A bidirectional screw-fixed base structure

Abstract

This utility model belongs to the field of dental implant technology, specifically relating to a bidirectional screw-retained abutment structure, including a restorative abutment and an implant, wherein the restorative abutment and the implant are connected by a bidirectional screw; the bidirectional screw includes: an upper fine-thread section for threaded connection with the restorative abutment; a central cylindrical boss with a diameter larger than the diameters of the fine-thread section and the lower coarse-thread section; the lower coarse-thread section has a pitch greater than the pitch of the fine-thread section; the upper end of the implant has a groove, the middle of which has a stop surface that mates with the boss, and the bottom has an internal thread, the pitch of which is the same as the pitch of the coarse-thread section; the diameter of the abutment interface at the lower end of the restorative abutment is smaller than the diameter of the top of the groove of the implant. This utility model forms a "bidirectional preload field" through the double-ended thread, dynamically compensating for thread clearance under the action of biting force, reducing fretting wear.

Description

Technical Field

[0001] This utility model belongs to the field of dental implant technology, specifically relating to a bidirectional screw-retained abutment structure. Background Technology

[0002] In modern life, there is an increasing focus on quality of life. Implant systems are highly sought after because their chewing function is significantly superior to other traditional dentures and they can effectively restore tooth function. In dental surgery, the implant body, abutment, and central screw are usually assembled together. The stability of the connection between the abutment and the implant is crucial to the restoration effect. Traditional techniques generally use a unidirectional central screw retention structure, which achieves the connection through a single-pitch thread. However, this design has significant drawbacks in clinical application.

[0003] Traditional unidirectional screws rely on a single thread to transmit engagement force. When subjected to lateral forces, this can easily lead to localized stress concentration on the thread, exceeding the material's fatigue limit, affecting screw stability, and even causing breakage. Traditional screws without a stop mechanism rely on operator experience to control torque, which can easily result in insufficient preload, increasing the risk of loosening, or overload, increasing the risk of breakage. Furthermore, the interface between the abutment and implant is prone to fretting wear due to poor thread matching precision (such as in non-integral designs), increasing bone resorption rate by 3-5 times. Additionally, aesthetic restorations are limited by the inability to adjust the screw channel in the center of the abutment.

[0004] In existing technologies, increasing the diameter or using high-rigidity materials to improve the strength of unidirectional screws leads to technical contradictions such as limited internal space of the implant, reduced adaptability, and a single path for the transmission of occlusal load to the patient, increasing the risk of stress concentration. Therefore, structural innovation is urgently needed to solve the above problems. Utility Model Content

[0005] In view of the above-mentioned shortcomings in the existing technology, this utility model provides a bidirectional screw-fixed base structure. By optimizing the thread structure and stop function design, it solves the problems of loosening, breakage and biomechanical instability caused by improper torque control of traditional unidirectional screws.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A bidirectional screw-retained abutment structure includes a prosthetic abutment and an implant, wherein the prosthetic abutment and the implant are connected by a bidirectional screw; the bidirectional screw includes: an upper fine-threaded section for threaded connection with the prosthetic abutment; a central cylindrical boss with a diameter larger than the diameters of the fine-threaded section and the lower coarse-threaded section; the lower coarse-threaded section has a pitch greater than the pitch of the fine-threaded section; the implant has a groove at its upper end, a stop surface in the middle of the groove that mates with the boss, and an internal thread at its bottom, the pitch of which is the same as the pitch of the coarse-threaded section; the diameter of the abutment interface at the lower end of the prosthetic abutment is smaller than the diameter of the top of the groove of the implant.

[0008] Furthermore, the repair base has an axially penetrating perforated channel in the middle, and the upper end of the perforated channel is a threaded hole.

[0009] Furthermore, the upper end of the restorative abutment is provided with a connecting part for connecting the crown; the crown is provided with a through hole in the middle, and when the crown is installed, the restorative screw passes through the through hole and is threadedly connected to the threaded hole.

[0010] Furthermore, the axial length of the boss matches the axial position of the stop surface, and when the coarse thread section is fully screwed into the internal thread of the implant, the boss abuts against the stop surface.

[0011] Furthermore, the head of the bidirectional screw is provided with a drive groove for connecting a screwdriver, and the connection between the repair abutment and the implant is achieved by rotating the screwdriver with a torque wrench.

[0012] Compared with the prior art, this utility model has the following advantages:

[0013] 1. The double-ended screw consists of a fine-pitch thread section, a boss, and a coarse-pitch thread section. The fine-pitch thread section precisely meshes with the internal thread of the implant, achieving precise control of the preload force through a small pitch (error ≤ ±1 N·cm). The coarse-pitch thread section engages with the large-pitch thread within the implant, dispersing the biting force and reducing thread shear stress (stress peak reduced by 40%). The boss diameter is larger than the upper and lower thread sections, and during assembly, mechanical limits are used to achieve torque-displacement decoupling control (stop tolerance ≤ ±0.05 mm). The double-ended thread forms a "double-sided preload force field," dynamically compensating for thread clearance under biting force and reducing fretting wear.

[0014] 2. Traditional angled abutment central screws require a through-hole, which thins the abutment sidewalls and weakens the support. Double-ended threads, on the other hand, allow the screw to pass through the bottom of the abutment, eliminating the need for a through-hole. This increases the thickness of the abutment sidewalls and thus enhances the abutment's support strength. Furthermore, the traditional angled abutment central screw requires a through-hole, and the hole direction directly determines the crown opening direction. Double-ended threads, however, allow the abutment opening direction to be freely adjusted to a suitable position, which in turn allows for adjustment of the crown opening direction, making it very convenient.

[0015] 3. By cooperating with the boss and the stop surface, and rotating the screwdriver with a torsion wrench, the torsion wrench has an audible and visual alarm function and a preset threshold. Through staged torque control (pre-tightening → dynamic compensation → final tightening), the abutment and implant are passively positioned. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of a bidirectional screw-fixed base structure according to the present invention;

[0017] Figure 2 This is a cross-sectional view of a bidirectional screw-fixed base structure according to the present invention.

[0018] Figure 3 This is a schematic diagram of a two-way screw-fixed base structure for mounting dental crowns according to the present invention;

[0019] Figure 4 This is a cross-sectional structural diagram of a bidirectional screw-fixed base structure for mounting a dental crown according to the present invention.

[0020] Figure 5 This is a schematic diagram of a two-way screw.

[0021] The reference numerals in the accompanying drawings include:

[0022] 1. Abutment repair; 11. Abutment interface; 12. Screw hole; 13. Through-hole channel; 2. Two-way screw; 21. Fine thread section; 22. Boss; 23. Coarse thread section; 24. Drive slot; 3. Implant; 31. Stop surface; 4. Crown; 5. Repair screw. Detailed Implementation

[0023] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of this utility model, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Example 1:

[0028] like Figure 1-5 As shown, this utility model specifically discloses a bidirectional screw-retained abutment structure, comprising a repair abutment 1 and an implant 3, wherein the repair abutment 1 and the implant 3 are connected by a bidirectional screw 2. The bidirectional screw 2 comprises three parts: the first part is an upper fine-thread section 21 for threaded connection with the repair abutment 1; the second part is a cylindrical boss 22, the diameter of which is larger than the diameters of the fine-thread section 21 and the lower coarse-thread section 23; the third part is composed of the coarse-thread section 23, the pitch of which is larger than the pitch of the fine-thread section 21, such as... Figure 5 As shown, the three parts are connected sequentially from top to bottom.

[0029] The fine-pitch thread segment 21 precisely engages with the thread in the abutment interface 11 at the lower end of the abutment 1, achieving precise control of the preload force through a small pitch (error ≤ ±1 N·cm). The coarse-pitch thread segment 23 engages with the large-pitch internal thread of the implant, dispersing the biting force and reducing the thread shear stress (stress peak reduced by 40%).

[0030] Secondly, the head of the bidirectional screw 2 is provided with a drive groove 24 for connecting a screwdriver. The connection between the repair base 1 and the implant 3 is achieved by rotating the screwdriver with a torque wrench. The repair base 1 has an axially penetrating through-hole channel 13 in the middle, and the upper end of the through-hole channel 13 is a threaded hole 12.

[0031] Secondly, the upper end of the implant 3 is provided with a groove, the middle of which is provided with a stop surface 31, and the bottom is provided with an internal thread, the pitch of which is consistent with the pitch of the coarse thread section 23. The axial length of the boss 22 matches the axial position of the stop surface 31. When the coarse thread section 23 is fully screwed into the internal thread of the implant, the boss 22 abuts against the stop surface 31.

[0032] Secondly, the diameter of the abutment interface 11 at the lower end of the repair abutment 1 is smaller than the diameter of the top of the groove of the implant 3. With this design, after the repair abutment 1 and the bidirectional screw 2 are installed, the repair abutment 1 and the bidirectional screw 2 can be aligned with the groove of the implant 3 to complete the initial positioning.

[0033] Specifically, when connecting the repair abutment 1 and the implant 3, a dedicated screwdriver is inserted through the through-hole channel 13 of the repair abutment 1 into the drive groove 24 of the head of the bidirectional screw 2. The screwdriver is then rotated using a torque wrench, which has an audible and visual alarm function. A threshold torque range of 20-35 N·cm is preset on the torque wrench. When 20 N·cm is reached, the boss 22 contacts the stop surface 31 of the implant 3, triggering the audible and visual alarm. Pressure is continuously applied until the final torque of 35 N·cm is reached, completing the installation. Passive positioning of the abutment and implant is achieved through staged torque control (pre-tightening → dynamic compensation → final tightening).

[0034] Secondly, such as Figure 3-4 As shown, the upper end of the restoration base 1 is provided with a connecting part for connecting the crown 4, and the crown 4 is provided with a through hole in the middle. When the crown 4 needs to be installed, the restoration screw 5 passes through the through hole and is threadedly connected to the threaded hole 12.

[0035] Working principle:

[0036] Connect the bidirectional screw 2 to the abutment interface 11 at the lower end of the abutment 1. The internal thread of the abutment interface 11 matches the fine thread section 21. After installation, align the connected abutment 1 and bidirectional screw 2 with the groove of the implant 3 to complete the initial alignment. Use a special screwdriver to insert it into the drive groove 24 of the central screw 2 through the through hole 13 of the abutment 1, and begin screwing in the central screw 2. Rotate the special screwdriver with a torque wrench until it reaches 20 N·cm. At this point, the boss 22 contacts the stop surface 31 of the implant 3, triggering an audible and visual alarm. Continue applying pressure until the final torque reaches 35 N·cm. At this point, the lower coarse thread end 23 is completely embedded in the bottom of the groove of the implant 3, completing the connection between the abutment 1 and the implant 3. Figure 1 , 2 As shown, at this time, the bidirectional screw 2 is wrapped by the repair abutment 1 and the implant 3, and the bottom end of the repair abutment 1 is embedded in the implant 3.

[0037] When it is necessary to install the crown 4, the repair screw 5 passes through the through hole of the crown 4, and the repair screw 5 is rotated to achieve a threaded connection with the threaded hole 12. Figure 3 , Figure 4 As shown.

[0038] The above are merely embodiments of this utility model. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The content protected by this application does not involve improvements to the software or methods. Commonly known structures and characteristics in the solution are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field to which this utility model pertains prior to the application date or priority date, are able to access all existing technologies in that field, and possess the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in conjunction with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent.

Claims

1. A bidirectional screw-retained abutment structure comprising a prosthetic abutment (1) and an implant (3), characterized in that: The repair abutment (1) and the implant (3) are connected by a two-way screw (2); The bidirectional screw (2) includes: The fine thread section (21) at the upper end is used for threaded connection with the repair base (1); The cylindrical boss (22) in the middle has a diameter larger than the diameter of the fine thread section (21) and the coarse thread section (23) at the lower end; The lower end is composed of a coarse thread section (23), whose pitch is greater than that of the fine thread section (21); The implant (3) has a groove at the upper end, a stop surface (31) that cooperates with the boss (22) in the middle of the groove, and an internal thread at the bottom. The pitch of the internal thread is consistent with the pitch of the coarse thread section (23). The diameter of the abutment interface (11) at the lower end of the repair abutment (1) is smaller than the diameter of the top of the groove of the implant (3).

2. The bi-directional screw-retained abutment structure of claim 1, wherein: The repair base (1) has an axially penetrating perforated channel (13) in the middle, and the upper end of the perforated channel (13) is a threaded hole (12).

3. The bidirectional screw-fixed base structure as described in claim 2, characterized in that: The upper end of the restorative abutment (1) is provided with a connecting part for connecting the crown (4); the crown (4) is provided with a through hole in the middle. When the crown (4) is installed, the restorative screw (5) passes through the through hole and is threadedly connected to the threaded hole (12).

4. The bi-directional screw-retained abutment structure of claim 1, wherein: The axial length of the boss (22) matches the axial position of the stop surface (31). When the coarse thread segment (23) is fully screwed into the internal thread of the implant, the boss (22) abuts against the stop surface (31).

5. The bi-directional screw-retained abutment structure of claim 4, wherein: The head of the bidirectional screw (2) is provided with a drive groove (24) for connecting a screwdriver. The connection between the repair abutment (1) and the implant (3) is achieved by rotating the screwdriver with a torque wrench.

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