A hollow pier-type stent for vertical bone augmentation

Abstract

The present invention discloses a hollow pier-type stent for vertical bone augmentation, which comprises: a plurality of stent units; the stent unit comprises: a porous stent and a hollow pillar; wherein the porous stent comprises: a porous main body, and a porous top layer as the top with a smaller pore size than the main body; the pore size of the porous top layer is 20 to 50 μm; the upper part of the hollow pillar penetrates into the main body, and the tube wall of the upper part of the hollow pillar is provided with a connecting hole for communicating with the porous stent; the lower part of the hollow pillar is used to be fixed in the jaw; in the use state, osteoblast-related cells can migrate from the bone marrow area of ​​the jaw to the porous stent through the hollow pillar. The porous top layer can limit the growth of relatively large fibroblasts and epithelial cells into the defect area. The hollow pillar is conducive to quickly draining the bone marrow and blood in the jaw upward; the pier-type stent is used in conjunction with the use of "bone powder + bone repair membrane" to confine the bone powder to the surgical area, avoiding the displacement and collapse of traditional bone powder implantation.

Description

Technical Field

[0001] The invention relates to the technical field of oral medical instruments, and in particular to a hollow pier-type bracket for vertical bone augmentation. Background Art

[0002] In recent years, oral implants have been widely used in clinical practice to treat edentulous and missing teeth. Ensuring good initial stability is the key to successful implantation. Therefore, insufficient bone quality and bone volume often lead to the failure of oral implants. In response to this problem, bone augmentation technology has emerged, expanding the indications of oral implants, including guided bone regeneration (GBR), distraction osteogenesis, maxillary sinus lift, etc. Among them, guided bone regeneration is to cover the surface of the bone graft implanted in the bone defect area with a biological barrier membrane to block the growth of epithelial cells and fibroblasts into the defect area, thereby providing a good regeneration space for the growth of the underlying bone tissue.

[0003] However, guided bone regeneration still faces problems that have not been effectively solved. For example, the bone powder covered under the membrane cannot obtain good retention. Under the action of chewing force or external force, the bone powder is easy to move and collapse, resulting in insufficient recovery of bone height; and block-shaped scaffold materials with specific sizes are difficult to meet personalized needs, which is not conducive to mass production and productization. For this reason, titanium mesh or tent nails are often used clinically to fix bone powder to achieve a stable bone augmentation effect. However, due to the inability of the corresponding support materials to degrade and the existence of stress accumulation, it often causes complications such as soft tissue wound rupture, titanium mesh exposure, and secondary bone absorption. Metal support materials have a "stress shielding" phenomenon, which is not conducive to new bone growth. In addition, after bone regeneration is achieved, a second operation is required to remove the titanium mesh or tent nails, which increases surgical trauma.

[0004] In addition, the osteoinductive properties of bone powder implant materials still need to be improved to increase bone regeneration efficiency. As we all know, osteogenesis requires sufficient blood perfusion, induction stimulants, mesenchymal stem cells, etc. In clinical practice, holes are usually drilled in the cortical bone to form a structure similar to a nutrient hole, which allows new blood vessels to grow quickly into the bone implant area to establish blood supply. Antibiotics and other drugs can also enter the defect area through blood circulation to prevent infection and inflammation. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a hollow pier-type scaffold for vertical bone augmentation, which can guide the bone marrow to perfuse into the scaffold and the bone augmentation lifting area, establish a migration channel for osteoblast-related cells, and improve the bone regeneration effect.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a hollow pier-type stent for vertical bone augmentation, which comprises: a plurality of stent units; the stent units comprise: a porous stent and a hollow pillar; wherein the porous stent comprises: a porous main body, and a porous top layer as a top with a pore size smaller than that of the main body; the pore size of the porous top layer is 20 to 50 μm; the upper part of the hollow pillar penetrates into the main body, and the tube wall of the upper part of the hollow pillar is provided with a connecting hole for communicating with the porous stent; the lower part of the hollow pillar is used to be fixed in the jawbone; in a state of use, osteoblast-related cells can migrate to the porous stent through the hollow pillar.

[0007] Preferably, the thickness of the porous top layer is 0.2-0.5 mm.

[0008] Preferably, the pore size of the main body of the porous support is 200-500 μm.

[0009] Preferably, the porous bracket has a length of 5mm-10mm in the buccal-lingual direction of the alveolar bone and a height of 3mm-10mm.

[0010] Preferably, the support unit comprises: 2 hollow pillars in a cylindrical shape.

[0011] Preferably, the upper portion of the hollow pillar extends to the porous top layer.

[0012] Preferably, the lower portion of the hollow pillar has a length of 3-8 mm, a thickness of 0.3-0.5 mm, and an inner diameter of 0.4-0.8 mm.

[0013] Preferably, in use, bone powder is provided around the support units or between the support units, and the surfaces of the support units and the bone powder are covered with a bone repair membrane.

[0014] Preferably, the bracket unit is made of degradable material.

[0015] Preferably, the hollow pier-type stent can be adapted to different bone defect cases by adopting stent units of different sizes and adjusting the number and spacing of the stent units.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The hollow pillars of the pier-type stent of the present invention are conducive to the rapid upward drainage of bone marrow and blood in the jawbone, providing a migration channel for osteoblast-related cells, accelerating the growth of cells inside the stent and thus accelerating the bone regeneration process; the porous design of the stent can accelerate the vascularization inside the stent and nourish the osteoblast-related cells inside the stent.

[0018] 2. The pore size of the porous top layer on the top of the porous scaffold is 20-50 μm. The small pore size can limit the growth of relatively large fibroblasts and epithelial cells into the defect area, but it can serve as a channel for blood to pass and bone cells to grow into the scaffold, thereby providing a good bone regeneration environment.

[0019] 3. The hollow pier-type scaffold designed in the present invention can be loaded with one or more induction factors such as BMP-2, PDGF-BB, VEGF, SDF-1, etc. to recruit cells to migrate along the hollow pillars to the defect area and induce cell differentiation, thereby improving the bone regeneration effect.

[0020] 4. The use of the hollow pier-type stent in combination with "bone powder + bone repair membrane" can confine the bone powder to the surgical area, effectively avoiding the displacement and collapse of traditional bone powder implantation, and has a better bone regeneration effect.

[0021] 5. Compared with bone powder implanted by covering titanium mesh or tent pegs, the pier-type support stent of the present invention can reduce the "stress shielding" phenomenon.

[0022] 6. Bracket units of different sizes can be used in combination. In addition, the number and spacing of the bracket units used can be further adjusted to adapt to bone defect cases of different length ranges. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A three-dimensional diagram of the bracket unit.

[0024] Figure 2 A cross-sectional view of a bracket unit.

[0025] Figure 3 Schematic diagram of the use status of the bracket unit.

[0026] Figure 4 It is a schematic diagram of the steps of using the hollow pier type support of the present invention.

[0027] Figure 5 This is a diagram of the animal experiment model used in animal experiment verification.

[0028] Figure 6 This is the flow chart of animal experiment operation in animal experiment verification.

[0029] Figure 7 This is the X-ray result of the control group in the animal experiment verification.

[0030] Figure 8 This is the X-ray result of the experimental group in animal experiment verification. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0032] The terms "top", "upper" and the like used in the present invention to describe the orientation refer to the end away from the autologous bone.

[0033] The hollow pier-type stent for vertical bone augmentation provided by the present invention comprises a plurality of stent units, which are used for implanting into a bone defect area to support bone regeneration space. Figure 1 is a three-dimensional diagram of the bracket unit. Figure 2 is a cross-sectional view of the bracket unit. Figure 1 and Figure 2 As shown, the scaffold unit 1 comprises: a porous scaffold and a hollow pillar 12. The porous scaffold comprises: a porous main body 11, and a porous top layer 15 as the top with a pore size smaller than that of the main body 11; the pore size of the porous top layer 15 is 20-50 μm. The upper part of the hollow pillar 12 penetrates into the main body 11, and the upper part of the hollow pillar 12 is provided with a connecting hole 14 for connecting with the porous scaffold, and the connecting hole 14 can allow cells to pass through. Please refer to Figure 3 The lower part of the hollow support 12 is used to be fixed in the jawbone 2; in the use state, osteogenic related cells can migrate into the porous scaffold through the hollow support 12. The periphery of the jawbone is the soft tissue 4.

[0034] Figure 1 In the embodiment shown, the support unit 1 is provided with two symmetrically arranged hollow pillars 12. The hollow pillars 12 are similar to bridge piers and can play a supporting role. At the same time, since the hollow pillars 12 are inserted into the jawbone, a channel for guiding the upward perfusion of bone marrow and cell migration can be established, thereby accelerating the migration and ingrowth of osteogenic related cells.

[0035] Guided bone regeneration requires the use of bone powder to increase bone mass. Bone powder can be placed around the stent unit 1 or between the stent units 1, and the bone repair membrane can be covered on the stent unit 1 and the surface of the bone powder. The use of a hollow pier-type stent in conjunction with "bone powder + bone repair membrane" can effectively avoid the displacement and collapse of traditional bone powder implantation, and has a better bone regeneration effect. The stent unit 1 is set to three models: large, medium, and small. Stent units 1 of different sizes can be used in combination. In addition, the number and spacing of the stent units 1 used can be further adjusted to adapt to bone defect cases of different length ranges, and only several stents of different sizes and models need to be equipped to suit alveolar bones of different widths and different lifting heights, avoiding the disadvantages of complex preparation process of personalized stents, high cost, and long cycle.

[0036] Figure 1In the embodiment shown, the square porous scaffold is in a grid shape with interconnected holes. The pore size of the porous top layer 15 on the top of the porous scaffold is 20-50 μm. The pore size is small, blood can flow, and small osteoblasts can pass through relatively easily, which can limit the passage of relatively large fibroblasts and epithelial cells. Together with the bone repair membrane, it further prevents fibroblasts and epithelial cells from growing into the defect area, providing a good bone regeneration environment.

[0037] The bone marrow and blood are drained upward through the hollow pillars 12, and combined with the porous design of the porous scaffold, the entire bone defect area can be infiltrated, and osteoblast-related cells can migrate and grow into the scaffold, accelerating the vascularization inside the scaffold and nourishing the osteoblast-related cells inside the scaffold.

[0038] In some embodiments, the thickness of the porous top layer 15 is 0.2-0.5 mm. The main pore size of the porous scaffold is 200-500 μm. The length of the porous scaffold from the buccal and lingual direction of the alveolar bone is 5 mm-10 mm, and the height is 3 mm-10 mm. The length of the lower part of the hollow pillar 12 is 3-8 mm, the thickness is 0.3-0.5 mm, and the inner diameter 13 is 0.4-0.8 mm (see Figure 2 or Figure 5 ). The upper part of the hollow pillar 12 extends to the porous top layer 15.

[0039] Figure 1 In the embodiment shown, the hollow support 12 is cylindrical.

[0040] The hollow pier-type stent is preferably made of degradable materials, such as calcium / phosphorus inorganic materials, organic polymer materials, natural biomaterials, and degradable metal materials such as magnesium alloys. The stent has degradable properties and does not require a second surgery to remove, thus avoiding the trauma of another surgery.

[0041] Animal experiment verification:

[0042] like Figure 4 As shown, the use steps of the hollow pier type support designed by the present invention are roughly divided into five steps.

[0043] S1: Prepare an implantation socket on the jawbone that matches the hollow pillar 12 of the hollow pier-type stent, with a hole diameter of 1.2-1.5 mm and a length of 3-8 mm.

[0044] S2: Insert the hollow pillar 12 of the hollow pier-type stent into the implantation socket and fix it in the jawbone.

[0045] S3: Implanting bone powder in or around the areas between multiple scaffold units.

[0046] S4: Cover the surface of the scaffold and the implanted bone powder with a bone repair membrane.

[0047] S5: After separating and loosening the mucosal tissue to achieve sufficient tension relief, the gums are pulled together and sutured.

[0048] The hollow pier-type stent designed by the present invention was implanted into the bone defect area in the dog's body. Six weeks after the operation, the bone augmentation effect was detected by X-ray. According to whether the hollow pier-type stent was used, the experiment was divided into two groups, namely the control group (only bone powder + periosteum was used) and the hollow pier-type stent group (hollow pier-type stent + bone powder + periosteum was used). The use of the stent and bone powder can also be referred to Figure 5 .like Figure 6 As shown in the figure, the animal experiment process is as follows: (1) establish a canine mandibular defect model; (2) implant the hollow pillar of the hollow pier-type stent designed by the present invention into the mandibular bone; (3) implant bone powder around the stent; (4) cover the stent and the bone powder with a bone repair membrane. Figure 7 The control group and Figure 8 As shown in the hollow pier support group, Figure 7 The control group shown had poorer bone height recovery, while Figure 8 The hollow pier scaffold group shown achieved better bone augmentation height.

[0049] The scaffold of the present invention is used in combination with a growth factor that has the functions of recruiting cell migration and inducing cell differentiation, thereby obtaining a better bone regeneration effect.

[0050] In summary, the bridge-type degradable porous scaffold designed by the present invention has a special pipe composite porous structure, and can achieve a good rapid vertical bone augmentation effect in vivo with the use of "bone powder + bone repair membrane". The scaffold can support the bone regeneration space, stabilize the bone powder placed between or around the scaffold, avoid bone powder displacement and collapse, and thus better maintain bone height.

[0051] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A hollow pier-type stent for vertical bone augmentation, characterized in that: It comprises: a plurality of bracket units; the bracket units comprise: a porous bracket and a hollow pillar; wherein, The porous support comprises: a porous main body, and a porous top layer as the top with a pore size smaller than that of the main body; the pore size of the main body is 200 μm-500 μm; the pore size of the porous top layer is 20 μm-50 μm; the thickness of the porous top layer is 0.2 mm-0.5 mm; The upper part of the hollow support penetrates into the main body, and the tube wall of the upper part of the hollow support is provided with a connecting hole for connecting with the porous support; the lower part of the hollow support is used to be fixed in the jawbone; In use, osteoblasts can migrate to the porous scaffold through the hollow pillars; bone powder is provided between the scaffold units, and the surfaces of the scaffold units and the bone powder are covered with a bone repair membrane.

2. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The porous bracket has a length of 5mm-10mm in the buccal and lingual direction of the alveolar bone and a height of 3mm-10mm.

3. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The support unit comprises: 2 cylindrical hollow pillars.

4. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The upper portion of the hollow pillar extends to the porous top layer.

5. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The length of the lower part of the hollow pillar is 3mm-8mm, the thickness is 0.3mm-0.5mm, and the inner diameter is 0.4mm-0.8mm.

6. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The support unit is made of degradable material.

7. The hollow pier-type stent for vertical bone augmentation according to claim 1, characterized in that: The hollow pier-type stent can be adapted to different bone defect cases by adopting stent units of different sizes and adjusting the number and spacing of the stent units.

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