Novel bionic orthodontic planting nail structure based on elasticity modulus adaptation

Abstract

The invention discloses a novel bionic orthodontic planting nail structure based on elastic modulus adaptation, and relates to the technical field of orthodontic planting nails, the novel bionic orthodontic planting nail structure comprises a planting nail body, the interior of the planting nail body is provided with a pore structure, or the interior and the surface of the planting nail body are both provided with pore structures. The invention provides the implant nail body with the porous structure, the elastic modulus of the implant nail body is regulated and controlled through different porosities, and the implant nail bodies with different elastic moduli and imitated cancellous bone structures can be prepared so as to adapt to alveolar bone conditions of orthodontic patients with different bone mineral densities clinically; and the success rate and the orthodontic effect of the implant nail body after implantation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of orthodontic implants, and particularly to a novel bionic orthodontic implant structure based on elastic modulus adaptation. Background Art

[0002] The core of orthodontic treatment is the movement of teeth under the action of orthodontic forces, and the structure or device that resists the reaction force during orthodontics is called anchorage. The anchorage can be other teeth in the dental arch, the opposing teeth or the jawbone, or an additional device. Good anchorage control is the key to the successful movement of teeth to the target position. Traditional orthodontic methods for enhancing anchorage often use extraoral anchorage such as headgear and chincup. However, due to their impact on facial aesthetics and daily life, they can only be worn at night, and they will apply intermittent gravity to the teeth, and have high requirements for patient compliance. In some cases, the ideal treatment goals may not be achieved. Orthodontic implants are widely used in clinical practice as "absolute anchorage". Their function is to implant micro-implants into the bone, using the bone as anchorage, which can meet the need for anchorage during orthodontic treatment and obtain the maximum anchorage during orthodontic tooth movement. During orthodontic treatment, implants can assist tooth movement, dental arch distal movement, maxillary arch expansion and anterior traction, etc. Based on the dental and jaw anatomical characteristics and treatment goals, placing the implant in bone with sufficient quantity and quality and maintaining a safe distance from adjacent anatomical structures is a prerequisite for success.

[0003] The shedding of orthodontic implants is one of the key problems to be solved clinically. Unplanned shedding of orthodontic implants will prolong the orthodontic treatment cycle of patients, affect the orthodontic effect, and cause secondary implantation damage to patients, resulting in patient suffering. The key factors affecting the success of orthodontic implant placement are very complex, including host factors, implant material, implant structure, and surgery-related factors. When implanting an orthodontic implant, the hardness of the bone at the implant site, the root spacing, the mucosal thickness, and the bone anatomical characteristics should be fully considered to determine the appropriate implant position and angle. The stability and success rate of orthodontic implants are affected by factors such as the position of the implant, the implant angle, the thickness and density of the cortical bone, the contact surface between the implant and the bone, the surrounding tissue conditions, the craniofacial morphology of the patient, and the implant size. Some scholars have studied the soft tissue thickness at the implant sites of commonly used micro-implants in clinical practice to provide a reference for clinical selection of micro-implants. The results show that the thickest part of the buccal soft tissue is generally between the lateral incisor and the canine, and the thinnest part is generally between the second premolar and the first molar; the thickness of the palatal soft tissue is generally 2.5-3 times that of the buccal side; and the soft tissue thickness at the median palatal suture is generally the smallest, about 1 mm. Due to the different soft tissue thicknesses, doctors should also consider according to the location when clinically selecting micro-implants. Other scholars have studied the fracture moment values of micro-implants, analyzing 90 self-tapping orthodontic micro-implants from 6 manufacturers, attempting to compare the fracture performance of micro-implants with similar diameters and lengths due to different designs, with a diameter range of 1.4 mm to 1.8 mm. The results show that only a weak correlation (R = 0.450) between implant diameter and fracture torque was detected among the micro-implants from different manufacturers, indicating that other inherent design variables of each micro-implant may also play a role in affecting the fracture resistance force.

[0004] Although the success rate of orthodontic mini-implant anchorage reported in various literatures is not very low, generally ranging from 70% to 90%, there is no in-depth analysis of the differences in the success rate of orthodontic mini-implants among patients with different bone conditions. In fact, with the increasing number of adult orthodontic patients, adolescent and adult orthodontic patients have become the two major groups that clinicians face in clinical practice. Interestingly, the bone density of adults and adolescents is different, and the stability and histological changes after the implantation of orthodontic mini-implants are not exactly the same. Scholars such as Han measured the cortical bone and cancellous bone density of the palate in adolescents and adults and found that the cortical bone density and cancellous bone density of adults (816 and 154 HU respectively) were significantly higher than those of adolescents (606 and 135 HU; P < 0.001 and P = 0.032). At the same time, by evaluating the prognosis of 889 orthodontic mini-implants in 347 patients, it was found that the failure rate of orthodontic mini-implants in young people was significantly higher than that in adult patients clinically. Scholars such as Zhao used six adult beagle dogs and six juvenile beagle dogs as experimental subjects, placed 8 orthodontic mini-implants symmetrically in the mandible of each experimental dog, and measured the displacement of two adjacent mini-implants after applying a load to compare the mini-implant stability between the adult group and the adolescent group. The results showed that the average displacement of the mini-implants in the adult group was significantly smaller than that in the adolescent group after applying the load, and the mineral exposure rate in the adolescent group was higher than that in the adult group. In addition, compared with the adult group, more bone remodeling and new bone formation were observed in the adolescent group, but the bone-implant contact ratio decreased. Therefore, it is feasible for adult patients to load the mini-implants as early as possible or even immediately, but the author believes that the mini-implant loading in adolescents is recommended to wait for a period of time. Thus, at present, due to the relatively high elastic modulus, metal orthodontic mini-implants in clinical practice are more suitable for adult orthodontic patients with high bone density, and the failure rate is relatively high for adolescent orthodontic patients with relatively low elastic modulus of the alveolar bone.

[0005] To increase the early stability of orthodontic mini-implants and improve the implantation success rate, an ideal orthodontic mini-implant should be designed with different elastic moduli according to the bone density of patients of different ages, so that it can load the orthodontic force in the early stage after implantation, have sufficient initial stability and good biocompatibility. At present, the same mini-implants are implanted in patients of different ages in clinical practice. Due to their different bone densities, phenomena such as mini-implant loosening, poor bone bonding, and even detachment are likely to occur. Therefore, the design of mini-implants with personalized elastic moduli is particularly important. In addition, there is still a lack of theoretical basis for the appropriate elastic moduli of mini-implants at different age stages in existing research. If the appropriate elastic modulus can be selected according to imaging examinations before implanting the mini-implants to enhance the bone bonding of the mini-implants, it will contribute to the smooth progress of orthodontic clinical diagnosis and treatment, reduce the pain of patients, and improve the treatment efficiency.

[0006] During the implantation process, the stresses, strains, and deformations experienced by implants with different elastic moduli also vary. From a mechanical properties perspective, when the elastic modulus of a metal implant is similar to that of bone tissue, it is conducive to load transfer. Therefore, in recent years, some studies have fabricated implants with an elastic modulus similar to that of the alveolar bone by changing the implant material type, material structure, material properties, etc., to ensure the initial stability of the implant and the success rate of the surgery. However, studying only from these aspects has not yielded good usage effects for the implants developed.

[0007] Currently, the orthodontic implants commonly used clinically are all solid cylinder structures, and their elastic modulus is much higher than that of alveolar bone tissue. This results in a huge difference in the tissue deformation rate and the deformation rate between the implants during chewing in the oral and maxillofacial system, which may be one of the reasons for the poor stability of implants in adolescents with relatively thin cortical bone and orthodontic patients with low bone density.

[0008] Therefore, there is an urgent need in the art for a novel bionic orthodontic implant structure based on elastic modulus adaptation to solve the above problems. Summary of the Invention

[0009] The object of the present invention is to provide a novel bionic orthodontic implant structure based on elastic modulus adaptation to solve the problems existing in the above-mentioned prior art. By adjusting the elastic modulus of the implant body through the porosity of the pore structure, it can adapt to the alveolar bone conditions of orthodontic patients with different bone densities clinically, and improve the success rate and orthodontic effect after implanting the implant.

[0010] To achieve the above object, the present invention provides the following solution:

[0011] The present invention discloses a novel bionic orthodontic implant structure based on elastic modulus adaptation, including an implant body, and a pore structure is provided inside the implant body, or pore structures are provided both inside and on the surface of the implant body.

[0012] Preferably, the implant body is formed by 3D printing.

[0013] Preferably, the porosity of the pore structure is 20%-50%.

[0014] Preferably, the porosity of the pore structure is 30%.

[0015] The present invention has achieved the following technical effects compared with the prior art:

[0016] The implant screw body in the present invention is provided with a pore structure, and through the design of different porosities, the elastic modulus of the implant screw body is adapted to the alveolar bone under different conditions, thereby reducing the difference in deformation rates between the two and improving the stability of the implant screw body. The implant screw body with a pore structure designed in the present invention is expected to solve the clinical problem of poor stability of implant screws in orthodontic patients with low bone density, and has broad prospects for translational application and good social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0018] Figure 1 It is an external schematic diagram of the novel bionic orthodontic implant screw structure with a pore structure inside based on the elastic modulus adaptation in the embodiment of the present invention;

[0019] Figure 2 It is a disconnection schematic diagram of the novel bionic orthodontic implant screw structure with a pore structure inside based on the elastic modulus adaptation in the embodiment of the present invention;

[0020] Figure 3 It is a first structural schematic diagram of the novel bionic orthodontic implant screw structure with pore structures inside and on the surface based on the elastic modulus adaptation in the embodiment of the present invention;

[0021] Figure 4 It is a second structural schematic diagram of the novel bionic orthodontic implant screw structure with pore structures inside and on the surface based on the elastic modulus adaptation in the embodiment of the present invention;

[0022] Figure 5 It is a structural schematic diagram of the cross-section of the novel bionic orthodontic implant screw structure with a low porosity based on the elastic modulus adaptation in the embodiment of the present invention;

[0023] Figure 6 It is a structural schematic diagram of the cross-section of the novel bionic orthodontic implant screw structure with a medium porosity based on the elastic modulus adaptation in the embodiment of the present invention;

[0024] Figure 7 It is a structural schematic diagram of the cross-section of the novel bionic orthodontic implant screw structure with a high porosity based on the elastic modulus adaptation in the embodiment of the present invention;

[0025] Figure 8 It is the finite element analysis result of the elastic modulus and yield strength of the implant screw body with different porosities;

[0026] Figure 9Finite element analysis results of the relative displacement between the implant body with different porosities and the surrounding alveolar bone tissue after receiving a vertical force;

[0027] Figure 10 Finite element analysis results of the relative displacement between the implant body with different porosities and the surrounding alveolar bone tissue after receiving an inclined force;

[0028] Figure 11 Cell morphology of mouse bone marrow stem cells after growing on the surface of implant bodies with different porosities for 24 hours;

[0029] Figure 12 Analysis of cell proliferation of mouse bone marrow stem cells after growing on the surface of implant bodies with different porosities for 24 hours;

[0030] Figure 13 Cell skeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body with 20% porosity for 24 hours;

[0031] Figure 14 Cell skeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body with 30% porosity for 24 hours;

[0032] Figure 15 Cell skeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body with 50% porosity for 24 hours;

[0033] Figure 16 Analysis of the diameter of focal adhesion proteins of mouse bone marrow stem cells after growing on the surface of implant bodies with different porosities for 24 hours;

[0034] Figure 17 Expression of chemokine receptor Cxcr2 gene of mouse bone marrow stem cells after growing on the surface of implant bodies with different porosities for 24 hours;

[0035] Figure 18 Expression of chemokine receptor Ccr1 gene of mouse bone marrow stem cells after growing on the surface of implant bodies with different porosities for 24 hours;

[0036] Figure 19 Expression of alkaline phosphatase Alp gene of mouse bone marrow stem cells after osteogenic induction on the surface of implant bodies with different porosities for 3 days;

[0037] Figure 20 Analysis of the bleeding on probing index in oral examination after implanting implant bodies with different porosities into the alveolar bone of minipigs for 6 months;

[0038] Figure 21 Analysis of the probing depth of periodontal pockets in oral examination after implanting implant bodies with different porosities into the alveolar bone of minipigs for 6 months;

[0039] Figure 22 Analysis of periodontal attachment loss during oral examination 6 months after implanting the implant body with different porosities into the alveolar bone of minipigs;

[0040] Figure 23 Gene expression of the local tissue inflammatory factor Tnfa 6 months after implanting the implant body with different porosities into the alveolar bone of minipigs;

[0041] Figure 24 Gene expression of the local tissue inflammatory factor Il1b 6 months after implanting the implant body with different porosities into the alveolar bone of minipigs;

[0042] Figure 25 Gene expression of the local tissue inflammatory factor Ifng 6 months after implanting the implant body with different porosities into the alveolar bone of minipigs;

[0043] Figure 26 Observation of local methylene blue acid fuchsin staining 6 months after implanting the implant body with 30% porosity into the alveolar bone of minipigs;

[0044] Figure 27 Observation of local methylene blue acid fuchsin staining 6 months after implanting the implant body with 50% porosity into the alveolar bone of minipigs;

[0045] Figure 28 Analysis of the local alveolar bone resorption height 6 months after implanting the implant body with different porosities into the alveolar bone of minipigs;

[0046] Figure 29 Bone-implant body bonding rate of the implant body with different porosities 6 months after implanting into the alveolar bone of minipigs;

[0047] Figure 30 Toluidine blue basic fuchsin staining of normal tooth roots and alveolar bone;

[0048] Figure 31 Observation of local toluidine blue basic fuchsin staining 6 months after implanting the implant body with 30% porosity into the alveolar bone of minipigs;

[0049] Figure 32 Observation of local toluidine blue basic fuchsin staining 6 months after implanting the implant body with 50% porosity into the alveolar bone of minipigs;

[0050] In the figure: 1 - implant body; 2 - pore structure. Specific implementation manner

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0052] The object of the present invention is to provide a novel bionic orthodontic implant structure based on elastic modulus adaptation to solve the problems existing in the above-mentioned prior art. The elastic modulus of the implant body is adjusted by the porosity of the pore structure, so as to adapt to the alveolar bone conditions of orthodontic patients with different bone densities clinically and improve the success rate and orthodontic effect after implanting the implant.

[0053] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0054] As Figures 1 - 32 shown, this embodiment provides a novel bionic orthodontic implant structure based on elastic modulus adaptation, including an implant body 1. The shape of the implant body 1 is the same as that of the existing implant. The difference is that the implant body 1 is internally provided with a pore structure 2, or the implant body 1 is internally and externally provided with a pore structure 2. Specifically as Figures 1 - 2 shown, there may be no pore structure on the surface of the implant body 1. Or as Figures 3 - 4 shown, the pore structure 2 may also penetrate to the surface of the implant body 1. In addition, the pore structure penetration area may be located in a partial area of the implant body 1 (such as Figure 3 shown), or cover the entire surface without affecting the physical properties of the implant itself (such as Figure 4 shown).

[0055] In actual use, the pore structure 2 with different porosities can be designed according to the actual conditions of the patients, so as to better adapt to the alveolar bone conditions of orthodontic patients with different bone densities clinically and improve the success rate and orthodontic effect after implanting the implant body 1.

[0056] In this embodiment, the implant body 1 is manufactured by 3D printing. Specifically, it is integrally formed by selective laser melting 3D printing. By using the selective laser melting (SLM) technology, the implant body 1 with basically the same appearance and different porosity designs is designed and prepared, so as to achieve the purpose of adjusting the elastic modulus of the implant body 1 without affecting the implant body 1.

[0057] In this embodiment, the porosity of the pore structure 2 is 20%-50%. The porosity is the percentage of the volume of the porous part of the implant body 1 in the total volume of the implant body 1. In this embodiment, 20%, 30%, and 50% are selected for comparison. Among them, when the porosity is 20%, it is the minimum porosity (as Figure 5 shown), when the porosity is 30%, it is the medium porosity (as Figure 6 shown), and when the porosity is 50%, it is the maximum porosity (as Figure 7 shown).

[0058] The following combines Figures 8 - 32 to illustrate the experimental results of the novel bionic orthodontic implant structure based on elastic modulus adaptation provided by this embodiment:

[0059] Figure 8 are the finite element analysis results of the elastic modulus and yield strength of implants with different porosities. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G40 is the implant body 1 with a porosity of 40%, G50 is the implant body 1 with a porosity of 50%, Elasitic modulus is the elastic modulus, and Yieldstrength is the yield strength. From Figure 8 we can conclude that as the porosity increases, the elastic modulus and yield strength of the implant body 1 will gradually decrease.

[0060] Figure 9 are the finite element analysis results of the relative displacement between the implant body 1 with different porosities and the surrounding alveolar bone tissue after being subjected to a vertical force. Among them, Gyrold-20% is the implant body 1 with a porosity of 20%, Gyrold-30% is the implant body 1 with a porosity of 30%, Gyrold-40% is the implant body 1 with a porosity of 40%, Gyrold-50% is the implant body 1 with a porosity of 50%, Vertical Force is the vertical force, Height is the height, and Micromotion is the micromotion distance. From Figure 9 we can conclude that the implant body 1 with a porosity of 30% has the smallest micromotion distance under the action of a vertical force.

[0061] Figure 10 are the finite element analysis results of the relative displacement between the implant body 1 with different porosities and the surrounding alveolar bone tissue after being subjected to an oblique force. Among them, Oblique Force is the oblique force, Height is the height, and Micromotion is the micromotion distance. From Figure 10 we can conclude that the implant body 1 with a porosity of 30% has the smallest micromotion distance under the action of an oblique force.

[0062] Figure 11The cell morphology of mouse bone marrow stem cells after growing on the surface of the implant body 1 with different porosities for 24 hours. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Phallordin-iFluor488 is the cytoskeleton fluorescent dye, DAPI is the nuclear dye, and Merge shows the adhesion and proliferation of mouse bone marrow stem cells on the implant body 1 with different porosities. From Figure 11 it can be concluded that the number of mouse bone marrow stem cells on the implant body 1 with a porosity of 30% is relatively large.

[0063] Figure 12 Analysis of the cell proliferation of mouse bone marrow stem cells after growing on the surface of the implant body 1 with different porosities for 24 hours. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Control is the control variable group (i.e., the implant without pores), and Cellvialbility is the cell viability. From Figure 12 it can be known that the cell viability of mouse bone marrow stem cells in the implant body 1 with a porosity of 30% is the best.

[0064] Figure 13 The cytoskeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body 1 with a 20% porosity for 24 hours;

[0065] Figure 14 The cytoskeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body 1 with a 30% porosity for 24 hours;

[0066] Figure 15 The cytoskeleton and focal adhesion protein morphology of mouse bone marrow stem cells after growing on the surface of the implant body 1 with a 50% porosity for 24 hours;

[0067] Figure 16 Analysis of the diameter of focal adhesion proteins of mouse bone marrow stem cells after growing on the surface of the implant body 1 with different porosities for 24 hours. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, and Focal adhesion length is the length of the focal adhesion protein. From Figure 16 it can be concluded that the focal adhesion protein of mouse bone marrow stem cells in the implant body 1 with a porosity of 30% is the longest.

[0068] Figure 17The chemokine receptor Cxcr2 gene expression of mouse bone marrow stem cells after growing on the surface of the implant body 1 with different porosities for 24 hours. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Control is the control variable group (i.e., the implant without pores), and Relative expression Cxcr2 / Gapdh is the relative expression level of the Cxcr2 gene of mouse bone marrow stem cells. From Figure 17 it can be concluded that the Cxcr2 gene expression level of mouse bone marrow stem cells on the implant body 1 with a porosity of 30% is significantly higher than that on the implant body 1 with porosities of 20% and 50%.

[0069] Figure 18 The chemokine receptor Ccr1 gene expression of mouse bone marrow stem cells after growing on the surface of the implant body 1 with different porosities for 24 hours. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Control is the control variable group (i.e., the implant without pores), and Relative expression Ccr1 / Gapdh is the relative expression level of the Ccr1 gene of mouse bone marrow stem cells. From Figure 18 it can be concluded that the Ccr1 gene expression levels of mouse bone marrow stem cells on the implant body 1 with different porosities are all significantly higher than that on the implant without pores, and the Ccr1 gene expression level of mouse bone marrow stem cells on the implant body 1 with a porosity of 50% is the highest.

[0070] Figure 19 The alkaline phosphatase Alp gene expression of mouse bone marrow stem cells after osteogenic induction on the surface of the implant body 1 with different porosities for 3 days. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Control is the control variable group (i.e., the implant without pores), and Relative expressionAlp / Gapdh is the relative expression level of the Alp gene of mouse bone marrow stem cells. From Figure 19 it can be concluded that the Alp gene expression level of mouse bone marrow stem cells on the implant body 1 with a porosity of 30% is the highest.

[0071] Figure 20Analysis of the bleeding index during oral examination after the implant body 1 with different porosities was implanted into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and SBI score is the bleeding index score. The higher the score, the more severe the bleeding. From Figure 20 it can be concluded that the implant body 1 with different porosities can all cause bleeding on probing, but the implant body 1 with a porosity of 30% has the lowest bleeding index.

[0072] Figure 21 Analysis of the probing depth of the periodontal pocket during oral examination after the implant body 1 with different porosities was implanted into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and PPD is the probing depth. The greater the depth, the more severe the destruction of the periodontal tissue. From Figure 21 it can be concluded that there is no significant difference in the periodontal probing depth of the implant body 1 with a porosity of 30% compared with natural teeth.

[0073] Figure 22 Analysis of the periodontal attachment loss during oral examination after the implant body 1 with different porosities was implanted into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and CAL is the height of periodontal attachment loss. The larger the value, the less the amount of periodontal tissue. From Figure 22 it can be concluded that the degree of periodontal attachment loss of the implant body 1 with a porosity of 30% is the smallest and there is no significant difference compared with natural teeth.

[0074] Figure 23 Analysis of the gene expression of the local tissue inflammatory factor Tnfa after the implant body 1 with different porosities was implanted into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and Relativeexpression Tnfa / Gapdh is the relative expression level of the Tnfa gene in the periodontal tissue around the implant body 1 with different porosities. From Figure 23 it can be concluded that the implant body 1 with different porosities did not cause obvious inflammation, and the relative expression levels of the Tnfa gene in the periodontal tissue around the implant body 1 with porosities of 20% and 30% are similar to those of natural teeth.

[0075] Figure 24 The gene expression of local tissue inflammatory factor Il1b after the implant of implant bodies 1 with different porosities into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and Relativeexpression Il1b / Gapdh is the relative expression of Il1b gene in the periodontal tissue around the implant bodies 1 with different porosities. From Figure 24 it can be concluded that the relative expression of Il1b gene in the periodontal tissue around the implant bodies 1 with porosities of 20% and 30% is similar to that of natural teeth.

[0076] Figure 25 The gene expression of local tissue inflammatory factor Ifng after the implant of implant bodies 1 with different porosities into the alveolar bone of minipigs for 6 months. Among them, G20 is the implant body 1 with a porosity of 20%, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, Blank is the blank control group (i.e., natural teeth), and Relativeexpression Ifng / Gapdh is the relative expression of Ifng gene in the periodontal tissue around the implant bodies 1 with different porosities. From Figure 25 it can be concluded that there is no significant difference in the relative expression of Ifng gene in the periodontal tissue around the implant bodies 1 with different porosities.

[0077] Figure 26 Observation of local methylene blue acid fuchsin staining after the implant of implant body 1 with 30% porosity into the alveolar bone of minipigs for 6 months. From Figure 26 it can be concluded that new bone tissue can be seen on the surface of the implant body 1, and the bone tissue can grow into the interior of the implant body 1 along the pore structure 2.

[0078] Figure 27 Observation of local methylene blue acid fuchsin staining after the implant of implant body 1 with 50% porosity into the alveolar bone of minipigs for 6 months. From Figure 27 it can be concluded that new bone tissue can be seen on the surface of the implant body 1, and the bone tissue can grow into the interior of the implant body 1 along the pore structure 2.

[0079] Figure 28 Analysis of the local alveolar bone resorption height after the implant of implant bodies 1 with different porosities into the alveolar bone of minipigs for 6 months. Among them, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, and Boneresorption height is the bone resorption height. From Figure 28From this, we can conclude that the bone resorption height of the implant body 1 with a porosity of 30% is significantly lower than that of the implant body 1 with a porosity of 50%.

[0080] Figure 29 The bone-implant binding rate of the implant body 1 with different porosities after being implanted into the alveolar bone of minipigs for 6 months. Among them, G30 is the implant body 1 with a porosity of 30%, G50 is the implant body 1 with a porosity of 50%, and BLC% / Total area is the proportion of the area of the bone-implant binding region to the total surface area of the implant. From Figure 29 From this, we can conclude that the bone-implant binding rate of the implant body 1 with a porosity of 30% is significantly higher than that of the implant body 1 with a porosity of 50%.

[0081] Figure 30 This is the toluidine blue basic fuchsin staining of normal tooth roots and alveolar bone. From Figure 30 From this, we can conclude that there are regularly arranged collagen fibers between the natural tooth root and the alveolar bone, and osteoblasts (indicated by the yellow arrow) are present at the edge of the alveolar bone.

[0082] Figure 31 This is the observation of local toluidine blue basic fuchsin staining after the implant body 1 with a 30% porosity is implanted into the alveolar bone of minipigs for 6 months. From Figure 31 From this, we can conclude that a collagen fiber arrangement area can be seen between the implant body 1 with a porosity of 30% and the alveolar bone, and osteoblasts (indicated by the yellow arrow) can be seen at the edge of the alveolar bone, which is similar to the natural tooth root structure.

[0083] Figure 32 This is the observation of local toluidine blue basic fuchsin staining after the implant body 1 with a 50% porosity is implanted into the alveolar bone of minipigs for 6 months. From Figure 31 From this, we can conclude that there is no situation similar to the natural tooth root structure around the implant body 1 with a porosity of 50%.

[0084] The implant body 1 material of the pore structure 2 designed with the maximum porosity (50%), medium porosity (30%), and minimum porosity (20%) was co-cultured with mouse bone marrow mesenchymal stem cells to evaluate the biocompatibility of the material and its effect on cell function. The results show that in the culture results of this batch of mouse bone marrow mesenchymal stem cells, each group can promote the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSC) as Figure 11 shown, and the promoting effect on cell proliferation is significantly higher than that of the control group, among which the 30% group has the strongest effect (as Figure 12As shown). Through the fluorescence staining observation of the cytoskeleton and focal adhesion proteins in bone marrow mesenchymal stem cells, it was found that too low porosity (20%) hindered the cytoskeleton extension of bone marrow mesenchymal stem cells, which was not conducive to cell adhesion and chemotaxis. Although the scaffold materials in the 30% and 50% groups allowed cell cytoskeleton extension, too high porosity (50%) led to an increased cell distance and a reduced maturity of focal adhesion proteins, which was not conducive to the osteogenic differentiation function of cells ( Figures 13 - 16 As shown).

[0085] By establishing a minipig implantation model, the success rate and bone integration effect after the implantation of implants with different pore structures were explored in vivo. The results of real-time PCR of tissues 6 months after implantation showed that the alveolar bone around the 30% implant was more stable than the other two groups, without obvious inflammation (as Figures 20 - 25 shown), and the bone integration effect was relatively ideal. Moreover, the histological staining results showed that a fiber ligament buffer zone similar to the periodontal ligament was formed around the implant (as Figures 26 - 32 shown).

[0086] In this embodiment, as Figures 8 - 10 shown, finite element analysis was used to deeply analyze the stress distribution of each structural implant during the chewing process of the stomatognathic system and the micro-motion changes between the implant and the alveolar bone. The results showed that the porosity design of 30% was theoretically beneficial to the stability and bone integration after implant implantation. And combined with the above Figures 8 - 32 comparison, by actually detecting the elastic modulus of the cortical bone, cancellous bone, tooth root and other parts of the minipig, it was finally confirmed that the elastic modulus of the 30% porosity implant was matched with the elastic modulus of the cortical bone in the implantation area. Therefore, the porosity of the nail hole 2 in this embodiment is preferably 30%.

[0087] Of course, it should also be noted that the result that the 30% porosity implant is more stable after implantation is based on the application scenarios of the titanium alloy material used in this study, the biological function characteristics of mouse bone marrow stem cells, and the adaptation of the elastic modulus of the minipig cortical bone. It is a relatively good embodiment obtained by comparison among 20%, 30% and 50%. Those skilled in the art can also obtain a more appropriate porosity by adjusting relevant parameters, not limited to 30% only.

[0088] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A novel bionic orthodontic implant screw structure based on elastic modulus adaptation, comprising an implant screw body, characterized in that: The implant nail body has a pore structure inside, or the implant nail body and the surface thereof have pore structures inside.

2. The novel bionic orthodontic implant structure based on elastic modulus adaptation according to claim 1 is characterized in that: The implant nail body is manufactured by 3D printing.

3. The novel bionic orthodontic implant structure based on elastic modulus adaptation according to claim 1 is characterized in that: The porosity of the pore structure is 20%-50%.

4. The novel bionic orthodontic implant structure based on elastic modulus adaptation according to claim 3 is characterized in that: The porosity of the pore structure is 30%.

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