CN115671378A

CN115671378A - Magnesium alloy guided bone regeneration implant with controllable degradation rate

Info

Publication number: CN115671378A
Application number: CN202110827923.4A
Authority: CN
Inventors: 郭传瑸; 韩建民; 谭成文; 郭雨竹; 刘冠旗
Original assignee: Peking University School of Stomatology
Current assignee: Peking University School of Stomatology
Priority date: 2021-07-21
Filing date: 2021-07-21
Publication date: 2023-02-03
Anticipated expiration: 2041-07-21
Also published as: CN115671378B

Abstract

The invention relates to a heterogeneous magnesium alloy guided bone regeneration implant with controllable degradation rate and adaptive to a tissue to be contacted with an implanted part, belonging to the technical field of medical instruments. Aiming at the condition that the degradation rate of different parts of the pure magnesium and magnesium alloy implant in the body is different, the regeneration characteristics of the contacted different tissues are different, and the reaction conditions of different tissues to the degradation rate of the magnesium alloy are different, so that the adaptability of the degradation of the magnesium alloy implant to the growth of the tissues of the implanted part is poor, the degradation rate of the magnesium alloy guided bone regeneration implant of different types (including oral barrier membranes, bone nails, bone plates and the like) is controllable by utilizing the matching of different alloy element proportions, extrusion ratios and structural coupling, so as to meet the specific requirements of the different implanted parts on the degradation performance.

Description

Magnesium alloy guided bone regeneration implant with controllable degradation rate

Technical Field

The invention relates to the technical field of medical instruments, in particular to a magnesium alloy guided bone regeneration implant with a controllable degradation rate.

Background

With the rapid development of medical science and technology, metal materials such as Stainless Steel (SS), titanium alloy, cobalt-chromium alloy and the like have been widely applied to the orthopedic repair fields such as oral implantation, fracture fixation and repair and the like due to good mechanical strength and biocompatibility.

At present, the problems of insufficient implant bone mass and peripheral bone mass in stomatological clinical repair such as oral implantation and the like are urgently needed to be solved, and the bone Guided Bone Regeneration (GBR) is more and more widely accepted clinically as a novel means. GBR is reported to provide optimal and most predictable results when clinically filling periodontal bone defects with new bone. The basic principle of the GBR technique is to incorporate a mechanical barrier membrane to isolate the bone defect from the surrounding connective tissue. Five design requirements are therefore placed on barrier membranes: good biocompatibility, maintenance of adequate osteogenic space, selective isolation of cells, ability to integrate tissue, and clinical operability. Barrier membranes currently in clinical use can be largely classified into non-absorbable membranes (including polytetrafluoroethylene and titanium mesh) and absorbable membranes (commonly including collagen membranes, polylactic acid (PLA) membranes, and polylactic-co-glycolic acid (PLGA) membranes). The non-absorbable membrane has good biocompatibility and high mechanical strength, can maintain an osteogenic space, but needs to be taken out through a secondary operation, and has potential risks. Although the absorbable membrane avoids secondary operation, the absorption degree of the absorbable membrane is unpredictable, the strength maintaining time after implantation is short, and meanwhile, the acidic environment caused by degradation of most organic materials is easy to induce inflammatory reaction, so that bone reconstruction failure is finally caused.

The materials for bone nails and bone plates clinically used for fracture repair can also be divided into absorbable materials and non-absorbable materials. The absorbable bone nail and the bone lamella are mainly made of polylactic acid, the polylactic acid has no bone inductivity, the speed of repairing bone defect is slow, and the mechanical strength is low and is not enough to be used as a fracture internal fixation material of a bearing part; the non-absorbable bone nail and bone plate is mainly made of titanium, titanium alloy or stainless steel, the Young modulus of the non-absorbable bone nail and bone plate is far higher than that of bones, the generated stress shielding effect causes a fracture patient suffering from osteoporosis to have high risk of re-fracture, the non-absorbable bone nail and bone plate is non-degradable, and the non-absorbable bone nail and bone plate needs to be taken out after fracture repair is completed, so that secondary injury is caused to the patient.

The magnesium alloy has wide application prospect in the aspect of implanting medical instruments due to good mechanical strength and degradability, however, the magnesium alloy material has poor adaptability to tissue regeneration due to uncontrollable degradation performance in complex environments in vivo and lack of adaptability to implantation environments, so that the material performance and the tissue regeneration adaptability are poor, the repair effect is directly influenced, and the clinical application is limited. How to realize programmed degradation regulation of magnesium alloy materials so as to be adaptive to the regeneration time sequence of different tissues in vivo is a key problem of poor adaptability of the current magnesium alloy in the regeneration and repair process of hard tissues.

The invention provides a concept of matching performance with tissue regeneration time sequence in the whole life cycle of a magnesium alloy implantation instrument, aims to determine performance requirements on three-dimensional space positions of the implantation instrument according to characteristics of tissues in vivo expected to be contacted with an implantation part, and adopts different alloy element proportions, deformation (extrusion ratio) and implant structure coupling to realize programmed multi-dimensional precise regulation and control of material performance so as to be matched with the tissue regeneration time sequence in vivo. The invention provides a new idea for the clinical individualized design and application of a magnesium alloy implanting instrument by the established technology for regulating and controlling the programmed microstructure of the magnesium alloy.

The invention relates to a magnesium alloy guided bone regeneration implant with controllable degradation rate, which adopts magnesium alloy, the mechanical property and the degradation property of the magnesium alloy guided bone regeneration implant can be realized by controlling the content and the extrusion ratio (deformation) of different alloy elements, and the requirements of different implant parts on the stress and the degradation process of the implant can be met by matching the structural design of the implant. The magnesium element released by degradation can promote osteogenesis and accelerate the bone healing process.

Disclosure of Invention

The invention aims to realize controllable degradation rate of magnesium alloy guided bone regeneration implants of different types (including oral barrier membranes, bone nails, bone plates and the like) by utilizing different alloy element contents, extrusion ratios and structural coupling matching aiming at the condition that the prior implant material degradation and the implant tissue growth adaptability are poor so as to meet the specific requirements of different implant parts on the alloy degradation performance.

In order to achieve the above object, the present invention can be achieved by the following technical solutions.

A magnesium alloy guided bone regeneration implant with controllable degradation rate is characterized by mainly comprising an oral barrier membrane, bone nails, bone plates and the like, wherein the oral barrier membrane can block soft tissues and provide a stable space environment for bone growth, the corrosion resistance of different parts of the barrier membrane is regulated and controlled by controlling the proportion of alloy elements and sectional extrusion of alloy according to different stress distribution of the different parts of the barrier membrane at the implant part, and the barrier membrane is uniformly and controllably degraded in the bone tissue healing process; the bone nail can fix the oral barrier membrane or the bone plate with the bone, can also be independently used for fracture reduction, and regulates and controls the corrosion resistance of different parts of the bone nail by controlling the alloy element proportion and alloy sectional extrusion according to different growth rates of cortical bone and cancellous bone tissues and different stress distribution of the bone nail at the fixing part so as to realize the sectional and controllable degradation of the bone nail; the bone plate is mainly used for maintaining the stability of the fracture broken end, and the degradation process of the bone plate is matched with the bone tissue healing by controlling the alloy element proportion and the alloy extrusion ratio according to the bone tissue healing time, so that the bone plate is uniformly and controllably degraded in the bone tissue healing process.

The length of the oral barrier membrane is 10.0-35.0mm, the width is 6.0-20.0mm, the thickness is 0.10-0.30mm, the barrier membrane is provided with retention through holes with the diameter of 0.5-3.0mm which are matched with the nail body of the bone nail, and through holes with the aperture size of 0.1-0.6mm are uniformly distributed in the range of 2.0-5.0mm from the bottom, 3.0-7.0mm from the top and 4.0-10.0mm from the upper part and the lower part of the waist line of the barrier membrane according to the requirement on the degradation rate of different parts of the barrier membrane; the extrusion ratio of the alloy material adopted in the range of 4.0-10.0mm from the upper part and the lower part of the barrier film waist line is 10-100, and the extrusion ratio of the alloy material at the other parts is 0-10; the barrier film structure profile and the through holes can be prepared using laser marking equipment.

The diameter of the nail body of the bone nail is 0.7-3.0mm, the length of the nail body is 5.5-15.5mm, the diameter of the nail cap is 1.5-4.0mm, the height of the nail cap is 0.5-3.0mm, and the nail body is provided with threads; according to the requirements on the degradation rates of different parts of the bone nail, the extrusion ratio of the alloy at the parts within 1.5-4.5mm of the bottom of the talus nail and within 4.5-6.5mm of the top of the talus nail is 10-100, and the extrusion ratio of the alloy at the bottom of the talus nail within the range of 1.5-4.4mm to 3.0-13.0mm is 0-10; the bone screw may be rotated into place using a special screwdriver or other rotating tool.

The length of the bone plate is 10.5-25.5mm, the width is 2.5-10.5mm, the thickness is 0.5-3.5mm, the bone plate is provided with a through hole matched with the diameter of the bone screw body, a sinking base station matched with the height of the bone screw cap is arranged above the through hole, and the bone plate alloy is extruded by adopting the same extrusion ratio of 0-10 corresponding to the requirement of uniform degradation of the bone plate.

When the implant is used, the oral barrier membrane and the bone plate need to be matched with the bone nail, and the bone nail can be used independently.

The surfaces of the oral barrier membrane, bone screws, and bone plates may be modified by a variety of methods to improve their biocompatibility and degradability.

Compared with the prior magnesium alloy guided bone regeneration implant, the invention has the following advantages:

1. proper amount of alloy elements are added into a magnesium matrix to generate the effects of solid solution strengthening, fine crystal strengthening and the like, so that the mechanical property of the material can be improved, the degradation rate of the material can be influenced due to different contents of the alloy elements, and part of the alloy elements (such as Ag, zn and the like) have certain antibacterial property, so that the biocompatibility of the material can be improved.

2. According to the requirements of different parts for implantation, the implant body is extruded in sections with different extrusion ratios, so that the precise regulation and control of tissues are realized, and further the mechanical property and the degradation characteristic of the implant body are finely regulated and controlled.

Drawings

FIG. 1 is a macro-topographic map of the alloy of example 1 at different extrusion ratios.

FIG. 2 shows the microstructure of samples of pure Mg and Mg-3Ag alloys of example 1 with different extrusion ratios observed by scanning electron microscopy.

FIG. 3 is the tensile test results for samples of pure Mg and Mg-3Ag alloys of example 1 at different extrusion ratios.

FIG. 4 is the results of electrochemical corrosion testing of samples of pure Mg and Mg-3Ag alloys of example 1 at different extrusion ratios.

FIG. 5 is the surface macro topography after in vitro corrosion of pure Mg and Mg-3Ag alloy samples of different extrusion ratios in example 1.

FIG. 6 is the XPS test results after in vitro corrosion of samples of pure Mg and Mg-3Ag alloys of example 1 at different extrusion ratios.

FIG. 7 shows the micro-CT analysis results of Mg-3Ag alloy samples with different extrusion ratios in example 1 after 1 month of in vivo implantation.

FIG. 8 is a schematic illustration of the design and application of an oral barrier membrane;

a is the front view of the design of oral barrier membrane using Mg-3Ag alloy, and b is the schematic view of the implantation and fixation of oral barrier membrane.

FIG. 9 is the microstructure of the Mg-3Ag and Mg-6Ag alloy samples with different extrusion ratios in example 2 observed by scanning electron microscope.

FIG. 10 shows the tensile test results of the Mg-3Ag and Mg-6Ag alloy samples with different extrusion ratios in example 2.

FIG. 11 shows the results of electrochemical corrosion tests on samples of Mg-3Ag and Mg-6Ag alloys of example 2 at different extrusion ratios.

FIG. 12 is the surface macro topography after in vitro corrosion of Mg-3Ag and Mg-6Ag alloy samples of different extrusion ratios in example 2.

FIG. 13 is the XPS test results after in vitro corrosion of Mg-6Ag and Mg-3Ag alloy specimens of different extrusion ratios from example 2.

FIG. 14 is the micro-CT analysis results of Mg-3Ag and Mg-6Ag alloy samples with different extrusion ratios in example 2 after being implanted in vivo for 1 month.

FIG. 15 is a schematic illustration of a bone screw, bone plate design and application;

the bone nail is characterized in that a is a bone nail design drawing, the bone nail uses Mg-3Ag alloy, b is a bone plate design drawing, the bone plate uses Mg-3Ag alloy, c is a schematic drawing of the bone nail for fixing a small-range joint or avulsion fracture, and d is a schematic drawing of the bone nail and the bone plate matched for use.

FIG. 16 shows the degradation of an oral barrier membrane made of an as-cast MgZnYNd alloy after one month implantation in a bone defect area of a beagle dog.

1: a retention through hole matching the screw; 2: a through hole; 3: a waist line; 4: the extrusion ratio of materials at the upper and lower parts of the waist line, which are respectively 2.0-4.0mm, is 72.2;5: the extrusion ratio of materials at two ends of the barrier film is 7.1;6: an oral barrier membrane; 7: bone nails; 8: alveolar bone; 9: bone meal; 10: a nail cap; 11: a nail body; 12: the extrusion ratio of the lower part of the bone nail is 72.2;13: the extrusion ratio of the middle part of the bone nail is 7.1;14: the extrusion ratio of the upper part of the bone nail is 72.2;15: a bone plate; 16: a through hole; 17: sinking the base platform; 18: the extrusion ratio of the bone plate material is 7.1;19: loosening bones; 20: cortical bone; 21: the marrow cavity.

Detailed Description

The following detailed description of the claimed invention is provided in connection with specific examples, but the scope of the invention is not limited thereto.

Example 1

This example is for the preparation of oral barrier films and barrier film applications.

The barrier film material uses Mg-3Ag alloy with diameter phi of 85mm and 3% silver by mass (Fe <0.0022%, cu <0.001%, ni < 0.001%), and the alloy is extruded in a sectional mode (extrusion ratio is respectively 7.1, 72.2 and 7.1) in the following steps:

and continuously extruding the alloy ingot along the length direction in a sectional manner. Heating the cast ingot to 300 ℃, controlling the temperature of the container and the steel die to 300 ℃, performing hot extrusion processing at the stamping advancing speed of 5-10m/min, and extruding the first section to phi 32mm (the extrusion ratio is about 7.1) and the length is 7mm; the second section was extruded to a diameter of 10mm (extrusion ratio of about 72.2) and a length of 10mm; the third stage was extruded to 32mm phi (extrusion ratio about 7.1) and 7mm long. Three sections are a group, and the extrusion process from the first section to the third section is continuously repeated to obtain a plurality of groups of magnesium-silver alloy by sectional extrusion.

Fig. 1 shows the macro morphology of magnesium-silver alloy with different extrusion ratios. The diameter of the as-cast alloy ingot is 85mm, the diameter of the alloy rod with the extrusion ratio of 7.1 is 32mm, and the diameter of the alloy rod with the extrusion ratio of 72.2 is 10mm.

FIG. 2 shows the microstructure of a sample of pure magnesium and Mg-3Ag alloy after different degrees of extrusion observed by a scanning electron microscope. As the extrusion ratio increases, the grain size of the pure magnesium decreases first and then increases slightly, and the content of the second phase increases first and then decreases; after 3% silver addition, the grain size decreases and the second phase content increases as the alloy extrusion ratio increases.

FIG. 3 shows the tensile test results of samples of pure Mg and Mg-3Ag alloy after being extruded in different degrees. After extrusion, the yield strength of the pure magnesium group is increased by more than 35 percent, and the plasticity is reduced by half; the alloy added with 3 percent of Ag is increased by more than 50 percent in yield strength after extrusion compared with pure magnesium, and the plasticity change is not obvious.

FIG. 4 shows the electrochemical corrosion test results of samples of pure Mg and Mg-3Ag alloy after being extruded to different degrees. Compared with pure magnesium, the alloy has increased self-corrosion current after 3% of silver is added, which shows that Ag can accelerate corrosion to form a second phase, and the second phase and a matrix form a micro-battery. However, as the alloy extrusion ratio increases, the self-corrosion current decreases and the corrosion rate decreases.

FIG. 5 shows the surface macro-morphology of a sample after in vitro corrosion after extrusion of pure magnesium and Mg-3Ag alloy to different degrees. White material is a corrosion product. The Mg-3Ag alloy has a local corrosion phenomenon due to the generation of a second phase in the crystal grains.

FIG. 6 shows XPS test results of samples of pure magnesium alloyed with Mg-3Ag after being extruded to different degrees for corrosion in vitro. After corrosion, the surface deposition elements mainly comprise C, N, O, na, P, S, cl and Ca.

FIG. 7 shows micro-CT analysis results of Mg-3Ag alloy samples implanted in vivo for 1 month after different degrees of extrusion. An alloy with an extrusion ratio of 72.2 degrades less than an alloy with an extrusion ratio of 7.1, and an alloy with an extrusion ratio of 72.2 forms a higher amount of bone in the implanted bone defect region.

The silver content was 3% and the magnesium silver alloy oral barrier films were prepared by step extrusion (extrusion ratios of 7.1, 72.2 and 7.1, respectively) as follows:

(1) And taking the group of segmented extruded magnesium-silver alloy, and cutting the alloy rod on the alloy rod in parallel to the axial direction by using a diamond wire cutting machine. The diameter of the diamond cutting line is 0.14mm, the cutting speed is 0.15mm/min, the cutting span is 0.3mm, the cutting depth is 24mm, and finally, a plurality of magnesium-silver alloy sheets with the thickness of 0.6mm and the length of 24mm are obtained.

(2) And preparing an oral barrier film on the cut magnesium-silver alloy thin sheet by using a laser marking machine. Laser wavelength 355nm, laser power 5W, frequency 20KHz, pulse width 10us, and processing speed 100mm/s.

Figure 8 is a schematic illustration of the design and application of an oral barrier membrane.

Fig. 8a is a front view of the oral barrier membrane and fig. 8b is a schematic view of implantation and fixation of the oral barrier membrane. The barrier membrane covers the bone defect area, the upper end and the lower end of the barrier membrane are fixed by bone nails, and the bone defect area at the lower side of the barrier membrane is filled with bone powder. When the barrier film is used, the bending degree of materials of the waist line and the nearby area is larger, and the materials are more easily degraded under the influence of tensile stress and fatigue load generated in the chewing process, so that the materials at the position are treated by an extrusion process with the extrusion ratio of 72.2 to improve the corrosion resistance; the influence of tensile stress and fatigue load of materials at the upper end and the lower end of the barrier film is small, and an extrusion process with an extrusion ratio of 7.1 is selected for treatment. The influence of stress corrosion on each part of the oral barrier membrane is different, and different extrusion processes are selected to regulate and control material tissues, so that the degradation rate is regulated and controlled, and the uniform and controllable degradation of the oral barrier membrane in the using process is realized.

Example 2

The example is the preparation of bone nail and bone plate and their application in fracture repair.

The bone nail uses Mg-3Ag alloy cast ingot with the diameter of phi 85mm and the mass percent of silver of 3 percent (wherein Fe is less than 0.0022 percent, cu is less than 0.001 percent, and Ni is less than 0.001 percent), and the alloy cast ingot is continuously extruded in sections along the length direction. Heating the cast ingot to 300 ℃, controlling the temperature of the container and the steel die to 300 ℃, performing hot extrusion processing at a stamping advancing speed of 5-10m/min, and extruding the first section to phi 32mm (the extrusion ratio is about 7.1) and the length is 4.5mm; the second section was extruded to a diameter of 10mm (extrusion ratio of about 72.2) and a length of 8.5mm; the third stage was extruded to 32mm phi (extrusion ratio of about 7.1) and 6.5mm long. Three sections are one group, and the extrusion process from the first section to the third section is continuously repeated to obtain a plurality of groups of sectionally extruded magnesium-silver alloys. The bone plate uses a diameter of 85mm, a 6% silver by mass Mg-6Ag alloy (where Fe <0.0022%, cu <0.001%, ni < 0.001%), and the plate is integrally extruded with the alloy to 32mm (an extrusion ratio of about 7.1).

FIG. 9 shows the microstructure of the samples of Mg-3Ag and Mg-6Ag alloys after different degrees of extrusion observed by scanning electron microscopy. As the extrusion ratio and silver content increase, the grain size of the alloy decreases and the second phase content increases.

FIG. 10 shows the results of tensile tests on samples of Mg-3Ag and Mg-6Ag alloys after different degrees of extrusion. The yield strength of the Ag-magnesium alloy group increased by 6% after extrusion, relative to 3% without significant plastic change.

FIG. 11 shows the results of electrochemical corrosion tests on samples of Mg-3Ag and Mg-6Ag alloys after different degrees of extrusion. Compared with Mg-3Ag, the Mg-6Ag alloy has slightly increased self-corrosion current and reduced corrosion resistance.

FIG. 12 shows the surface macro-morphology of Mg-3Ag and Mg-6Ag alloys after external corrosion of samples extruded to different degrees. The local corrosion phenomenon of the Mg-6Ag alloy is more obvious.

FIG. 13 shows XPS test results of samples of Mg-3Ag and Mg-6Ag alloys after different degrees of extrusion. After corrosion, the surface deposition elements mainly comprise C, N, O, na, P, S, cl and Ca.

FIG. 14 shows micro-CT analysis results of samples implanted in vivo for 1 month after different degrees of extrusion of Mg-3Ag and Mg-6Ag alloys. At an extrusion ratio of 7.1, the Mg-6Ag alloy corrodes less in vivo than the alloy with 3% silver added, but the amount of bone formation is lower.

The bone nail is processed and formed by cutting, thread rolling and other processes according to the design drawing, and the bone plate is processed and formed by cutting, polishing and other processes according to the design drawing.

Fig. 15 is a schematic view of the design and application of the bone screw and bone plate.

Fig. 15a is a design drawing of a bone nail made of a magnesium-silver alloy with a silver content of 3%.

Fig. 15b is a design of a bone plate using a magnesium silver alloy with 6% silver.

FIG. 15c is a schematic view of a bone screw fixing a small range joint or avulsion fracture. The bone nail runs through the fracture position after being implanted, nail body front end and rear end and cortical bone contact, nail body middle part and cancellous bone contact, and the position that bone nail and cortical bone contact undertakes most load, and it is bigger to receive stress corrosion to influence, and cortical bone more cancellous bone healing is slower. Therefore, the contact part of the bone nail and the cortical bone adopts an extrusion process with the extrusion ratio of 72.2, so that the bone nail has higher corrosion resistance, reduces the degradation rate and prevents over-quick corrosion and fracture in the bone healing process; the contact part of the bone nail and the cancellous bone is processed by adopting an extrusion process with the extrusion ratio of 7.1, so that the part of the material can bear a small load in the bone healing process and can be degraded more quickly after the bone is healed. The purpose that the programmed degradation regulation and control of the magnesium-silver alloy are adapted to the regeneration time sequence of different tissues in vivo can be realized through the technical treatment.

Fig. 15d is a schematic view of a bone screw used in conjunction with a bone plate to fix a wide range of fractures. After the bone nail and the bone plate are implanted, the front end and the rear end of the nail body are in contact with the cortical bone, the middle part of the nail body is positioned in a bone marrow cavity, the contact part of the bone nail and the cortical bone bears most of load, the stress concentration of the contact part of the bone nail and the bone plate is obvious, and the materials at the contact parts are greatly influenced by stress corrosion, so that the contact part of the bone nail and the cortical bone adopts an extrusion process with an extrusion ratio of 72.2, so that the bone nail has higher corrosion resistance, the degradation rate is reduced, and the osteogenesis promoting capability is strong; the part of the bone nail in the marrow cavity is processed by adopting an extrusion process with the extrusion ratio of 7.1; the whole bone plate uses the Mg-6A alloy with the extrusion ratio of 7.1, and has good mechanical property and higher corrosion resistance.

Comparative example 1

An oral barrier film is prepared by using a MgZnYNd alloy (the mass percent of each element in the alloy is respectively Zn1 percent, Y0.23 percent, nd 0.5 percent and the balance of Mg) with an extrusion ratio of 17.4. The preparation steps are as follows:

(1) And taking the MgZnYNd alloy, and cutting the alloy bar on the alloy bar by a diamond wire cutting machine in parallel to the axial direction. The diameter of a diamond cutting line is 0.14mm, the cutting speed is 0.15mm/min, the cutting span is 0.3mm, the cutting depth is 24mm, and finally a plurality of MgZnYNd alloy sheets with the thickness of 0.6mm are obtained.

(2) An oral barrier film was prepared on the above-cut MgZnYNd alloy sheet using a laser marker. The laser wavelength is 355nm, the laser power is 5W, the frequency is 20KHz, the pulse width is 10us, and the processing speed is 100mm/s.

The prepared barrier membrane is ultrasonically cleaned for 5min by alcohol, then the barrier membrane is implanted into a alveolar bone defect area of a beagle, and the degradation condition of the barrier membrane is observed after 1 month, as shown in figure 16, the bent part of the barrier membrane is corroded and broken, more complete materials remain at two ends, and new bones at the bone defect part are not reconstructed, which indicates that after the MgZnYNd alloy is uniformly extruded, the corrosion resistance of the bent part of the barrier membrane is not high enough, and the barrier membrane cannot be uniformly degraded to meet the requirement of bone defect repair.

Claims

1. A magnesium alloy guided bone regeneration implant with controllable degradation rate comprises an oral barrier membrane, bone nails and a bone plate, and is characterized in that the implant material takes Mg as a matrix, alloy elements with different contents are added, and the alloy degradation rate is controlled by using different extrusion ratios, wherein the alloy elements include but are not limited to Ag, zn and Al.

2. The magnesium alloy guided bone regeneration implant with a controllable degradation rate according to claim 1, wherein the implant is processed into an oral barrier membrane, the oral barrier membrane has a length of 10.0-35.0mm, a width of 6.0-20.0mm and a thickness of 0.10-0.30mm, and the barrier membrane is provided with through holes with a diameter of 0.5-3.0mm which are matched with the nail body of the bone nail; according to the requirement of the degradation rate of different parts of the barrier film, through holes with the aperture size of 0.1-0.6mm are uniformly distributed in the range of 2.0-5.0mm from the bottom, 3.0-7.0mm from the top and 4.0-10.0mm from the upper and lower parts of the waist line of the barrier film.

3. The magnesium alloy guided bone regeneration implant according to claim 2, wherein the extrusion ratio of the alloy material is 10-100 and the extrusion ratio of the alloy material is 0-10 at the rest parts within 4.0-10.0mm from the upper and lower parts of the waist line of the barrier membrane according to the requirement of the degradation rate at different parts of the barrier membrane.

4. The magnesium alloy guided bone regeneration implant according to claim 1, wherein the magnesium alloy guided bone regeneration implant is processed into a bone screw, the diameter of the screw body is 0.7-3.0mm, the length of the screw body is 5.5-15.5mm, the diameter of the screw cap is 1.5-4.0mm, the height of the screw cap is 0.5-3.0mm, and the bone screw is threaded.

5. The magnesium alloy guided bone regeneration implant according to claim 4, wherein the extrusion ratio of the alloy within 1.5-4.5mm of the bottom of the talus nail and within 4.5-6.5mm of the top of the talus nail is 10-100, and the extrusion ratio of the alloy within 1.5-4.4mm to 3.0-13.0mm of the bottom of the talus nail is 0-10, according to the requirement of the degradation rate of different parts of the bone nail.

6. The magnesium alloy guided bone regeneration implant with a controllable degradation rate according to claim 1, wherein the magnesium alloy guided bone regeneration implant is processed into a bone plate, the length of the bone plate is 10.5-25.5mm, the width of the bone plate is 2.5-10.5mm, the thickness of the bone plate is 0.5-3.5mm, the bone plate is provided with a through hole matched with the diameter of a bone screw body, and a sinking abutment matched with the height of a bone screw cap is arranged above the through hole.

7. The controlled degradation rate magnesium alloy guided bone regeneration implant of claim 6, wherein the bone plate alloy is compressed at the same compression ratio of 0-10 to meet the requirement of uniform degradation of the bone plate.