Degradable dental restoration support membrane

Abstract

The invention relates to the field of oral medical materials, and particularly discloses a degradable oral restoration support membrane. The degradable dental restoration support membrane comprises a support matrix and a degradable outer protection layer, the support matrix is made of a pure magnesium or magnesium alloy material, and the degradable outer protection layer is one of a poly (lactide-caprolactone) coating, a poly (glycolide-caprolactone) coating and a poly (lactide-caprolactone) blended poly (glycolide-caprolactone) coating; in addition, the preparation method disclosed by the invention has the advantage of balancing the mechanical strength and biodegradability of the dental restoration support membrane.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oral medical materials, more particularly, it relates to a degradable oral repair support film. BACKGROUND

[0002] With the continuous progress of oral medical technology, dental implant has become an important method for repairing missing teeth. However, not all patients' alveolar bone is suitable for direct implantation. Under normal circumstances, dental implant requires at least 5mm in width and 8mm in height of alveolar bone support. When the bone mass is insufficient, the implant is prone to loosen and fall off. Bone augmentation technology mainly aims at patients with insufficient alveolar bone mass. By implanting bone powder or other bone substitute materials, the bone mass and bone density of the alveolar bone are increased, effectively improving the height and width of the alveolar bone, providing a stable support environment for the dental implant, meeting the conditions of the dental implant, and achieving higher success rate and long-term stability of the implant treatment. In the bone augmentation surgery, guided bone regeneration (GBR) is a commonly used method. The core of GBR is to use absorbable or non-absorbable barrier membranes such as collagen membrane and titanium membrane to cover the bone defect area, form a physical barrier to prevent soft tissue such as gum from growing in, and at the same time fill bone powder materials such as autologous bone and artificial bone powder as a scaffold to guide the directional growth of bone cells.

[0003] The currently used absorbable collagen membrane barrier membrane and non-absorbable titanium barrier membrane have distinct advantages and disadvantages. The absorbable collagen barrier membrane has good biocompatibility and biodegradable absorption, but it lacks mechanical support in maintaining the time and space of filling bone powder. The non-absorbable metal titanium barrier membrane can well maintain the time and space of filling bone powder in mechanical support, but the metal titanium mesh is not degradable and absorbable, and as a foreign body implant, the titanium mesh may cause postoperative infection, and a secondary surgery is required to remove it after bone augmentation is completed. Therefore, researchers have developed degradable metal barrier membranes such as pure magnesium / magnesium alloy barrier membranes and zinc alloy barrier membranes. Whether it is pure magnesium, zinc or its alloy products, the degradation rate is relatively fast, which leads to a high local concentration of degradation products, causing cytotoxicity, osteolysis and other side effects; at the same time, it also leads to premature decay of the mechanical support in maintaining the time and space of filling bone powder, and poor bone formation quality. Researchers have further modified the surface of degradable metals, such as magnesium fluoride coating, calcium phosphate coating, organic polymer polylactic acid, and polyurethane coating.

[0004] Up to 40% of implant osseointegration implants require guided bone regeneration surgery. From the perspective of material design, an ideal barrier membrane should have good biocompatibility, sufficient mechanical support performance and stability, and biodegradability. Magnesium metal membrane as a guided bone regeneration membrane has good biocompatibility, sufficient mechanical support performance and stability. However, pure magnesium membrane as a barrier membrane is prone to degradation, and is prone to insufficient mechanical support due to rapid degradation. Thickened pure magnesium membrane is prone to cause difficulty in closing the gum during surgery, resulting in membrane exposure and infection, and bone formation failure. Some technologies use pure magnesium membrane surface modification or coating methods, such as magnesium fluoride coating, calcium phosphate coating, and organic polymer polylactic acid coating. However, these modified coatings are brittle, and the magnesium membrane needs to be bent by 90° or more to wrap the bone powder. The brittle coating cracks during bending, exposing the magnesium material and failing to protect the magnesium material. SUMMARY

[0005] In order to balance the mechanical strength and biodegradability of the oral repair support membrane, the application provides a degradable oral repair support membrane.

[0006] In a first aspect, the application provides a degradable oral repair support membrane, which adopts the following technical solution: A degradable oral repair support membrane, comprising a support base and a degradable outer protective layer, the support base is a pure magnesium or magnesium alloy material, and the degradable outer protective layer is one of a poly(lactide-co-caprolactone) coating, a poly(glycolide-co-caprolactone) coating, and a poly(lactide-co-caprolactone) blended poly(glycolide-co-caprolactone) coating.

[0007] By adopting the above technical solution, the poly(lactide-co-caprolactone) coating, the poly(glycolide-co-caprolactone) coating, and the poly(lactide-co-caprolactone) blended poly(glycolide-co-caprolactone) coating have high elongation at break, can withstand 90° bending while maintaining the integrity and sealing of the coating, effectively protecting the magnesium metal substrate from buffer solution penetration, improving the corrosion resistance of the magnesium metal material of the oral repair membrane, and improving the mechanical support maintenance time of the coated magnesium metal sheet oral membrane product, so that it can provide sufficient support for the whole cycle of bone repair, and ensure the smooth progress of bone repair.

[0008] Preferably, the preparation method of the support base comprises the following steps: pure magnesium or magnesium alloy material is extruded into a rod, the rod is rolled and cut to obtain a sheet with a thickness of 1-2 mm, the sheet is cut, laser drilled, polished with a phosphoric acid-ethylene glycol solution, and washed with anhydrous ethanol to obtain a porous sheet of pure magnesium or magnesium alloy material with a thickness of 0.1-0.4 mm, which is the support base.

[0009] By adopting the above technical scheme, the pure magnesium or magnesium alloy material is prepared into a porous sheet with a specific thickness as a support matrix through extrusion, rolling, cutting, cutting, laser punching, polishing, cleaning and other steps, a support matrix suitable for the use of an oral repair support film is obtained, a basis is provided for subsequent coating of a degradable outer protective layer, and the overall performance of the degradable oral repair support film is also improved.

[0010] Preferably, the degradable outer protective layer is prepared by coating a degradable outer protective layer solution on the surface of the support matrix, and the coating method is selected from one of a rotary dip coating method, a pull-up dip coating method, an ultrasonic rotary spraying method or a film forming covering method.

[0011] Preferably, the preparation method of the poly(lactide-co-caprolactone) solution comprises the following steps: dissolving poly(lactide-co-caprolactone) in an organic solvent under magnetic stirring at room temperature to obtain a poly(lactide-co-caprolactone) solution with a concentration of 0.1-10% (mass / volume ratio), and the molar ratio of L-lactide to ε-caprolactone in the poly(lactide-co-caprolactone) is (0.4-0.7):(0.3-0.6).

[0012] Preferably, the preparation method of the poly(lactide-co-caprolactone) solution comprises the following steps: dissolving poly(lactide-co-caprolactone) in an organic solvent under magnetic stirring at room temperature to obtain a poly(lactide-co-caprolactone) solution with a concentration of 0.1-10% (mass / volume ratio), and the molar ratio of L-lactide to ε-caprolactone in the poly(lactide-co-caprolactone) is (0.4-0.7):(0.3-0.6).

[0013] By adopting the above technical scheme, the molar ratio of L-lactide to ε-caprolactone and the molar ratio of glycolide to ε-caprolactone are controlled, the coating material obtained has good toughness and ductility, can completely cover the support matrix, is not easy to crack or break after bending, and can protect the support matrix during bone repair.

[0014] Preferably, the preparation method of the poly(lactide-co-caprolactone) solution comprises the following steps: dissolving poly(lactide-co-caprolactone) in an organic solvent under magnetic stirring at room temperature to obtain a poly(lactide-co-caprolactone) solution with a concentration of 0.1-10% (mass / volume ratio), and the molar ratio of L-lactide to ε-caprolactone in the poly(lactide-co-caprolactone) is (0.4-0.7):(0.3-0.6).

[0015] By adopting the above technical solution, the mixture obtained by blending poly(lactide-caprolactone) and poly(glycolide-caprolactone) has better protective effect and mechanical properties, and has good biocompatibility, which can provide more comprehensive and long-term protection for the supporting matrix.

[0016] Preferably, in the spin coating, dip coating, and film coating methods, the concentration of the degradable outer protective layer solution is 0.1-10%, and in the ultrasonic spin coating method, the concentration of the degradable outer protective layer solution is 0.1-1%.

[0017] By adopting the above technical solution, the biodegradable outer protective layer solution was diluted in the ultrasonic rotary spraying method, ensuring the spraying effect and making the biodegradable outer protective layer uniform in texture and of moderate thickness.

[0018] Preferably, when the coating method for the biodegradable outer protective layer solution is selected as spin coating, dip coating, or film coating, post-treatment is also required. The post-treatment includes the following steps: using a micro-diameter needle with a diameter of 0.3-0.6 mm to puncture the biodegradable outer protective layer or heating the micro-diameter needle to 130-160°C to melt it through, forming a 0.3-0.6 mm puncture hole on the biodegradable outer protective layer at the position corresponding to the puncture hole of the supporting substrate.

[0019] By adopting the above technical solution, a 0.3-0.6mm perforation hole is formed at the corresponding position of the support substrate perforation hole. This ensures the unobstructed flow of the support substrate perforation hole, maintains the good protective effect of the biodegradable outer protective layer on the support substrate, and makes the biodegradable outer protective layer less prone to cracking or breakage after bending. It also improves the corrosion resistance of the magnesium metal material of the oral repair membrane and the mechanical support maintenance time of the coated magnesium metal sheet oral membrane product, providing good support and coverage for the bone repair process. At the same time, it has good biocompatibility and promotes bone tissue repair.

[0020] In summary, this application has the following beneficial effects: 1. In this application, the poly(lactide-caprolactone) coating, poly(glycolic acid-caprolactone) coating, and poly(lactide-caprolactone) blend coating have high elongation at break, and can maintain the integrity and sealing of the coating after being bent at 90°. This effectively protects the magnesium metal matrix from the penetration of the buffer solution, improves the corrosion resistance of the magnesium metal material in the oral repair membrane, and also improves the mechanical support maintenance time of the coated magnesium metal sheet oral membrane product, so that it can provide sufficient support for the entire bone repair cycle and ensure the smooth progress of bone repair.

[0021] 2、In the application, pure magnesium or magnesium alloy material is prepared into a porous sheet with a specific thickness as a support matrix through extrusion, rolling, cutting, cutting, laser punching, polishing, cleaning and other steps, which can obtain a support matrix suitable for oral repair support film, provide a basis for subsequent coating of degradable outer protective layer, and also help to improve the overall performance of the degradable oral repair support film.

[0022] 3、In the application, the mixture obtained by blending poly(lactide-co-caprolactone) and poly(ethylene glycol-co-caprolactone) has better protection effect and mechanical properties, and has better biocompatibility, which can comprehensively and long-acting protect the support matrix. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The morphology of the sample prepared for Example 1 at 0d, 50d, 90d and 180d respectively; Figure 2 The morphology of the sample prepared for Example 2 at 0d, 50d, 90d and 180d respectively; Figure 3 The morphology of the sample prepared for Example 3 at 0d, 50d, 90d and 180d respectively; Figure 4 The morphology of the sample prepared for Comparative Example 1 at 0d, 50d, 90d and 180d respectively; Figure 5 The morphology of the sample prepared for Comparative Example 2 at 0d, 50d, 90d and 180d respectively; Figure 6 CT examination results of beagle dogs at immediate postoperative, 4 weeks postoperative and 12 weeks postoperative, Figure 6 -a is the result of the experimental group at immediate postoperative, Figure 6 -b is the result of the experimental group at 4 weeks postoperative, Figure 6 -c is the result of the experimental group at 12 weeks postoperative, Figure 6 -d is the result of the control group at immediate postoperative, Figure 6 -e is the result of the control group at 4 weeks postoperative, Figure 6 -f is the result of the control group at 12 weeks postoperative; Figure 7 Gingival tissue evaluation results at 12 weeks postoperative, Figure 7 -a is the experimental group, Figure 7 -b is the control group; Figure 8 Osteogenesis performance evaluation results at 12 weeks postoperative, Figure 8 -a is the experimental group, Figure 8 -b is the control group. DETAILED DESCRIPTION

[0024] The application will be further described in detail below in conjunction with the accompanying drawings and examples. Embodiment

[0025] Embodiment 1 A degradable oral repair support film, comprising a support substrate and a degradable outer protective layer, the support substrate is a pure magnesium material, the preparation method of the support substrate comprises the following steps: the pure magnesium material is extruded into a rod, the rod is rolled and cut to obtain a sheet with a thickness of 2 mm, the sheet is cut, laser drilled, polished with a phosphoric acid-ethylene glycol solution, and washed with anhydrous ethanol to obtain a porous sheet of pure magnesium or magnesium alloy material with a length of 18 mm, a width of 10 mm, and a thickness of 0.2 mm, which is the support substrate.

[0026] The degradable outer protective layer is a poly(lactide-co-caprolactone) coating, the degradable outer protective layer is prepared by coating a degradable outer protective layer solution on the surface of the support substrate, the degradable outer protective layer solution is a poly(lactide-co-caprolactone) solution, and the preparation method of the poly(lactide-co-caprolactone) solution comprises the following steps: 5 g of poly(lactide-co-caprolactone) is dissolved in 500 mL of ethyl acetate solution under magnetic stirring at room temperature to obtain a poly(lactide-co-caprolactone) solution with a concentration of 0.2% (mass / volume), and the molar ratio of L-lactide to ε-caprolactone in the poly(lactide-co-caprolactone) is 0.4:0.6.

[0027] The poly(lactide-co-caprolactone) solution is coated on the surface of the support substrate by rotary immersion coating, and the specific steps are as follows: the support substrate is fixed on a speed reducer clamp, the rotating speed is 30 r / min, the rotating support substrate is immersed in the above-mentioned 0.2% poly(lactide-co-caprolactone) solution, the metal porous sheet is taken out from the solution after 4 s and kept horizontal, and the rotary volatilization drying is continued in a 25°C room, the rotary immersion coating can be repeatedly operated until the thickness of the dried polymer coating reaches 0.4±0.2 mm, and a 0.6 mm diameter micro-diameter needle tube is used to roll through the covered degradable outer protective layer at the place covering the metal penetration hole.

[0028] Embodiment 2 A degradable oral repair support film, comprising a support substrate and a degradable outer protective layer, the support substrate is a pure magnesium material, the preparation method of the support substrate comprises the following steps: the pure magnesium material is extruded into a rod, the rod is rolled and cut to obtain a sheet with a thickness of 2 mm, the sheet is cut, laser drilled, polished with a phosphoric acid-ethylene glycol solution, and washed with anhydrous ethanol to obtain a porous sheet of pure magnesium or magnesium alloy material with a length of 18 mm, a width of 10 mm, and a thickness of 0.2 mm, which is the support substrate.

[0029] The degradable outer protective layer is a poly(glycolide-caprolactone) coating, the degradable outer protective layer is a degradable outer protective layer solution coated on the surface of the support matrix, the degradable outer protective layer solution is a poly(glycolide-caprolactone) solution, the preparation method of the poly(glycolide-caprolactone) solution comprises the following steps: 5g of poly(glycolide-caprolactone) is dissolved in 500mL of ethyl acetate solution under magnetic stirring at room temperature to obtain a poly(glycolide-caprolactone) solution with a concentration of 0.2% (mass / volume ratio), and the molar ratio of glycolide and epsilon-caprolactone in the poly(glycolide-caprolactone) is 0.4:0.6.

[0030] The poly(glycolide-caprolactone) solution is coated on the surface of the support matrix by rotary immersion coating, and the specific steps are as follows: the support matrix is fixed on a speed reducer clamp, the rotating speed is 30r / min, the rotating support matrix is immersed in the above-mentioned 0.2% poly(glycolide-caprolactone) solution, the metal porous sheet is taken out from the solution after 4s and kept horizontal, and the rotary volatilization drying is continued in a 25°C indoor environment, the rotary immersion coating can be repeatedly operated until the thickness of the dried polymer coating reaches 0.4±0.2mm, and the degradable outer protective layer covering the metal penetration hole is rolled through the covering degradable outer protective layer by using a micro-diameter needle tube with a diameter of 0.6mm.

[0031] Example 3 A degradable oral repair support film comprises a support matrix and a degradable outer protective layer, the support matrix is a pure magnesium material, and the preparation method of the support matrix comprises the following steps: the pure magnesium material is extruded into a rod, the rod is rolled and cut to obtain a sheet with a thickness of 2mm, the sheet is cut, laser drilled, polished with a phosphoric acid-ethylene glycol solution, and washed with anhydrous ethanol to obtain a porous sheet of pure magnesium or magnesium alloy material with a length of 18mm, a width of 10mm, and a thickness of 0.2mm, which is the support matrix.

[0032] The degradable outer protective layer is a poly(glycolide-caprolactone) coating, the degradable outer protective layer is a degradable outer protective layer solution coated on the surface of the support matrix, the degradable outer protective layer solution is a poly(glycolide-caprolactone) solution, the preparation method of the poly(glycolide-caprolactone) solution comprises the following steps: 5g of poly(glycolide-caprolactone) is dissolved in 500mL of ethyl acetate solution under magnetic stirring at room temperature to obtain a poly(glycolide-caprolactone) solution with a concentration of 0.2% (mass / volume ratio), and the molar ratio of glycolide and epsilon-caprolactone in the poly(glycolide-caprolactone) is 0.4:0.6.

[0033] The poly(lactide-co-caprolactone) blended poly(glycolide-co-caprolactone) solution is coated on the surface of the support substrate by rotary dip coating. The specific steps are as follows: the support substrate is fixed on the deceleration motor clamp, the rotating speed is 30 r / min, the rotating support substrate is immersed in the above-mentioned 0.2% poly(lactide-co-caprolactone) blended poly(glycolide-co-caprolactone) solution, after 4s, the metal porous sheet is taken out of the solution and kept horizontal, and the rotary volatilization drying is continued at 25°C in the room. The rotary dip coating can be stacked and repeated until the thickness of the dried polymer coating reaches 0.4±0.2mm. The diameter of the micro-diameter needle tube is 0.6mm, and the covered degradable outer protective layer is rolled through the covered metal penetrating hole.

[0034] Example 4 The difference between Example 4 and Example 1 is that in Example 4, the coating method is pull-up dip coating. The specific operation is as follows: the support substrate is fixed on the pull-up machine clamp, the degradable metal porous sheet is immersed in the 0.2% poly(lactide-co-caprolactone) solution, after 4s, the pull-up machine is started, the pull-up speed is 1.5mm / min, and the degradable metal porous sheet is taken out of the solution. The rotary volatilization drying is continued at 25°C in the room. The pull-up dip coating can be stacked and repeated until the thickness of the dried polymer coating reaches 0.4±0.2mm. The diameter of the micro-diameter needle tube is 0.6mm, and the covered degradable outer protective layer is rolled through the covered metal penetrating hole.

[0035] Example 5 The difference between Example 5 and Example 1 is that in Example 5, the coating method is ultrasonic rotary spraying. The specific operation is as follows: the support substrate is fixed on the ultrasonic spraying machine rotary clamp, 0.2% poly(lactide-co-caprolactone) solution is taken, the ultrasonic spraying is started, the rotary speed is 30r / min, and the ultrasonic rotary spraying is continued after the ultrasonic spraying is finished. The rotary volatilization drying is continued at 25°C in the room. The ultrasonic rotary spraying can be stacked and repeated until the thickness of the dried polymer coating reaches 0.4±0.2mm.

[0036] Example 6 The difference between Example 6 and Example 1 is that in Example 6, the coating method is film forming covering. The specific operation is as follows: 0.2% poly(lactide-co-caprolactone) solution is poured on a flat and smooth glass surface, the solvent is dried at 25°C in the room to form a film, the thickness of the polymer coating reaches 0.4±0.2mm, the support substrate is placed in the middle of the polymer coating formed in the previous step, and pressed into a sandwich shape. The sandwich sample is soaked in ethanol, the film is peeled off, and a degradable metal porous sheet sample with a double-sided coating thickness of 0.02-2mm is obtained. According to the requirements, the polymer coating is cut to obtain a degradable outer protective layer with an extension of 0.3mm or more than the support substrate, forming a skirt-like structure.

[0037] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain a degradable outer protective layer, i.e., a pure magnesium support matrix.

[0038] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, a polylactic acid coating is selected as the degradable outer protective layer, and the specific operation is as follows: 5 g of polylactic acid with a number average molecular weight of 10-15 million Daltons is accurately weighed, and is dissolved in 500 mL of ethyl acetate solution under magnetic stirring at room temperature to obtain a polylactic acid solution with a concentration of 0.2% (mass / volume). The support matrix is fixed on a speed reducer clamp with a rotation speed of 30 r / min, and the rotating support matrix is immersed in the above-mentioned 0.2% polylactic acid solution. After 4 s, the metal porous sheet is taken out of the solution and kept horizontal, and continues to rotate and dry under volatilization at 25°C in the room. The rotating immersion coating can be repeatedly operated until the thickness of the dried polymer coating reaches 0.4±0.2 mm. A micro-diameter needle tube with a diameter of 0.6 mm is used to roll through the covered degradable outer protective layer at the place covering the metal penetration hole.

[0039] Performance detection test 1. The degradable oral repair support film prepared in Examples 1-6 and Comparative Examples 1-2, as well as the control material, is immersed in a 37°C phosphate buffer solution, and the fresh phosphate buffer solution is replaced every 24 hours. The samples are observed for morphology, and three-point bending mechanical tests are performed at different times, and the results of the three-point bending mechanical tests are recorded in Table 1.

[0040] Table 1 Mechanical test of samples Item 0 days / N 50 days / N 90 days / N 180 days / N Example 1 3.82±0.11 3.71±0.07 2.57±0.12 1.62±0.14 Example 2 3.56±0.09 3.34±0.12 2.89±0.13 1.74±0.12 Example 3 3.67±0.08 3.55±0.09 2.23±0.15 1.65±0.09 Example 4 3.79±0.07 3.70±0.12 2.53±0.09 1.61±0.09 Example 5 3.81±0.08 3.69±0.11 2.56±0.08 1.59±0.12 Example 6 3.80±0.10 3.72±0.09 2.59±0.09 1.60±0.11 Comparative Example 1 2.82±0.07 1.78±0.03 Mechanical failure Mechanical failure Comparative Example 2 3.74±0.06 3.68±0.14 1.88±0.21 Mechanical failure As can be seen from Table 1, Examples 1-3 and Comparative Examples 1-2, the pure magnesium sheet loses support mechanics within 60 days due to the lack of coating protection, while the pure magnesium sheet coated with a polylactic acid coating loses support mechanics after in vitro immersion degradation for 90 days. The reason is that the polylactic acid coating is brittle and hard, and after being bent by 90°, the PLA coating forms cracks or breaks, which easily causes the buffer solution to penetrate into the magnesium sheet, leading to magnesium degradation. The polylactic acid coating is easily detached during PBS immersion, thereby losing the protective effect on the magnesium sheet.

[0041] And no matter is poly (lactide-co-caprolactone) coating, poly (glycolide-co-caprolactone) coating, poly (lactide-co-caprolactone) blend poly (glycolide-co-caprolactone) film, all have high elongation at break, so can withstand 90° bending after still can keep coating integrity and sealing, effectively protect the magnesium metal matrix from the penetration of the buffer solution. The coating integrity remains good over time, thereby improving the corrosion resistance of the oral repair film magnesium metal material, also improves the mechanical support maintenance time of the coated magnesium metal sheet oral film product, realizes its use function as a medical device product.

[0042] According to examples 1 and 6, it can be seen that the rotatory dip-coating method, the pulling dip-coating method, the ultrasonic rotatory spraying method or the film forming covering method can obtain the degradable outer protective layer which has good protective effect on the supporting matrix, and the degradable outer protective layer is not easy to crack or break after bending, and can maintain good protective effect.

[0043] 2. Animal experiment research The beagle dogs were used as animal models, and the alveolar bone defect model was established. The experimental group oral film, i.e. the degradable oral repair supporting film prepared in example 1, and the control group oral film, i.e. the collagen film, were implanted to evaluate the safety and effectiveness of the test material.

[0044] After the animals were successfully anesthetized, the P4 premolar and M1 molar roots on both sides of the mandible were removed, and two single-wall defects with a size of 8mm in length, 5mm in width and 5mm in depth were manufactured on one side (not completely truncated, in the form of "L" sofa), and the defects were spaced 5mm apart. After debridement, the corresponding materials conforming to the defect size were implanted into the defects according to the grouping, shaped, compacted, and the defects were covered with the experimental group oral film or the control group oral film. The experimental group oral film needs to be fixed with degradable magnesium nails (0.8mm kirschner wire). This experiment involved 6 beagle dogs, and the postoperative 1st month and 3rd month were set as the observation time endpoints, and 3 animals at each time point. The CT examination results at postoperative 0th week, 4th week and 12th week are shown in Figure 6 The gingival tissue evaluation results are shown in Figure 7 The osteogenesis performance evaluation results are shown in Figure 8

[0045] At 4 weeks after the operation, there was a gap between the left experimental group implant material and the alveolar bone; the right control group gingival tissue was closely attached to the bone surface. At 12 weeks after the operation, the left experimental group implant material was closely attached to the bone; the right control group gingival tissue was closely attached to the bone surface.

[0046] As shown in Figure 7 The stratified squamous epithelium completely covers the wound surface, the number of fibroblasts decreases and turns into slender resting state, the vascular density approaches that of normal gingival tissue, the collagen fiber bundles are arranged in parallel with the stress direction, and there is focal lymphocyte and macrophage infiltration under the epidermis.​

[0047] As shown in Figure 8 , a large number of newly formed bone can be seen in the bone defect area, which is trabecular and connected with the host cortical bone, and part of the bone is transformed into mature bone, and the osteoid component is mainly distributed on the edge of the newly formed bone, and the interstitial fibrous tissue proliferates.

[0048] According to Figures 6-8 It can be seen that the repair support film of Example 1 has good mechanical properties compared with the repair support film of Comparative Example 1, which can provide good support force and coating effect for bone repair process, and has good biocompatibility, no adverse effect on the growth of biological tissue cells, and the bone tissue repair effect is better, the surrounding collagen fibers, epithelial tissue and other compatible with the newly formed bone are better.

[0049] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A biodegradable oral repair support membrane, characterized in that: It includes a supporting substrate and a biodegradable outer protective layer. The supporting substrate is made of pure magnesium or magnesium alloy material, and the biodegradable outer protective layer is one of poly(lactide-caprolactone) coating, poly(glycolic acid-caprolactone) coating, or poly(lactide-caprolactone) blended poly(glycolic acid-caprolactone) coating.

2. The biodegradable oral repair support membrane according to claim 1, characterized in that: The method for preparing the support substrate includes the following steps: extruding pure magnesium or magnesium alloy material into rods, rolling and cutting the rods to obtain sheets with a thickness of 1-2 mm, and then cutting, laser drilling, polishing with phosphate-ethylene glycol solution, and cleaning with anhydrous ethanol to obtain a porous sheet of pure magnesium or magnesium alloy material with a thickness of 0.1-0.4 mm, which is the support substrate.

3. The biodegradable oral repair support membrane according to claim 1, characterized in that: The biodegradable outer protective layer is obtained by coating a biodegradable outer protective layer solution onto the surface of a support substrate. The coating method is selected from one of the following: spin coating, dip coating, ultrasonic spin spraying, or film coating. The biodegradable outer protective layer solution is one of the following: poly(lactide-caprolactone) solution, poly(glycolic acid-caprolactone) solution, or poly(lactide-caprolactone) blended poly(glycolic acid-caprolactone) solution.

4. The biodegradable oral repair support membrane according to claim 3, characterized in that: The method for preparing the poly(lactide-caprolactone) solution includes the following steps: dissolving poly(lactide-caprolactone) in an organic solvent under magnetic stirring at room temperature to obtain a poly(lactide-caprolactone) solution with a mass-volume ratio of 0.1-10%, wherein the molar ratio of L-lactide to ε-caprolactone in the poly(lactide-caprolactone) is (0.4-0.7):(0.3-0.6).

5. The biodegradable oral repair support membrane according to claim 3, characterized in that: The method for preparing the poly(glycolic acid-caprolactone) solution includes the following steps: dissolving poly(glycolic acid-caprolactone) in an organic solvent under magnetic stirring at room temperature to obtain a poly(glycolic acid-caprolactone) solution with a mass-volume ratio of 0.1-10%, wherein the molar ratio of glycolide to ε-caprolactone in the poly(glycolic acid-caprolactone) solution is (0.4-0.7):(0.3-0.6).

6. The biodegradable oral repair support membrane according to claim 3, characterized in that: The preparation method of the poly(lactide-caprolactone) blend poly(lactide-caprolactone) solution includes the following steps: mixing the poly(lactide-caprolactone) solution and the poly(lactide-caprolactone) solution at a mass ratio of (1-9):10, adding an organic solvent, and magnetically stirring to mix evenly to obtain a poly(lactide-caprolactone) blend poly(lactide-caprolactone) solution with a mass-volume ratio of 0.1-10%.

7. The biodegradable oral repair support membrane according to claim 3, characterized in that: In the rotary dip coating, dip coating, and film coating methods, the concentration of the degradable outer protective layer solution is 0.1-10%, and in the ultrasonic rotary spraying method, the concentration of the degradable outer protective layer solution is 0.1-1%.

8. The biodegradable oral repair support membrane according to claim 3, characterized in that: When the coating method for the biodegradable outer protective layer solution is selected as spin coating, dip coating, or film coating, post-processing is required. The post-processing includes the following steps: using a micro-diameter needle with a diameter of 0.3-0.6 mm to puncture the biodegradable outer protective layer or heating the micro-diameter needle to 130-160℃ to melt it through, forming a 0.3-0.6 mm puncture hole on the biodegradable outer protective layer at the position corresponding to the puncture hole in the supporting substrate.

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