Personalized multipurpose rigid connecting rod

Abstract

The invention relates to the technical field of edentulous jaw implantation repair, in particular to a personalized multipurpose rigid connecting rod which comprises a main body structure integrally formed by a plurality of connecting rod sections, a plurality of through type positioning cavities formed between the connecting rod sections and functional interfaces. The through-type positioning cavity and the functional interface are through-type cavities with the same shape, and the main body structure is obtained based on preoperative three-dimensional data fusion modeling of a patient. On the basis of integrated arrangement of a single digital model and integral forming, a rigid geometric constraint relation (such as coplane, coaxial and distance correlation) is established for the through type positioning cavity and the functional interface in the modeling stage for the first time, so that the through type positioning cavity and the functional interface are converted into an organic whole with logic coupling and function cooperation from independent parts which exist in parallel physically; therefore, the core problems of assembly error accumulation, weak interface strength, non-reproducible spatial relationship and the like of a traditional splicing type, adhesive type or segmented printing connecting rod are solved.

Description

Technical Field

[0001] This invention relates to the field of edentulous jaw implant restoration technology, and more specifically to a personalized, multi-purpose rigid connecting rod. Background Technology

[0002] In the field of edentulous implant restoration, achieving good passive placement of the prosthesis is a prerequisite for ensuring long-term clinical stability and reducing the risk of mechanical and biological complications. The realization of passive placement highly depends on the high-fidelity reproduction of the patient's intraoral anatomy and functional information by the extraoral working model. To achieve this goal, the current clinical practice generally adopts the windowed splint impression technique: multiple implant transfer devices or temporary abutments are rigidly connected intraorally using self-curing acrylic resin material to lock the relative spatial relationship between multiple implants. Then, impression material is poured around the connection structure to complete the overall impression, and an extraoral model is formed by plaster casting, which is used by doctors and technicians to design and fabricate prostheses. In addition, some solutions use pre-formed standardized rigid connecting rods (such as utility model patent 201922028563.2 and invention patent 201911148991.7) to assist in impression taking. Some can also obtain occlusal records simultaneously or serve as a reinforcing structure for transitional dentures, which improves the efficiency and reliability of the impression to a certain extent. However, existing technologies have the following limitations: Firstly, both traditional resin splints and prefabricated connecting rods are general-purpose or semi-customized devices. Their geometric configurations do not establish a data-driven mapping relationship with the individual patient's implant spatial distribution and final repair goals. This often requires intraoral adjustment of the connecting rods or reliance on a large amount of self-curing material for shaping and fixation during clinical use. This not only prolongs the operation time and increases patient discomfort, but also causes micron-level deformation due to material polymerization shrinkage, resulting in distortion of implant position information transmission. Secondly, the functional units of the existing connecting devices (such as the positioning structure for fitting the abutment, the interface for docking the guide plate, and the platform for carrying occlusal recording) are designed, manufactured, and assembled independently, lacking a spatial constraint mechanism set in the modeling stage. This makes it impossible for the functional components to form a collaborative positioning relationship, making it difficult to stably support multiple uses such as surgical guidance, impression connection, and denture reinforcement in a single structure. Third, due to limitations in manufacturing processes, most connecting rods are formed by segmented casting, welding, bonding, or mechanical assembly, resulting in problems such as stress concentration, weak strength, and dimensional drift at the connection interface. Especially after being embedded in a transitional denture, they are prone to fracture due to the mechanical discontinuity between multiple structural segments. Summary of the Invention

[0003] This invention relates to a personalized, multi-purpose rigid connecting rod, aiming to solve the technical problems in existing edentulous implant restorations caused by fragmented connecting device structures, discrete manufacturing methods, and separate functional units, resulting in insufficient impression accuracy, cumbersome clinical procedures, long time-consuming multiple visits, and the inability to simultaneously achieve integrated surgical guidance, precise impression taking, and transitional denture enhancement. By fusing and modeling based on the patient's preoperative 3D data, a single digital model is constructed. Within this model, multiple connecting rod segments, through-type positioning cavities, and functional interfaces are designed as continuous topological entities with preset geometric constraints. These are then integrally formed in one step using 3D printing or CNC machining, creating a continuous metal structure without welding, bonding, or secondary processing. This fundamentally ensures high-fidelity transmission of implant spatial relationships and multi-functional synergy.

[0004] To achieve the above objectives, the present invention specifically adopts the following technical solution: A personalized multi-purpose rigid connecting rod includes a main structure, which is integrally composed of multiple connecting rod segments and multiple through-type positioning cavities and functional interfaces disposed between each connecting rod segment. The through-type positioning cavities and functional interfaces are through-type cavities with the same shape. The main structure is a single digital model obtained by fusing and modeling the patient's preoperative three-dimensional data, and designed in reverse according to the actual spatial distribution of implants in the oral cavity and the final restoration goal. In the digital model, each through-type positioning cavity and at least one functional interface have a preset geometric constraint relationship in terms of spatial position, axial angle, or reference plane, so that the same through-type cavity can be used as a positioning cavity for implant abutment, a guiding interface for surgical guide, a bearing surface for occlusion recording, or a reinforcing anchor point for transitional dentures at different clinical stages by changing the mating parts or adjusting the usage method, and can synergistically achieve at least two of the following functions: implant spatial positioning, surgical guidance, impression support, occlusion recording, or transitional dentures. The main structure is formed in one piece by biocompatible metal material through 3D printing or CNC cutting process, forming a continuous metal structure without welding, bonding, or secondary processing. Preferably, the preset geometric constraint relationship includes at least one of the following: coplanar relationship, coaxial relationship, parallel relationship, perpendicular relationship, or distance relationship; Preferably, the functional interface includes at least one of the following: guide plate fitting groove, implant cavity preparation guide cavity, temporary abutment positioning boss, occlusion recording platform, or transitional denture embedding reinforcement end; Preferably, the inner contour of the through-type positioning cavity is geometrically matched with the outer contour of the corresponding implant repair abutment or transfer rod or implant placement tool (drill bit shape), which is used to fit and limit a single implant accessory and to facilitate the use of a simple guide plate to guide implant preparation and placement. Preferably, the preoperative three-dimensional data includes CBCT data, intraoral scan data, and facial scan data. The three are spatially registered through anatomical landmarks to form a fusion model in a unified coordinate system. Preferably, the 3D printing process is selective laser melting, and the CNC cutting process is five-axis linkage precision machining; Preferably, the biocompatible metallic material is pure titanium or titanium alloy, conforming to ASTM F67 or ASTM F136 standards. Preferably, the main structure is configured to function as a guide plate component during implant surgery, to be immediately connected to the prosthetic abutment after surgery as an impression support framework, and to serve as an internal reinforcement structure for the transitional denture. Preferably, the number of the through-type positioning cavities is 2–12, corresponding to the connection requirements of 2–12 implants; Preferably, the relative positional relationship between the functional interface and the adjacent through-type positioning cavity is defined in the digital model through a parameterized driving method, so that when the position of any positioning cavity is adjusted, the associated functional interface is automatically updated synchronously. Preferably, the connecting rod segments of the main structure are arranged in an arc shape along the curvature of the dental arch, and the line connecting the centers of each through-type positioning cavity fits the midline of the patient's dental arch; Preferably, the edge of the through-type positioning cavity is provided with a rounded or chamfered structure to reduce stress concentration and adapt to the soft tissue morphology; Preferably, the main structure is not subjected to any mechanical trimming, drilling, tapping or surface coating treatment after integral forming, so as to maintain the structural integrity and dimensional accuracy of the original manufacturing state; Preferably, the inner surface of the through-type positioning cavity is provided with a groove to facilitate a more stable bonding with the impression material or restoration material.

[0005] The beneficial effects of this invention are as follows: This invention, through an integrated design based on a single digital model and overall forming, establishes rigid geometric constraints (such as coplanarity, coaxiality, and distance correlation) between the through-type positioning cavity and functional interface for the first time during the modeling stage. This transforms the two from physically parallel independent components into a logically coupled and functionally coordinated organic whole, thereby solving the core problems of traditional assembled, glued, or segmented printed connecting rods, such as the accumulation of assembly errors, weak interface strength, and unreproducible spatial relationships. This significantly improves the accuracy and stability of the transmission of implant spatial position information. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a schematic diagram of CBCT data of a patient according to an embodiment of the present invention; Figure 3 This is a schematic diagram of intraoral scanning data according to an embodiment of the present invention; Figure 4 This is a schematic diagram of an embodiment of the present invention; Figure 5 This is a schematic diagram of the ideal implantation site and axial structure of the implant according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the integrated digital model according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the main structure forming structure according to an embodiment of the present invention; Figure 8 A schematic diagram of the three-dimensional model of the main structure in an embodiment of the present invention.

[0007] Reference numerals: 1. Main structure; 11. Connecting rod segment; 12. Through-type positioning cavity; 13. Functional interface. Detailed Implementation

[0008] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. The components of this invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this invention, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0009] Currently, the connecting devices used in clinical practice for edentulous multi-implant restorations generally adopt universal prefabricated rods or on-site resin splint structures. Although these devices can achieve basic spatial connection functions, their structure lacks data correlation with the patient's individual anatomy and restoration goals. Each functional unit (such as positioning cavity, guide plate interface, and occlusal platform) exists independently and is not constrained by each other. In terms of manufacturing, they mostly rely on segmented casting, welding, or gluing, resulting in low interface strength and poor dimensional repeatability. Especially when it needs to be embedded in a transitional denture, the spliced ​​structure is prone to becoming the stress fracture point. These problems make it difficult for existing connecting rods to meet the triple requirements of high-precision positioning, surgical collaborative guidance, and long-term mechanical stability. Therefore, the present invention provides a personalized, multi-purpose rigid connecting rod, referring to... Figure 1As shown, it includes a main structure, which is integrally composed of multiple connecting rod segments and multiple through-type positioning cavities and functional interfaces arranged between each connecting rod segment. The through-type positioning cavities and functional interfaces are through-type cavities with the same shape. The main structure is a single digital model obtained by fusing and modeling the patient's preoperative three-dimensional data, and designed in reverse according to the actual spatial distribution of implants in the oral cavity and the final restoration goal. In the digital model, each through-type positioning cavity and at least one functional interface have a preset geometric constraint relationship in terms of spatial position, axial angle, or reference plane, so that the same through-type cavity can be used as a positioning cavity for implant abutment, a guiding interface for surgical guide, a bearing surface for occlusion recording, or a reinforcing anchor point for transitional dentures at different clinical stages by changing the mating parts or adjusting the usage method, and can synergistically achieve at least two of the following functions: implant spatial positioning, surgical guidance, impression support, occlusion recording, or transitional dentures. The main structure is formed in one piece by biocompatible metal material through 3D printing or CNC cutting process, forming a continuous metal structure without welding, bonding, or secondary processing. Example: The above-mentioned main structure is constructed by importing the patient's CBCT data (DICOM format) into 3D modeling software (such as Exocad DentalCAD ​​or 3ShapeImplant Studio). Figure 2 As shown), intraoral scan data (STL format, Figure 3 (as shown) and facial scan data (OBJ format, Figure 4 As shown), spatial registration of the three-source data was completed using stable bony landmarks such as the nasal base, chin point, or zygomatic arch, with the error controlled within 0.1 mm. Under a unified coordinate system, the ideal implantation site and axis were derived in reverse based on the pre-set arrangement of the prosthetic dentition, the occlusal plane, and the gingival margin contour. Figure 5 As shown), this generates an integrated digital model containing multiple connecting rod segments, a through-type positioning cavity, and functional interfaces. Figure 6 The central axis of each positioning cavity strictly corresponds to the long axis of the implant. Each functional interface (such as the front guide plate groove, the middle occlusal platform, and the end reinforcement) is subject to parametric constraints such as coplanarity, coaxiality, or distance-driven relationships with its adjacent positioning cavities to ensure synchronized response during model updates. After Boolean operations and surface smoothing, the model is exported as an STL file. Figure 8 As shown), the integral forming is performed by laser selective melting equipment or a five-axis machining center; after forming, no mechanical finishing, drilling, or surface coating treatment is performed, maintaining the structural integrity of the original manufacturing state, such as... Figure 7 As shown; in practical applications, the modeling software can also be selected from other commercial platforms with multimodal registration and parametric modeling capabilities, and the embodiments of the present invention do not limit this.

[0010] The working principle of this implementation method is as follows: starting from the repair target, a unified digital space is constructed through the fusion of multi-source data. In this space, the originally separate functional structures (positioning cavities, interfaces) are defined as a topological whole governed by the same set of geometric constraints. This allows the physical manufacturing results to naturally carry the collaborative logic in the design intent. For example, when a positioning cavity needs to be adjusted axially due to bone volume limitations, the guide plate slot bound to it automatically deflects synchronously to ensure consistency of intraoperative guidance. Another example is that the occlusal platform plane always remains parallel to the occlusal plane that fits the axes of multiple positioning cavities, ensuring accurate acquisition of occlusal relationships when taking impressions. The entire process eliminates the traditional fragmented mode of "building the structure first and then adding the function". By adopting this specific implementation method, a closed-loop control of the entire link from the data source to the physical entity is realized, which fundamentally avoids the problems of assembly error accumulation and functional disconnection, significantly improves the fidelity of implant spatial information transmission and the reliability of multi-functional integration, and provides core tool support for high-precision, high-efficiency and highly adaptable digital implant restoration.

[0011] In the existing technology, the functional interface of the connecting rod is often an additional structure added later, such as drilling and tapping holes in the formed rod body, bonding bosses or manually welding slots, which leads to problems such as positioning deviation between the interface and the main body, insufficient bonding strength and performance degradation of the heat-affected zone, and cannot meet the micron-level repeatability accuracy required for surgical guide plate fitting or occlusion recording. The preset geometric constraints include at least one of the following: coplanar, coaxial, parallel, perpendicular, or distance-related relationships. During the digital modeling phase, corresponding constraint types are set for different clinical applications: for example, the bottom surface of the front fitting groove used for embedding the surgical guide is set as a coplanar constraint (tolerance ±0.01 mm) with the reference plane defined by the axes of the first and third positioning cavities; the central normal vector of the middle platform used for occlusal recording is set as a coaxial constraint (deviation ≤0.3°) with the average direction of the axes of the second, fourth, and sixth positioning cavities; the mounting surface of the end reinforcement end used for embedding transitional dentures is set as a perpendicular constraint (angle 90° ±0.1°) with the axis of the adjacent positioning cavity; and the distance from the center of the guide groove to the center of the first positioning cavity is set as a parameterized driving variable, automatically updated as the implant spacing changes. All constraints are implemented in the modeling software using reference planes, reference axes, measurement dimensions, and relationships (such as "D = L × 0.85", where L is the center distance between the two cavities). In practical applications, this constraint type can also be combined according to specific functional requirements, and the embodiments of the present invention do not limit this; The working principle of this constraint mechanism is to transform the spatial relationship between the functional interface and the positioning cavity from "manual assembly result" to "mathematically defined attribute", so that the two form an inseparable geometric couple at the model level, ensuring that the manufacturing output is completely consistent with the design intent.

[0012] By adopting this specific implementation method, a strict geometric correlation between the functional interface and the positioning cavity is ensured, the guide plate fitting repeatability reaches ±0.02 mm, the occlusal platform flatness is better than 0.03 mm, and the accuracy of surgical guidance and the reliability of synchronous impression acquisition are significantly improved.

[0013] Currently, the functional interfaces used in clinical practice are diverse, but most are general structures that lack deep matching with specific implantation systems and repair procedures, resulting in unstable placement, easy loosening, or poor compatibility, which affects the functional performance. The functional interface includes at least one of the following: a guide plate fitting groove, an implant cavity preparation guide cavity, a temporary abutment positioning boss, an occlusion recording platform, or a transitional denture embedding reinforcement end; the guide plate fitting groove is a U-shaped through-slot structure for inserting a guide pin into the guide plate; the temporary abutment positioning boss is a Φ3.5 mm cylinder with a height of 3-4 mm; all the above structures are directly constructed in the digital model, and the aforementioned geometric constraints are established with the adjacent positioning cavity; in practical applications, other structures adapted to different brands or uses can also be selected for this functional interface form, and the embodiments of the present invention do not limit this; The working principle of this functional interface structure is to provide a standardized, verifiable, and easily identifiable physical interaction interface based on the core needs of different clinical stages. This allows the same connecting rod to perform guide plate coordination, occlusion acquisition, temporary retention, and denture enhancement functions at different stages, completing the entire process without changing instruments. By adopting this specific implementation method, the connecting rod can be reused throughout the entire cycle of implantation, restoration, and denture fabrication, reducing the frequency of instrument switching and sources of operational error, and improving the continuity of clinical procedures and the predictability of treatment.

[0014] The inner contour of the through-type positioning cavity is geometrically matched with the outer contour of the corresponding implant restoration abutment or transfer rod or implant placement tool (drill bit shape), which is used to fit and limit a single implant accessory and to facilitate the preparation and placement of the implant as a simple guide plate; the positioning cavity is a through-type internal cavity structure, and its inner contour is accurately modeled according to the target implant system standard; in practical applications, the inner contour can also be customized according to the specifications of other implant systems, and the embodiments of the present invention do not limit this.

[0015] The working principle of this positioning cavity structure is to accurately replicate the interface standard of the implantation system and build a native matching cavity on the connecting rod body, so that after the abutment is inserted, a rigid connection with zero gap, zero rotation, and zero axial movement is achieved, thereby truly reflecting the spatial posture of the implant. By adopting this specific implementation method, a high-precision and highly repeatable connection between each implant and the connecting rod is ensured, providing a reliable spatial reference for subsequent impression making and passive positioning.

[0016] In existing technologies, preoperative 3D data is often used in isolation—CBCT is used only for bone analysis, intraoral scans are used only for dental arch modeling, and facial scans are used only for aesthetic evaluation. There is a lack of collaborative modeling foundation under a unified coordinate system, which leads to design results deviating from real clinical conditions. The preoperative three-dimensional data includes CBCT data, intraoral scan data, and facial scan data. These three data are spatially registered using anatomical landmarks to form a fusion model in a unified coordinate system. Specifically, the CBCT data is first reconstructed into a three-dimensional model of the jawbone, identifying and marking the nasal floor point, mental point, and the highest points of the bilateral zygomatic arches. Secondly, the intraoral scan data is used to generate STL models of teeth and alveolar ridges, extracting the gingival margin and occlusal plane. Thirdly, the facial scan data is used to construct a facial contour model, locating the line connecting the pupils and the midpoint of the vermilion border. The three sets of data are automatically registered in Exocad software with the nasal floor point as the origin, the Frankfort plane as the XY reference, and the sagittal midline as the X-axis. After registration, the residual root mean square is controlled within 0.08 mm through algorithm optimization. The fusion model serves as the sole data source for all subsequent structural designs. In practical applications, this registration method can also utilize other software platforms with multimodal fusion capabilities; this embodiment of the invention does not limit this approach. The working principle of this data fusion method is to construct a full-dimensional digital twin covering "bone-soft tissue-face", so that the design of the connecting rods not only meets anatomical feasibility, but also fits functional and aesthetic goals, truly realizing reverse planning "starting with the end in mind". By adopting this specific implementation method, the spatial layout of the connecting rod is highly consistent with the patient's actual physiological structure, which significantly improves the accuracy of surgical implantation and the final placement quality of the prosthesis.

[0017] Traditional metal connecting rods are mostly manufactured by casting or machining, which makes it difficult to achieve integrated molding of complex curved surfaces and thin-walled structures. In addition, the surface is rough and the dimensions fluctuate greatly, which cannot meet the clinical requirements of precision oral components. The 3D printing process is laser selective melting, and the CNC cutting process is five-axis linkage precision machining. In practical applications, the manufacturing equipment can also be selected from other additive or subtractive systems with the same precision and material adaptability. This embodiment of the invention does not limit this. The working principle of this manufacturing process is to rely on high-precision digital manufacturing methods to restore complex topological structures (such as arc-shaped rod segments, irregularly shaped positioning cavities, and micro-functional interfaces) into physical entities in one go, avoiding the cumulative errors caused by multiple clamping, tool changing, and thermal deformation in traditional processes. By adopting this specific implementation method, the geometric fidelity and mechanical uniformity of the overall structure of the connecting rod are guaranteed, providing a reliable hardware foundation for high-precision clinical applications.

[0018] The selection of materials for existing connecting rods is rather arbitrary, with some using stainless steel or ordinary titanium alloys. This results in problems such as insufficient biocompatibility, excessively high elastic modulus, or low fatigue strength, affecting the safety and stability of long-term intraoral use. Therefore, the biocompatible metal material described in this invention is pure titanium or titanium alloy. In practical applications, other medical metals that meet medical standards can also be selected, and this invention does not limit this choice. The working principle of this material selection is based on medical-grade titanium-based material that has been clinically proven over a long period of time, taking into account biosafety, mechanical compatibility and processing feasibility, to ensure long-term stable use of the connecting rod in complex oral environments.

[0019] Existing connecting rods are mostly single-function designs, such as only used for mold taking or only used for guide plates, and cannot be reused in different clinical stages, resulting in a wide variety of instruments, high management costs, and poor operational coordination. Therefore, the main structure described in this invention is configured to function as a guide plate component during implant surgery (the connecting rod itself can also serve as a simple implant guide plate or as a guide plate component in conjunction with a full-length guide plate). Immediately after surgery, it is connected to the prosthesis abutment as an impression support framework and as an internal reinforcement structure for the transitional denture. During surgery, the connecting rod's front end slot is inserted into the guide plate guide pin, and its positioning cavity axis serves as the drill guide path. Immediately after surgery, the connecting rod is fitted onto the installed multi-base prosthesis abutment, fixed with a small amount of acrylic resin, and then combined with polyether impression material to complete the overall impression. In the laboratory, the connecting rod, along with the implant position information on the plaster model, is transferred to the temporary abutment, and after being embedded and cured with PMMA resin, it becomes the internal reinforcement framework of the transitional denture. Throughout the process, the connecting rods maintain the same spatial configuration and functional positioning. In practical applications, this multi-stage configuration can also be flexibly adjusted in conjunction with other clinical pathways, and this embodiment of the invention does not limit this.

[0020] The working principle of this multi-stage configuration is to define the connecting rod as a "digital-physical" anchor point that runs through the entire planting process, so that it serves as the same spatial reference carrier at different stages, achieving seamless information flow and natural functional extension; This specific implementation method significantly simplifies the clinical operation chain, reduces the number of instrument replacements and repositioning attempts, and improves treatment efficiency and repair consistency.

[0021] In clinical practice, the number of implants varies greatly, ranging from immediate restoration of 2 anterior teeth to full mouth 12 implants. However, universal connecting rods are difficult to cover the entire span and arrangement, and often need to be used in combination or temporarily modified. Therefore, the number of through-type positioning cavities described in this invention is 2–12, corresponding to the connection requirements of 2–12 implants; for restoration of 2–4 anterior teeth, a short-span structure (total length 25–35 mm) is adopted, containing 2–4 positioning cavities with a slight arc shape; for restoration of 6–8 posterior teeth, a mid-span structure (total length 45–55 mm) is adopted, containing 6–8 positioning cavities with a moderate curvature; for restoration of edentulous jaws, a long-span structure (total length 65–80 mm) is adopted, containing 10–12 positioning cavities, naturally curving along the dental arch; all structures are modeled according to the individual dental arch curvature, and the cavity spacing is dynamically set according to the implant center distance measured by CBCT (range 5–30 mm); in practical applications, this number and arrangement can be expanded or simplified according to specific cases, and this embodiment of the invention does not limit this; The working principle of this quantity configuration is based on the implant distribution density and dental arch geometry, providing modular coverage capabilities to ensure that cases of varying complexity can obtain structurally matched and mechanically balanced connection solutions; By adopting this specific implementation method, the clinical applicability of the connecting rod is expanded, enabling it to stably serve the full spectrum of needs, from local immediate repair to complete oral function reconstruction.

[0022] In existing connecting rods, each functional unit is often created and edited independently during the modeling process. This results in the inability of other related structures to respond automatically when one structure is modified, leading to low design iteration efficiency and susceptibility to human error. In this invention, the relative positional relationship between the functional interface and the adjacent through-type positioning cavity is defined in the digital model through a parametric driving method, so that when the position of any positioning cavity is adjusted, the associated functional interface is automatically updated synchronously. In practical applications, this parametric modeling method can also use other CAD platforms that support variable-driven operation, and this embodiment of the invention does not limit this. The working principle of this parameterized drive is to transform the spatial logic between structures into computable, traceable, and verifiable mathematical relationships, so that design changes have global consistency and process traceability.

[0023] Traditional connecting rods are mostly arranged in straight lines, making it difficult to conform to the actual curvature of the patient's dental arch. This leads to stress concentration in the middle when connecting long spans, affecting overall rigidity and positioning stability. Therefore, in this invention, the connecting rod segments of the main structure are arranged in an arc shape along the curvature of the dental arch. The center line of each through-type positioning cavity is fitted to the patient's dental arch midline. The dental arch midline is generated by weighted averaging of the line connecting the midpoints of the upper and lower dentition, the line connecting the highest points of the gingival margin, and the facial midline in the fusion model. The radius of curvature of the connecting rod segments is dynamically set according to the alveolar ridge curvature measured by CBCT. The center of each positioning cavity strictly falls on this curve with a deviation ≤0.05mm. In practical applications, this curvature arrangement can also be adaptively corrected according to special anatomical morphology (such as severely resorbed alveolar ridges). This embodiment of the invention does not limit this. The working principle of this arc-shaped arrangement is to make the connecting rod body conform to the patient's physiological shape, disperse and transmit the external load along the natural direction of the dental arch, and reduce the local stress peak. By adopting this specific implementation method, the structural stability and wearing comfort of the connecting rod in long-span applications are improved, and the risk of impression distortion caused by bending deformation is reduced. Existing connecting rod positioning cavity edges are mostly right angles or untreated, which can easily scratch soft tissue during placement. Furthermore, right angle structures can easily cause stress concentration, reducing fatigue life. Therefore, the through-type positioning cavity described in this invention has rounded or chamfered edges to reduce stress concentration and adapt to soft tissue morphology. All positioning cavity entrances are equipped with a 0.3 mm radius rounded corner, and the cavity wall transition area uses a gradient chamfer (15° angle, 0.2 mm depth) to ensure smooth abutment insertion without the risk of tissue embedding. In practical applications, other transition forms that meet oral biomechanical requirements can also be selected for this edge treatment method; this embodiment of the invention does not limit this. The working principle of this edge structure is to eliminate stress singularities through geometric optimization and improve human-machine interaction friendliness, balancing functional rigidity and clinical safety. Using this specific implementation method ensures connection rigidity, avoids soft tissue damage and early fatigue crack initiation, and extends the instrument's service life.

[0024] Existing connecting rods often require secondary processing after manufacturing (such as burr removal, drilling, tapping, and spraying), which not only increases the number of processes and costs but may also damage the original forming accuracy and surface integrity, affecting the final performance. Therefore, in this invention, the main structure is not subjected to any mechanical finishing, drilling, tapping, or surface coating treatment after overall forming, maintaining the structural integrity and dimensional accuracy of the original manufacturing state. SLM formed parts are directly packaged and sterilized after heat treatment and vacuum cleaning; cut parts are delivered for use after ultrasonic cleaning and passivation. All key dimensions (such as the inner diameter of the positioning cavity, the depth of the functional interface, and the curvature of the rod) are met in the manufacturing process in one go, without the need for post-processing correction. In practical applications, this "zero post-processing" process can also be combined with other high-precision manufacturing paths, which are not limited in this embodiment of the invention. The working principle of this raw delivery is to move the manufacturing precision control forward to the modeling and process parameter setting stage, so that the final product is exactly what the design requires, eliminating the uncertainty introduced by post-processing; By adopting this specific implementation method, millimeter-level and even micrometer-level consistency between digital models and clinical physical objects is ensured, providing a reliable physical benchmark for high-precision implant restoration.

[0025] To facilitate a more stable bonding with impression materials or prosthetic materials, the inner surface of the through-type positioning cavity described in this invention is provided with a groove.

[0026] In summary, because all structural elements of this invention originate from the same data source, coordinate system, and manufacturing process, the positioning cavity axis is highly consistent with the implant's long axis, and the spatial relationship between the functional interface and adjacent positioning cavities is strictly controlled. This characteristic presents multiple values ​​in clinical applications: it can guide the implant placement direction during surgery, avoiding secondary adjustments due to spatial relationship deviations; it can simultaneously lock the relative positions of multiple abutments and the occlusal plane during impression taking, ensuring the spatial matching of subsequent denture fabrication; in addition, this structure can be directly used as a denture reinforcement framework, truly achieving the goal of "one-time modeling, multiple uses of one model, and integrated delivery"; In terms of clinical benefits, this technology simplifies the operation process, reduces the need for repeated adjustments and multiple visits for patients, reduces the dependence of the treatment process on the doctor's experience, and improves patient comfort and treatment predictability. From the perspective of extended technological value, its parametric-driven modeling and original state delivery process provide full-process data support for subsequent quality traceability, lay a standardized foundation for mass customized production, and provide quantifiable and reusable digital models for AI-assisted design, further expanding the application scenarios and development potential of the technology.

[0027] The present invention also provides a method for using the aforementioned personalized multi-purpose rigid connecting rod, comprising the following steps: 1. Preoperative digital preparation: Collect 3D data of the patient's CBCT (bone information), intraoral scan (soft and hard tissues), and facial scan (aesthetic parameters). Complete spatial registration with the nasal floor / chin point as the reference in Exocad or 3Shape software to build a fusion model in a unified coordinate system. Based on this, design the ideal implant site and axis in reverse and generate a single digital model containing multiple connecting rod segments, through-type positioning cavity and functional interface. Preset geometric constraints (such as coplanarity and coaxiality) are set between all structures. Finally, the implant is formed in one piece in one go by selective laser melting (SLM) or five-axis CNC cutting. There is no welding, no splicing and no secondary processing throughout the process. 2. Guiding application in implantation surgery: Insert the functional interface (such as a U-shaped fitting groove) at the front end of the connecting rod into the guide pin of the special surgical guide plate, and use the central axis of its corresponding positioning cavity as the drill bit guide path to complete the hole preparation and implantation; after the implant is in place, directly fit the connecting rod and fix it with a small amount of resin material to make it an integral rigid structure, that is, to achieve the seamless transformation of "digital design - physical execution"; 3. To facilitate simultaneous postoperative impression taking and occlusion recording: Keep the connecting rod in place, apply occlusion recording material to its pre-designed flat area (such as between the two positioning cavities), and allow the patient to close their mouth naturally for curing; then inject polyether impression material around the connecting rod, and after it has cured, loosen the abutment screws and remove the connecting rod, abutment, and impression material as a whole, obtaining three key types of information at once: implant spatial position, soft tissue morphology, and occlusion relationship; 4. Fabrication of transitional dentures for the dental laboratory: The impression is poured into a plaster model, and the connecting rod is left on the model. The technician directly arranges the teeth based on the center of each positioning cavity to ensure that the dentition is consistent with the preoperative design. Then, the connecting rod and wax pattern are transferred to the PMMA temporary base and hot-pressed to be completely embedded in the upper 1 / 3 area of ​​the base, serving as an internal reinforcing skeleton and significantly improving the denture's fracture resistance.

[0028] The present invention also provides applications of the aforementioned personalized multi-purpose rigid connecting rod, including: All-on-4 (2 tilted implants in the anterior region + 2 vertical implants in the posterior region) / All-on-6 (2 vertical implants in the anterior region added to All-on-4) provides immediate loading restoration, suitable for edentulous patients, especially when there is insufficient bone volume and tilted implantation is required. The connecting rod can be adapted to different brands and tilt angles of implant systems (such as Nobel tilted + Straumann upright). The arc-shaped structure fits the alveolar ridge and supports the teeth to be worn on the same day. Multiple implant restorations in localized areas such as the anterior teeth are performed, relying on facial scanning data to drive the matching of the positioning cavity with the labial-dental relationship. The anterior occlusal platform can simultaneously record the protrusion and lateral jaw relationship, meeting high aesthetic requirements. For safe implantation under complex anatomical conditions, such as high nerve canal and low maxillary sinus floor, CBCT data-driven modeling enables the positioning cavity to actively avoid risk areas axially, and the guide plate interlocking groove is coplanarly constrained with key cavities to ensure the safety of the surgical path. For those who need to wear transitional dentures for a long time, a one-piece molded titanium alloy frame is embedded in PMMA. Accelerated fatigue testing has proven that its fracture resistance life exceeds 12 months, and it eliminates the need for traditional metal framework welding, reducing the risk of deformation and manufacturing costs.

[0029] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A personalized multi-purpose rigid connecting bar, comprising a main structure (1) integrally formed by a plurality of connecting bar segments (11) and a plurality of through-type positioning cavities (12) and functional interfaces (13) arranged between the connecting bar segments, the through-type positioning cavities (12) and the functional interfaces (13) being through-type cavities of the same shape; characterized in that the main structure (1) is a single digital model obtained based on preoperative three-dimensional data fusion modeling of a patient and reverse designed according to the actual spatial distribution of oral implants and the final restoration target; in the digital model, each through-type positioning cavity (12) and at least one functional interface (13) have a preset geometric constraint relationship in spatial position, axial angle or reference plane, so that the same through-type cavity can be used as a positioning cavity of an implant abutment, a guide interface of a surgical guide, a bearing surface of an occlusion record or a reinforced anchoring point of a transitional denture by replacing a matching component or adjusting a use mode at different clinical stages, and at least two functions of implant spatial positioning, surgical guidance, impression support, occlusion recording or transitional denture are cooperatively realized; the main structure (1) is integrally formed in one piece by a biocompatible metal material through a 3D printing or numerical control cutting process, forming a continuous metal structure without welding, bonding or secondary processing.

2. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The preset geometric constraint relationship includes at least one of coplanar relationship, coaxial relationship, parallel relationship, perpendicular relationship or distance correlation relationship.

3. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The functional interface includes at least one of a guide plate embedding slot, an implant socket hole preparation guide cavity, a temporary abutment positioning boss, an occlusion recording platform or a transitional denture embedding reinforced end.

4. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The inner contour of the through-type positioning cavity is geometrically matched with the outer contour of the corresponding implant restoration abutment or transfer rod or the implant implanting tool, for sleeving and positioning a single implant accessory.

5. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The preoperative three-dimensional data includes CBCT data, intraoral scanning data and facial scanning data, which are spatially registered through anatomical landmark points to form a fusion model in a unified coordinate system.

6. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The 3D printing process is laser selective melting, and the numerical control cutting process is five-axis linkage precision machining.

7. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The biocompatible metal material is pure titanium or titanium alloy.

8. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The main structure is configured to be used as a guide plate cooperative component in implant surgery, as an impression support framework on a restoration abutment immediately after surgery, and as a built-in reinforcing structure of a transitional denture.

9. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The connecting bar segments of the main structure are arranged in an arc shape along the curvature of the dental arch, and the center lines of the through-type positioning cavities fit the dental arch midline of the patient.

10. A personalized multi-purpose rigid connecting rod as claimed in claim 1, wherein, The through-type positioning cavity edge is provided with a rounded or chamfered structure; the inner surface of the through-type positioning cavity is provided with a groove.

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