Screening equipment and method for selecting simulated bone materials and cancellous structures

Abstract

The invention discloses a screening device and method for selecting a simulated bone material and a cancellous structure, and the method comprises the steps: firstly designing and manufacturing a simulated planting nail which is clinically matched and a planting bone test block which is provided with an upper bone cortex simulation layer, a cancellous bone simulation layer and a lower bone cortex simulation layer; the bone implanting test block is fixedly installed on a measuring workbench of a torque measuring instrument of screening equipment through a test block fixing mechanism, a balance weight mechanism is installed on the screening equipment, a rotation driving device is started to drive a screwdriver to rotate to simulate that an implanting nail is screwed into a bottom hole of the test block, the screwdriver reads torque data once every time the screwdriver rotates by a circle, and screening is completed. By the adoption of the screening device, materials for simulating the alveolar bone in the dental implant training model can be more objectively selected, errors caused by subjective hand feeling selection are avoided, the operation hand feeling of a revision doctor on the implant model is closer to the reality, and the screening device is simple in structure, convenient to operate and high in practicability. And the configuration cost of the test is saved.

Description

Technical Field

[0001] The invention relates to a material verification device applied in the field of oral clinical teaching, and in particular to a screening device and method for selecting simulated bone materials and cancellous structures. Background Art

[0002] Oral implant surgery training requires an implant training model, and the bone-mimicking material in the model is particularly critical. According to the classic clinical theory, bones are divided into four categories based on the thickness of the cortical bone (also called compact bone) and the density of trabeculae in the cancellous bone (also called spongy bone). Type 1 bone is the most difficult to penetrate into the implant screw, that is, the greater the torque required, the easier it is to cause the implant screw to break if you are not careful. Type 4 bone is the easiest to penetrate into the implant screw, but the retention force of the implant screw is insufficient. Different types of bones have different corresponding clinical operation techniques. Therefore, oral implant surgery training courses have specific requirements for specific bone-mimicking materials to imitate certain types of bones.

[0003] In traditional training courses, in order to train interns to drill holes in the alveolar bone and screw in implant screws, oak or maple blocks are used to simulate Class 1 bone, white pine or spruce is used to simulate Class 2 bone, balsa wood is used to simulate Class 3 bone, and expanded polystyrene is used to simulate Class 4 bone. Although this type of simulation material has been supported academically, it cannot be formed into a bone model. Traditional simulated bone materials, regardless of the material, molding method, or internal trabecular dense design, have no ready-made method to correspond to the texture of the four types of bones required by classic clinical practice, resulting in the bone quality that doctors operate on the oral implant model not being strictly consistent with the four types of bone required, greatly reducing the level of training. Summary of the invention

[0004] In order to make up for the above shortcomings, the present invention provides a screening device and method for selecting simulated bone materials and cancellous structures. The screening device and method for selecting simulated bone materials and cancellous structures can accurately select the simulated bone materials and the densely packed size of the simulated trabeculae inside them.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a screening device for selecting simulated bone materials and cancellous structures, including a test block fixing mechanism, a fixing frame, a rotation drive device, a counterweight mechanism, a screwdriver, a torque measuring instrument and a controller, wherein the torque measuring instrument is fixedly arranged below the fixing frame, the test block fixing mechanism is fixedly installed on the measuring workbench of the torque measuring instrument, the test block fixing mechanism can fix and position the implanted bone test block to be tested, the screwdriver can be rotated in the circumferential direction and can be lifted and lowered a set distance in the axial direction and is installed on the fixing frame, the lower end of the screwdriver is provided with a flower pattern matching the head of the simulated implant screw to be locked on the implanted bone test block, the rotation drive device is installed on the fixing frame, the rotation drive device can drive the screwdriver to rotate, the counterweight mechanism can be lifted and lowered on the fixing frame, the counterweight mechanism provides axial downward pressure to the screwdriver, the torque measuring instrument can detect the torque applied by the screw on the implanted bone test block, and the controller controls the start and stop and forward and reverse drive of the rotation drive device.

[0006] As a further improvement of the present invention, a handle folding plate is fixedly installed on the power output end of the rotary drive device, and a counterweight support plate is installed on the handle folding plate, which is stopped in the circumferential direction and can slide axially a set distance. A screwdriver fixing seat is fixedly installed on the counterweight support plate, and the upper end of the screwdriver can be fixedly inserted in the screwdriver fixing seat. The counterweight mechanism is a plurality of counterweight plates, and the plurality of counterweight plates can be stacked on the counterweight support plate.

[0007] As a further improvement of the present invention, the handle folding plate is a U-shaped structure with an open upper end, the bottom surface of the U-shaped structure of the handle folding plate is fixedly connected to the power output end of the rotary drive device, longitudinally extending slots are respectively provided on the two side walls of the U-shaped structure of the handle folding plate, and outwardly extending sliding plugs are respectively provided on the two side walls of the counterweight support plate, and the sliding plugs on the two side walls of the counterweight support plate can be slid up and down and inserted into the slots.

[0008] As a further improvement of the present invention, a limiting column is fixedly provided on the upper end surface of the counterweight support plate, and a limiting hole is provided on the counterweight plate. The limiting column can be inserted into the limiting holes of each counterweight plate stacked on the counterweight support plate, thereby positioning the counterweight plate in the horizontal direction.

[0009] As a further improvement of the present invention, a non-circular screwdriver insertion hole matching the non-circular cross-sectional shape of the upper end of the screwdriver is provided on the inner side of the screwdriver fixing seat, and the upper end of the screwdriver is inserted in the screwdriver insertion hole for stopping in the circumferential direction. At least one locking screw is provided on the side wall of the screwdriver fixing seat, and the end of the locking screw can be tightly pressed against the outer circumferential surface of the upper end of the screwdriver, thereby stopping and positioning the screwdriver.

[0010] As a further improvement of the present invention, the rotary drive device includes a motor, a driving gear and a driven gear. The motor is fixedly mounted on a fixed frame, the power output end of the motor is coaxially fixedly connected to the driving gear, the driven gear is axially stopped by a sleeve and can be rotated in the circumferential direction on the fixed frame, the driven gear is meshed with the driving gear for transmission, the handle folding plate is fixedly mounted on the upper end surface of the driven gear, and the lower end of the screwdriver passes through the inner hole of the sleeve.

[0011] As a further improvement of the present invention, the test block fixing mechanism includes a test block fixing plate, the test block fixing plate is provided with a test block fixing threaded hole and a torque measuring instrument connecting hole, the torque measuring instrument includes a fixed base plate, a torque sensor, a measuring workbench, a horizontal position adjustment mechanism and a movable clamping block, the lower end of the torque sensor is fixedly installed on the fixed base plate, the measuring workbench is fixedly installed on the upper end of the torque sensor, the movable clamping block can be installed on the measuring workbench in a horizontal direction, the horizontal position adjustment mechanism can drive two movable clamping blocks to slide relatively straight in a horizontal direction on the measuring workbench, and the movable clamping block that slides to any position is stopped and positioned.

[0012] As a further improvement of the present invention, the torque meter communicates with the controller via wired or wireless means, a torque storage and output module is provided in the controller, and the measurement data of the torque meter is transmitted to the controller and stored and data read and output by the torque storage and output module of the controller.

[0013] A method for screening simulated bone materials and cancellous structures comprises the following steps:

[0014] Step 1: Design and manufacture a simulated implant nail that matches the material and most commonly used size of the implant nail used in clinical practice. In the test, in order to ensure that the measured torque is not affected by the wear of the simulated implant nail during each test, it is best to use it once. The implant nails used in actual clinical practice are very expensive. The implant nails used in the present invention are customized according to the material, most commonly used size, and needs of the test device of the actual clinical implant nail. The head of the simulated implant nail is preferably a hexagonal head. Compared with a cross head or a slotted head, the screwdriver head is not easy to come out upwards even if the torque is relatively large when screwed in. The major diameter of the screw is consistent with the most commonly used The pitch and angle of the thread of the simulated implant screw can be close to the commonly used dental implant screws, such as M4. The tip of the screw of the simulated implant screw is close to the shape of the commonly used dental implant screws, with a certain taper. The minor diameter of the simulated implant screw is slightly larger than the bottom hole diameter of the bone implant test block, such as the bottom hole of the implant bone test block is 3.0mm, and the minor diameter of the screw is 3.1mm. The thread length of the simulated implant screw is larger than the thickness of the bone implant test block, such as the thread length of the simulated implant screw is 17mm, the pitch is 0.7mm, and the maximum number of turns is 24 to 25.

[0015] Step 2: design and manufacture a bone implant test block, wherein the bone implant test block sequentially forms an upper cortical bone simulation layer, a cancellous bone simulation layer and a lower cortical bone simulation layer from top to bottom, the bone implant test block is provided with a bottom hole for screwing in a simulated implant screw, and the bone implant test block is also provided with mounting holes for at least two test blocks, and the lower end of the bone implant test block is provided with a downwardly convex air avoidance foot located at the periphery of the bottom hole;

[0016] The test block is usually 3D printed or cast. During the test, in the direction of screwing in the simulated implant screw from top to bottom, the implant bone test block is divided into three layers: upper cortical bone simulation layer, cancellous bone simulation layer (i.e. simulated trabecular dense layer, bone marrow space layer), and lower cortical bone simulation layer. The usual clinical oral alveolar bone area implantation only involves the upper cortical bone layer and cancellous bone layer. However, the two more difficult clinical procedures of zygomatic bone implantation and pterygoid plate implantation require the use of very long implant screws to pass through the two layers of cortical bone to obtain better retention stability. Considering this requirement, the implant bone test block is designed as a sandwich structure of cortical bone simulation layer + cancellous bone simulation layer + cortical bone simulation layer.

[0017] For example, the central bottom hole of the test block corresponds to the size of the simulated implant screw, which is designed to be 3mm and runs through the upper and lower layers of the test block. The upper cortical bone simulation layer and the lower cortical bone simulation layer are both 2mm thick. In the same group of tests, the thickness of the upper cortical bone simulation layer and the lower cortical bone simulation layer is uniform;

[0018] The thickness of the cancellous bone simulation layer is 9mm, plus the upper cortical bone simulation layer and the lower cortical bone simulation layer are 2mm each, and the implant screw is screwed in to a length of 13mm. This length is shorter than the selected implant screw thread length of 17mm, which is just right;

[0019] The bottom of the implant bone test block is designed with a clearance foot, which is to simulate that the implant screw tip passes through the test block without any obstruction, to prevent the simulated implant screw from being unable to be screwed into place;

[0020] Step 3: Fix the implant bone test block on the test block fixing mechanism, and then fix the test block fixing mechanism on the measuring workbench of the torque measuring instrument;

[0021] Step 4: Place a simulated implant screw on the bottom hole of the implant bone test block;

[0022] Step 5: Insert the flower-shaped part at the bottom of the screwdriver into the flower-shaped groove at the head of the simulated implant nail;

[0023] Step 6: Install the counterweight mechanism according to design requirements;

[0024] Step 7: Turn on the rotary drive device through the controller, drive the screwdriver to rotate clockwise at a constant speed to screw the simulated implant nail into the bottom hole of the test block;

[0025] Step 8: The rotating drive device drives the screwdriver to rotate one circle and reads the torque data once;

[0026] Step nine: Calculate the depth of the simulated implant screw screwed into the implant bone test block for each turn of the screwdriver, and draw a curve analysis of the screwing distance and torque data with the depth of the simulated implant screw screwed into the implant bone test block as the horizontal coordinate and the torque value as the vertical coordinate.

[0027] As a further improvement of the present invention, three mutually perpendicular directions are respectively X direction, Y direction and Z direction, wherein the Z direction is the up and down direction, and the cancellous bone simulation layer of the test block is provided with a plurality of hollow tubes staggered and closely arranged along the X direction, the Y direction and the Z direction to simulate the bone marrow space.

[0028] The characteristic of the cancellous bone simulation layer is to simulate the anatomical structure of densely packed trabeculae. The actual trabeculae are empty bone marrow spaces. The bone marrow spaces of the test block are simulated with densely packed hollow tubular geometric shapes. The aperture of the hollow tube is the key variable parameter of the test. The Z direction is inside the test block, and the small holes in the X and Y directions pass through the side of the test block. This design is to easily identify the difference between the test blocks. The most important thing is that during light-curing 3D printing, if all the holes are enclosed in the test block, the uncured printing material will remain inside the test block, causing the test block to deteriorate and crack over time. In addition, the anatomy of the hollow tube can be circular, hexagonal or other forms. For example, a hollow tube with a circular cross-section is used. The hollow tubular aperture of the same group of implanted bone test blocks is set to 0.3mm to 1.5mm, with an interval of 0.1mm. There are 13 different implanted bone test blocks in one group of tests, and the hole spacing is uniform in the same group of tests.

[0029] The beneficial effects of the present invention are as follows: the present invention designs a simulated implant screw that matches the actual clinical implant screw, so that it can be used as a disposable device, and the cost of use is relatively low. The present invention also designs an implant bone test block for the four categories of bones that need to be implanted with reference to the dental implant theory, and then simulates each category of bone. The designed implant test block is divided into a three-layer structure of an upper cortical bone simulation layer, a middle cancellous bone simulation layer, and a lower cortical bone simulation layer to simulate the implant bone. The present invention measures the torque change data of each circle when the simulated implant screw is screwed into the test block of the simulated bone to analyze which material and the structural parameters of the internal cancellous bone can respectively correspond to the four types of bones proposed in the clinical theory of simulated dental implantation. By measuring the torque data when the implant screw is screwed into the test block formed by the test material, the material for simulating the alveolar bone in the dental implant training model is selected, thereby making the selection of various implant bones more objective, avoiding the errors caused by subjective hand feeling selection, and making the operation feel of the intern on the implant model closer to reality. The present invention uses a special device to detect the implanted bone test block. The device measures the torque data when the implant screw is screwed into the test block with different internal size parameters, and selects the size of the bone marrow space characteristics that simulates the alveolar bone by analyzing the data curve. The screening device of the present invention uses a motor to drive the screwdriver to rotate through a transmission mechanism, and the handle provides axial pressure to the screwdriver through a counterweight mechanism. This method of simulating screwing in the implant screw is more stable than clinical operation, and the measurement data is more accurate. The screening device of the present invention has a simple structure and is easy to operate. It only needs to read the torque data through a controller, saving the configuration cost of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A three-dimensional diagram of the simulated implant nail of the present invention;

[0031] Figure 2 This is a front view of the simulated implant nail of the present invention;

[0032] Figure 3 This is a first stereoscopic image of the implant bone experimental block of the present invention;

[0033] Figure 4 This is a second stereoscopic view of the implanted bone experimental block of the present invention;

[0034] Figure 5 This is a front view of the implant bone experimental block of the present invention;

[0035] Figure 6 for Figure 5 Middle AA section view;

[0036] Figure 7 for Figure 5 Middle BB section view;

[0037] Figure 8It is a left view of the implant bone experimental block of the present invention;

[0038] Fig. 9 A bottom view of the implant bone experimental block of the present invention;

[0039] Fig.10 for Fig. 9 Middle CC section view;

[0040] Fig.11 A three-dimensional diagram of the screwdriver of the present invention;

[0041] Fig.12 It is a front view of the screwdriver of the present invention;

[0042] Fig.13 is a first stereoscopic view of the screening device of the present invention;

[0043] Fig.14 is a second stereoscopic view of the screening device of the present invention;

[0044] Fig.15 It is a front view of the screening device of the present invention;

[0045] Fig.16 It is a right view of the screening device of the present invention;

[0046] Fig.17 for Fig.17 Middle DD section view;

[0047] Fig.18 It is a rear view of the screening device of the present invention;

[0048] Fig.19 A top view of the screening device of the present invention;

[0049] Fig. 20 It is a three-dimensional diagram of the counterweight support plate of the present invention;

[0050] Fig.21 It is a curve analysis diagram of screw-in distance and torque data of the present invention. DETAILED DESCRIPTION

[0051] Embodiment: A screening device for selecting simulated bone materials and cancellous structures, comprising a test block fixing mechanism, a fixing frame 1, a rotation drive device, a counterweight mechanism, a screwdriver 2, a torque meter and a controller, wherein the torque meter is fixedly arranged below the fixing frame 1, the test block fixing mechanism is fixedly installed on the measuring workbench 16 of the torque meter, the test block fixing mechanism can fix and position the implanted bone test block 3 to be tested, the screwdriver 2 can rotate in the circumferential direction and can be lifted and lowered a set distance in the axial direction and is installed on the fixing frame 1, the lower end of the screwdriver 2 is provided with a flower pattern matching the head of the simulated implant nail 4 to be locked on the implanted bone test block 3, the rotation drive device is installed on the fixing frame 1, the rotation drive device can drive the screwdriver 2 to rotate, the counterweight mechanism can be lifted and lowered on the fixing frame 1, the counterweight mechanism provides axial downward pressure to the screwdriver 2, the torque meter can detect the torque applied by the screw on the implanted bone test block 3, and the controller controls the start and stop and forward and reverse drive of the rotation drive device.

[0052] When in use, the pre-made implant bone test block 3 is fixed on the measuring workbench 16 of the torque measuring instrument through the test block fixing mechanism, and then the simulated implant nail 4 is pre-installed in the bottom hole 34 of the implant bone test block 3, the upper end of the screwdriver 2 is passed through the fixing frame 1, and the lower end of the screwdriver 2 is inserted into the flower pattern of the upper end head of the simulated implant nail 4, and a weight matching counterweight mechanism is selected according to the design, and the counterweight mechanism provides a downward axial pressure to the screwdriver 2, and the rotary drive device is started to drive the screwdriver 2 to rotate. The screwdriver 2 rotates to make the simulated implant nail 4 screwed into the bottom hole 34 of the implant bone test block 3. At the same time, the torque measuring instrument performs real-time detection and data output of the screwing-in torque. After the simulated implant nail 4 is screwed into the implant bone test block 3 for a certain number of turns, its screwing-in depth reaches the required depth. At this time, the torque data of the implant bone test block 3 being screwed into the simulated implant nail 4 can be obtained, and then the torque data can be used to judge whether the implant bone test block 3 corresponds to various types of bone in the clinic, so as to facilitate the selection of simulated bone materials matching various types of bone in the clinic.

[0053] A handle folding plate 5 is fixedly installed at the power output end of the rotary drive device, and a counterweight support plate 6 is installed on the handle folding plate 5, which is stopped in the circumferential direction and can slide axially for a set distance. A screwdriver fixing seat 7 is fixedly installed on the counterweight support plate 6, and the upper end of the screwdriver 2 can be fixedly inserted in the screwdriver fixing seat 7. The counterweight mechanism is a plurality of counterweight plates 8, and the plurality of counterweight plates 8 can be stacked on the counterweight support plate 6.

[0054] The screwdriver fixing seat 7 is fixed by screws on the lower side of the counterweight support plate 6, and the upper side of the counterweight support plate 6 is provided with downward pressure by a plurality of counterweight plates 8. When the screwdriver 2 screws the simulated implant nail 4, the counterweight support plate 6 and the counterweight plates 8 on the upper side will drop synchronously with the drop of the screwdriver 2. The number of counterweight plates 8 installed is selected according to the axial pressure required by the screwdriver 2. The counterweight plates 8 are specially designed to have a specified weight, so that when the screw is screwed in, the counterweight plates 8 with the specified weight can provide a uniform axial force when screwing in. For example, adding two 250g counterweight plates 8, plus the handle folding plate 5 assembly of 0.5kg, a total of 1kg, can provide exactly 1kg of axial force.

[0055] The handle folding plate 5 is a U-shaped structure with an open upper end. The bottom surface of the U-shaped structure of the handle folding plate 5 is fixedly connected to the power output end of the rotary drive device. The two side walls of the U-shaped structure of the handle folding plate 5 are respectively provided with longitudinally extending slots 51, and the two side walls of the counterweight support plate 6 are respectively provided with outwardly extending sliding plugs 61. The sliding plugs 61 on the two side walls of the counterweight support plate 6 can be slid up and down and inserted into the slots 51.

[0056] When the power output end of the rotary drive device rotates, the handle folding plate 5 can be driven to rotate synchronously, thereby driving the screwdriver 2 to rotate synchronously. The screwdriver 2 synchronously drives the simulated implant nail 4 to rotate and thereby screws it into the bottom hole 34 of the implant bone test block 3. The slots 51 on the two side walls of the U-shaped structure of the handle folding plate 5 are preferably an upper end opening structure, which is convenient for loading the counterweight support plate 6. The sliding inserts 61 on the two side walls of the counterweight support plate 6 slide up and down in the slots 51 on the two side walls of the U-shaped structure of the handle folding plate 5 to achieve synchronous lifting and lowering movement with the screwdriver 2. In addition to the above structure, the handle folding plate 5 can also be designed as a barrel-shaped structure with a non-circular cross-section (such as a square), and the counterweight support plate 6 is installed in this barrel-shaped structure. The bottom surface of the barrel-shaped structure is designed with a hollow portion to realize the extension of the screwdriver 2. This is an equivalent replacement that can be easily thought of by technical personnel in this field based on the present application and belongs to the protection scope of the present application.

[0057] A limiting column 62 is also fixed on the upper end surface of the counterweight support plate 6, and a limiting hole is provided on the counterweight plate 8. The limiting column 62 can be inserted into the limiting holes of each counterweight plate 8 stacked on the counterweight support plate 6, thereby positioning the counterweight plate 8 in the horizontal direction.

[0058] The counterweight support plate 6 and the counterweight plate 8 are preferably designed as circular plate structures, with the limit column 62 located at the center of the counterweight support plate 6. The center of the counterweight support plate 6 is connected to the limit column 62 through a countersunk hole and a countersunk screw. The limit hole is located at the center of the counterweight plate 8, and the screwdriver fixing seat 7 is also fixed at the center position of the lower end of the counterweight support plate 6. In this way, pressure balance can be achieved and uneven pressure distribution can be avoided. The present invention preferably designs the total weight of the screwdriver 2, the screwdriver fixing seat 7, the counterweight support plate 6, the limit column 62 and the matching countersunk screw to be 0.5 kg. This weight is not too heavy to damage the thread of the implant bone test block 3 when the screw is screwed out.

[0059] The inner side of the screwdriver fixing seat 7 is provided with a non-circular screwdriver 2 insertion hole matching the non-circular cross-sectional shape of the upper end of the screwdriver 2. The upper end of the screwdriver 2 is inserted into the screwdriver 2 insertion hole in a circumferentially stopped manner. At least one locking screw 71 is provided on the side wall of the screwdriver fixing seat 7. The end of the locking screw 71 can be tightly pressed against the outer circumferential surface of the upper end of the screwdriver 2, thereby stopping and positioning the screwdriver 2.

[0060] The screwdriver 2 insertion hole on the inner side of the screwdriver fixing seat 7 is preferably a hexagonal hole, and a hexagonal connecting handle is formed on the upper end of the screwdriver 2. The upper end of the screwdriver 2 can be stopped in the circumferential direction by inserting the screwdriver 2 insertion hole, and then the screwdriver 2 can be fixed and positioned by locking it with the locking screw 71. This structure is simple, the screwdriver 2 is easy to install and disassemble, and the screwdriver 2 is firmly fixed. In addition, a radial annular groove can be provided on the side wall of the upper end of the screwdriver 2, and an elastic clamping bead that can slide radially along the screwdriver 2 insertion hole is provided on the side wall of the screwdriver 2 insertion hole of the screwdriver fixing seat 7. The radial annular groove of the screwdriver 2 is clamped by the elastic clamping bead to realize automatic axial positioning while the screwdriver 2 is inserted, or a magnetic suction device is provided at the bottom of the screwdriver 2 insertion hole, and the axial positioning of the screwdriver 2 is realized by magnetic suction. This is an equivalent replacement that can be easily thought of by technicians in this field based on the present application, and belongs to the protection scope of the present application.

[0061] The rotary drive device includes a motor 9, a driving gear 10 and a driven gear 11. The motor 9 is fixedly mounted on the fixed frame 1. The power output end of the motor 9 is coaxially fixedly connected with the driving gear 10. The driven gear 11 is axially stopped by a sleeve 12 and can be rotated in the circumferential direction. The driven gear 11 is meshed with the driving gear 10 for transmission. The handle folding plate 5 is fixedly mounted on the upper end surface of the driven gear 11, and the lower end of the screwdriver 2 passes through the inner hole of the sleeve 12.

[0062] The motor 9 drives the driving gear 10 mounted thereon to rotate, and the driving gear 10 drives the driven gear 11 to rotate. It is best to set the driving gear 10 as a small gear and the driven gear 11 as a large gear to achieve a deceleration effect. A handle folding plate 5 is fixedly installed on the driven gear 11 (large gear), and the handle folding plate 5 rotates synchronously with the driven gear 11, which can drive the counterweight support plate 6 installed with the screwdriver 2 to rotate synchronously. For example, the speed of the motor 9 is set to 100rpm, the driving gear 10 has 30 teeth, and the driven gear has 150 teeth, so that the speed of screwing the screwdriver 2 is reduced to 20rpm, which is consistent with the speed of the mobile phone when the dentist uses a dental implant machine to screw the implant nail into the alveolar bone. In addition, a deceleration transmission ratio is adopted, even if the power of the motor 9 used is relatively small, a larger torque is provided to the screwdriver 2. As a preference, the motor 9 of the present invention adopts a closed-loop stepping motor 9 or a servo motor 9, and the controller can control the stepping motor 9 or the servo motor 9 to drive the driven gear 11 to calculate the number of turns from any starting position, thereby reading the torque data of each turn. There is no need to install a position sensor to identify the number of turns.

[0063] The test block fixing mechanism includes a test block fixing plate 13, on which a test block fixing threaded hole and a torque measuring instrument connecting hole are provided. The torque measuring instrument includes a fixed base plate 14, a torque sensor 15, a measuring workbench 16, a horizontal position adjustment mechanism and a movable clamping block 17. The lower end of the torque sensor 15 is fixedly installed on the fixed base plate 14, the measuring workbench 16 is fixedly installed on the upper end of the torque sensor 15, and the movable clamping block 17 can be slidably installed on the measuring workbench 16 in the horizontal direction. The horizontal position adjustment mechanism can drive two movable clamping blocks 17 to slide relatively linearly along the horizontal direction on the measuring workbench 16, and the movable clamping block 17 that slides to any position is stopped and positioned.

[0064] The fixing frame 1 serves as a main structural frame, supports the transmission mechanism, and plays a role in threading the shaft and positioning when the screwdriver 2 screws the simulated implant nail 4.

[0065] The fixing frame 1 adopts a gantry structure, and its two lower legs are firmly fixed on the fixed bottom plate 14 of the torque meter. Its crossbeam spans directly above the measuring workbench 16 of the torque meter. The crossbeam is provided with a center hole for the screwdriver 2 to pass through, and its center hole is concentrically matched with the bottom hole 34 in the center of the implant bone test block 3. The center hole of the fixing frame 1 is optimally installed with a sleeve 12 and a sliding washer 18, so that the screwdriver 2 rotates smoothly and the driven gear 11 pressed on the fixing frame 1 rotates with low friction. The center hole of the driven gear 11 (large gear) is inserted into the sleeve 12 in the center of the fixing frame 1, and covered by gravity on the sliding washer concentric with the center hole of the fixing frame 1. The motor 9 that drives the gear to rotate is installed on one side of the fixing frame 1.

[0066] The implant bone test block 3 is centered on the bottom hole 34 of the simulated implant nail 4, which is screwed into the center. After it is tightly fixed to the test block fixing plate below by screws, the test block fixing plate 13 is then installed on the movable clamping block 17 through a connecting mechanism.

[0067] The torque meter communicates with the controller by wire or wireless means. The controller is provided with a torque storage and output module. The measurement data of the torque meter is transmitted to the controller and stored and the data is read and output by the torque storage and output module of the controller.

[0068] The controller starts the rotation drive device to rotate forward, so that the screwdriver 2 screws the simulated implant nail 4 into the implant bone test block 3. When the screwdriver 2 is screwed exactly one circle, the torque data is read from the torque measuring instrument. This is repeated. After the torque of the specified number of circles is read, the torque data is stored in the memory card and the motor 9 is turned off. After the operator removes the counterweight, the controller starts the rotation drive device to rotate in the reverse direction, screwing out the simulated implant nail 4 from the implant bone test block 3, and the test is finished.

[0069] A method for screening simulated bone materials and cancellous structures, the specific steps are as follows:

[0070] Step 1: Design and manufacture a simulated implant nail 4 that matches the material and most commonly used size of the implant nail used in the bed;

[0071] The size parameters of simulated implant screw 4 are as follows:

[0072] Tooth pitch: 0.7mm; Tooth angle: 60 degrees; Thread major diameter: 4mm; Thread minor diameter: 3.1mm; Thread length: 17mm; Head type: Hexagon countersunk head

[0073] Step 2: Use a photocurable material to make a implanted bone test block 3 by 3D printing. The implanted bone test block 3 sequentially forms an upper cortical bone simulation layer 31, a cancellous bone simulation layer 32 and a lower cortical bone simulation layer 33 from top to bottom. The implanted bone test block 3 is provided with a bottom hole 34 for screwing in a simulated implant screw 4. The implanted bone test block 3 is also provided with at least two test block mounting holes 35. The lower end of the implanted bone test block 3 is located at the periphery of the bottom hole 34 and is provided with a downward convex air avoidance foot 36. The physical properties of this photocurable material are shown in the following table:

[0074] density 1.10~1.15g / cm3 hardness 88shore D Tensile Strength 35Mpa Tensile modulus 2300Mpa Elongation at break 6％ Bending Strength 74Mpa Flexural modulus 2091Mpa Impact performance (notched) 25J / m

[0075] The size parameters of the implant bone trial block are as follows:

[0076] 1) Thickness of upper cortical bone simulation layer 31: 2 mm;

[0077] 2) thickness of lower cortical bone simulation layer 33: 2 mm;

[0078] 3) Thickness of cancellous bone simulation layer 32: 9 mm;

[0079] 4) The cross-sectional shape of the hollow tube of the cancellous bone simulation layer: round;

[0080] 5) The center distance of the hollow tubes in the cancellous bone simulation layer: 1.67 mm;

[0081] 6) The diameters of the hollow tubes in the cancellous bone simulation layer of the 13 test blocks are: 0.3, 0.4, 0.5...1.5 mm;

[0082] Step 3: Fix the bone graft test block on the test block fixing mechanism, and then fix the test block fixing mechanism on the measuring workbench 16 of the torque measuring instrument;

[0083] Step 4: placing a simulated implant pin 4 on the bottom hole 34 of the implant bone test block;

[0084] Step 5: Insert the flower-shaped portion at the lower end of the screwdriver 2 into the flower-shaped groove at the head of the simulated implant nail 4;

[0085] Step 6: Install the 0.5kg counterweight mechanism;

[0086] Step 7: Start the motor and drive the screwdriver 2 to rotate clockwise at a constant speed to screw the simulated implant nail 4 into the bottom hole 34 of the bone graft test block 3;

[0087] Step 8: The rotating driving device drives the screwdriver 2 to rotate one circle, and reads the torque data once;

[0088] According to the above steps, the torque data obtained when the implant bone test blocks 3 with 13 different cancellous bone hollow circular tube diameters were screwed into the simulated implant screws 4 are shown in the following table;

[0089] Number of screw-in turns Screw-in distance Td0.3 Td0.4 Td0.5 Td0.6 Td0.7 Td0.8 Td0.9 Td1.0 Td1.1 Td1.2 Td1.3 Td1.4 Td1.5 1 0.70 0.018 0.013 0.012 0.010 0.016 0.010 0.011 0.010 0.015 0.020 0.018 0.013 0.020 2 1.40 0.049 0.022 0.023 0.043 0.028 0.027 0.023 0.022 0.051 0.060 0.032 0.023 0.060 3 2.10 0.123 0.091 0.065 0.115 0.100 0.085 0.066 0.054 0.112 0.114 0.086 0.069 0.122 4 2.80 0.183 0.172 0.137 0.192 0.170 0.150 0.117 0.105 0.173 0.161 0.140 0.123 0.162 5 3.50 0.261 0.245 0.208 0.243 0.233 0.206 0.162 0.153 0.230 0.194 0.183 0.163 0.175 6 4.20 0.332 0.291 0.270 0.272 0.257 0.247 0.181 0.174 0.235 0.183 0.193 0.171 0.163 7 4.90 0.382 0.338 0.320 0.283 0.258 0.245 0.178 0.181 0.220 0.172 0.184 0.159 0.146 8 5.60 0.460 0.386 0.350 0.284 0.260 0.244 0.166 0.168 0.206 0.174 0.166 0.148 0.138 9 6.30 0.519 0.403 0.372 0.308 0.260 0.242 0.164 0.161 0.192 0.170 0.160 0.142 0.138 10 7.00 0.608 0.440 0.387 0.312 0.272 0.255 0.164 0.162 0.202 0.168 0.158 0.137 0.140 11 7.70 0.668 0.468 0.419 0.331 0.283 0.247 0.161 0.150 0.196 0.165 0.152 0.135 0.139 12 8.40 0.750 0.507 0.426 0.348 0.297 0.259 0.169 0.152 0.201 0.165 0.150 0.137 0.136 13 9.10 0.820 0.563 0.460 0.364 0.298 0.263 0.178 0.159 0.197 0.167 0.149 0.132 0.134 14 9.80 0.831 0.603 0.465 0.378 0.298 0.262 0.179 0.163 0.201 0.166 0.153 0.130 0.131 15 10.50 0.918 0.646 0.494 0.396 0.308 0.263 0.174 0.167 0.197 0.165 0.147 0.133 0.126 16 11.20 1.000 0.680 0.516 0.408 0.318 0.273 0.178 0.166 0.198 0.170 0.149 0.126 0.123 17 11.90 1.019 0.720 0.538 0.437 0.336 0.285 0.180 0.170 0.209 0.177 0.159 0.127 0.132 18 12.60 1.083 0.765 0.561 0.470 0.380 0.322 0.207 0.192 0.242 0.247 0.203 0.151 0.152 19 13.30 1.150 0.789 0.583 0.561 0.472 0.402 0.251 0.231 0.332 0.327 0.258 0.214 0.212 20 14.00 1.125 0.852 0.632 0.597 0.496 0.479 0.326 0.300 0.388 0.331 0.339 0.280 0.261 21 14.70 1.162 0.885 0.716 0.589 0.528 0.496 0.346 0.340 0.403 0.393 0.392 0.317 0.268 22 15.40 1.131 0.889 0.727 0.561 0.494 0.476 0.333 0.330 0.383 0.374 0.401 0.313 0.240 23 16.10 1.036 0.852 0.701 0.534 0.453 0.444 0.325 0.308 0.362 0.344 0.358 0.291 0.238 24 16.80 1.050 0.826 0.659 0.522 0.443 0.431 0.316 0.297 0.353 0.341 0.358 0.283 0.237 25 17.50 1.058 0.816 0.642 0.518 0.436 0.423 0.303 0.283 0.342 0.336 0.353 0.277 0.235

[0090] Step 9: Calculate the depth of the simulated implant screw 4 screwed into the implant bone test block 3 for each turn of the screwdriver 2, and draw a screwing distance and torque data curve analysis diagram with the depth of the simulated implant screw 4 screwed into the implant bone test block 3 as the horizontal coordinate and the torque value as the vertical coordinate, as shown in FIG. Fig.21 As shown;

[0091] We can easily select from the curve diagram which cancellous bone parameter design value can correspond to which type of bone required by dental implant clinical practice.

[0092] On the curve graph, we marked 0-2mm as the curve range of the upper cortical bone simulation layer 31, 2-11mm as the cancellous bone simulation layer 32, and 11-13mm as the lower cortical bone simulation layer 33. Considering that the implant screws will penetrate the lower cortical bone simulation layer 33 when implanting through the zygomatic bone and the pterygoid plate, if 2mm is allowed to penetrate, the range of our observation and analysis curve should be 0-16mm, which is sufficient.

[0093] From the curve trend, we can see that the torque value is constantly increasing. When screwing from the previous circle to the next circle, the residual torque of the previous circle will be added to the torque value generated by the current circle. In fact, we can summarize a formula from these curve data to generalize the torque change in the tapping process of this material, that is, to form a mathematical model.

[0094] The two horizontal lines of 0.35Nm and 0.45Nm in the curve represent the most common torque range set by the dental implant machine when screwing the implant screw into the alveolar bone. These two lines are located roughly in the middle range of the 13 curves, indicating that we have a lot of room to match 4 types of bone from 13 designs, indicating that the selected material is more suitable for simulating alveolar bone.

[0095] In the 13 curves of this example, we first eliminate the two extreme designs of d0.3 and d1.5, because the very small aperture of 0.3mm and the very thin wall thickness caused by the aperture of 1.5mm will have a high defective rate if produced by 3D printing, and these two curves are also far away from the torque values ​​required for clinical implants, so they are unnecessary.

[0096] Then we find d0.5 or d0.6 as Class 2 bone within the relatively wide range of cancellous bone simulation layer between 0.35 and 0.45 Nm. In this way, d0.4 with higher density than d0.5 is used as Class 1 bone, d0.7 or d0.8 with lower density than d0.6 is used as Class 3 bone, and the rest of d0.9 to d1.4 with lower density can be used as Class 4 bone. In order to keep improving, we can make samples and ask dentists with rich implant experience to confirm the selection, whether to use d0.5 or d0.6 for Class 2 bone, and whether to use d0.7 or d0.8 for Class 3 bone. This greatly saves the time and experimental cost of selecting simulated alveolar bone materials and determining cancellous bone design parameters.

Claims

1. A screening device for selecting simulated bone materials and cancellous structures, characterized in that: The invention comprises a test block fixing mechanism, a fixing frame (1), a rotation drive device, a counterweight mechanism, a screwdriver (2), a torque measuring instrument and a controller. The torque measuring instrument is fixedly arranged below the fixing frame. The test block fixing mechanism is fixedly installed on a measuring workbench of the torque measuring instrument. The test block fixing mechanism can fix and position a test bone implant block (3) to be tested. The screwdriver is installed on the fixing frame so as to be rotatable in a circumferential direction and to be able to move up and down axially for a set distance. The lower end of the screwdriver is provided with a flower pattern matching the head of a simulated implant screw (4) to be locked on the test bone implant block. The rotation drive device is installed on the fixing frame so as to be able to move up and down. The counterweight mechanism is installed on the fixing frame so as to be able to move up and down. The counterweight mechanism provides axial downward pressure to the screwdriver. The torque measuring instrument can detect the torque applied by the screw on the test bone implant block. The controller controls the start and stop and forward and reverse driving of the rotation drive device.

2. The screening device for selecting simulated bone materials and cancellous structures according to claim 1, characterized in that: A handle folding plate (5) is fixedly mounted on the power output end of the rotary drive device, a counterweight support plate (6) is mounted on the handle folding plate so as to be stopped in the circumferential direction and capable of sliding a set distance in the axial direction, a screwdriver fixing seat (7) is fixedly mounted on the counterweight support plate, and the upper end of the screwdriver can be fixedly inserted in the screwdriver fixing seat, and the counterweight mechanism is a plurality of counterweight plates (8), and the plurality of counterweight plates can be stacked on the counterweight support plate.

3. The screening device for selecting simulated bone materials and cancellous structures according to claim 2, characterized in that: The handle folding plate is a U-shaped structure with an open upper end. The bottom surface of the U-shaped structure of the handle folding plate is fixedly connected to the power output end of the rotary drive device. The two side walls of the U-shaped structure of the handle folding plate are respectively provided with longitudinally extending slots (51). The two side walls of the counterweight support plate are respectively provided with outwardly extending sliding inserts (61). The sliding inserts on the two side walls of the counterweight support plate can be inserted into the slots in an upward and downward manner.

4. The screening device for selecting simulated bone materials and cancellous structures according to claim 2, characterized in that: A limiting column (62) is fixedly provided on the upper surface of the counterweight support plate, and a limiting hole is provided on the counterweight plate. The limiting column can be inserted into the limiting hole of each counterweight plate stacked on the counterweight support plate, thereby positioning the counterweight plate in the horizontal direction.

5. The screening device for selecting simulated bone materials and cancellous structures according to claim 2, characterized in that: The inner side of the screwdriver fixing seat is provided with a non-circular screwdriver insertion hole matching the non-circular cross-sectional shape of the upper end of the screwdriver, and the upper end of the screwdriver is inserted into the screwdriver insertion hole in a circumferential direction. At least one locking screw (71) is provided on the side wall of the screwdriver fixing seat, and the end of the locking screw can be tightly pressed against the outer circumferential surface of the upper end of the screwdriver, thereby stopping and positioning the screwdriver.

6. The screening device for selecting simulated bone materials and cancellous structures according to claim 2, characterized in that: The rotary drive device comprises a motor (9), a driving gear (10) and a driven gear (11); the motor is fixedly mounted on a fixed frame; the power output end of the motor is coaxially fixedly connected with the driving gear; the driven gear is axially stopped by a shaft sleeve (12) and is rotatable in the circumferential direction; the driven gear is meshed with the driving gear for transmission; the handle folding plate is fixedly mounted on the upper end surface of the driven gear; and the lower end of the screwdriver passes through the inner hole of the shaft sleeve.

7. The screening device for selecting simulated bone materials and cancellous structures according to claim 2, characterized in that: The test block fixing mechanism comprises a test block fixing plate (13), the test block fixing plate is provided with a test block fixing threaded hole and a torque measuring instrument connecting hole, the torque measuring instrument comprises a fixed base plate (14), a torque sensor (15), a measuring workbench (16), a horizontal position adjustment mechanism and a movable clamping block (17), the lower end of the torque sensor is fixedly mounted on the fixed base plate, the measuring workbench is fixedly mounted on the upper end of the torque sensor, the movable clamping block is mounted on the measuring workbench in a manner that it can slide in a horizontal direction, the horizontal position adjustment mechanism can drive two movable clamping blocks to slide relatively linearly in a horizontal direction on the measuring workbench, and the movable clamping block that slides to any position is stopped and positioned.

8. The screening device for selecting simulated bone materials and cancellous structures according to claim 1 or 7, characterized in that: The torque meter communicates with the controller by wire or wireless means. The controller is provided with a torque storage and output module. The measurement data of the torque meter is transmitted to the controller and stored and the data is read and output by the torque storage and output module of the controller.

9. A method for screening simulated bone materials and cancellous structures using the screening device for selecting simulated bone materials and cancellous structures according to claims 1-8, characterized in that: The steps include: Step 1: Design and manufacture a simulated implant nail that matches the material and most commonly used size of the implant nails used in clinical practice; Step 2: Design and manufacture a bone implant test block, wherein the bone implant test block sequentially forms an upper cortical bone simulation layer (31), a cancellous bone simulation layer (32) and a lower cortical bone simulation layer (33) from top to bottom, the bone implant test block is provided with a bottom hole (34) for the simulated implant screw to be screwed in, the bone implant test block is also provided with at least two test block mounting holes (35), and the lower end of the bone implant test block is located at the periphery of the bottom hole and is provided with a downwardly convex air avoidance foot (36); Step 3: Fix the implant bone test block on the test block fixing mechanism, and then fix the test block fixing mechanism on the measuring workbench of the torque measuring instrument; Step 4: Place a simulated implant screw on the bottom hole of the implant bone test block; Step 5: Insert the flower-shaped part at the bottom of the screwdriver into the flower-shaped groove at the head of the simulated implant nail; Step 6: Install the counterweight mechanism according to design requirements; Step 7: Turn on the rotary drive device through the controller, drive the screwdriver to rotate clockwise at a constant speed to screw the simulated implant nail into the bottom hole of the test block; Step 8: The rotating drive device drives the screwdriver to rotate one circle and reads the torque data once; Step nine: Calculate the depth of the simulated implant screw screwed into the implant bone test block for each turn of the screwdriver, and draw a curve analysis of the screwing distance and torque data with the depth of the simulated implant screw screwed into the implant bone test block as the horizontal coordinate and the torque value as the vertical coordinate.

10. The method for screening simulated bone materials and cancellous structures according to claim 9, characterized in that The three mutually perpendicular directions are respectively the X direction, the Y direction and the Z direction, wherein the Z direction is the up-down direction. The cancellous bone simulation layer of the test block is provided with a plurality of hollow tubes (37) which are staggered and closely arranged along the X direction, the Y direction and the Z direction to simulate the bone marrow space.

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