devices from grinding the mouth, but also effectively protect the oral mucosa contacted by the end of the archwire. When the end of the archwire falls out and damages the mucosa, a protective patch of the corresponding shape can be prepared according to the area where the end mucosa contacts the archwire, and adhered to the corresponding oral mucosa.

[0025] In summary, the oral mucosa protective patch of the present invention has good mechanical properties and meets the application requirements in the oral environment; the preparation method is simple and has excellent comfort, adjustability and long-term effective protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Stress-strain curve of the tensile test of the protective layer PDMS elastomer;

[0027] Figure 2 Stress-strain curve for tensile test of adhesion layer hydrogel;

[0028] Figure 3 These are photos of the lower lip mucosa of rats corresponding to the brackets after different treatments. Figure 3 (a) is a photo of the lower lip mucosa of rats in the negative control group (Control) at the initial stage (0d) and 14d after modeling. Figure 3 (b) is a photo of the lower lip mucosa of rats in the orthodontic wax group (Wax) at the initial stage (0d) and 14d after modeling. Figure 3 (c) Photos of the lower lip mucosa of rats in the mucosal protective patch group (PDMS) at the initial stage (0d) and 14d after modeling;

[0029] Figure 4 The H&E staining results of the lower lip mucosa of rats corresponding to the brackets treated in different ways, among which, Figure 4 (a) is the H&E staining result of the lower lip mucosa of the negative control group (Control) at 14 days after modeling. Figure 4 (b) H&E staining results of the lower lip mucosa of rats in the orthodontic wax group (Wax) at 14 days after modeling. Figure 4 (c) H&E staining results of the lower lip mucosa of rats at 14 days after modeling for the mucosal protective patch group (PDMS);

[0030] Figure 5 The results of H&E staining of the heart, liver, spleen, lung, and kidney of rats after different treatments. Figure 5 (a) H&E stained sections of rat hearts in the negative control group (Control) and the mucosal protective patch group (PDMS). Figure 5 (b) H&E staining sections of rat liver in the negative control group (Control) and the mucosal protective patch group (PDMS). Figure 5 (c) H&E stained sections of the spleen of rats in the negative control group (Control) and the mucosal protective patch group (PDMS). Figure 5 (d) H&E stained sections of rat lungs in the negative control group (Control) and the mucosal protective patch group (PDMS). Figure 5(e) H&E stained sections of the kidneys of rats in the negative control group (Control) and the mucosal protective patch group (PDMS). DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with embodiments, but these embodiments are not intended to limit the present invention.

[0032] Example 1

[0033] An oral mucosa protective patch for preventing orthodontic traumatic ulcers comprises a double-layer structure of a protective layer and an adhesive layer, wherein the protective layer raw materials comprise a PDMS prepolymer and a cross-linking agent in a mass ratio of 33:1; each portion of the adhesive layer raw materials contains 7.7 g of acrylic acid, 0.80 g of polyvinyl alcohol, 0.044 g of α-ketoglutaric acid, 0.58 g of N-hydroxysuccinimide acrylate, and 11.0 μL of polyethylene glycol diacrylate.

[0034] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0035] Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 33:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 35 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 325 rpm for 110 seconds, and then dry it at 62.5°C for 27 hours, and take it out after the PDMS is completely cured;

[0036] Step 2. Preparation of the adhesive layer: 7 g acrylic acid, 0.735 g polyvinyl alcohol, 0.04 g α-ketoglutaric acid, 0.58 g N-hydroxysuccinimide acrylate, and 10.0 μL polyethylene glycol diacrylate were weighed and set aside; first, 11.55 mL of deionized water was placed in a container, and then the weighed acrylic acid was slowly added to the deionized water while stirring with a glass rod. After the rotor was placed in the container, it was placed on a magnetic stirrer and the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate were slowly added in sequence while stirring at a speed of 500 rpm. Stir at 0°C for 1.5h, add polyethylene glycol diacrylate to the above solution and continue stirring at 500rpm on a magnetic stirrer at room temperature for 5min to obtain an initial adhesion layer hydrogel precursor solution; then add 0.58g of N-hydroxysuccinimide acrylate, use a vortex oscillator to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution, use a pipette to inject an appropriate amount of this solution into a custom mold, and form an adhesive hydrogel by UV crosslinking. The UV crosslinking instrument has a light source power of 7.2W, a wavelength of 229nm, and a crosslinking time of 1200s;

[0037] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 33:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" facing up in a mixed solution of 1wt% 1.5wt% 3-aminopropyltriethoxysilane, 49.25wt% ethanol and 49.25wt% deionized water for 1 hour. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 2 hours until the protective layer and the adhesion layer are firmly bonded.

[0038] Example 2

[0039] An oral mucosa protective patch for preventing orthodontic traumatic ulcers comprises a double-layer structure of a protective layer and an adhesive layer, wherein the protective layer raw materials comprise a PDMS prepolymer and a cross-linking agent in a mass ratio of 20:1, and each portion of the adhesive layer raw materials contains 6.3 g of acrylic acid, 0.7376 g of polyvinyl alcohol, 0.04 g of α-ketoglutaric acid, 0.52 g of N-hydroxysuccinimide acrylate, and 10.0 μL of polyethylene glycol diacrylate.

[0040] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0041] Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 20:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 30 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 300 rpm for 90 seconds, and then dry it at 60°C for 24 hours, and take it out after the PDMS is completely cured;

[0042] Step 2. Preparation of adhesion layer: Weigh 6.3 g of acrylic acid, 0.7376 g of polyvinyl alcohol, 0.04 g of α-ketoglutaric acid, 0.52 g of N-hydroxysuccinimide acrylate, and 10 μL of polyethylene glycol diacrylate for use; first, take 11.55 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in turn while stirring at a speed of 500 rpm. Stir at 55° C. for 2 h. Add polyethylene glycol diacrylate. Add the above solution and continue stirring at 450 rpm on a magnetic stirrer at room temperature for 4 to 6 minutes to obtain an initial adhesion layer hydrogel precursor solution, then add 0.52 g of N-hydroxysuccinimide acrylate, use a vortex oscillator to assist in oscillation and complete dissolution to obtain a final adhesion layer hydrogel precursor solution, use a pipette to inject an appropriate amount of this solution into a custom mold, and form an adhesive hydrogel by UV crosslinking. The UV crosslinking instrument has a light source power of 7.8 W, a wavelength of 254 nm, and a crosslinking time of 900 s.

[0043] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 20:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 30 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" facing up in a mixed solution of 1.25wt% 3-aminopropyltriethoxysilane, 49.375wt% ethanol and 49.375wt% deionized water for 2 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 3 hours until the protective layer and the adhesion layer are firmly bonded.

[0044] Example 3

[0045] An oral mucosal protective patch for preventing orthodontic traumatic ulcers, characterized in that: the protective patch includes a double-layer structure of a protective layer and an adhesive layer, wherein the protective layer raw material includes a PDMS prepolymer and a cross-linking agent in a mass ratio of 25:1, and each portion of the adhesive layer raw material includes 7.7g of acrylic acid, 0.80g of polyvinyl alcohol, 0.044g of α-ketoglutaric acid, 0.64g of N-hydroxysuccinimide acrylate, and 11.0μL of polyethylene glycol diacrylate.

[0046] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0047] Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 25:1, stir thoroughly until the two components are evenly mixed, and then evacuate for 40 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 350 rpm for 60 seconds, and then dry it at 65°C for 24 hours, and take it out after the PDMS is completely cured;

[0048] Step 2. Preparation of the adhesion layer: Weigh 7.7 g of acrylic acid, 0.80 g of polyvinyl alcohol, 0.044 g of α-ketoglutaric acid, 0.64 g of N-hydroxysuccinimide acrylate, and 11.0 μL of polyethylene glycol diacrylate for use; first, take 12.7 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in sequence while stirring at a speed of 550 rpm. Stir at 65° C. for 1 hour, and add polyethylene glycol diacrylate into the above solution. The initial adhesion layer hydrogel precursor solution was obtained by stirring at a speed of 550 rpm for 4 min at room temperature on a magnetic stirrer, and then 0.64 g of N-hydroxysuccinimide acrylate was added, and a vortex oscillator was used to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution. A proper amount of this solution was injected into a custom mold using a pipette, and an adhesive hydrogel was formed by UV crosslinking. The UV crosslinking instrument had a light source power of 8.5 W, a wavelength of 240 nm, and a crosslinking time of 1100 s.

[0049] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 25:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" facing up in a mixed solution of 1.00wt% 3-aminopropyltriethoxysilane, 49.50wt% ethanol and 49.50wt% deionized water for 3 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 1.5 hours until the protective layer and the adhesion layer are firmly bonded.

[0050] Example 4

[0051] An oral mucosal protective patch for preventing orthodontic traumatic ulcers, characterized in that: the protective patch includes a double-layer structure of a protective layer and an adhesive layer, wherein the protective layer raw material includes a PDMS prepolymer and a cross-linking agent in a mass ratio of 30:1; each portion of the adhesive layer raw material contains 6.3g of acrylic acid, 0.67g of polyvinyl alcohol, 0.036g of α-ketoglutaric acid, 0.60g of N-hydroxysuccinimide acrylate, and 9.0μL of polyethylene glycol diacrylate.

[0052] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0053] Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 30:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 25 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 275 rpm for 75 seconds, and then dry it at 57.5°C for 25 hours, and take it out after the PDMS is completely cured;

[0054] Step 2. Preparation of adhesive layer: Weigh 6.3 g acrylic acid, 0.67 g polyvinyl alcohol, 0.036 g α-ketoglutaric acid, 0.60 g N-hydroxysuccinimide acrylate and 9.0 μL polyethylene glycol diacrylate are set aside; first, 10.4 mL of deionized water is placed in a container, and then the weighed acrylic acid is slowly added to the deionized water while stirring with a glass rod, a rotor is placed in the container, and the container is placed on a magnetic stirrer, and the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate are slowly added in sequence while stirring at a speed of 450 rpm, and stirred at 55°C for 2 hours, polyethylene glycol diacrylate is added to the above solution on a magnetic stirrer and continued to stir at a speed of 450 rpm at room temperature for 6 minutes to obtain an initial adhesion layer hydrogel precursor solution, and then 0.60 g of N-hydroxysuccinimide acrylate is added, and a vortex oscillator is used to assist its oscillation and complete dissolution to obtain a final adhesion layer hydrogel precursor solution, and an appropriate amount of this solution is injected into a custom mold using a pipette, and an adhesive hydrogel is formed by UV crosslinking, and the UV crosslinking instrument light source power of the UV crosslinking is 8 W, the wavelength is 254 nm, and the crosslinking time is 1200 s;

[0055] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 30:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 45 seconds, mark the bonded treated surface as "+", and then soak the elastomer with the "+" facing up in a mixed solution of 1.25wt% 3-aminopropyltriethoxysilane, 49.38wt% ethanol and 49.38wt% deionized water for 3.5 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 2 hours until the protective layer and the adhesion layer are firmly bonded.

[0056] Example 5

[0057] An oral mucosal protective patch for preventing orthodontic traumatic ulcers, characterized in that: the protective patch includes a double-layer structure of a protective layer and an adhesive layer, wherein the protective layer raw material includes a PDMS prepolymer and a cross-linking agent in a mass ratio of 10:1; each portion of the adhesive layer raw material contains 7g of acrylic acid, 0.735g of polyvinyl alcohol, 0.04g of α-ketoglutaric acid, 0.57g of N-hydroxysuccinimide acrylate, and 10.0μL of polyethylene glycol diacrylate.

[0058] A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows:

[0059] Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 10:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 30 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 300 rpm for 90 seconds, and then dry it at 60°C for 24 hours, and take it out after the PDMS is completely cured;

[0060] Step 2. Preparation of the adhesion layer: Weigh 7.7 g of acrylic acid, 0.80 g of polyvinyl alcohol, 0.044 g of α-ketoglutaric acid, 0.56 g of N-hydroxysuccinimide acrylate, and 11.0 μL of polyethylene glycol diacrylate for use; first, take 12.7 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in turn while stirring at a speed of 550 rpm. Stir at 65° C. for 1 hour, and add polyethylene glycol diacrylate into the above solution. The initial adhesion layer hydrogel precursor solution was obtained by continuing to stir at a speed of 550 rpm at room temperature on a magnetic stirrer for 4 min, and then 0.56 g of N-hydroxysuccinimide acrylate was added, and a vortex oscillator was used to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution. A proper amount of this solution was injected into a custom mold using a pipette, and an adhesive hydrogel was formed by UV crosslinking. The UV crosslinking instrument light source power was 8.8 W, the wavelength was 279 nm, and the crosslinking time was 1200 s.

[0061] Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 10:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded treated surface as "+", and then soak the elastomer with "+" facing up in a mixed solution of 1.25wt% of 0.5wt% 3-aminopropyltriethoxysilane, 49.75wt% of ethanol and 49.75wt% of deionized water for 4 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 2.5 hours until the protective layer and the adhesion layer are firmly bonded.

[0062] By mixing PDMS prepolymer and cross-linking agent in different proportions, PDMS elastomers with different elastic moduli can be prepared. The modulus can be adjusted in an individualized manner to match the mechanical properties of the mucosal tissue in the corresponding area, thereby reducing the adverse consequences caused by mechanical mismatch. It can perfectly fit the morphology of different parts of the oral cavity and minimize friction and pressure.

[0063] The protective patch samples prepared by the method described in Example 1 were used to conduct animal experiments to test the properties of the protective patch:

[0064] Experimental Example 1

[0065] This experimental example provides the tensile test method and results of the PDMS elastomer protective layer.

[0066] Prepare a dumbbell-shaped tensile test sample (dumbbell length 12mm, width 5mm, thickness 2mm), use a vernier caliper to measure the sample size, connect and fix the two ends of the sample to be tested with the fixture, use a microcomputer tensile testing machine to perform a tensile test, from the initial state until the sample breaks, the tensile speed is 10mm / min, draw a stress-strain curve, and calculate the Young's modulus in the strain range of about 0% to 10%. Figure 1 As shown, the Young's modulus of the PMDS elastomer with a mass ratio of 33:1 is 35.55±2.15 kPa, and the fracture strain is higher than 80%, which has good mechanical properties and meets the application requirements in the oral environment.

[0067] Experimental Example 2

[0068] This embodiment provides a tensile test method and results of an adhesion layer.

[0069] A dumbbell-shaped tensile test sample (dumbbell length 12 mm, width 5 mm, thickness 2 mm) was prepared, and both ends were connected and fixed with clamps. A tensile test was performed using a microcomputer tensile testing machine. The tensile speed was 10 mm / min from the initial state until the sample broke. The stress-strain curve was plotted, and the Young's modulus was calculated in the strain range of 0% to 10%.

[0070] Figure 2 The tensile test results showed that the average value of the adhesive's Young's modulus was 13.55 kPa, the tensile strength was greater than 100 kPa, and the fracture strain was greater than 700%, which is conducive to its application in dynamic oral environments.

[0071] Experimental Example 3

[0072] This experimental example provides an example of using an oral mucosal protective patch to prevent orthodontic bracket stimulation and trauma to the lower lip mucosa of rats.

[0073] After anesthetizing the rats, the limbs were fixed in the supine position. The maxillary teeth were fixed with a 0.25 mm diameter ligature to assist in fixing the rat head. An opener made of 0.8 mm diameter stainless steel wire was used to assist in opening the mouth. The surgical area was covered with a drape, and the local mucosa was checked. After ensuring the health of the mucosa, the rat gingival mucosa was wiped and disinfected with 1% medical iodine tincture. The iodine was removed with 75% medical alcohol. The domestic straight wire bracket was sutured to the labial gingiva of the lower anterior teeth using the "cross method". The position of the bracket was based on the complete coverage of the metal bracket by the lower lip when the rat closed its mouth. All rats were randomly divided into three groups: PDMS group, protective wax group and control group, with 4 rats in each group. The brackets and surrounding mucosa were rinsed with saline, dried with dry cotton balls and isolated from moisture, and the rats in different groups were treated accordingly. In the PDMS experimental group, the mucosal protective patch was adhered to the lower lip mucosa of the rats and pressed for 15 seconds to ensure its firm adhesion; in the orthodontic wax group, a "soybean"-sized orthodontic wax was taken and rubbed into a ball, placed on the bracket, and then pressed to adjust; in the negative control group, only the bracket was sutured, rinsed and dried. The corresponding mucosal protective patch and orthodontic wax were replaced every 48 hours in the experimental group. During the experiment, the retention of the brackets in the mouth of the rats was observed every day, and they were re-sutured once they were found to be detached. On the 14th day, all rats in the experimental group and the control group were euthanized, and photos of the intraoral mucosa were taken and the mucosal conditions were recorded. The brackets and sutures were removed, and the full-thickness tissue of the lower lip mucosa was cut with a punch and a scalpel. Pay attention to the protection of the lower lip mucosa during the operation. Finally, the removed tissue was fixed for 24 hours using 4% paraformaldehyde tissue fixative.

[0074] The results of the observation of the mucosal conditions of the three groups of rats on the 14th day were as follows: Figure 1 As shown: There were 4 rats in the control group, 1 rat had obvious mucosal edema, and 3 rats had ulcers; there were 4 rats in the orthodontic wax group, 2 rats had obvious mucosal edema, and 2 rats had ulcers; there were 4 rats in the mucosal protection patch group, 1 rat had obvious mucosal edema, 1 rat had ulcers, and 2 rats had no obvious damage. Comparison of the lower lip mucosal conditions of rats in different groups during modeling and sampling Figure 3 As shown, it shows that the mucosal protection sticker can reduce the friction damage of orthodontic brackets to the oral mucosa, and the protective effect is better than orthodontic protective wax.

[0075] Experimental Example 4

[0076] This experimental example provides H&E staining of oral mucosal protective patch to prevent orthodontic bracket stimulation to rat lower lip mucosa trauma.

[0077] The rat lower lip mucosa samples and heart, liver, spleen, lung and kidney samples fixed with paraformaldehyde were rinsed with PBS for 20 minutes, and then dehydrated with 70.0%, 80.0%, 90.0% and 100% ethanol solutions; after drying, the samples were waxed, embedded and sliced; the slices were placed in xylene I, xylene II, anhydrous ethanol I, anhydrous ethanol II, 95% ethanol, 85% ethanol and 75% ethanol in turn, with the action time of 8min, 8min, 5min, 5min, 5min, 5min, 5min, and 5min, respectively, and rinsed with running water. Hematoxylin was applied for 5min, rinsed with running water for 3s, 1% hydrochloric acid ethanol was applied for 3s, rinsed with running water for 30s, and washed with distilled water for 2s; eosin stain was applied for 3min, and washed with distilled water for 2s. Dehydration and sealing: Dehydrate the slices in 75% ethanol, 95% ethanol I, 95% ethanol II, anhydrous ethanol I, anhydrous ethanol II, xylene I, and xylene II in turn until transparent. The action time is 30s, 1min, 2min, 5min, 5min, 5min, and 7min respectively. Then take out the slices, control them to dry, and seal them with neutral gum. Scan the images with a digital slice scanner for analysis.

[0078] H&E staining results Figure 2 As shown: the spinous layer thickening occurred in the lower lip mucosa of the three groups of rats at 14 days, the negative control group > orthodontic wax group > mucosal protection patch group, the surface keratinized layer of the blank control group was discontinuous, the spinous layer was significantly thickened, and obvious inflammatory cell infiltration was observed in the subcutaneous tissue; the surface keratinized layer of the orthodontic wax group was thinner, the spinous layer was partially thickened, and partial inflammatory cell infiltration was observed in the subcutaneous tissue; the surface keratinized layer of the mucosal protection patch group was partially thinner, the spinous layer was slightly thickened, and no obvious inflammatory cell infiltration was observed in the subcutaneous tissue, which was similar to the normal epithelial structure, indicating that the mucosal protection patch can reduce the inflammatory response of the oral mucosal tissue in the corresponding part of the bracket, further confirming the excellent effect of the mucosal protection patch on preventing oral mucosal damage caused by orthodontic bracket wear from a histological level.

[0079] The H&E staining results of the heart, liver, spleen, lung, and kidney of rats in different groups are shown in Figure 2. Figure 3 As shown: On day 14, the H&E staining results of the heart, liver, spleen, lung, and kidney of rats in the mucosal protection patch group and the blank control group were similar, with no obvious abnormalities, indicating that the mucosal protection patch has good in vivo biological safety.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

Claims

1. An oral mucosal protective patch for preventing orthodontic traumatic ulcers, characterized in that: The invention comprises a double-layer structure of a protective layer and an adhesive layer, wherein the raw materials of the protective layer comprise a PDMS prepolymer and a crosslinking agent in a mass ratio of 10:1 to 33:1; each portion of the raw materials of the adhesive layer contains 6.3 to 7.7 g of acrylic acid, 0.67 to 0.80 g of polyvinyl alcohol, 0.036 to 0.044 g of α-ketoglutaric acid, 0.52 to 0.64 g of N-hydroxysuccinimide acrylate, and 9.0 to 11.0 μL of polyethylene glycol diacrylate.

2. The oral mucosa protective patch for preventing orthodontic traumatic ulcers according to claim 1, characterized in that: The protective layer covers the surface of the adhesive layer to isolate the friction of the correction device. The thickness of the protective layer is 0.5 to 1 mm, and the Young's modulus of the protective layer is 33.4 to 37.7 kPa.

3. The oral mucosa protective patch for preventing orthodontic traumatic ulcers according to claim 1, characterized in that: The adhesive layer is in direct contact with the oral mucosa, the thickness of the adhesive layer is 240-480 μm, and the Young's modulus of the adhesive layer is 12.20-14.90 kPa.

4. The oral mucosa protective patch for preventing orthodontic traumatic ulcers according to claim 1, characterized in that: The protective layer has the same bottom area as the adhesive layer, and the protective layer has the same shape as the base surface of the orthodontic correction device to be isolated, and the area of ​​the protective layer is greater than or equal to the base surface of the orthodontic correction device.

5. A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, characterized in that: The specific steps are as follows: Step 1. Preparation of protective layer: weigh PDMS prepolymer and cross-linking agent in a mass ratio of 10:1 to 33:1, stir thoroughly until mixed evenly, and then evacuate for 20 to 40 minutes to remove bubbles to obtain a mixture of PDMS prepolymer and cross-linking agent; evenly apply the mixture of PDMS prepolymer and cross-linking agent on the surface of a culture dish, spin-coat at 250 to 350 rpm for 60 to 120 seconds, and then dry it at 55 to 65° C. for 24 to 30 hours, and take it out after the PDMS is completely cured; Step 2. Preparation of adhesive layer: Weigh 6.3-7.7 g acrylic acid, 0.67-0.80 g polyvinyl alcohol, 0.036-0.044 g α-ketoglutaric acid, 0.52-0.64 g N-hydroxysuccinimide acrylate and 9.0-11.0 μL polyethylene glycol diacrylate are set aside; first, 10.4-12.7 mL of deionized water is placed in a container, and then the weighed acrylic acid is slowly added into the deionized water while stirring with a glass rod, a rotor is placed in the container, and the container is placed on a magnetic stirrer, and the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate are slowly added in sequence while stirring at a speed of 450-550 rpm, and stirred at 55-65° C. for 1-2 hours, and polyethylene glycol diacrylate is added to the above solution and continued to stir at a speed of 450-550 rpm at room temperature for 4-6 minutes to obtain an initial adhesion layer hydrogel precursor solution; then, 0.52-0.64 g of N-hydroxysuccinimide acrylate is added, and the final adhesion layer hydrogel precursor solution is obtained after complete dissolution by oscillation, and an appropriate amount of this solution is injected into a customized mold, and an adhesive hydrogel is formed by UV crosslinking; Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 10:1 to 33:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 30 to 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" side facing up in a mixed solution of 0.5wt% to 1.5wt% 3-aminopropyltriethoxysilane, 49.25wt% to 49.75wt% ethanol and 49.25wt% to 49.75wt% deionized water for 1 to 4 hours, take it out and rinse the elastomer with deionized water, clean and dry the surface, and now the amino group has been successfully grafted on the "+" surface of the PDMS elastomer protective layer, fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 1.5 to 3 hours until the protective layer and the adhesion layer are firmly bonded.

6. The method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers according to claim 5, characterized in that: In the step 2, the light source power of the ultraviolet cross-linking instrument for ultraviolet cross-linking is 7.2-8.8W, the wavelength is 229-279nm, and the cross-linking time is 900-1200s.

7. The method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers according to claim 5, characterized in that: A method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers, the specific steps are as follows: Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 33:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 35 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 325 rpm for 110 seconds, and then dry it at 62.5°C for 27 hours, and take it out after the PDMS is completely cured; Step 2. Preparation of the adhesive layer: 7 g acrylic acid, 0.735 g polyvinyl alcohol, 0.04 g α-ketoglutaric acid, 0.58 g N-hydroxysuccinimide acrylate, and 10.0 μL polyethylene glycol diacrylate were weighed and set aside; first, 11.55 mL of deionized water was placed in a container, and then the weighed acrylic acid was slowly added to the deionized water while stirring with a glass rod. After the rotor was placed in the container, it was placed on a magnetic stirrer and the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate were slowly added in sequence while stirring at a speed of 500 rpm. Stir at 0°C for 1.5h, add polyethylene glycol diacrylate to the above solution and continue stirring at 500rpm on a magnetic stirrer at room temperature for 5min to obtain an initial adhesion layer hydrogel precursor solution; then add 0.58g of N-hydroxysuccinimide acrylate, use a vortex oscillator to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution, use a pipette to inject an appropriate amount of this solution into a custom mold, and form an adhesive hydrogel by UV crosslinking. The UV crosslinking instrument has a light source power of 7.2W, a wavelength of 229nm, and a crosslinking time of 1200s; Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 33:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" side facing up in a mixed solution of 1wt% 1.5wt% 3-aminopropyltriethoxysilane, 49.25wt% ethanol and 49.25wt% deionized water for 1 hour. After taking it out, rinse the elastomer with deionized water and clean and dry the surface. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 2 hours until the protective layer and the adhesion layer are firmly bonded.

8. The method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers according to claim 5, characterized in that: The specific steps are as follows: Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 20:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 30 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 300 rpm for 90 seconds, and then dry it at 60°C for 24 hours, and take it out after the PDMS is completely cured; Step 2. Preparation of adhesion layer: Weigh 6.3 g of acrylic acid, 0.7376 g of polyvinyl alcohol, 0.04 g of α-ketoglutaric acid, 0.52 g of N-hydroxysuccinimide acrylate, and 10 μL of polyethylene glycol diacrylate for use; first, take 11.55 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in turn while stirring at a speed of 500 rpm. Stir at 55° C. for 2 h. Add polyethylene glycol diacrylate. Add the above solution and continue stirring at 450 rpm on a magnetic stirrer at room temperature for 4 to 6 minutes to obtain an initial adhesion layer hydrogel precursor solution, then add 0.52 g of N-hydroxysuccinimide acrylate, use a vortex oscillator to assist in oscillation and complete dissolution to obtain a final adhesion layer hydrogel precursor solution, use a pipette to inject an appropriate amount of this solution into a custom mold, and form an adhesive hydrogel by UV crosslinking. The UV crosslinking instrument has a light source power of 7.8 W, a wavelength of 254 nm, and a crosslinking time of 900 s. Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 20:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 30 seconds, mark the bonded surface as "+", and then soak the elastomer with the "+" side facing up in a mixed solution of 1.25wt% 3-aminopropyltriethoxysilane, 49.375wt% ethanol and 49.375wt% deionized water for 2 hours. After taking it out, rinse the elastomer with deionized water and clean and dry the surface. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 3 hours until the protective layer and the adhesion layer are firmly bonded.

9. The method for preparing an oral mucosal protective patch for preventing orthodontic traumatic ulcers according to claim 5, characterized in that: The specific steps are as follows: Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 25:1, stir thoroughly until the two components are evenly mixed, and then evacuate for 40 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 350 rpm for 60 seconds, and then dry it at 65°C for 24 hours, and take it out after the PDMS is completely cured; Step 2. Preparation of the adhesion layer: Weigh 7.7 g of acrylic acid, 0.80 g of polyvinyl alcohol, 0.044 g of α-ketoglutaric acid, 0.64 g of N-hydroxysuccinimide acrylate, and 11.0 μL of polyethylene glycol diacrylate for use; first, take 12.7 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in sequence while stirring at a speed of 550 rpm. Stir at 65° C. for 1 hour, and add polyethylene glycol diacrylate into the above solution. The initial adhesion layer hydrogel precursor solution was obtained by stirring at a speed of 550 rpm for 4 min at room temperature on a magnetic stirrer, and then 0.64 g of N-hydroxysuccinimide acrylate was added, and a vortex oscillator was used to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution. A proper amount of this solution was injected into a custom mold using a pipette, and an adhesive hydrogel was formed by UV crosslinking. The UV crosslinking instrument had a light source power of 8.5 W, a wavelength of 240 nm, and a crosslinking time of 1100 s. Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 25:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded surface as "+", and then soak the elastomer with the "+" side facing up in a mixed solution of 1.00wt% 3-aminopropyltriethoxysilane, 49.50wt% ethanol and 49.50wt% deionized water for 3 hours. After taking it out, rinse the elastomer with deionized water and keep the surface clean and dry. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 1.5 hours until the protective layer and the adhesion layer are firmly bonded.

10. The method for preparing the oral mucosa protective patch for preventing orthodontic traumatic ulcers according to claim 5, comprising the following steps: Step 1. Preparation of protective layer: weigh PDMS prepolymer and crosslinker in a mass ratio of 10:1, stir thoroughly until the two components are evenly mixed, and then vacuum for 30 minutes to remove bubbles; obtain a mixture of PDMS prepolymer and crosslinker; evenly apply the mixture of PDMS prepolymer and crosslinker on the surface of the culture dish, spin coat at 300 rpm for 90 seconds, and then dry it at 60°C for 24 hours, and take it out after the PDMS is completely cured; Step 2. Preparation of the adhesion layer: Weigh 7.7 g of acrylic acid, 0.80 g of polyvinyl alcohol, 0.044 g of α-ketoglutaric acid, 0.56 g of N-hydroxysuccinimide acrylate, and 11.0 μL of polyethylene glycol diacrylate for use; first, take 12.7 mL of deionized water and place it in a container. Then, slowly add the weighed acrylic acid into the deionized water while stirring with a glass rod. After placing a rotor in the container, place it on a magnetic stirrer and slowly add the weighed polyvinyl alcohol, α-ketoglutaric acid, and N-hydroxysuccinimide acrylate in turn while stirring at a speed of 550 rpm. Stir at 65° C. for 1 hour, and add polyethylene glycol diacrylate into the above solution. The initial adhesion layer hydrogel precursor solution was obtained by continuing to stir at a speed of 550 rpm at room temperature on a magnetic stirrer for 4 min, and then 0.56 g of N-hydroxysuccinimide acrylate was added, and a vortex oscillator was used to assist in oscillation and complete dissolution to obtain the final adhesion layer hydrogel precursor solution. A proper amount of this solution was injected into a custom mold using a pipette, and an adhesive hydrogel was formed by UV crosslinking. The UV crosslinking instrument light source power was 8.8 W, the wavelength was 279 nm, and the crosslinking time was 1200 s. Step 3. Bonding of the protective layer and the adhesion layer: Place the prepared 10:1 PDMS elastomer in a vacuum plasma surface treatment device for bonding for 60 seconds, mark the bonded treatment surface as "+", and then soak the elastomer with the "+" side facing up in a mixed solution of 1.25wt% of 0.5wt% 3-aminopropyltriethoxysilane, 49.75wt% of ethanol and 49.75wt% of deionized water for 4 hours. After taking it out, rinse the elastomer with deionized water and clean and dry the surface. At this time, amino groups have been successfully grafted on the "+" surface of the PDMS elastomer protective layer. Fit the "+" surface of the elastomer to the surface of one side of the adhesion layer of the same size, and react in the dark at room temperature for 2.5 hours until the protective layer and the adhesion layer are firmly bonded.

Images