Dental pulp extraction device

Abstract

The invention relates to the technical field of medical instruments, in particular to a dental pulp extraction device. The invention aims to solve the problem that the existing dental pulp extraction technology causes great damage to dental pulp tissues and affects the activity of stem cells. The device comprises a tooth fixing subsystem, a girdling nicking subsystem, a controllable rupture subsystem and a medullary cavity tissue extraction subsystem. The method is characterized in that a stress line is scribed on a dental crown through the girdling nicking subsystem, then static radial pressure is applied by the controllable rupture subsystem to guide the dental crown to break along the nicking line in a lossless mode to open a medullary cavity, and finally the dental pulp is completely taken out through the medullary cavity tissue extraction subsystem in a lossless mode. The low-energy, high-precision and heat-damage-free tooth opening is realized, the dental pulp tissue integrity and cell viability are protected, the high-activity dental pulp stem cells are obtained, the structure is simple, and the operation is convenient.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and in particular relates to a dental pulp extraction device. BACKGROUND

[0002] Under the background of the deep integration of regenerative medicine and modern oral treatment technology, dental pulp stem cells (DPSCs) have become a research hotspot in the field of tissue engineering and cell therapy due to their excellent multi-directional differentiation potential and easy accessibility. As the key source for obtaining high-quality dental pulp stem cells, the research and development of dental pulp extraction technology and supporting devices directly determine the success or failure of subsequent cell culture, expansion and clinical application, and the technical level significantly affects the overall effectiveness and feasibility of regenerative therapy. However, early dental pulp extraction mainly relies on rough mechanical means, such as forcibly breaking the coronal crown with dental forceps or drilling a hole with a conventional dental drill, which can initially obtain dental pulp tissue, but the process easily causes serious mechanical tearing and thermal damage, resulting in low cell activity and insufficient quantity, which is difficult to meet the high-standard biomedical research and clinical transformation needs.

[0003] To overcome the defects of early technology, the skilled person in the art has proposed a series of optimization schemes. For example, an automatic dental pulp extraction device is disclosed in the invention patent with the authorization announcement number CN118240656B, which constructs a complex power system coordinated by driving motors, cutting wheels and drilling sheets, and introduces magnetic rheological liquid dynamic regulation and control of power transmission, trying to reduce the uncertainty of human operation through automatic control to realize the precision and standardization of cutting and extraction. This scheme has made progress in improving the repeatability of operation, but it is still trapped in the traditional paradigm of "high-energy mechanical force breaking hard tissue": the high-speed rotating cutting wheel becomes a strong heat source and vibration source while efficiently breaking the tooth, and the local high temperature and high-frequency mechanical stress will directly cause heat shock or apoptosis of dental pulp cells, damaging the extraction target - high-activity stem cells. Although the magnetic rheological liquid can precisely control the "size of force", it cannot change the "nature of force" and cannot eliminate the physical impact of high-speed machinery on biological tissues. In addition, the complex automatic system also brings practical problems such as high equipment cost, complex maintenance and high skill requirements for operators, which limits its popularization in primary medical institutions.

[0004] Therefore, the present application proposes a dental pulp extraction device to solve the problems existing in the prior art. SUMMARY

[0005] Therefore, the present application proposes a dental pulp extraction device to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the basic idea of the technical solution adopted by the present application is:

[0007] A dental pulp extraction device comprises:

[0008] A tooth fixing subsystem comprises a base for clamping and positioning a target tooth so that the longitudinal axis of the target tooth coincides with the preset operation axis of the device;

[0009] A ring incision scoring subsystem comprises an incision head assembly rotatably arranged on the base, capable of circumferential movement around the target tooth clamped by the tooth fixing subsystem, and capable of scoring a closed stress concentration line at a preset height on the crown surface of the target tooth;

[0010] A controllable fracture subsystem is arranged on the base above the ring incision scoring subsystem, for applying a static and radially distributed compound pressure to the crown of the target tooth after the stress concentration line is formed, so that the crown can be controllably and directionally fractured along the stress concentration line to open the pulp chamber roof;

[0011] A pulp chamber tissue extraction subsystem is used to non-destructively extract the dental pulp tissue after the pulp chamber roof is opened.

[0012] In a preferred embodiment of the present application, the base is internally provided with a central accommodating cavity for accommodating the target tooth, and three radially distributed guide rail grooves are uniformly distributed on the inner wall of the central accommodating cavity at an angle of 120 degrees, each of the guide rail grooves is slidably fitted with a clamping pawl, the lower side of each clamping pawl is provided with a driven tooth, the driven tooth is engaged with a planar spiral groove arranged on the upper side of the driving ring of the base, and the three clamping pawls are driven to move towards or away from each other by rotating the driving ring.

[0013] In a preferred embodiment of the present application, the inner side end of each clamping pawl is provided with an elastic gasket, and the working surface of the elastic gasket in contact with the tooth is provided with parallel anti-skid grooves.

[0014] In a preferred embodiment of the present application, the incision head assembly is sleeved on the outside of the base through a bearing, and the ring incision scoring subsystem further comprises a manual driving mechanism matched with the incision head assembly and a vertical positioning mechanism, the manual driving mechanism is in transmission connection with the incision head assembly and is configured to drive the incision head assembly to rotate, and the vertical positioning mechanism is in fixed connection with the incision head assembly and is configured to adjust the axial position of the incision head assembly along the preset operation axis to determine the height of the stress concentration line.

[0015] In a preferred embodiment of the present application, a radially extending incision arm is arranged on the incision head assembly, and an incision needle tip is detachably mounted on the distal end of the incision arm.

[0016] In a preferred embodiment of the present application, the manual driving mechanism comprises a thumb wheel arranged on the outer wall of the base, which is engaged with the outer edge tooth ring of the notch head assembly through the gear transmission structure; the vertical positioning mechanism comprises a precision lead screw arranged on the outer wall of the base and a locking nut fixedly connected with the notch head assembly, and a millimeter scale is correspondingly engraved on the outer wall of the base.

[0017] In a preferred embodiment of the present application, the controllable fracture subsystem is integrated in the interior of the notch head assembly, comprising:

[0018] At least three fracture actuating blocks uniformly distributed along the circumference, which can move in the radial direction, and the end facing the tooth is a wedge-shaped working surface matched with the internal groove arranged on the notch head assembly;

[0019] Fracture driving ring, which is sleeved on the outside of the notch head assembly and can rotate circumferentially relative to the notch head assembly, and is connected with the fracture actuating block in linkage, can drive the fracture actuating block to move radially to the center synchronously, so that the wedge-shaped working surface thereof simultaneously extrudes the crown area where the stress concentration line has been formed.

[0020] In a preferred embodiment of the present application, on the inner wall of the fracture driving ring, corresponding to the position of each fracture actuating block, a spiral cam track is arranged, a guide block is fixedly arranged in the cam track, an arc-shaped guide groove is opened in the guide block, and the guide groove is matched with a driven pin arranged at the tail end of the fracture actuating block.

[0021] In a preferred embodiment of the present application, the pulp cavity tissue extraction subsystem comprises:

[0022] A guide rod part with super elasticity;

[0023] A spiral working head arranged at the front end of the guide rod part, which is a micro Archimedes spiral structure, and the edge of the spiral blade thereof is treated to form a non-edged smooth chamfer;

[0024] A manually operated handle located at the end of the guide rod part.

[0025] In a preferred embodiment of the present application, a depth mark in millimeters is engraved on the rod body of the guide rod part, and a positioning ring which can slide and lock along the axial direction of the rod body is further sleeved on the rod body, which is used to control the maximum insertion depth of the spiral working head in the pulp cavity.

[0026] Compared with the prior art, the present application provides a dental pulp extraction device, which has the following beneficial effects:

[0027] 1. The design of the tooth fixation subsystem allows this device to be adapted to fix human target teeth of different sizes, providing a stable and reliable reference for all subsequent precision operations. It facilitates the use of the circumferential scoring subsystem to accurately score circumferential stress concentration lines on the crown surface, the controllable fracture subsystem to apply static composite pressure to achieve guided fracture, and the pulp tissue extraction subsystem to perform non-destructive extraction of pulp tissue, effectively improving the extraction efficiency of pulp tissue.

[0028] 2. By setting up the circumferential scoring subsystem and the controllable fracture subsystem, a two-step method of "circumferential scoring-static guided fracture" can be formed, which completely abandons the high energy generated by high-speed rotation or impact in traditional technology, and instead uses a precise pure mechanical structure to achieve low-energy, high-precision, and thermally damage-free opening of tooth hard tissue.

[0029] 3. The pulp extraction subsystem enables the extraction of dental pulp via a spiral extraction method, maximizing the preservation of the structural integrity and cell viability of the pulp tissue. This device boasts a compact overall structure, requiring no external power or gas source. The entire operation is precisely controlled manually, significantly reducing reliance on operator experience and ensuring high consistency and repeatability of extraction results. Furthermore, its manufacturing cost and maintenance difficulty are far lower than complex automated equipment. This invention fundamentally solves the long-standing core contradiction between efficiency and damage in the field of dental pulp extraction, providing a revolutionary and widely applicable technical solution for obtaining high-quality, highly active dental pulp stem cells.

[0030] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the pulp extraction device of the present invention;

[0033] Figure 2 For the present invention Figure 1 An explosion diagram of the device shown;

[0034] Figure 3 This is a cross-sectional view of the dental fixation subsystem of the present invention;

[0035] Figure 4 For the present invention Figure 3An enlarged structural schematic view at A in FIG. 1;

[0036] Figure 5 An enlarged structural schematic view at B in FIG. 1;

[0037] Figure 6 An enlarged structural schematic view at B in FIG. 1; Figure 5 An enlarged structural schematic view at B in FIG. 1;

[0038] Figure 7 An enlarged structural schematic view at B in FIG. 1;

[0039] Figure 8 An enlarged structural schematic view at B in FIG. 1;

[0040]

Main component label description

[0041] 100, base; 110, driving ring; 111, planar spiral groove; 120, clamping claw; 121, elastic gasket; 122, driven tooth; 123, anti-skid groove; 130, central accommodating cavity; 140, radial guide rail groove; 150, scale; 200, notch head assembly; 201, tooth ring; 210, thumb wheel; 211, worm; 212, intermediate gear; 220, vertical positioning mechanism; 230, notch arm; 240, notch needle tip; 250, radial sliding groove; 260, inner groove; 300, controllable breaking subsystem; 310, breaking actuating block; 320, breaking driving ring; 321, cam rail; 330, driving wrench; 340, guide clamping block; 341, guide groove; 400, medullary cavity tissue extraction subsystem; 410, guide rod part; 420, spiral working head; 430, manually operated handle; 440, positioning ring. DETAILED DESCRIPTION

[0042] The structure of the tooth pulp extraction device will be further described in detail below in combination with the drawings and embodiments of the present application.

[0043] It should be noted that the embodiments and features in the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments of the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and / or "include" as used herein indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] It is to be understood that the terms "first", "second", and the like, used in the description and the claims of the present application as well as the above description of the drawings merely refer to structure that is different, and not necessarily to a specific order or sequence. It is to be understood that the use of the term "about" with respect to a given numerical value or range of values refers to a range of values that fall within 10% of that value, unless otherwise stated. The use of the term "including" and "comprising" and variations thereof as used herein is intended to cover the various steps or units of process, method, system, product, or apparatus that are described herein, including but not limited to those that are clearly listed, and any other steps or units of process, method, system, product, or apparatus that are inherent in such processes, methods, products, or apparatus.

[0046] For the purposes of the description hereinafter, a spatial relative term, such as "above", "below", "top", "bottom", and the like, can be used herein for ease of description to describe one device or feature's spatial position relation to another device or feature as illustrated in the figures. It is to be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, then a device described as "above" or "below" other devices or structures would then be oriented "below" or "above" the other devices or structures. Accordingly, the exemplary term "above" can encompass both an orientation of above and below. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial relative descriptions used herein interpreted accordingly.

[0047] The following description is provided in relation to the drawings. Figures 1 to 8 A dental pulp extraction device is described.

[0048] As Figures 1 to 8 shown, the overall structure of a dental pulp extraction device. The device aims to achieve non-destructive opening of the tooth crown and complete extraction of the pulp tissue through a completely new, stress-guided, purely mechanical action. It includes a tooth fixation subsystem, a ring-cutting notch subsystem, a controllable fracture subsystem 300, and a pulp cavity tissue extraction subsystem 400. The tooth fixation subsystem is used to stably hold the target tooth during compression extraction; the ring-cutting notch subsystem is used to accurately draw a ring-shaped stress concentration line on the tooth crown surface; the controllable fracture subsystem 300 is used to apply static composite pressure to achieve guided fracture; the pulp cavity tissue extraction subsystem 400 is used to non-destructively remove the dental pulp tissue.

[0049] In a preferred embodiment, referring to Figure 1 , Figure 2 and Figure 3, the dental fixation subsystem is used to provide a stable and reliable reference for all subsequent precision operations. The main body of the subsystem is a one-piece base 100, which is made of medical-grade 316L stainless steel to ensure excellent biocompatibility and corrosion resistance. Inside the base 100, there is a central receiving cavity 130 that runs from the top to the bottom, with an inner diameter of 30 mm, which is sufficient to accommodate most human teeth in clinical practice. On the inner wall of the central receiving cavity 130, there are three radial guide grooves 140 evenly distributed along the circumference of 120 degrees, and each guide groove 140 is slidably connected with a clamping pawl 120. The material of the three clamping pawls 120 is high-strength titanium alloy Ti-6Al-4V, which takes into account the lightweight and high rigidity.

[0050] Specifically, referring to Figure 1 、 Figure 2 and Figure 3 , to achieve the synchronous radial movement of the three clamping pawls 120 and achieve self-centering clamping of teeth of different sizes, a precision linkage mechanism is adopted in this embodiment. Specifically, on the upper outer edge of the base 100, a driving ring 110 is fitted with a pair of P5 angular contact ball bearings. The upper side of the driving ring 110 is machined with a precise planar spiral line groove 111. The lower side of each clamping pawl 120 is provided with a driven tooth 122 that precisely engages with the spiral line groove. When the operator rotates the driving ring 110 manually, the spiral line groove 111 on the inner wall of the driving ring 110 will simultaneously and equally push or pull the driven teeth 122 of the three clamping pawls 120, thereby forcing the clamping pawls 120 to synchronously tighten or release outward along their respective radial planar spiral line grooves 111. This structure ensures that the geometric center of the tooth can always coincide with the preset operation axis of the device regardless of the shape of the tooth, and the positioning repeatability can reach ±0.02 mm.

[0051] Specifically, referring to Figure 1 、 Figure 2 and Figure 3To avoid stress concentration damage to the enamel or cementum surface of the tooth during clamping and to provide sufficient clamping friction, an elastic pad 121 is fixed to the inner end of each clamping jaw 120 by high-strength medical epoxy resin bonding. In this embodiment, the material of the elastic pad 121 is preferably medical-grade polyether ether ketone (PEEK), and the thickness is 2.0 mm. PEEK material not only has excellent mechanical strength and wear resistance, but also has a modulus of elasticity closer to the tooth tissue, which can effectively disperse the clamping force. On the working surface of the elastic pad 121 in contact with the tooth, a plurality of anti-skid grooves 123 are prepared by laser fine machining, the groove depth is accurately controlled at 0.2 mm, the groove pitch is 0.5 mm, and the cross-sectional shape of the groove is circular arc. This microstructure greatly increases the friction coefficient of the contact surface on the macro level, ensuring that the tooth does not rotate or displace at all during subsequent scoring and breaking operations.

[0052] In a preferred embodiment, with reference to Figure 1 , Figure 2 , Figure 5 and Figure 6 , the core function of the ring scoring sub-system is to score a circle of deep and uniform width, closed ring-shaped marks on the surface of the tooth crown held by the tooth fixing sub-system at a predetermined height, as a stress concentration source for subsequent guided fracture. With reference to Figure 5 , the sub-system can be rotated circumferentially and axially positioned around the tooth fixing sub-system as a whole. The specific structure includes a scoring head assembly 200, which is an integral ring structure made of aviation-grade 7075-T6 aluminum alloy and has undergone hard anodizing treatment to improve surface hardness and wear resistance. The assembly is precisely fitted on the outer middle part of the base 100 through a set of thin-wall deep-groove ball bearings, so that it can rotate circumferentially around the predetermined operation axis of the device with low friction and high stability. On the outer edge of the scoring head assembly 200, a tooth ring 201 with 100 teeth is integrally machined.

[0053] Specifically, with reference to Figure 1 , Figure 2 , Figure 5 and Figure 6To drive the scoring head assembly 200 to rotate smoothly and controllably, in the embodiment, a set of manual driving mechanism is provided. The manual driving mechanism includes a thumb wheel 210 arranged on the outer wall of the base 100 and a set of built-in transmission gear train. The outer surface of the thumb wheel 210 is prepared with a network of anti-slip texture by knurling process, with a diameter of 25 mm, facilitating the operator to apply fine and smooth torque. The rotating shaft of the thumb wheel 210 is fixedly connected with a worm 211 with a module of 0.5 and a number of heads of 1, the worm 211 is engaged with an intermediate gear 212, and the intermediate gear 212 is engaged with the outer edge gear ring 201 of the scoring head assembly 200.

[0054] Specifically, referring to Figure 1 、 Figure 2 、 Figure 5 and Figure 6 , on the scoring head assembly 200, a protruding scoring arm 230 is arranged radially, and a precision chuck (prior art, not specifically shown in the figure) is arranged at the end of the scoring arm 230 for detachably mounting a scoring needle tip 240. The scoring needle tip 240 is a key execution element for effective scoring. The material selected for the tip part is polycrystalline diamond (PCD), which is firmly welded on a cemented carbide substrate by vacuum brazing process. PCD material has extremely high hardness and wear resistance close to natural diamond, which is sufficient to form clear scores on enamel, the hardest tissue in the human body. The geometry of the tip is precisely ground to form a standard cone with a vertex angle of 60 degrees, and the curvature radius of the tip of the cone is strictly controlled between 5 microns and 10 microns. This parameter range is the result of a large number of experimental optimization. A smaller curvature radius will cause the needle tip to be prone to cracking, while a larger curvature radius will make the scoring line too wide and unable to form effective stress concentration.

[0055] Specifically, referring to Figure 1 、 Figure 2 、 Figure 5 and Figure 6In order to precisely position the annular score at the desired height of the crown, the annular scoring subsystem further comprises a vertical positioning mechanism 220, which is a precision lead screw arranged on the outer wall of the base 100 parallel to its axis, with a pitch of 1.0 mm. The entire annular scoring subsystem, including the scoring head assembly 200 and its driving mechanism, is mounted on a sliding saddle fixed to the nut block on the lead screw. By rotating the adjusting knob at the bottom end of the precision lead screw, the entire annular scoring subsystem can be smoothly moved up and down along the axial direction of the base 100. On the outer wall of the base 100, corresponding to the position of the lead screw, there is a precision scale 150 etched by laser, with a minimum scale value of 0.1 mm. The operator can use the scale 150 to visually adjust the plane of the scoring needle tip 240 to the predetermined height relative to the tooth neck or specific anatomical landmarks, with a positioning accuracy better than 0.1 mm. When adjusted to the predetermined position, a butterfly locking screw on the sliding saddle is tightened to firmly lock the entire subsystem at the operating height, preventing any accidental axial displacement during subsequent operations.

[0056] In a preferred embodiment, referring to Figure 1 , Figure 2 and Figure 7 , the design idea of the controllable fracture subsystem is to use the previously scored annular score as a structural weak point, generate a huge ring tensile stress inside the crown by applying a pure static and uniformly distributed radial composite pressure, and highly concentrate it at the root of the score, so that the crack initiates from there and expands along the pre-set annular path, finally achieving the neat and controllable separation of the crown top cover. Referring to Figure 7 , the controllable fracture subsystem is integrated inside the scoring head assembly 200. Its main components include at least three circumferentially uniformly distributed fracture actuating blocks 310 and a fracture driving ring 320 linked thereto. In this embodiment, three fracture actuating blocks 310 are provided, which are symmetrically distributed in the radial sliding grooves 250 reserved inside the scoring head assembly 200. The material of these actuating blocks is selected as Cr12MoV die steel after overall quenching and low-temperature tempering treatment, with a working hardness of HRC60-62, to withstand huge contact stress without plastic deformation. The end of each fracture actuating block 310 facing the tooth is machined into a wedge-shaped working surface with a wedge angle of 15 degrees. This angle is also an optimized result verified by finite element analysis and experiments, and a smaller angle will result in a longer stroke, while a larger angle will easily generate excessive local compressive stress at the contact point, possibly leading to fragmentation rather than overall fracture. In the non-working state, these fracture actuating blocks 310 are completely accommodated in the internal grooves 260 of the scoring head assembly 200, with a safety gap of about 1.5 mm between the wedge-shaped working surface and the tooth surface.

[0057] In particular, referring to Figure 1 , Figure 2 and Figure 7 , the breakage driving ring 320 is sleeved on the outside of the score head assembly 200 and can rotate at a small angle in the circumferential direction relative to the score head assembly 200 through a precisely fitted sliding key groove, and the maximum rotation angle is designed to be 30 degrees. On the inner wall of the breakage driving ring 320, a spiral cam track 321 is milled through a five-axis numerical control machining center corresponding to the position of each breakage actuating block 310, a guide block 340 is fixedly installed in the cam track 321, an arc-shaped guide groove 341 is formed in the guide block 340, and the guide groove 341 is matched with the driven pin arranged at the tail end of the breakage actuating block 310 to realize the rotational installation of the breakage actuating block 310. By rotating the breakage driving ring 320, the three breakage actuating blocks 310 can be driven away from each other and close to each other, and thus the radial pressure exerted by the breakage actuating block 310 on the crown can be linearly and uniformly increased from zero without impact. This static loading method is the fundamental difference from all impact or vibration tooth breaking technologies, and is also the key to protecting the internal fragile pulp tissue from mechanical stress wave damage.

[0058] In operation, an operator sleeves a specially designed driving wrench 330 with a long force arm on the hexagonal interface (prior art, not shown in the figure) on the outer edge of the breakage driving ring 320. Then, the torque is steadily and slowly applied to rotate the driving wrench 330. As the breakage driving ring 320 rotates, the guide grooves 341 on the guide blocks 340 on the inner wall of the breakage driving ring 320 simultaneously and uniformly push the driven pins of the three breakage actuating blocks 310 to move, thereby driving the three actuating blocks to move radially and centrally synchronously and steadily. The wedge-shaped working surfaces of the three actuating blocks simultaneously and accurately contact and press the crown region where the incision has been formed. As the applied torque increases, the radial pressure also linearly increases. This composite pressure generates a complex stress field in the enamel and dentin inside the crown, of which the most notable is the huge circumferential tensile stress. Due to the existence of the annular score, the cross-sectional area of this region is sharply reduced, forming a very strong stress concentration effect, and almost all the circumferential tensile stress is concentrated at the tip of the score root. When the stress value at this point exceeds the fracture toughness threshold of the enamel, a microcrack will start to crack from the score root and rapidly expand along the entire annular score path under the guidance of the stress field. Finally, in a nearly silent and crisp breaking sound, the crown top cap is completely separated from the tooth body as an independent and extremely neat-edged "hat". At this point, the top cap of the pulp cavity is completely and non-thermally damaged and non-vibrationally opened, creating ideal conditions for subsequent extraction of the dental pulp.

[0059] In a preferred embodiment, referring to Figure 1 ,Figure 2 and Figure 8 The pulp cavity tissue extraction subsystem 400 is used to perform complete extraction of the dental pulp. Referring to Figure 8 The pulp cavity tissue extraction subsystem 400 is a self-contained, precision micro-invasive surgical tool independent of the main device. It mainly includes a super-elastic guide rod portion 410, a spiral working head 420 arranged at the front end of the guide rod portion, and a manually operated handle 430 at the end of the guide rod portion. The guide rod portion 410 is the key to achieving deep exploration of the pulp cavity. Its core material is medical-grade Nitinol shape memory alloy, with a diameter precisely controlled at 0.8 mm. The super-elastic properties of Nitinol alloy make it exhibit extremely low bending modulus and up to 8% recoverable strain at room temperature, which means that the guide rod portion 410 has extraordinary flexibility and resistance to metal fatigue while maintaining sufficient axial thrust transmission rigidity. It can easily adapt to the inherent, complex, even S-shaped bending shape of the root canal, smoothly enter the apical region of the pulp cavity, and will not produce lateral pressure or plastic deformation to the root canal wall.

[0060] The spiral working head 420 at the front end of the guide rod portion 410 is the core structure for non-destructive extraction. It is not a traditional cutting or scraping tool, but a miniature Archimedes spiral structure. The working head is made of medical-grade SUS316L stainless steel bar stock, machined by Swiss-type longitudinal cutting and milling composite center once, or processed by precision wire electrical discharge machining (WEDM). Its main geometric parameters are: spiral outer diameter 1.5 mm, pitch 1.2 mm, and spiral length 5 mm. The essence of its design lies in the edge treatment of the spiral blades. All blade edges are subjected to fine electrochemical polishing treatment to form a smooth chamfer with a constant curvature radius of 50 microns. This completely non-edged design aims to avoid any form of cutting or tearing of cells and blood vessels in the dental pulp tissue. Its working principle is that when the operator slowly rotates the handle, the spiral structure generates a gentle, axially upward wrapping and lifting force when it advances in the soft tissue of the dental pulp tissue with certain viscosity and fiber structure. The dental pulp tissue as a whole is wrapped, wrapped and "screwed" out by the spiral blades, rather than being violently pulled.

[0061] A manually operated handle 430 is located at the end of the guide rod 410, which is designed according to the principle of ergonomics, usually T-shaped or ring-shaped, and the surface is covered with anti-slip medical silicone, providing the operator with comfortable, stable grip and fine force feedback. Directional indicators and rotation circle scale are provided on the handle to facilitate the operator to accurately control the rotation direction and feed of the spiral working head. To further improve the safety of operation, a precise depth marker is laser engraved on the rod body of the guide rod 410, starting from the end of the spiral working head, with 1mm as a unit. At the same time, a silicone positioning ring 440 is also installed on the rod body, which can freely slide along the rod body and can be locked at any time. Before operation, the positioning ring 440 can be set at the corresponding depth marker according to the working length of the root canal measured by the X-ray film. In this way, during the operation process, when the positioning ring 440 contacts the fracture plane of the tooth crown, it indicates that the spiral working head has reached the preset maximum safe depth, thereby effectively preventing accidental puncture injury to the periapical tissue caused by excessive operation.

[0062] The use process and principle of the overall structure of the pulp extraction device include that the experimental object is a healthy human maxillary first premolar extracted due to orthodontic needs, the in vitro time is less than 1 hour, and the premolar is preserved in a DMEM culture medium containing 1% penicillin-streptomycin.

[0063] The operation process is as follows:

[0064] Step 1: After washing the premolar with physiological saline, the premolar is placed into the central receiving cavity 130 of the tooth fixing subsystem of the device. The rotating drive ring 110 is rotated until the elastic gasket 121 on the three clamping claws 120 stably clamps the tooth in the center of the device. It is confirmed by visual observation that the longitudinal axis of the tooth coincides with the operation axis of the device.

[0065] After washing the premolar with physiological saline, the premolar is placed into the adjusting knob of the operation vertical positioning mechanism 220 of the tooth fixing subsystem of the device, and the tip plane of the notch needle tip 240 is adjusted to a height of 3.5mm above the anatomical neck of the tooth crown by referring to the millimeter scale on the outer wall of the base 100, and then the locking screw is tightened.

[0066] Step 2: The operator holds the device with one hand and slowly and uniformly rotates the thumb roller 210 with the thumb of the other hand. Through the worm gear reduction, the notch head assembly 200 rotates stably. In about 120 seconds, the notch head assembly rotates 360 degrees completely, forming a closed ring-shaped notch with a width of about 20 microns and a depth of about 150 microns on the surface of the tooth crown. Through the stereomicroscope observation, the notch is continuous and uniform without collapse.

[0067] Step 3: The drive wrench 330 is fitted onto the fracture drive ring 320 and a steady force is applied at a torque increase rate of about 2 Nm / sec. When the total applied torque reaches about 6 Nm, a slight "click" sound is heard and the crown cap neatly breaks along the score line. The drive wrench is removed and the fully separated crown cap is gently removed with a pair of tweezers. The pulp chamber access is clearly and completely exposed, the fracture surface is smooth and no radial cracks are visible.

[0068] Step 4: The working length of the tooth is measured from the preoperative X-ray to be 21 mm. The positioning ring 440 on the pulp tissue extraction subsystem 400 is set on the guide stem 410 at the 20 mm mark from the front end of the helical working head.

[0069] The helical working head 420 is aligned with the pulp chamber opening and the hand-operated handle 430 is slowly rotated in the clockwise direction while a slight axial pressure is applied. The guide stem 410 conforms to the slight curvature of the root canal and the helical working head is rotated in at a speed of about 30 rpm. When the positioning ring 440 contacts the crown fracture surface, the rotation is stopped.

[0070] Step 5: Subsequently, a slight clockwise rotation tendency is maintained while the entire extraction subsystem is slowly pulled upward. The complete, pink-colored pulp tissue is seen to be wrapped and wound around the helical working head and is smoothly and completely extracted from the root canal. The entire extraction process takes about 3 minutes.

[0071] The above description is only the preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A dental pulp extraction device, characterized by, The application relates to a tooth fixing system, a ring incision system, a controllable breaking system and a pulp cavity tissue extracting system. The tooth fixing system comprises a base (100) for clamping and positioning a target tooth so that the longitudinal axis of the target tooth coincides with the preset operation axis of the device. The ring incision system comprises an incision head assembly (200) rotatably arranged on the base (100) and capable of moving circumferentially around the target tooth clamped by the tooth fixing system to incise a closed stress concentration line at a preset height on the crown surface of the target tooth. The controllable breaking system (300) is arranged on the upper side of the base (100) of the ring incision system and is used for applying a static and radially distributed compound pressure to the crown of the target tooth after the stress concentration line is formed so that the crown can be broken along the stress concentration line in a controllable and guided manner to open the pulp cavity top cover. The pulp cavity tissue extracting system (400) is used for extracting the pulp cavity tissue in a non-destructive manner after the pulp cavity top cover is opened.

2. The dental pulp extraction device according to claim 1, characterized in that The base (100) is internally provided with a central accommodating cavity (130) for accommodating the target tooth, and three radial guide grooves (140) are uniformly distributed on the inner wall of the central accommodating cavity (130) at an angle of 120 degrees.

3. The dental pulp extraction device according to claim 2, characterized in that The lower side of each clamping claw (120) is provided with a driven tooth (122) which is engaged with a planar spiral groove (111) on the upper side of a driving ring (110) arranged on the base (100).

4. The dental pulp extraction device of claim 1, wherein, The inner side end of each clamping claw (120) is provided with an elastic pad (121).

5. The dental pulp extraction device according to claim 4, characterized in that The incision head assembly (200) is sleeved on the outer side of the base (100) through a bearing, and the ring incision system further comprises a manual driving mechanism matched with the incision head assembly (200) and a vertical positioning mechanism (220). The manual driving mechanism is in transmission connection with the incision head assembly (200) and is configured to drive the incision head assembly (200) to rotate. The vertical positioning mechanism (220) is fixedly connected with the incision head assembly (200) and is configured to adjust the axial position of the incision head assembly (200) along the preset operation axis so as to determine the height of the stress concentration line. A radial incision arm (230) is arranged on the incision head assembly (200), and an incision needle tip (240) is detachably mounted on the end of the incision arm (230).

6. The dental pulp extraction device according to claim 4, wherein The manual driving mechanism comprises a thumb wheel (210) arranged on the outer wall of the base (100), which is engaged with the outer edge tooth ring (201) of the scoring head assembly (200) through the gear transmission structure; the vertical positioning mechanism (220) comprises a precision lead screw arranged on the outer wall of the base (100) and a locking nut fixedly connected with the scoring head assembly (200), and a millimeter scale is correspondingly engraved on the outer wall of the base (100).

7. The dental pulp extraction device according to claim 1, wherein The controllable fracture subsystem is integrated in the interior of the scoring head assembly (200), comprising: At least three fracture actuating blocks (310) uniformly distributed along the circumference, which can move in the radial direction, and the end facing the tooth is a wedge-shaped working surface matched with the internal groove (260) arranged on the scoring head assembly (200); Fracture driving ring (320) is sleeved on the outside of the scoring head assembly (200) and can rotate relative to the scoring head assembly (200) in the circumferential direction, and is connected with the fracture actuating block (310) in linkage, which can drive the fracture actuating block (310) to move radially to the center synchronously, so that the wedge-shaped working surface is simultaneously extruded on the tooth crown area where the stress concentration line has been formed.

8. The dental pulp extraction device according to claim 7, characterized in that The inner wall of the fracture driving ring (320) is provided with a spiral cam track (321) corresponding to the position of each fracture actuating block (310), and a guide block (340) is fixedly arranged in the cam track (321), and an arc-shaped guide groove (341) is formed in the guide block (340), which is matched with the driven pin arranged at the tail end of the fracture actuating block (310).

9. The dental pulp extraction device according to claim 1, wherein The pulp cavity tissue extraction subsystem (400) comprises: A guide rod portion (410) with super elasticity; A spiral working head (420) arranged at the front end of the guide rod portion (410), which is a micro Archimedes spiral structure, and the edges of the spiral blades are treated to form a non-edged smooth chamfer; A manually operated handle (430) located at the end of the guide rod portion (410).

10. The dental pulp extraction device according to claim 9, characterized in that The rod body of the guide rod portion (410) is engraved with depth marks in millimeters, and a positioning ring (440) which can slide and lock along the axial direction of the rod body is sleeved on the rod body, which is used to control the maximum insertion depth of the spiral working head (420) in the pulp cavity.

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