Bionic multi-root molar implant and system

Abstract

The application discloses a kind of bionic multi-root molar implant and system, implant body includes neck platform area from top to bottom, root bifurcation transition area and multi-root area;The top surface of neck platform area is wide plane, and is provided with abutment connecting hole, the abutment connecting hole is provided with anti-rotation structure and internal thread;Multi-root area includes at least two bionic roots distributed circumferentially around the central axis of implant body;The end or middle section of each bionic root is provided with a hook structure, which provides a mechanical locking force against extraction after implanting into the alveolar bone.The application also discloses an assembly system comprising the above-mentioned implant, abutment, central screw and prosthetic crown, and a manufacturing method thereof.

Description

Technical Field

[0001] This invention relates to the field of oral implant restoration technology, and in particular to a biomimetic multi-rooted molar implant and system. Background Technology

[0002] Molars play a major role in chewing, and their loss often leads to decreased chewing efficiency and tilting or displacement of adjacent teeth. While threaded cylindrical or conical implants commonly used in clinical practice can restore missing anterior teeth and premolars, in posterior tooth regions where bone height is insufficient but bone width is adequate, single cylindrical implants are limited in axial height, making it difficult to achieve sufficient initial stability and long-term pull-out resistance, thus posing a risk of dislodgement.

[0003] Natural molars have a multi-branched anatomical structure, with each root penetrating deep into the cancellous layer of the alveolar bone and forming a tight bond with the surrounding bone tissue, thereby generating excellent three-dimensional retention. However, current implant designs do not fully simulate this natural multi-branched structure, and there is a lack of specialized implant solutions tailored to the bone anatomy of the molar region.

[0004] Therefore, there is an urgent need for a bionic implant and its supporting system that can simulate the multi-rooted anatomy of natural molars, is suitable for areas with limited bone height but ample bone width where molars are missing, and has excellent anti-extraction capabilities. Summary of the Invention

[0005] To address the technical problems of insufficient pull-out resistance and inability to fully utilize bone width resources in existing molar implants, this invention provides a biomimetic multi-root molar implant and system.

[0006] In a first aspect, the present invention provides a biomimetic multi-rooted molar implant, comprising: an implant body 1, the implant body 1 including, from top to bottom, a cervical plateau region 11, a root bifurcation transition region 12, and a multi-rooted region 13; the top surface of the cervical plateau region 11 is a wide plane, the cross-sectional area of ​​which is larger than the overall cross-sectional area of ​​the multi-rooted region 13; the cervical plateau region 11 is provided with an abutment connection hole 15, the abutment connection hole 15 is provided with an anti-rotation structure 151, for forming an anti-rotation fit with the abutment; the bottom of the abutment connection hole 15 is provided with an internal thread 152, for engaging with a screw to fix the abutment; the multi-rooted region 13 includes at least two biomimetic roots 14 circumferentially distributed around the central axis of the implant body 1; each biomimetic root 14 is provided with a hook structure at its end or middle, the hook structure extending outward or inward along a direction parallel to the central axis of the implant body 1, for providing a mechanical locking force against pullout after implantation into the alveolar bone.

[0007] In some embodiments, the hook structures on each bionic tooth root 14 bend in the same direction and are arranged clockwise or counterclockwise in the circumferential section around the central axis of the implant body 1, so that the hook structures together form a rotational self-locking effect after osseointegration.

[0008] In some embodiments, at least some of the hook structures are bent toward the central axis of the implant body 1, so that each hook structure clamps the surrounding bone tissue toward the center of the implant after osseointegration, thereby enhancing the anti-dislodgement locking force.

[0009] In some embodiments, the bending directions of the hook structures of each bionic tooth root 14 are partially the same and partially opposite, forming an alternating arrangement.

[0010] In some embodiments, the hook angle between the hook structure and the corresponding bionic tooth root 14 is 15° to 160°, and the free end of the hook structure is rounded.

[0011] In some embodiments, the number of bionic tooth roots 14 is three, which are evenly distributed at 120° around the central axis of the implant body 1 to simulate the three-root anatomical morphology of the maxillary molar; the bionic tooth roots 14 form osseointegration gaps between them to allow bone tissue to ingrow and form three-dimensional bone anchors. In other embodiments, the number of bionic tooth roots 14 is two, which are symmetrically distributed along the mesiodistal direction of the implant body 1 to simulate the two-root anatomical morphology of the mandibular molar.

[0012] In some embodiments, the outer peripheral surface of the root bifurcation transition zone 12 gradually expands outward from top to bottom to form an arc-shaped outward transition surface, so that the outer contour of the cervical plateau zone 11 to the multi-root zone 13 has a waist-outward shape in the sagittal section, and forms a surface contact with the cortical bone after implantation, thereby improving initial stability.

[0013] In some embodiments, the cross-sectional profile of the top surface of the cervical plateau region 11 corresponds to the anatomical profile of the corresponding molar occlusal surface, and the profile is any one of a rounded rectangle, an ellipse, or a drum shape; the maximum crown diameter of the cervical plateau region 11 is greater than the maximum bifurcation outer diameter of the multi-root region 13, and the ratio between the two is not less than 1.2, so that the implant as a whole presents a biomimetic molar shape that is wider at the top and bifurcation at the bottom.

[0014] In some embodiments, a platform shoulder is provided at the outer peripheral edge of the top surface of the cervical plateau region 11. After the implant is placed, the platform shoulder is flush with or slightly lower than the top surface of the alveolar bone. It is used to support the autologous bone powder or bone substitute material covering the top surface during the implantation procedure. After the bone heals, the bone cap formed will lock the top surface of the cervical plateau region 11 into the bone, thus forming a top surface bone locking anti-dislodgement mechanism.

[0015] In some embodiments, the top surface of the cervical plateau region 11 is a rough bone-bonding surface, which is used to cover autologous bone powder after implantation, so that the bone powder fills the space between the wide plane and the alveolar bone, and a bony holding structure is formed after bone healing.

[0016] In some embodiments, the overall axial height of the implant body 1 is 4 mm to 12 mm to accommodate areas of molar loss where alveolar bone height is insufficient; wherein the axial height of the multi-rooted region 13 is not less than one-third of the overall axial height and not less than 2 mm, ensuring that the hook structure has sufficient anchoring depth when implanted into the cancellous bone layer.

[0017] In some embodiments, the outer surface of the implant body 1 is subjected to surface activation treatment in whole or in part, and the surface activation treatment is at least one of the following: sandblasting and acid etching treatment, anodizing treatment, hydroxyapatite plasma spraying, tantalum metal coating treatment or niobium metal coating treatment; the inner wall surface of the osseointegration gap between the bionic tooth roots 14 must be subjected to surface activation treatment to promote osseointegration within the gap.

[0018] In some embodiments, the inner wall of the osseointegration gap between the bionic tooth roots 14 is provided with microgrooves, which are longitudinal microgrooves or spiral microgrooves, to increase the mechanical interlocking area between the bone and the implant, and to guide the bone tissue to grow in a directional manner along the direction of the microgrooves, thereby enhancing the osseointegration anchoring effect.

[0019] In some embodiments, the outer surface of each bionic tooth root 14 and / or the interroot space surface between adjacent bionic tooth roots 14 are provided with a bioactive coating; the bioactive coating is selected from at least one of tantalum coating, niobium coating, hydroxyapatite coating, and titanium plasma spray coating, and the coating thickness is 1 μm to 50 μm.

[0020] In some embodiments, the implant body 1 is made of any one of medical-grade pure titanium, titanium alloy, titanium-zirconium alloy, cobalt-chromium alloy, or zirconia ceramic; when the material is metal, the implant body 1 is manufactured by CNC machining or metal additive manufacturing; when the material is zirconia ceramic, the implant body 1 is shaped by computer-aided manufacturing.

[0021] Secondly, the present invention provides a biomimetic multi-root molar implant assembly system, comprising: a biomimetic multi-root molar implant as described in any of the above embodiments; an abutment 2, the root insertion end of the abutment 2 forming an anti-rotation fit connection with the abutment connection hole 15 of the implant; a central screw 3, the central screw 3 passing through the central through hole of the abutment 2 and engaging with the internal thread 152 at the bottom of the abutment connection hole 15 to lock and fix the abutment 2 onto the implant; and a composite crown connected to the coronal end of the abutment 2, the occlusal surface of which corresponds to the occlusal surface of a natural molar.

[0022] In some embodiments, the outer contour of the transgingival segment of the abutment 2 is conical or concave arc-shaped, and the outer surface of the transgingival segment is polished to reduce the surface roughness of the intraosseous segment of the implant, thereby reducing plaque adhesion in the transgingival segment and maintaining the health of the soft tissue around the implant; the restorative crown is a screw-retained crown or an adhesive-retained crown.

[0023] In some embodiments, the outer surface of the root insertion end of the base 2 is provided with a non-circular anti-rotation mating surface that matches the anti-rotation structure 151 of the base connection hole 15, and the number of anti-rotation contact surfaces is 2 to 8.

[0024] This invention designs the implant body as a biomimetic three-segment structure, comprising a cervical plateau region, a root bifurcation transition region, and a multi-root region from top to bottom. This allows the overall shape of the implant to mimic the multi-root bifurcation anatomical features of a natural molar, enabling effective implantation by fully utilizing existing bone resources in areas with limited bone height but ample bone width where molars are missing. By setting a large plane in the cervical plateau region with a cross-sectional area larger than the overall cross-sectional area of ​​the multi-root region, the implant gains a larger coronal bearing area within the bone, effectively dispersing masticatory stress and reducing stress concentration at the alveolar ridge. Furthermore, by incorporating hook structures at the ends or middle of each biomimetic root, it utilizes… The mechanical interlocking relationship formed between the hook structure and the surrounding alveolar bone tissue after osseointegration significantly improves the axial pull-out resistance of the implant. Various arrangements of the hook structure can also provide rotational self-locking or central clamping locking effects. By setting an abutment connection hole in the cervical plateau area and configuring an anti-rotation structure and internal threads, a reliable anti-rotation fit and screw fixation connection between the implant and the abutment are achieved, ensuring the stability of the superstructure under long-term masticatory loads. The osseointegration gap formed between the biomimetic tooth roots provides ideal space for bone ingrowth, enabling the implant to achieve a three-dimensional bone anchoring effect after osseointegration. The assembly system of this invention integrates the implant, abutment, central screw, and restorative crown into one unit, with precise fit and reliable connection between the components. The manufacturing method of this invention is based on patient imaging data for personalized design and digital manufacturing, enabling high-precision personalized customization.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0027] The invention will be more clearly understood with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 A three-dimensional structural view of a biomimetic multi-rooted molar implant according to an embodiment of the invention is shown; Figure 2 A top view showing the structure of a biomimetic multi-rooted molar implant according to an embodiment of the invention is provided. Figure 3 A bottom view showing the structure of a biomimetic multi-rooted molar implant according to an embodiment of the invention; Figure 4A cross-sectional view of a biomimetic multi-rooted molar implant according to an embodiment of the invention is shown. Figure 5 A schematic diagram of the structural assembly of a biomimetic multi-root molar implant system according to an embodiment of the invention is shown. Figure 6 A perspective view of a base according to an embodiment of the invention is shown; Figure 7 A front view of a base structure according to an embodiment of the invention is shown; Figure 8 A cross-sectional view of a base according to an embodiment of the invention is shown; Figure 9 A structural diagram of a screw for fixing a base is shown according to an embodiment of the invention.

[0028] Explanation of reference numerals in the attached diagram: 1. Implant body; 11. Neck plateau area; 12. Root bifurcation transition area; 13. Multi-root area; 14. Bionic root; 15. Abutment connection hole; 151. Anti-rotation structure; 152. Internal thread; 2. Abutment; 21. Root insertion end; 22. Transgingival segment; 23. Coronal end; 24. Central through hole; 25. Anti-rotation mating surface; 3. Central screw; 31. Screw part; 32. Nut part. Detailed Implementation

[0029] The present application will be further described below with reference to specific embodiments and accompanying drawings. It is understood that the illustrative embodiments of this disclosure include, but are not limited to, related methods, devices, and systems. The specific embodiments described herein are merely for explaining the present application and not for limiting it. Furthermore, for ease of description, the accompanying drawings show only the parts relevant to the present application, and not all of the structures or processes.

[0030] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application will be presented in conjunction with preferred embodiments, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details will be included in the following description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0031] Reference Figures 1 to 4This invention provides a biomimetic multi-rooted molar implant, which includes an integrally molded implant body 1. The overall shape of the implant body 1 simulates the anatomical shape of a natural molar, and from top to bottom includes three functional areas: a cervical plateau area 11, a root bifurcation transition area 12, and a multi-root area 13.

[0032] like Figure 1 and Figure 2 As shown, the cervical plateau region 11 is located at the top of the implant body 1, and its top surface is a wide plane. The cross-sectional area of ​​this wide plane is larger than the overall cross-sectional area of ​​the multi-root region 13. The cross-sectional contour of the top surface of the cervical plateau region 11 corresponds to the anatomical contour of the corresponding molar occlusal surface, and can be any one of a rounded rectangle, an ellipse, a circle, or a drum shape. In this embodiment, the top surface contour of the cervical plateau region 11 is preferably an approximately rounded rectangle to correspond to the occlusal surface morphology of the mandibular molar. The maximum crown diameter of the cervical plateau region 11 is larger than the maximum bifurcation outer diameter of the multi-root region 13, giving the implant an overall biomimetic molar shape that is wider at the top and bifurcation at the bottom. After the implant is inserted into the alveolar bone, the wide cervical plateau region 11 can provide a large load-bearing area at the top of the bone ridge, effectively dispersing the masticatory force transmitted by the restoration to the cortical bone layer, reducing stress concentration at the bone interface, and thus reducing the risk of marginal bone resorption.

[0033] like Figure 2 and Figure 4 As shown, an abutment connection hole 15 is provided in the center of the neck platform area 11. The abutment connection hole 15 extends downward from the top surface of the neck platform area 11, penetrating to a certain depth inside the implant body 1. The abutment connection hole 15 is provided with an anti-rotation structure 151 and an internal thread 152. The anti-rotation structure 151 is located in the upper or middle region of the abutment connection hole 15 and is used to form an anti-rotation fit with the corresponding mating surface of the abutment 2 to prevent the abutment 2 from rotating and loosening under chewing load. The anti-rotation structure 151 can be in the form of at least one of internal hexagonal, internal octagonal, spline structure or Morse taper surface. The internal thread 152 is located in the bottom region of the abutment connection hole 15 and is used to screw into the screw portion 31 of the central screw 3, locking and fixing the abutment 2 to the implant by applying a preload torque. In some embodiments, the abutment connection hole 15 may further include a tapered mating section, which is a Morse taper structure with a taper angle of 2° to 16°. When the root insertion end 21 of the abutment 2 is inserted into the abutment connection hole 15, a cold welding effect is generated between the tapered mating surfaces under the action of pre-tightening torque, which can effectively eliminate the micro-movement gap between the abutment 2 and the implant and reduce the stress concentration of bone tissue at the connection interface.

[0034] like Figure 1As shown, the root bifurcation transition zone 12 is located between the cervical plateau region 11 and the multi-rooted region 13, serving as a structural transition and stress transfer function. The outer peripheral surface of the root bifurcation transition zone 12 gradually expands outward from top to bottom, forming an arc-shaped outward transition surface. This arc-shaped outward transition surface makes the outline of the cervical plateau region 11 to the multi-rooted region 13 have a waist-shaped and outward shape in the sagittal section. This waist-shaped and outward shape has two technical effects: on the one hand, after the implant is inserted into the bone, the arc-shaped outward surface of the root bifurcation transition zone 12 forms a large area of ​​surface contact with the inner wall of the cortical bone layer, utilizing the high density and high strength characteristics of the cortical bone to provide good initial stability for the implant; on the other hand, the waist-shaped structure creates a natural structural boundary between the cervical plateau region 11 and the multi-rooted region 13, which is conducive to the adhesion and sealing of bone tissue in this area and reduces the risk of bacteria invading deeper along the implant surface.

[0035] like Figure 1 and Figure 3 As shown, the multi-rooted region 13 is located at the bottom of the implant body 1, including at least two bionic roots 14 circumferentially distributed around the central axis of the implant body 1. Each bionic root 14 extends independently downward from the lower edge of the root bifurcation transition region 12, simulating the bifurcation morphology of a natural molar root. In this embodiment, there are two bionic roots 14, which are symmetrically distributed along the mesiodistal direction of the implant body 1 to simulate the double-root anatomy of the mandibular molar. An osseointegration gap is formed between the two bionic roots 14, providing a spatial channel for bone ingrowth. After osseointegration is completed, the bone tissue within the ingrowth gap bridges the two bionic roots 14 together, forming a three-dimensional bone anchoring effect similar to the natural periodontal ligament, significantly improving the overall retention of the implant.

[0036] Each biomimetic tooth root 14 has a hook structure at its distal or mid-section. The hook structure extends outward or inward along a direction parallel to the central axis of the implant body 1. The hook structure is the core technical feature of this invention to achieve the anti-removal function. After the implant is inserted into the alveolar bone and osseointegration is completed, the hook structure forms a mechanical locking relationship with the surrounding bone tissue. When the implant is subjected to a force in the axial pull-out direction, the hook tip of the hook structure abuts against the surrounding bone tissue, generating a mechanical locking force to resist pull-out. The design inspiration for this hook structure comes from the curved shape of natural molar roots and the design concept of barbed fixation screws in the field of orthopedics, realizing dual biomimicry from form to function.

[0037] In this embodiment, the hook angle between the hook structure and the corresponding bionic tooth root 14 root body can be from 15° to 160°. The size of the hook angle can be individually selected according to clinical needs and the patient's bone condition. When the hook angle is smaller (e.g., 15° to 45°), the hook structure provides less resistance to implantation, which is suitable for areas with denser bone; when the hook angle is larger (e.g., 90° to 160°), the hook structure provides stronger mechanical locking force, which is suitable for areas with more porous bone or areas requiring higher resistance to pull-out force. The free end of the hook structure is rounded, which avoids excessive cutting or damage to the surrounding bone tissue during implantation, and also facilitates the attachment and growth of bone tissue on the hook surface.

[0038] The beneficial effects of the above embodiments are as follows: through the three-segment biomimetic structural design of the cervical plateau area, the root bifurcation transition area and the multi-root area, combined with the hook structure at the end of the biomimetic root, the implant has both biocompatibility with the anatomical shape of a natural molar and excellent mechanical anti-extraction performance, which is especially suitable for areas with limited bone height where molars are missing.

[0039] In another embodiment, the arrangement of the hook structures is further optimized. The hook structures on each bionic root 14 bend in the same direction and are arranged clockwise or counterclockwise within the circumferential section surrounding the central axis of the implant body 1. Specifically, when the implant has two bionic roots 14, the hook structures at the ends of both bionic roots 14 bend in the same direction of rotation (e.g., clockwise). After osseointegration, if the implant is subjected to a rotational torque, the tips of each hook structure will form a unidirectional anti-rotation mechanical occlusion with the surrounding bone tissue, jointly producing a rotational self-locking effect. This rotational self-locking effect can effectively prevent the implant from micro-rotating due to rotational forces during chewing, further improving the long-term stability of the implant-abutment connection.

[0040] In another embodiment, at least some of the hook structures are bent towards the central axis of the implant body 1, i.e., the hook structures bend inward rather than outward. After osseointegration, the tips of each hook structure point towards the center of the implant, forming a centripetal clamping relationship with the surrounding bone tissue. When the implant is subjected to pullout force, the hook structures not only generate axial locking force but also simultaneously generate radial clamping force pointing towards the center of the implant, firmly clamping the surrounding bone tissue within the implant root region and enhancing the anti-dislodgement locking force from multiple directions.

[0041] In another embodiment, the hook structures of each bionic root 14 have partially the same and partially opposite bending directions, forming an alternating arrangement. For example, when the implant has two bionic roots 14, the hook structure of one bionic root 14 bends outward, while the hook structure of the other bionic root 14 bends inward. This alternating arrangement gives the implant good locking ability in different directions, resisting multi-directional dislodgement forces and lateral forces.

[0042] The beneficial effects of the above-described hook arrangement are as follows: by designing multiple hook arrangement methods, the implant can flexibly select the optimal hook configuration according to different clinical scenarios and mechanical needs, thereby achieving comprehensive anti-dislodgement capabilities against axial pull-out force, rotational torque, and multi-directional lateral forces, and improving the clinical adaptability of implant design.

[0043] In another embodiment, three bionic tooth roots 14 are provided, evenly distributed at 120° angles around the central axis of the implant body 1, to simulate the three-root anatomical morphology of the maxillary molar. The maxillary molar typically has a three-root morphology with two buccal roots and one palatal root; the spatial distribution of the three bionic tooth roots 14 in this embodiment simulates this anatomical feature. Three osseointegration gaps are formed between the three bionic tooth roots 14. Compared to the two-root approach, the three-root approach provides a larger osseointegration interface area, allowing bone tissue to grow into the implant root region from the three gaps, forming a more robust three-dimensional bone anchoring network. Each of the three bionic tooth roots 14 has a hook structure at its end, and these three hook structures are evenly distributed at 120° angles in space, providing uniform pull-out locking force in all directions.

[0044] The beneficial effects of the above three bionic tooth root embodiments are as follows: through the design of three evenly distributed bionic tooth roots, the implant obtains a larger bone contact surface area and a more uniform mechanical distribution, which is particularly suitable for implant restoration in the area of ​​missing maxillary molars.

[0045] In another embodiment, a platform shoulder is provided at the outer peripheral edge of the top surface of the cervical plateau region 11. The platform shoulder is a stepped structure surrounding the edge of the top surface of the cervical plateau region 11, and its width can be 0.5 mm to 2 mm. After implantation, the platform shoulder is flush with or slightly lower than the top surface of the alveolar bone by 0.5 mm to 1.5 mm. During the implantation procedure, a layer of autologous bone powder or bone substitute material can be covered on the wide top surface of the cervical plateau region 11. The stepped structure of the platform shoulder can support and confine the covered bone powder material, preventing bone powder loss during healing. After a bone healing period of 3 to 6 months, the bone powder material covering the top surface of the cervical plateau region 11 completes mineralization and bone remodeling, forming a dense bone cap. This bone cap covers the wide top surface of the cervical plateau region 11, locking the top surface of the implant within the bone. When the implant is subjected to axial pull-out force, a mechanical locking relationship is formed between the bone cap and the wide top surface of the cervical plateau region 11, constituting a top surface bone locking anti-dislodgement mechanism. The top surface bone locking anti-removal mechanism works in conjunction with the root-square locking anti-removal mechanism provided by the bionic root 14 end hook structure to form a dual anti-removal system on both the coronal and root sides of the implant, thereby significantly improving the overall axial pull-out resistance of the implant.

[0046] Furthermore, the top surface of the neck plateau region 11 can be a roughened bone-bonding surface, which can be obtained through sandblasting and acid etching. The roughened surface microstructure increases the contact area between the top surface of the neck plateau region 11 and the bone powder material, promoting the adhesion and mineralization process of bone powder particles on the top surface, thereby forming a more robust bone-bonding interface between the bone cap and the top surface of the implant.

[0047] The beneficial effects of the above-mentioned platform shoulder and bony support embodiment are as follows: by constructing a bone cap locking mechanism on the top surface of the cervical platform area, the bone locking and anti-dislodgement effect of the implant coronal side is achieved. Together with the mechanical locking of the root side hook structure, a double anti-dislodgement system is formed, which significantly improves the overall anti-pullout ability of the implant. It has important clinical value, especially for areas with limited bone height.

[0048] In another embodiment, the overall axial height of the implant body 1 is 4 mm to 12 mm. This height range allows the implant to be suitable for areas of molar loss where alveolar bone height is insufficient. Specifically, when the remaining alveolar bone height is between 4 mm and 6 mm, an ultra-short bionic implant with an overall axial height of 4 mm to 6 mm can be selected; when the remaining alveolar bone height is between 6 mm and 12 mm, a standard bionic implant of the corresponding height can be selected. The axial height of the multi-rooted region 13 is not less than one-third of the overall axial height and not less than 2 mm, ensuring that the hook structure can be completely implanted into the cancellous bone layer and has sufficient anchoring depth. For example, when the overall axial height of the implant is 6 mm, the axial height of the multi-rooted region 13 is at least 2 mm; when the overall axial height of the implant is 12 mm, the axial height of the multi-rooted region 13 is at least 4 mm.

[0049] The beneficial effects of the above-described dimensional parameter embodiments are as follows: through reasonable axial height distribution, the implant can adapt to clinical scenarios with different bone height conditions, and while ensuring the effective anchoring depth of the hook structure, it maximizes the use of existing bone volume, thereby expanding the clinical indications of biomimetic multi-root molar implants.

[0050] In another embodiment, the outer surface of the implant body 1 is subjected to surface activation treatment in whole or in part. Surface activation treatment can be at least one of sandblasting and acid etching, anodizing, hydroxyapatite plasma spraying, tantalum metal coating, or niobium metal coating. In particular, the inner wall of the osseointegration gap between the bionic tooth roots 14 must be surface activated. The osseointegration gap is a key area for bone ingrowth and bone bridging formation. Surface activation treatment of this area can increase the bone contact area at the microscale, promote the adhesion, proliferation, and differentiation of osteoblasts on the inner wall of the gap, accelerate the osseointegration process, and enable the bone bridging within the gap to achieve ideal bone density and mechanical strength within a shorter healing period.

[0051] In some embodiments, the inner wall of the osseointegration space between the bionic tooth roots 14 is further provided with microgrooves. These microgrooves can be longitudinal or spiral, with a depth of 0.2 mm to 1.0 mm and a spacing of 0.5 mm to 2.0 mm. The microgrooves enhance the bonding strength of the bone-implant interface by increasing the mechanical interlocking area between the bone and the implant. Simultaneously, the directional arrangement of the microgrooves guides bone tissue to grow directionally along the microgroove direction, resulting in an ordered layered structure of newly formed bone tissue, which exhibits higher mechanical strength compared to randomly arranged bone tissue.

[0052] In some embodiments, the outer surface of each bionic tooth root 14 and / or the interroot space surface between adjacent bionic tooth roots 14 are provided with a bioactive coating. The bioactive coating may be selected from at least one of tantalum coating, niobium coating, hydroxyapatite coating, and titanium plasma spray coating, with a coating thickness of 1 μm to 50 μm. Tantalum and niobium coatings have excellent osteoinductive activity and corrosion resistance, and can form a bioactive oxide layer on the implant surface, promoting direct osteogenic formation of bone tissue on the implant surface. Hydroxyapatite coating has a chemical composition similar to bone tissue and can form chemical bonds with newly formed bone tissue, achieving faster and stronger osseointegration.

[0053] The beneficial effects of the above surface treatment embodiments are that, through a multi-level surface treatment strategy, osseointegration is promoted synergistically from two dimensions: micromorphology optimization and bioactivity enhancement, which shortens the healing period and improves the long-term stability of the bone-implant interface.

[0054] In another embodiment, the implant body 1 is made of medical-grade pure titanium (ASTM Grade 4). Medical-grade pure titanium possesses excellent biocompatibility, corrosion resistance, and a moderate modulus of elasticity, enabling it to maintain stable physicochemical properties in the long-term oral environment. In alternative embodiments, the implant body 1 can be made of any one of titanium alloys (such as Ti-6Al-4V ELI), titanium-zirconium alloys, cobalt-chromium alloys, or zirconia ceramics. When the material is metallic, the implant body 1 can be manufactured by CNC machining or metal additive manufacturing (such as selective laser melting); when the material is zirconia ceramic, the implant body 1 is shaped using computer-aided design and computer-aided manufacturing (CAD / CAM). Zirconia ceramic implants have a color and aesthetic effect similar to natural teeth, making them suitable for patients with high aesthetic requirements.

[0055] Reference Figures 5 to 9 The present invention also provides a biomimetic multi-rooted molar implant assembly system, which includes the biomimetic multi-rooted molar implant, abutment 2, central screw 3 and restorative crown as described in any of the above embodiments.

[0056] like Figures 6 to 8As shown, the abutment 2 includes a lower root insertion end 21, a middle transgingival segment 22, and an upper coronal end 23. A central through-hole 24 extends axially through the interior of the abutment 2. The outer surface of the root insertion end 21 has a non-circular anti-rotation mating surface 25 that matches the anti-rotation structure 151 within the implant abutment connection hole 15. The number of anti-rotation mating surfaces 25 can be 2 to 8. In this embodiment, the anti-rotation mating surfaces 25 are six planes that mate with the internal hexagonal anti-rotation structure 151 within the abutment connection hole 15. After the root insertion end 21 is inserted into the implant abutment connection hole 15, the anti-rotation mating surfaces 25 and each surface of the anti-rotation structure 151 fit together, forming a reliable anti-rotation connection. In some embodiments, the outer surface of the root insertion end 21 also has a tapered surface that matches the tapered mating section of the abutment connection hole 15. When the root insertion end 21 is fully inserted into the abutment connection hole 15, a cold welding effect is formed between the tapered mating surfaces under the action of pre-tightening torque, eliminating the micro-movement gap between the abutment 2 and the implant.

[0057] The transgingival segment 22 is located between the root insertion end 21 and the coronal end 23, and is the part of the abutment 2 that penetrates the gingival soft tissue. The outer contour of the transgingival segment 22 is conical or concave arc-shaped. This design facilitates the natural fit and closure of the gingival tissue on the surface of the transgingival segment 22, forming a good soft tissue cuff and preventing oral bacteria from invading the bone tissue along the implant-abutment interface. The outer surface of the transgingival segment 22 is polished, and its surface roughness is lower than that of the implant intraosseous segment. The smooth surface of the transgingival segment 22 can effectively reduce plaque adhesion and accumulation in this area, maintaining the health of the soft tissue around the implant.

[0058] The coronal end 23 is located at the top of the abutment 2 and is used to connect to the restorative crown. The shape of the coronal end 23 can be designed according to the retention method of the restorative crown: when the restorative crown is a screw-retained crown, the coronal end 23 is provided with a screw channel; when the restorative crown is an adhesive-retained crown, the outer surface of the coronal end 23 is roughened to enhance the bonding force with the adhesive.

[0059] like Figure 9 As shown, the central screw 3 includes a screw portion 31 and a nut portion 32. The outer surface of the screw portion 31 is provided with an external thread, which matches the internal thread 152 at the bottom of the implant abutment connection hole 15. The process of using the central screw 3 is as follows: the root insertion end 21 of the abutment 2 is inserted into the abutment connection hole 15 of the implant, and then the central screw 3 passes through the central through hole 24 from the coronal end 23 of the abutment 2, with the screw portion 31 entering the bottom of the abutment connection hole 15 and engaging with the internal thread 152. A specified preload torque (e.g., 15 N·cm to 35 N·cm) is applied by a screwing tool, and the nut portion 32 presses down on the shoulder of the central through hole 24 of the abutment 2, pressing and fixing the abutment 2 axially onto the implant.

[0060] The restorative crown is attached to the coronal end 23 of the abutment 2. The occlusal surface morphology of the restorative crown corresponds to the occlusal anatomy of the natural molar, restoring the chewing function and occlusal relationship of the missing molar. The restorative crown can be a screw-retained crown or a cement-retained crown.

[0061] The beneficial effects of the above-described assembly system embodiment are as follows: the four components of the implant, abutment, central screw and restorative crown are precisely assembled through multiple connection mechanisms such as anti-rotation fit, thread locking and cold welding effect. The entire system has excellent connection stability and fatigue resistance under long-term masticatory load, reducing the risk of clinical complications such as abutment loosening and screw breakage.

[0062] This invention also provides a method for manufacturing the above-mentioned biomimetic multi-root molar implant, comprising the following steps.

[0063] First, imaging data of the patient's edentulous area was acquired. Cone-beam computed tomography (CBCT) was used to scan the area of ​​the missing molars to obtain three-dimensional imaging data of the alveolar bone. The image data was then processed using 3D reconstruction software to analyze the height, width, and bone density parameters of the alveolar bone.

[0064] Then, based on the image data, a three-dimensional model of the implant is constructed in computer-aided design software. The overall structure of the three-dimensional model meets the technical requirements of the implant described above, while personalized parameters are set according to the specific morphology of the patient's alveolar bone. These personalized parameters include the number of bionic roots 14 (two or three roots), the bifurcation angle between each bionic root 14, the bending direction of the hook structure (outward, inward, or staggered arrangement), and the bending angle of the hook structure (specific values ​​within the range of 15° to 160°). During the design process, finite element analysis is used to simulate the stress distribution of the implant under simulated masticatory loads, optimizing the angle and direction of the hook structure to achieve optimal pull-out resistance under the patient's bone conditions.

[0065] Next, based on the 3D model data, implant blanks are manufactured using CNC machining or metal additive manufacturing processes. When using CNC machining, medical-grade pure titanium or titanium alloy rods are clamped on a five-axis machining center and shaped through milling, turning, and other processes. When using metal additive manufacturing, selective laser melting, electron beam melting, or selective laser-area melting processes can be selected to deposit metal powder layer by layer. Metal additive manufacturing is particularly suitable for manufacturing biomimetic implants with complex hook shapes, enabling the one-piece molding of biomimetic tooth roots with hook structures, avoiding the complex spatial surface machining problems that are difficult to achieve with traditional machining.

[0066] Next, the outer surface of the implant blank undergoes surface activation treatment. Surface activation treatment may include sandblasting and acid etching the top surface of the cervical plateau region 11 to form a rough osseointegration surface, and forming a bioactive coating on the outer surface of the bionic tooth root 14 and the surface of the interroot space using magnetron sputtering or plasma spraying. In some embodiments, microgrooves may also be machined on the inner wall surface of the osseointegration space between the bionic tooth roots 14 before surface activation treatment.

[0067] Finally, the implants are ultrasonically cleaned to remove processing residues, dried, and then aseptically packaged. They are then sterilized using gamma rays or ethylene oxide to obtain sterile implants.

[0068] The beneficial effects of the above manufacturing method embodiments are as follows: by combining personalized computer-aided design based on patient image data with digital manufacturing, precise personalized customization of biomimetic multi-root molar implants is achieved, so that the three-dimensional shape of the implant is highly matched with the anatomical shape of the patient's alveolar bone, thereby improving the accuracy of the implantation surgery and the initial stability of the implant.

[0069] The biomimetic multi-rooted molar implant and system provided by this invention have the following comprehensive beneficial effects: First, through the three-segment biomimetic structural design of the cervical plateau region, the root bifurcation transition region, and the multi-root region, the overall shape of the implant highly simulates the multi-root bifurcation anatomical characteristics of natural molars. This allows for effective implantation by fully utilizing existing bone volume in posterior molar loss scenarios where bone height is limited but bone width is ample, thus expanding the clinical indications for implant restoration. Second, through the mechanical locking relationship between the hook structure at the distal or mid-segment of the biomimetic root and the bone tissue, the implant provides axial pull-out resistance far exceeding that of traditional cylindrical implants. The various arrangements of the hook structure (clockwise, counterclockwise, inward, staggered) can also provide additional anti-removal effects such as rotational self-locking and central clamping according to different clinical needs. Third, through the bone cap locking mechanism of the wide top surface of the cervical plateau region and the mechanical locking mechanism of the root-square hook structure, a crown-root dual anti-removal system is formed, preventing the implant from falling out. The implant provides anti-extraction protection in both the coronal and apical directions, significantly improving its overall pull-out resistance and long-term stability. Fourth, the osseointegration gap between the biomimetic tooth roots provides an ideal spatial channel for bone ingrowth, and the three-dimensional bone anchoring effect formed after bone bridging gives the implant multi-dimensional retention force similar to that of natural molars. Fifth, through multi-level surface treatment strategies and bioactive coating design, osseointegration is synergistically promoted from two dimensions: micro-morphology optimization and enhanced biochemical activity, shortening the healing period and improving the long-term stability of the bone-implant interface. Sixth, the components of the assembly system achieve precise assembly through multiple connection mechanisms such as anti-rotation fit, thread locking, and cold welding effect, exhibiting excellent connection stability under long-term chewing loads. Seventh, the manufacturing method is based on personalized computer-aided design and digital manufacturing using patient imaging data, achieving precise matching of implant morphology with patient bone anatomy and efficient customized production.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0071] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0072] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A bionic multi-root molar implant, characterized in that, include: The implant body (1) includes, from top to bottom, a cervical plateau region (11), a root bifurcation transition region (12), and a multi-root region (13). The top surface of the neck platform area (11) is a wide plane, and its cross-sectional area is larger than the overall cross-sectional area of ​​the multi-root area (13); the neck platform area (11) is provided with a base connection hole (15), the base connection hole (15) is provided with an anti-rotation structure (151) for forming an anti-rotation fit with the base; the bottom of the base connection hole (15) is provided with an internal thread (152) for screwing and fixing the base with a screw; The multi-rooted region (13) includes at least two bionic roots (14) circumferentially distributed around the central axis of the implant body (1). Each of the bionic tooth roots (14) has a hook structure at its end or middle, which bends outward or inward along a direction parallel to the central axis of the implant body (1) to provide a mechanical locking force against pullout after implantation into the alveolar bone.

2. The bionic multi-root molar implant according to claim 1, characterized in that, The bending direction of the hook structures on each of the bionic tooth roots (14) is the same, and they are arranged clockwise or counterclockwise in the circumferential section around the central axis of the implant body (1), so that the hook structures together form a rotational self-locking effect after osseointegration.

3. The bionic multi-root molar implant according to claim 1, characterized in that, At least some of the hook structures are bent toward the central axis of the implant body (1), so that each hook structure clamps the surrounding bone tissue toward the center of the implant after osseointegration, thereby enhancing the anti-dislodgement locking force.

4. The bionic multi-thread molar implant of claim 1, wherein, The bending directions of the hook structures of each of the bionic tooth roots (14) are partially the same and partially opposite, forming an alternating arrangement.

5. The bionic multi-root molar implant according to any one of claims 1 to 4, characterized in that, The hook angle between the hook structure and the corresponding bionic tooth root (14) is 15° to 160°, and the free end of the hook structure is rounded.

6. The biomimetic multi-root molar implant according to claim 1, characterized in that, The number of the bionic tooth roots (14) is three. The three bionic tooth roots (14) are evenly distributed at 120° around the central axis of the implant body (1) to simulate the anatomical morphology of the three roots of the maxillary molar. Osteointegration gaps are formed between each bionic tooth root (14) to allow bone tissue to grow in and form a three-dimensional bone anchor. and / or The number of the bionic tooth roots (14) is two, and the two bionic tooth roots (14) are symmetrically distributed along the mesiodistal direction of the implant body (1) to simulate the double-root anatomical morphology of the mandibular molar.

7. The bionic multi-thread molar implant of claim 1, wherein, The outer peripheral surface of the root bifurcation transition area (12) gradually expands outward from top to bottom to form an arc-shaped outward transition surface, so that the outer contour of the cervical plateau area (11) to the multi-root area (13) is waisted-outward in the sagittal section, and forms a surface contact with the cortical bone after implantation, thereby improving initial stability.

8. The bionic multi-thread molar implant of claim 1, wherein, The cross-sectional profile of the top surface of the cervical plateau region (11) corresponds to the anatomical profile of the corresponding molar occlusal surface. The profile is any one of rounded rectangle, ellipse, circle or waist drum shape. The maximum crown diameter of the cervical plateau region (11) is greater than the maximum bifurcation outer diameter of the multi-root region (13), so that the implant as a whole presents a biomimetic molar shape that is wider at the top and bifurcation at the bottom.

9. The bionic multi-thread molar implant of claim 1, wherein, The outer periphery of the top surface of the cervical plateau region (11) is provided with a platform shoulder. After the implant is inserted, the platform shoulder is flush with or slightly lower than the top surface of the alveolar bone. It is used to support the autologous bone powder or bone substitute material covering the top surface during the implantation procedure. The bone cap formed after bone healing locks the top surface of the cervical plateau region (11) into the bone, forming a top surface bone locking anti-dislodgement mechanism. and / or The top surface of the cervical plateau region (11) is a rough bone-bonding surface, which is used to cover autologous bone powder after implantation, so that the bone powder fills the space between the wide plane and the alveolar bone, and a bony holding structure is formed after bone healing. and / or The overall axial height of the implant body (1) is 4 mm to 12 mm to be suitable for areas of molar loss with insufficient alveolar bone height; wherein the axial height of the multi-rooted area (13) is not less than one-third of the overall axial height and not less than 2 mm, to ensure that the hook structure has sufficient anchoring depth when implanted into the cancellous bone layer.

10. A bionic multi-root molar implant assembly system, characterized in that, include: The biomimetic multi-root molar implant according to any one of claims 1 to 9; The abutment (2) has a root insertion end that forms an anti-rotation fit with the abutment connection hole (15) of the implant. The central screw (3) passes through the central through hole of the base (2) and engages with the internal thread (152) at the bottom of the base connecting hole (15) to lock and fix the base (2) onto the implant. The restorative crown is connected to the coronal end of the abutment (2), and its occlusal surface morphology corresponds to the occlusal surface of the natural molar.

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