Machining method for gradually-changed threads

Abstract

The invention relates to the technical field of thread machining, and provides a machining method for a gradually-changed thread, and the machining method comprises the steps that a first tool is used for turning a to-be-machined part to form a basic thread, and the basic thread comprises a top side face, a crown side face and a lateral surface connected with the top side face and the crown side face; the top side surface is provided with a plurality of gradient surfaces with different gradients; and a second tool is used for cutting the top side face to obtain a second top side face, the second top side face comprises a plurality of slope faces, the width ratio of the slope faces connected with the tooth bottoms to the second top side face is gradually increased in the direction of the central axis of the workpiece to be machined, and the gradient of the slope faces is smaller than that of other slope faces. The machining method is simple in process setting, low in machining cost and high in efficiency, and then the machining cost of the gradually-changed threads is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of thread processing, and in particular to a method for processing a gradual thread. Background Art

[0002] In the field of medical devices, bone implants (implants) can replace or repair bone tissue lost due to disease, injury or congenital defects. After the implant is implanted, the rationality of the stress distribution on its surface directly affects the formation of bone integration and the success rate of repair. During this period, the implant must be firmly held in the bone by mechanical means. This mechanical fixation of the implant in the bone is called "initial stability". Most modern implants have threads on the outer surface, which are used to screw and fix the implant in the preoperatively prepared drill hole. These threads provide initial stability during bone integration. After the implant is implanted, the implant does not loosen for a long time, and no peripheral inflammation and bone resorption occur, which is called long-term stability. The shape of the implant's external thread not only has a great influence on the initial stability and long-term stability, but also has a great influence on the speed and success rate of bone integration.

[0003] The existing processing technology of implant external threads is complicated, and it requires frequent tool changes and multiple cutting to complete the production, which has high processing costs and low efficiency, resulting in high production costs of implants and increased financial burden on patients.

[0004] Therefore, how to improve the existing thread processing technology level of medical implants so that it can reduce processing costs, improve processing efficiency, and thus reduce implant costs is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve at least one of the above technical problems, the present application provides a method for processing a gradual thread, which is applied to bone implants. The present application can process a gradual thread with multiple slopes through two cuts, and the process setting is simple, the cost is low, and the efficiency is high.

[0006] Therefore, the present application provides a method for processing a tapered thread, the method comprising:

[0007] Using a first tool to turn the workpiece to be processed to form a basic thread, the basic thread includes a top side surface, a crown side surface, and a lateral surface connecting the top side surface and the crown side surface, and the top side surface has a plurality of slope surfaces with different slopes;

[0008] A second top side surface is obtained by cutting the top side surface with a second tool, and the second top side surface includes multiple slope surfaces, wherein along the direction of the central axis of the workpiece to be processed, the slope surface connecting the tooth bottom gradually increases in proportion to the width of the second top side surface, and the slope of this slope surface is smaller than that of other slope surfaces.

[0009] This implementation method can process a gradient thread with multiple slope surfaces through two cuts, and the process setting is simple, low cost and high efficiency. Among them, the slope of the slope surface connecting the tooth bottom is set to the smallest. As the proportion of the slope surface to the width of the second top side surface increases, the thread width becomes wider and wider. Therefore, in the process of the thread being screwed into the bone tissue, the effect of the backward thread on the bone compression is more obvious, making it more stable. The gradient thread processed and manufactured according to this method can improve the initial stability of the implant, that is, during the implant insertion process, since a slope surface on the top side of the gradient thread gradually increases in the proportion of the width of the top side surface, the gradient thread section of the implant will squeeze the cortical bone and cancellous bone. At the same time, during the implant insertion process, the lower-level thread is screwed in along the trajectory of the upper-level thread in sequence, gradually increasing the squeezing force. Because the top side and coronal side of the gradual thread will form compression with the cartilage, the bone compression area is significantly increased, making it easier for bone attachment and the force-bearing area larger. The expected mechanical effect can be achieved with smaller bone compression per unit area, so the initial stability requirements can be achieved with smaller bone compression, which reduces damage to bone cells and blood vessels, increases the speed of implant integration with bone after implantation, and can significantly improve the success rate of implantation while reducing the pain of the recipient.

[0010] In combination with the above-mentioned method for machining the gradual thread, using a second tool to cut the top side surface to obtain a second top side surface comprises: the second tool feeds along the tooth bottom.

[0011] This implementation method uses a second tool to perform a second feed, cutting the top side surface to obtain a second top side surface, so that the width proportion of a slope surface of the second top side surface gradually increases. Two feeds can complete the processing of multiple slope surfaces and achieve the purpose of gradually increasing the width proportion of a slope surface. When the second tool is used for processing in this implementation method, the second tool feeds along the tooth bottom contour of the gradual thread, and can directly cut the slope surface connecting the tooth bottom starting from the tooth bottom, and the second top side surface can be cut without increasing the number of slope surfaces. The process setting is simple, the processing cost is low, and the efficiency is high.

[0012] In combination with the above-mentioned method for processing a gradual thread, the pitch set when processing with the first tool is greater than the pitch set when processing with the second tool.

[0013] In this implementation, the pitch of the first tool during processing is set to be greater than the pitch of the second tool during processing, so that the second tool gradually moves away from the crown side of the same thread during processing along the feed direction, thereby achieving the purpose of gradually increasing the proportion of the slope surface being processed to the width of the second top side surface.

[0014] In combination with the above-mentioned gradual thread processing method, the pitch of the first tool and the second tool is set using the following formula:

[0015] P 2 =P1 -D / m

[0016] Among them, P 1 is the pitch of the first tool, P 2 is the pitch of the second tool, D is the preset bone extrusion amount, and m is the number of threads of the gradual thread.

[0017] In this implementation, the pitch difference between the first tool and the second tool is negatively correlated with the number of threads and positively correlated with the preset bone extrusion amount. If the workpiece is longer and has more threads, each thread will have a certain width after cutting by the second tool. After the second tool completes cutting, the last thread will become wider, and the increased width is the preset bone extrusion amount. Therefore, this method can ensure that implant threads of different lengths have consistent implantation torque, which is convenient for operation.

[0018] In combination with the above-mentioned gradual thread processing method, using a second tool to cut the top side surface to obtain the second top side surface includes: when the second tool feeds along the direction of the center axis of the workpiece to be processed, the second tool gradually moves away from the bottom of the tooth; wherein the first tool and the second tool are set with the same pitch, and the pitch setting range is 0.3-4mm.

[0019] When the second tool is used for processing in this implementation, the second tool gradually moves away from the tooth bottom along the direction of the center axis of the workpiece to be processed, so that the proportion of the width of a slope surface gradually decreases along the feed direction until it is 0, and finally the purpose of gradually increasing the proportion of the width of the slope surface to be processed to the second top side surface is achieved, and the process is simple. The same pitch is set for the first tool and the second tool during processing, and the pitch setting range is 0.3-4mm, which can make the processed gradual thread more stable.

[0020] In combination with the above-mentioned method for processing a gradual thread, the workpiece to be processed includes a top side and a crown side. Along the feed direction of the first tool, the feed side is the top side, and the exit side is the crown side, wherein the top side is thinner; the first tool includes a main tool side and a secondary tool side, and along the direction extending from the top side to the crown side, the main tool side is used to form the top side surface, and the secondary tool side is used to form the crown side surface, wherein the main tool side also includes a plurality of connected cutting edges, and adjacent cutting edges have an included angle.

[0021] In this implementation, the top side is the end of the first tool that first enters the bone tissue, and when turning is started from the top side, the top side is the thinnest. Since the top side contacts the bone first, the smaller its cross-sectional area, the easier it is to screw the implant in. The main tool side and the auxiliary tool side of the first tool can be arranged relatively to each other, and the top side surface and the crown side surface can be processed simultaneously during feed. At least two cutting edges arranged on the main tool side are used to process multiple slope surfaces. Since there is a certain angle between adjacent cutting edges, there is also an angle between the multiple slope surfaces processed. Multiple slope surfaces can be processed in one feed, and the process is simple and the processing efficiency is high.

[0022] In combination with the above-mentioned method for machining the gradual thread, the main tool side has an arc-shaped cutting edge.

[0023] Compared with the prior art, the processing method of a gradual thread provided by the present application has at least the following beneficial effects: the slope of the slope surface connecting the tooth bottom is set to the minimum, and as the proportion of the slope surface to the width of the second top side increases, the thread width becomes wider and wider, so that in the process of the thread being screwed into the bone tissue, the effect of the backward thread on bone compression is more obvious and the stability is higher. The processing method of the gradual thread of the present application only requires two cuts to complete the processing of the gradual thread with multiple slope surfaces, and the process setting is simple, the cost is low, and the efficiency is high. It solves the technical problem in the prior art that the processing process of the tapered thread of the medical implant is complicated, the processing cost is high, the efficiency is low, and the cost of the implant is high.

[0024] Other features and advantages of the present application will be described in detail in the subsequent specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following is a brief introduction to the drawings required for describing the embodiments or prior art.

[0026] Figure 1 A schematic flow chart of a method for processing a tapered thread provided in an embodiment of the present application;

[0027] Figure 2 A schematic diagram of the structure of an intermediate state of machining a gradual thread and a first tool provided in an embodiment of the present application;

[0028] Figure 3 A schematic diagram of a processing state of a gradual thread and a second tool provided in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of another processing state of a gradual thread and a tool feed trajectory provided in an embodiment of the present application;

[0030] Figure 5 A schematic diagram of the structure of another first tool provided in an embodiment of the present application;

[0031] Figure 6 A schematic diagram of the structure of a gradual thread provided in an embodiment of the present application.

[0032] Reference numerals:

[0033] 210, first tool; 211, main tool side; 212, auxiliary tool side; 220, second tool; 230, basic thread; 231, top side; 232, crown side; 233, slope surface; 234, tooth bottom; 240, gradual thread; 241, second top side; 250, top end side; 260, crown end side. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0035] In the description of the present application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integrated connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0037] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments.

[0038] In the field of medical devices, bone implants (implants) can replace or repair bone tissue lost due to disease, injury or congenital defects. The rationality of stress distribution on the surface of the implanted part of the bone implant directly affects the formation of bone integration and the long-term success rate of implant restoration. However, the stress on the surface of the implanted part can be changed by designing the thread to change the mechanical transmission of the implant and the stress distribution at the bone interface. At the same time, the shape of the surface thread not only has a great influence on the speed of bone integration, but also can improve the initial stability of the implant, increase the surface area of ​​the implant, and improve the stress distribution at the bone interface. Therefore, the surface thread design occupies a very important position in the biomechanical optimization design of implants.

[0039] Taking dental implants as an example, during the screwing process of the commonly used implants with tapered core tops, the thread grooves rise along the direction of the crown, which will form obvious extrusion with the jawbone. At the same time, excessive extrusion means that the friction between the implant and the jawbone is large, which generates more heat during the screwing process. In addition, excessive extrusion of the bone can also cause damage to bone cells and blood vessels in the bone, delayed bone healing, and even implant failure. At the same time, due to the increase in friction and extrusion force, the resistance of this implant during the screwing process will increase, that is, a larger screwing torque is required, which also increases the risk of mechanical damage to the implant. At the same time, the bone extrusion amount of the implant cannot be too small, which will lead to poor initial stability. However, due to the great difference in the density and hardness of different people's jaws, the same implant has a great difference in the extrusion effect when implanted in different people's jaws, which determines that it is difficult to balance this implant. Therefore, there is a need for an implant with small bone extrusion but high initial stability.

[0040] In addition, since the strength of the cortical bone in the jaw is much greater than that of the cancellous bone, the threads on the cortical bone should have sufficient strength. The processing method of the tapered implant causes the groove between the crown threads to rise, which significantly improves the strength of the threads at the cortical bone. However, the contact area between the threads and the maxillary bone is significantly reduced, reducing the bone attachment area and the stress area. Therefore, this type of implant is prone to loosening during repeated loading, leading to peri-implantitis, which in turn causes bone absorption and reduces the long-term stability of the implant.

[0041] The existing processing technology of implant external threads is complicated, and it requires frequent tool changes and multiple cutting to complete the production, which has high processing costs and low efficiency, resulting in high production costs of implants and increased financial burden on patients.

[0042] Based on this, the present application provides a method for processing a gradual thread, which can complete the gradual thread with multiple slope surfaces with only two cuts, and the process setting is simple, the processing cost is low, and the efficiency is high. The gradual thread processed by this method has the characteristics of small bone extrusion force, high initial stability and long-term stability, and high thread strength at the cortical bone.

[0043] In order to facilitate the understanding of the present application, the following embodiments take a dental implant used in the field of dental implantation as an example.

[0044] like Figure 1 As shown, the present application provides a method for processing a gradual thread, which can be applied to bone implants (i.e. implants) in the field of medical devices. The bone implants are made by machining the workpiece through turning and other processes. The above-mentioned machining method may include:

[0045] In step S110 , the workpiece is turned using the first tool 210 to form a basic thread 230 . The basic thread 230 includes a top side surface 231 , a crown side surface 232 , and a lateral surface connecting the top side surface 231 and the crown side surface 232 . The top side surface 231 has a plurality of slope surfaces 233 with different slopes.

[0046] In step S120, the second top side surface 231 is cut using the second tool 220 to obtain a second top side surface 241. The second top side surface 241 includes a plurality of slope surfaces 233. Along the direction of the center axis of the workpiece to be processed, the slope surface 233 connecting the tooth bottom gradually increases in width of the second top side surface 241, and the slope of the slope surface 233 is smaller than that of other slope surfaces.

[0047] In this embodiment, the first tool 210 feeds along the central axis of the workpiece to be processed, wherein the feed side can be defined as the top side, and the exit side can be defined as the crown side, wherein the top side is thinner. During turning, the workpiece to be processed is fixed on the lathe and rotates at high speed with the axis. The first tool 210 is fixed on the lathe to process the surface of the workpiece to be processed.

[0048] like Figure 2 As shown, the first tool 210 includes a main tool side 211 and an auxiliary tool side 212. The main tool side 211 is used to machine the top side surface 231, and the auxiliary tool side 212 is used to machine the crown side surface 232. The second tool 220 cuts the top side surface 231 to obtain a second top side surface 241. The main tool side 211 also includes a plurality of connected cutting edges, and adjacent cutting edges have an included angle.

[0049] Specifically, the first tool 210 has two cutting sides, which are respectively defined as a main tool side 211 and an auxiliary tool side 212. The main tool side 211 is used to process and form the top side 231, and the auxiliary tool side 212 is used to process and form the crown side 232. The main tool side 211 and the auxiliary tool side 212 can be arranged at two ends of the first tool opposite to each other.

[0050] The main tool side 211 of the first tool 210 is provided with at least two connected cutting edges, and there is a certain angle between adjacent cutting edges. Exemplarily, the main tool side 211 and the auxiliary tool side 212 of the first tool 210 can be arranged relatively to each other, and the top side surface 231 and the crown side surface 232 can be processed simultaneously during feed. The at least two cutting edges provided on the main tool side 211 are used to process multiple slope surfaces 233. Since there is a certain angle between adjacent cutting edges, the multiple slope surfaces 233 processed also have angles between them. Multiple slope surfaces 233 can be processed by one feed, and the process is simple and the processing efficiency is high.

[0051] Exemplarily, the tool head of the second tool 220 is provided with a cutting edge, and the cutting edge of the second tool 220 cuts the top side surface 231, thereby obtaining the second top side surface 241. In this embodiment, the second tool 220 is used to perform a second feed, so that the width proportion of a slope surface 233 of the second top side surface 241 gradually increases. Two feeds can complete the processing of multiple slope surfaces 233, and achieve the purpose of gradually increasing the width proportion of a slope surface 233, with simple process settings, low processing costs and high efficiency.

[0052] It should be noted that the second tool 220 cuts the slope surface 233 connected to the tooth bottom 234 in the top side surface 231. Since the slope of the slope surface 233 connected to the tooth bottom 234 is the smallest, as the proportion of the slope surface 233 in the width of the second top side surface 241 increases, the thread width becomes wider and wider. Therefore, in the process of the thread being screwed into the bone tissue, the effect of the backward thread on the bone compression is more obvious, so as to achieve the expected mechanical effect.

[0053] In this embodiment, when the second tool 220 cuts the top side surface 231, various processing methods such as turning and milling can be used. For example, the second tool 220 is fixed and the workpiece to be processed is rotated to cut the top side surface 231; or the workpiece to be processed is fixed and the second tool 220 is rotated to cut the top side surface 231.

[0054] like Figure 2 As shown, the basic thread 230 includes a top side surface 231, a crown side surface 232, and a lateral surface connecting the top side surface 231 and the crown side surface 232, the lateral surface defines the radial outer surface of the basic thread 230, and the basic thread 230 extends spirally along the direction of the central longitudinal axis of the workpiece to be processed. The top side surface 231 includes two slope surfaces 233, which are cut by two cutting edges of the first tool 210. Among them, the angle between the cutting edge close to the tooth bottom 234 of the basic thread 230 and the radial direction of the workpiece to be processed is greater than the angle between the other cutting edge and the radial direction of the workpiece to be processed, that is, the angle between the cutting edge close to the tooth bottom 234 of the basic thread 230 and the radial direction of the workpiece to be processed is the largest. This setting can minimize the slope of a slope surface 233 connecting the tooth bottom 234.

[0055] like Figure 3 and 6As shown, the gradual thread 240 includes a second top side surface 241, a crown side surface 232, and a lateral surface, wherein a slope surface 233 connecting the tooth bottom 234 gradually increases the width of the second top side surface 241. Since the slope of the slope surface 233 is smaller than that of other slope surfaces 233, it is possible to achieve the purpose that as the slope surface 233 increases the width of the second top side surface 241, the thread width becomes wider and wider. Then, in the process of screwing the thread into the bone tissue, the effect of the backward thread squeezing the bone is formed. It should be noted that the slope in this embodiment refers to the angle formed between the surface of the slope surface 233 and the central longitudinal axis of the bone implant (implant).

[0056] In this embodiment, the multi-slope surface 233 of the gradual thread 240 can be processed by two cuttings, and the process setting is simple, the cost is low, and the efficiency is high. The gradual thread 240 processed and manufactured according to the method can improve the effect of the initial stability of the implant. During the screwing process of the bone implant, the gradual thread 240 of the bone implant will squeeze the cortical bone and the cancellous bone because the slope surface 233 on the top side of the gradual thread 240 gradually increases the proportion of the width of the top side. At the same time, during the screwing process of the bone implant, the lower thread is screwed in along the trajectory of the upper thread in sequence, gradually increasing the squeezing force. Since the top side and the crown side 232 of the gradual thread 240 will squeeze the cartilage, the bone squeezing area is significantly increased, which is easier for bone attachment, and the force area is larger. The expected mechanical effect can be achieved with less bone squeezing per unit area, so the initial stability requirement can be achieved with less bone compression, which reduces the damage to bone cells and blood vessels, improves the speed of the implant combining with the bone after implantation, and can significantly improve the implantation success rate while reducing the pain of the recipient.

[0057] See also Figure 2 and Figure 3 The workpiece to be processed includes a top side 250 and a coronal side 260. The feed side of the first tool 210 is the top side 250, and the side along the feed direction of the first tool 210 is the coronal side 260. The second top side surface 241 faces the top side 250, and the gradual thread 240 extends from the top side 250 to the coronal side 260.

[0058] The top side 250 is usually defined as the end of the bone implant that first enters the bone tissue, and the coronal side 260 is opposite to it and is the end that enters the bone tissue later, or is exposed outside the bone tissue. In the process of machining the gradual thread 240, according to the direction of the feed, the top area is the smallest, or it can be approximated as a tip to reduce resistance. In the process of the gradual thread 240 being screwed into the bone tissue, the second top side surface 241 facing the top side 250 can ensure that the second top side surface 241 with multiple slope surfaces 233 contacts the bone first, squeezes the bone tissue, achieves the expected mechanical effect, and improves stability.

[0059] In this embodiment, the above-mentioned one slope surface 233 is a slope surface 233 connecting the tooth bottom 234 of the gradual thread 240. The slope of the slope surface 233 connecting the tooth bottom 234 is set to be the smallest, and as the proportion of the width of the slope surface 233 to the second top side surface 241 increases, the thread width becomes wider and wider, so that in the process of screwing the thread into the bone tissue, the backward thread has a more obvious effect of squeezing the bone, making it more stable.

[0060] In one embodiment, using the second tool 220 to cut one of the plurality of slope surfaces 233 to obtain the gradual thread 240 includes: the second tool 220 feeds along the tooth bottom 234 of the gradual thread 240 .

[0061] Specifically, when the second tool 220 is used for processing in this embodiment, the second tool 220 feeds along the contour of the tooth bottom 234 of the gradual thread 240, and can directly cut the slope surface 233 connected to the tooth bottom 234 starting from the tooth bottom 234. This feeding method has a relatively simple processing technology, and only needs to feed along the contour of the tooth bottom 234 of the gradual thread 240, without adding other positioning measures to the tool.

[0062] In this embodiment, the pitch set when processing with the first tool 210 can be greater than the pitch set when processing with the second tool 220. This method can make the second tool 220 gradually move away from the crown side 232 of the same thread when processing along the feed direction, thereby achieving the purpose of gradually increasing the proportion of the processed slope surface 233 to the width of the second top side surface 241.

[0063] In one embodiment, the pitch of the first tool 210 and the second tool 220 can be set using the following formula:

[0064] P 2 =P 1 -D / m

[0065] Among them, P 1 is the pitch of the first tool 210, P 2 is the pitch of the second tool 220, D is the preset bone compression amount, and m is the number of threads of the gradual thread.

[0066] The difference in pitch between the first tool 210 and the second tool 220 is negatively correlated with the number of threads and positively correlated with the preset bone extrusion amount. If the workpiece is longer and has more threads, each thread will have a certain width after being cut by the second tool 220. After the second tool 220 completes the cutting, the last thread becomes wider, and the increased width is the preset bone extrusion amount. Therefore, this method can ensure that implant threads of different lengths have consistent implantation torque, which is convenient for operation.

[0067] For example, an implant with a length of 10 mm is provided with 10 threads of gradual change, and its pitch is 0.79 mm. Then, when the second tool 220 is cutting, each thread will be superimposed by a distance of 0.01 mm. After the second tool 220 cuts the last thread, the last thread becomes 0.1 mm wider than the first thread, that is, the preset bone extrusion amount is 0.1 mm. For another example, an implant with a length of 15 mm is provided with 20 threads of gradual change. At this time, according to the above formula, the pitch difference between the first tool 210 and the second tool 220 becomes 0.005 mm. At this time, when the second tool 220 is used for cutting, each thread increases the width of 0.005 mm compared with the previous thread, so that the last thread becomes 0.1 mm wider than the first thread. This ensures that the implant with a length of 15 mm has the same extrusion amount as the implant with a length of 10 mm, and further ensures that implants of different lengths have consistent implantation torques, which is convenient for operation.

[0068] In a specific embodiment, when the first tool 210 is used for processing, the pitch can be set to 0.8 mm, and when the second tool 220 is used for processing, the pitch can be approximately set to (0.78+0.001L) mm, where L is the length of the implant. The pitch of the second tool 220 should change with the length of the implant. Compared with short implants (bone implants), long implants need to be set to a smaller pitch to ensure that each thread is cut by the second tool 220. Therefore, this setting can ensure that the processed gradual thread 240 has a consistent implantation torque, which is convenient for operation. It should be noted that the pitch can also be adjusted according to the above formula by setting different parameter values.

[0069] In another embodiment, using the second tool 220 to cut one of the multiple slope surfaces 233 to obtain the gradual thread 240 includes: when the second tool 220 feeds, the second tool 220 gradually moves away from the tooth bottom along the direction of the center axis of the workpiece to be processed.

[0070] like Figure 4 As shown, when machining the gradual thread 240 , the first tool 210 is first used to lathe the surface of the workpiece to form the basic thread 230 , and then the second tool 220 is used to cut the basic thread 230 to complete the machining of the gradual thread 240 .

[0071] During this machining process, the cutting trajectories of the first tool 210 and the second tool 220 each include three segments: a 4 mm segment, a 2 mm segment, and a remaining segment.

[0072] When processing the 4 mm segment, the angle between the cutting track of the first tool 210 and the central axis of the workpiece to be processed is 7°; when processing the 2 mm segment, the angle between the cutting track of the first tool 210 and the central axis of the workpiece to be processed is 0°; when processing the remaining segments, the angle between the cutting track of the first tool 210 and the central axis of the workpiece to be processed is 3.8°. Preferably, the pitch of the first tool 210 in this embodiment is set to 0.8 mm.

[0073] After the first tool 210 completes turning, the second tool 220 is used to cut the top side surface of the basic thread 230. It should be noted that when the second tool 220 is used to cut a 4 mm segment, the angle between the cutting trajectory of the second tool 220 and the central axis of the workpiece to be processed is 7.5°. It can be seen that along the direction of the central axis of the workpiece to be processed, the trajectory of the second tool 220 is 0.5° higher than the trajectory of the first tool 210, that is, the tool is lifted for cutting. In other words, along the direction from the top to the crown end, the second tool 220 gradually moves away from the bottom of the tooth during processing, and forms an angle of 0.5° with the trajectory of the first tool 210. Therefore, the area of ​​the slope surface cut by the second tool 220 gradually decreases, so that the proportion of the slope surface gradually increases. The specific settings of the first tool 210 and the second tool 220 can be found in Figure 4 Partial view B.

[0074] Similarly, when the second tool 220 is used to cut a 2 mm segment, the angle between the cutting trajectory of the second tool 220 and the central axis of the workpiece to be processed is 0.5°, that is, along the direction of the central axis of the workpiece to be processed, the trajectory of the second tool 220 is 0.5° higher than the trajectory of the first tool 210, that is, along the direction from the top to the crown, the second tool 220 gradually moves away from the tooth bottom and forms an angle of 0.5° with the trajectory of the first tool 210. At this time, the area of ​​the slope surface cut by the second tool 220 gradually decreases, ensuring that the proportion of the slope surface is also gradually increased.

[0075] In addition, when the second tool 220 is used to cut the remaining section, the angle between the cutting trajectory of the second tool 220 and the central axis of the workpiece to be processed is 4.2°, that is, along the direction of the central axis of the workpiece to be processed, the trajectory of the second tool 220 is 0.4° higher than the trajectory of the first tool 210, that is, along the direction from the top to the crown, the second tool 220 gradually moves away from the tooth bottom and forms an angle of 0.4° with the trajectory of the first tool 210. At this time, the area of ​​the slope surface cut by the second tool 220 gradually decreases, so that the proportion of the slope surface has a tendency to gradually increase.

[0076] When the second tool 220 is used to cut the finishing thread, the angle between the trajectory of the cutting finishing thread and the central axis of the workpiece to be processed is 4°. When finishing, the pitch of the second tool 220 is also set to 0.8 mm.

[0077] It should be noted that the 4 mm segment, 2 mm segment and remaining segments set in this embodiment can be set to other length segments according to actual application conditions, and the number of length segments can also be set according to actual conditions, and this application does not make specific limitations.

[0078] It can be seen from the cutting trajectories of the first tool 210 and the second tool 220 that the cutting method of the second tool 220 in this embodiment is cutting with the tool lifted, that is, the second tool 220 gradually moves away from the tooth bottom in the direction from the top to the crown end, and cuts the slope surface of the basic thread 230. The area of ​​the slope surface cut by the second tool 220 gradually decreases, thereby ensuring that the proportion of the slope surface cut gradually increases. In this embodiment, the slope surface cut is the slope surface connecting the tooth bottom.

[0079] In this embodiment, the same pitch is set when the first tool 210 is used for processing and the second tool 220 is used for processing, and other values ​​can also be set according to actual conditions. The pitch setting range given in this embodiment is 0.3-4mm, preferably 0.8mm, so that the processed gradual thread 240 has better stability.

[0080] In another embodiment, if Figure 5 As shown, the main tool side of the first tool 210 can also be set as an arc-shaped cutting edge, so the above-mentioned slope surface turned by the first tool 210 is arc-shaped. The slope surface is gradually cut away from the tooth bottom by the second tool 220, so that the proportion of the width of the second top side surface 241 occupied by the slope surface 233 can gradually increase. It can also achieve that as the proportion of the width of the second top side surface 241 occupied by the slope surface 233 increases, the thread width becomes wider and wider, and in the process of the thread being screwed into the bone tissue, the backward thread has a more obvious effect on bone compression and higher stability.

[0081] In one embodiment, in an implant having the above-mentioned gradual thread 240, the gradual thread 240 extends from the top side 250 to the coronal side 260, and the proportion of the width of the second top side surface 241 occupied by one of the multiple slope surfaces is set to M, wherein the value range of M is 0%<M<100%. That is, the proportion of one of the slope surfaces constituting the second top side surface 241 gradually increases from nothing to something, until the entire second top side surface 241 is completely constituted by the above-mentioned one slope surface. Thus, the extrusion force is gradually increased during the screwing-in process of the bone implant until the extrusion force is maximum. This structure is easier for bone attachment, has a larger force-bearing area, and can achieve the expected mechanical effect with less bone extrusion per unit area, thereby meeting the requirements of initial stability.

[0082] Of course, along the direction extending from the top side 250 to the coronal side 260, the width of one of the multiple sloped surfaces can gradually increase as a constant variable as a proportion of the width of the second top side surface 241. This allows the force applied to the cortical bone and cancellous bone to increase steadily and evenly, thereby reducing the pain of the recipient and avoiding discomfort caused by too rapid an increase in the squeezing force.

[0083] This embodiment can make the extrusion effect (extrusion force) of the bone in each implanted section consistent, make the mechanical distribution more uniform and reasonable, and avoid excessive extrusion. At the same time, the implantation torque of the implant can be adjusted by changing the gradual angle increment to avoid implantation difficulties.

[0084] It should be noted that, along the direction extending from the top side 250 to the coronal side 260, the proportion of the width of one of the multiple slope surfaces to the width of the second top side surface 241 can be gradually increased with a constant variable, or can be set to gradually increase with a non-constant variable, and the increment of the above-mentioned slope surface in different sections of the gradual thread segment can be determined according to the actual bone quality of the patient. The increment can also be freely combined and set, for example: if the bone density of the implantation area of ​​the recipient is uniform in a certain section, then the section of the gradual thread segment in the bone implant that matches the implantation area with uniform bone density changes in a constant increment, and when the bone density of the implantation area of ​​the recipient changes in a gradient in a certain section, then the section of the gradual thread segment in the bone implant that matches the implantation area with uniform bone density changes in a gradient increment.

[0085] Compared with the existing tapered threads, the tapered threads 240 provided in the present application have a gradually increasing proportion of the width of a slope surface of the second top side surface 241, which means that the area of ​​the thread used to squeeze the bone tissue here is significantly larger, which disperses the heat generated when the implant is screwed in with the same torque, and the pain of the recipient will be much less. In addition, since the compression area between the thread and the cartilage is significantly larger, the expected stability effect can be achieved with less bone compression per unit area, which reduces the damage to bone cells and blood vessels in the bone. The speed of the implant combining with the bone after implantation is improved. At the same time, as the thread width becomes wider, the strength of the thread at the cortical bone is significantly enhanced, which increases the contact area between the thread and the cartilage and makes the force more dispersed, which increases the axial compression force that the implant can withstand.

[0086] In this embodiment, the bone implant (implant) realizes the axial step-by-step extrusion of the bone tissue in the implantation socket by setting a gradual thread. During the screwing process of the bone implant, due to the direction in which the thread of the gradual thread segment extends from the top side 250 to the crown side 260, one of the slope surfaces gradually increases the width of the second top side 241, and the gradual thread of the bone implant will squeeze the cortical bone and cancellous bone, and the lower thread will be screwed in along the trajectory of the upper thread in turn, gradually increasing the squeezing force. Since the second top side 241 and the crown side 232 of the gradual thread will squeeze the cartilage, the bone squeezing area is significantly increased, which is easier to attach the bone, and the force area is larger. The expected mechanical effect can be achieved with less bone squeezing per unit area, so the initial stability requirements can be achieved with less bone compression, which reduces the damage to bone cells and blood vessels, improves the speed of the implant combining with the bone after implantation, and can significantly improve the implantation success rate while reducing the pain of the recipient. The invention solves the technical problems in the prior art that when implanting a dental implant, the bone is severely damaged, the mechanical distribution of the implant in the alveolar bone is single, the initial stability is poor, and the high implant failure rate is caused.

[0087] In one embodiment, the top side surface 231 of the gradual thread includes N slope surfaces connected in sequence, N≥2, wherein the first slope surface is connected to the tooth bottom, the Nth slope surface is connected to the tooth top, and the width of the first slope surface gradually increases along the direction extending from the top side 250 to the crown side 260. The first slope surface is the slope surface connected to the tooth bottom. The second tool 220 cuts the first slope surface to form a second top side surface 241.

[0088] The gradient thread processing method provided by the present application sets the gradient of the gradient surface 233 connecting the tooth bottom to the minimum. As the gradient surface 233 accounts for an increasing proportion of the width of the second top side surface 241, the thread width becomes wider and wider. Therefore, in the process of screwing the thread into the bone tissue, the effect of the backward thread on bone compression is more obvious and the stability is higher. The present application only needs two cuts to complete the gradient thread with multiple gradient surfaces 233. The process setting is simple, the cost is low and the efficiency is high. The technical problem that the tapered thread processing technology of medical implants is complicated, the processing cost is high, the efficiency is low, and the cost of implants is high is solved.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and do not limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for processing a gradual thread, characterized in that: The processing method comprises: Using a first tool to turn a workpiece to be processed to form a basic thread, the basic thread includes a top side surface, a crown side surface, and a lateral surface connecting the top side surface and the crown side surface, the top side surface has a plurality of slope surfaces with different slopes; A second top side surface is obtained by cutting the top side surface with a second tool, wherein the second top side surface includes a plurality of slope surfaces, wherein, along the direction of the central axis of the workpiece to be processed, the slope surface connecting the tooth bottom gradually increases in proportion to the width of the second top side surface, and the slope of the slope surface is smaller than that of other slope surfaces.

2. The method for processing a gradual thread according to claim 1, characterized in that: The cutting process of the top side surface by using a second tool to obtain the second top side surface comprises: The second tool feeds along the tooth bottom.

3. The method for processing a gradual thread according to claim 2, characterized in that: The pitch set when the first tool is used for machining is greater than the pitch set when the second tool is used for machining.

4. The method for processing a gradual thread according to claim 3, characterized in that: The pitch of the first tool and the second tool is set using the following formula: P2=P1-D / m Among them, P1 is the pitch of the first tool, P2 is the pitch of the second tool, D is the preset bone compression amount, and m is the number of threads of the gradual thread.

5. The method for processing a gradual thread according to claim 1, characterized in that: The cutting process of the top side surface by using a second tool to obtain the second top side surface comprises: When the second tool advances along the direction of the central axis of the workpiece to be processed, the second tool gradually moves away from the tooth bottom; The first tool and the second tool are set with the same pitch, and the pitch setting range is 0.3-4mm.

6. The method for processing a tapered thread according to any one of claims 1 to 5, characterized in that: The workpiece to be processed includes a top end side and a coronal end side. Along the feed direction of the first tool, the feed side is the top end side, and the exit side is the coronal end side. The top end side is thinner. The first tool includes a main tool side and a secondary tool side. Along the direction extending from the top end side to the crown end side, the main tool side is used to form the top side surface, and the secondary tool side is used to form the crown side surface, wherein the main tool side also includes a plurality of connected cutting edges, and adjacent cutting edges have an included angle.

7. The method for processing a tapered thread according to claim 6, characterized in that: The main tool side has an arc-shaped cutting edge.

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