Pile channel preparation guide and method of making same

Abstract

The application discloses a pile channel preparation guide device and a manufacturing method thereof, and belongs to the technical field of oral cavity restoration. The application aims to manufacture a pile channel preparation guide device which can guide a doctor to accurately and simply realize the direction preparation and depth control of a predetermined pile channel. The pile channel preparation guide device manufactured by the manufacturing method has a retainer which can be embedded in a target dental pulp chamber. A guide structure is arranged in the retainer, and the guide structure has a direction which is extremely suitable for the preparation of a target root channel. The guide structure can effectively ensure the accuracy of the direction of the pile channel preparation. The length of the guide structure is equal to the working length recorded during the preparation of the root channel, minus the length of the target root channel from the target root channel opening to the root tip of the target root channel, and plus the reserved root tip sealing length. Therefore, the guide structure has a length which is extremely suitable for the preparation of the target root channel. It can be seen that the doctor can accurately and simply realize the preparation of the direction of the predetermined pile channel and the control of the depth by using the pile channel preparation guide device manufactured by the manufacturing method.

Description

Technical Field

[0001] This invention belongs to the field of oral restoration technology, specifically relating to a post preparation and guidance device and its manufacturing method. Background Technology

[0002] In the process of dental restoration, teeth often fail to form a sufficient full crown retention shape due to excessively large defects after root canal treatment. In such cases, a post and core restoration is necessary to provide adequate support and retention for subsequent crown fabrication. The first step in post and core restoration is post preparation. Using a reamer, the upper portion of the root canal filling material is removed in a predetermined direction, appropriately enlarging the root canal to fix the prefabricated post or cast post into the canal. Before preparation, the working length should be determined based on the X-ray and marked on the reamer. At least 3-5 mm of apical closure length should be retained, and the post diameter should be 1 / 3 of the horizontal cross-sectional diameter of the root to avoid damaging the integrity of the root filling material, which could lead to reinfection and reduce the lifespan of the tooth.

[0003] Due to the limited field of vision during post preparation, most post preparations in clinical practice currently rely on the experience of physicians. The preparation direction, the length of the residual apical seal after preparation, and the thickness of the root tooth tissue are all highly uncertain, making it difficult to completely restore the post designed before the operation, which affects the lifespan of the restoration after post and core restoration and the health of the residual tooth tissue. Summary of the Invention

[0004] This invention provides a method for manufacturing a pile preparation and guidance device, which aims to create a pile preparation and guidance device that can guide physicians to accurately and easily achieve the direction preparation and depth control of a predetermined pile path.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a method for manufacturing a pile preparation and guidance device, including the step of manufacturing a design prototype of the pile preparation and guidance device into a finished product; the design prototype of the pile preparation and guidance device includes a design prototype of a retaining body.

[0006] The design process of the prototype of the pile preparation guiding device is as follows:

[0007] S1. Obtain three-dimensional data of the target tooth position and its adjacent teeth, and generate a digital model of the crown including data of the target root canal and the target pulp chamber;

[0008] S2. Based on the digital model of the crown, the guiding direction is determined according to the direction of the target root canal, and the placement direction of the post preparation guide device is determined according to the undercut structure of the target tooth and its adjacent teeth.

[0009] S3. Design the prototype of the retainer according to the following steps;

[0010] A1. Based on the digital model of the crown, a matching retention body bottom surface is designed according to the bottom surface of the target pulp chamber and the shape of the target root canal orifice. A guide outlet is designed on the bottom surface of the retention body, and the projection of the guide outlet along the guiding direction is inside the target root canal orifice.

[0011] A2. Stretch the guide opening by a distance D in the opposite direction of the guiding direction to obtain the design prototype of the guide structure; D = b - a + c, where: a represents the length from the target root canal orifice to the root apex of the target root canal measured along the guiding direction, b represents the working length recorded during root canal preparation, and c represents the reserved root apex closure length.

[0012] A3. Extend the body of the fixation body in the opposite direction of the positioning direction with the bottom surface of the fixation body as the base surface. The extension distance must ensure that the body of the fixation body can at least completely cover the peripheral wall of the guide structure to obtain the design prototype of the body of the fixation body.

[0013] A4. Incorporate the design prototype of the guide structure into the design prototype of the main body of the fixation body, and make the guide inlet at the upper end of the guide structure located on the top surface of the main body of the fixation body to obtain the design prototype of the fixation body.

[0014] Furthermore, the digital model of the crown in step S1 is mainly generated by fitting the first digital model and the second digital model;

[0015] The first digital model is obtained by acquiring three-dimensional data of the target tooth position and its adjacent teeth through CBCT and importing them into reverse engineering software in DICOM format;

[0016] The second digital model is obtained by acquiring three-dimensional data of the target tooth position and its adjacent teeth through an intraoral scanner and importing it into reverse engineering software in STL format.

[0017] Furthermore, in step A1, the process of designing the guide exit is as follows: when the pre-loaded needle to be used is arranged along the guiding direction and its end faces the position on the bottom surface of the retainer corresponding to the target root canal opening, the outline of its projection on the bottom surface of the retainer corresponding to the target root canal opening is the theoretical guide outline; the outline formed on the bottom surface of the retainer after the theoretical guide outline is shifted outward by 0 to 0.1 mm is the outline of the guide exit.

[0018] Furthermore, the design prototype of the pile preparation guide device also includes a design prototype of the cover plate;

[0019] The design process of the prototype of the pile preparation guide device also includes steps S4 and S5;

[0020] S4. Based on the digital model of the crown, design a cover plate that can be worn on the target tooth position and obtain the design prototype of the cover plate;

[0021] S5. When the design prototypes of the retainer and the cover plate are installed together with the digital model of the crown, the overlapping parts are combined to obtain the design prototype of the assembly. An undercut structure is made on the top surface of the design prototype of the assembly to expose the guide inlet, thus obtaining the design prototype of the post preparation guide device.

[0022] Furthermore, in step S4, the specific design process of the cover plate prototype is as follows:

[0023] B1. Based on the digital model of the tooth crown, determine the mesial and distal margins of the buccal and lingual surfaces of the target tooth, as well as the observation line; the observation line is the line connecting the outermost contour line of the buccal surface of the tooth and the outermost contour line of the lingual surface of the tooth along the circumference of the tooth when the position direction is taken as the observation direction.

[0024] B2. The theoretical morphology of the tissue surface of the cover plate is designed, including the mesiodistal margin and the buccal-lingual margin; the mesiodistal margin is based on the teeth. The buccal and lingual margins are defined by the mesial and distal margins, and the buccal and lingual margins are defined by the lines where the observation line is moved down 0.5 to 1.0 mm along the placement direction and intersects with the buccal and lingual surfaces of the tooth, respectively.

[0025] B3. Offset the theoretical shape of the cover plate's structure surface outward along its normal direction by 0-0.2mm to obtain the design prototype of the cover plate's structure surface; thicken the design prototype of the cover plate's structure surface outward along its normal direction by a distance c, where c is 3-5mm, to obtain the design prototype of the cover plate.

[0026] Furthermore, step B3 also includes the process of designing lingual retention arms and labial-buccal retention arms on the lower buccal and lingual sides of the cover plate, respectively, wherein the lingual retention arms and labial-buccal retention arms are used to connect and fix to the adjacent teeth of the target tooth position.

[0027] Furthermore, in step A3, the extended distance is D;

[0028] In step A4, the design prototype of the guide structure is subtracted from the design prototype of the main body of the fixation body through a Boolean operation to obtain the design prototype of the fixation body.

[0029] In step S5, the design prototype of the fixed body and the design prototype of the cover plate are added together by Boolean operation to obtain the design prototype of the pile channel pre-guiding device.

[0030] The design prototype of the pile preparation and guidance device is output as design data in STL format, and then manufactured into a finished product by 3D printing equipment.

[0031] The present invention also provides a track preparation guide device that can guide physicians to accurately and easily achieve the direction preparation and depth control of a predetermined track, which is manufactured by the above-mentioned track preparation guide device manufacturing method.

[0032] Furthermore, the pre-guided pile path includes a retaining body and a cover plate;

[0033] The upper part of the retainer is integrated with the central part of the cover plate, and the part of it not connected to the cover plate can be embedded in the target pulp chamber.

[0034] The retainer body has a guide structure along the guiding direction. The upper opening of the guide structure is a guide inlet on the top surface of the cover plate, and the lower opening of the guide structure is a guide outlet on the bottom surface of the retainer body. When the retainer body is embedded in the target pulp chamber, the guide outlet corresponds to the target root canal orifice.

[0035] The bottom of the cover plate is designed to fit against the cheek, lingual, and other surfaces of the teeth. And the cover plate is used in conjunction with the connection.

[0036] Furthermore, the lower buccal and lingual sides of the cover plate are respectively provided with lingual retention arms and labial-buccal retention arms, both of which are used to connect and fix with adjacent teeth at the target tooth position.

[0037] The beneficial effects of this invention are as follows: The post preparation guide device manufactured by this method has a retainer that can be embedded in the target pulp chamber. The guide structure within the retainer is arranged along the guiding direction, and the guide outlet of the guide structure is on the bottom surface of the retainer and corresponds to the orifice of the target root canal. Therefore, the guide structure has a direction highly suitable for the preparation of the target root canal post, and during post preparation, it can better restrict the direction of the distal end of the post preparation bur, effectively ensuring the accuracy of the post preparation direction. Furthermore, the length of the guide structure is equal to the working length recorded during root canal preparation minus the length from the orifice of the target root canal to the apex of the target root canal measured along the guiding direction, plus the reserved apical closure length. Therefore, the guide structure has a direction highly suitable for the target root canal post. The length of post preparation is significant. It is evident that when using the post preparation guide device manufactured using this method, the dentist is largely unrestricted by field of vision. Even in poorly oriented conditions, precise control of the prepared post direction and depth can be achieved, preventing over-preparation, reducing damage to the patient's hard tissues, ensuring the apical closure length, and essentially replicating the pre-designed post. This effectively guarantees the lifespan of the restoration and the health of residual tooth structure after post-core restoration. Furthermore, using the post preparation guide device manufactured using this method is not only easy to operate and requires little experience, making it easy for beginners to quickly master, but it also significantly reduces post preparation time, thereby improving the dentist's clinical work efficiency. Attached Figure Description

[0038] Figure 1 This is a process flow diagram of the manufacturing method of the pile preparation and guiding device in this invention;

[0039] Figure 2 This is a schematic diagram of one embodiment of the pile preparation and guiding device of the present invention;

[0040] Figure 3 This is a schematic diagram of another embodiment of the pile preparation and guiding device in this invention;

[0041] Figure 4 This is a diagram showing the alignment of the pre-guided pile guide device in this invention before it is worn at the target tooth position.

[0042] Figure 5 This is a top view of the pile preparation guide device of the present invention worn on the target tooth position;

[0043] Figure 6 It is along Figure 5 Sectional view of the middle RR line;

[0044] Figure 7 This is a diagram showing the alignment of the pile preparation guide device before it is worn at the target tooth position in Embodiment 2 of the present invention.

[0045] Figure 8 This is a diagram showing the alignment of the pile preparation guide device before it is worn at the target tooth position in Embodiment 3 of the present invention.

[0046] The markings in the diagram are as follows: Target tooth position 100, Target root canal 110, Target root canal orifice 111, Guiding direction 112, Placement direction 113, Target pulp chamber 120, Mesial margin line 131, Distal margin line 132, Observation line 133, Buccal surface of tooth 141, Lingual surface of tooth 142, Tooth 143, Post preparation guide device 200, Retainer 210, Retainer bottom surface 211, Guiding exit 212, Guiding structure 213, Guiding inlet 214, Cover plate 220, Cover plate tissue surface 221, Lingual retention arm 222, Labial / buccal retention arm 223. Detailed Implementation

[0047] The invention will now be further described with reference to the accompanying drawings.

[0048] In the description of this invention, it should be noted that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for ease of description, not to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention; the expression "mainly composed of or generated from..." is interpreted as also including other components not mentioned in the sentence; the target tooth position 100 refers to the tooth for which post preparation is to be performed, the adjacent teeth of the target tooth position 100 include its mesial adjacent teeth and / or its distal adjacent teeth, and the target tooth root canal 110 refers to the root canal for which a post is to be implanted; "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist, for example: A and / or B, which can indicate: A alone, A and B simultaneously, and B alone. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] The present invention provides a method for manufacturing a pile preparation and guidance device, which includes the step of manufacturing a design prototype of the pile preparation and guidance device 200 into a finished product; the design prototype of the pile preparation and guidance device 200 includes a design prototype of the retaining body 210.

[0050] The design process of the prototype of the pile preparation guide device 200 is as follows:

[0051] S1. Acquire the three-dimensional data of the target tooth position 100 and its adjacent teeth, and generate a digital model of the crown including the data of the target root canal 110 and the target pulp chamber 120. The digital model of the crown refers to the digital model that is converted into a digital model by the acquisition of three-dimensional data information such as shape, size and position through digital technology, which is convenient for data processing and analysis on a computer.

[0052] S2. Based on the digital model of the crown, the guiding direction 112 is determined according to the direction of the target root canal 110, and the placement direction 113 of the post preparation guide device 200 is determined according to the undercut structure of the target tooth position 100 and its adjacent teeth. The guiding direction 112 is usually the optimal post preparation direction determined by the physician based on the CT image or three-dimensional image of the target tooth position 100, or the optimal post preparation direction obtained by computer calculation and analysis. The placement direction 113 usually refers to the insertion direction that is most conducive to the stable wearing of the post preparation guide device 200 on the target tooth position 100 to achieve placement.

[0053] S3. Design the prototype of the retainer 210 according to the following steps;

[0054] A1. Based on the digital model of the crown, a matching retention body bottom surface 211 is designed according to the bottom surface of the target pulp chamber 120 and the shape of the target root canal orifice 111 of the target root canal 110. A guide outlet 212 is designed on the retention body bottom surface 211, and the projection of the guide outlet 212 along the guide direction 112 should be inside the target root canal orifice 111. This ensures that the post preparation bur to be used can accurately probe into the target root canal orifice 111 after it passes through the guide outlet 212.

[0055] A2. Stretch the guide outlet 212 a distance D in the opposite direction of the guide direction 112 to obtain the design prototype of the guide structure 213; D = b - a + c, where: a represents the length from the target root canal orifice 111 to the root tip of the target root canal 110 measured along the guide direction 112, b represents the working length recorded during root canal preparation, and c represents the reserved root tip closure length; the guide structure 213 obtained by stretching in the opposite direction of the guide direction 112 can better restrict the direction of the distal end of the root canal preparation needle during the root canal preparation process, ensuring the accuracy of the root canal preparation direction; moreover, the guide structure 213 of length D can accurately control the predetermined root canal depth, basically avoiding over-preparation of the root canal, and can ensure the root tip closure length.

[0056] A3. Extending the base surface 211 of the retainer along the opposite direction of the placement direction 113 to form the main body of the retainer 210. The extension distance must ensure that the main body of the retainer 210 can at least completely cover the peripheral wall of the guide structure 213, thus obtaining the design prototype of the main body of the retainer 210. The retainer 210 mainly serves as a carrier for opening the guide structure 213 and provides retention force while facilitating the corresponding fit between the guide structure 213 and the target root canal 110 during pile preparation. Ensuring that the main body of the retainer 210 can at least completely cover the peripheral wall of the guide structure 213 is to ensure that the guide structure 213 designed in step A2 can be opened within the main body of the retainer 210. Using the base surface 211 of the retainer as the base... The surface is extended to facilitate the insertion and fitting of the obtained retainer 210 body into the target pulp chamber 120. If the inserted retainer 210 body interferes with the pulp chamber wall of the target pulp chamber 120 during the insertion and fitting process, the data of the interfering part needs to be cut off to modify the design prototype of the retainer 210 body. In this step, the bottom surface of the target pulp chamber 120 or the bottom surface and pulp chamber wall of the target pulp chamber 120 can be used to replace the bottom surface 211 of the retainer as the base surface for extension, as long as the obtained retainer 210 body can completely cover the peripheral wall of the guide structure 213. If the formed retainer 210 body has excess size, it can be cut and modified accordingly.

[0057] A4. The design prototype of the guide structure 213 is implanted into the design prototype of the main body of the retainer 210, and the guide inlet 214 at the upper end of the guide structure 213 is located on the top surface of the main body of the retainer 210, thus obtaining the design prototype of the retainer 210. In this step, if the height of the designed main body of the retainer 210 is appropriate, the guide inlet 214 can be located exactly on the top surface of the main body of the retainer 210. If the height is too high, a groove or an indentation can be made on the top surface of the main body of the retainer 210 to expose the guide inlet 214.

[0058] To obtain a more accurate and reliable digital model of the crown, it is preferable that the digital model of the crown in step S1 is mainly generated by fitting the first digital model and the second digital model.

[0059] The first digital model is obtained by acquiring three-dimensional data of the target tooth position 100 and its adjacent teeth through CBCT and importing it into reverse engineering software in DICOM format; CBCT is the abbreviation for Cone Beam Computer Tomography; CBCT typically uses X-rays to acquire three-dimensional data and can create corresponding images;

[0060] The second digital model is obtained by acquiring three-dimensional data of the target tooth position 100 and its adjacent teeth through an intraoral scanner and importing it into reverse engineering software in STL format. An intraoral scanner is a diagnostic and therapeutic device used to scan and capture images and data inside the oral cavity. During the process of acquiring three-dimensional data using an intraoral scanner, it is necessary to ensure that the structure of the pulp chamber wall and floor of the target pulp chamber 120 and the target root canal orifice 111 is clear.

[0061] In order to design a guide structure 213 that is more compatible with the intended post preparation bur and further improve the accuracy of post preparation, it is preferable that the process of designing the guide outlet 212 in step A1 is as follows: when the intended post preparation bur is arranged along the guide direction 112 and its end faces the position on the bottom surface 211 of the retainer corresponding to the target root canal opening 111, the outline of its projection on the bottom surface 211 of the retainer corresponding to the target root canal opening 111 is the theoretical guide outline; the outline formed on the bottom surface 211 of the retainer after the theoretical guide outline is offset outward by 0 to 0.1 mm is the outline of the guide outlet 212. Preferably, the contour of the guide outlet 212 is made to perfectly fit the outer periphery of the pre-stud in the pile channel, that is, the diameter of the guide outlet 212 is equal to the diameter of the pre-stud in the pile channel, so as to ensure that the formed guide structure 213 can effectively restrict the direction and movement of the pre-stud in the pile channel guide device and ensure the accuracy of its guiding direction; if the theoretical guide contour is offset outward by more than 0.1mm, the formed guide structure 213 is prone to causing the distal end of the pre-stud in the pile channel to deviate.

[0062] The aforementioned structure's guide outlet 212 and the guide structure 213 designed based on it have similar profiles to the post preparation bur to be used, and the length D of the guide structure 213 can limit the preparation depth of the post preparation bur. The direction is also the optimal post preparation direction determined by the physician through CT scan or computer software analysis before the operation. Therefore, under its guidance, the physician can accurately control the post preparation bur to prepare according to the post direction and depth limited by the guide structure 213, reduce unnecessary damage to the hard tooth tissue, and preserve as much tooth tissue as possible to provide resistance.

[0063] As a preferred embodiment of the present invention, combined with Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the design prototype of the pile preparation guide device 200 also includes the design prototype of the cover plate 220;

[0064] The design process of the prototype of the pile preparation guide device 200 also includes steps S4 and S5;

[0065] S4. Based on the digital model of the crown, a cover plate 220 that can be worn on the target tooth position 100 is designed, and the design prototype of the cover plate 220 is obtained.

[0066] S5. When the design prototypes of the retainer 210 and the cover plate 220 are installed together with the digital model of the crown, the overlapping parts are combined to obtain the design prototype of the assembly. An undercut structure is made on the top surface of the design prototype of the assembly so that the guide inlet 214 can be exposed, thus obtaining the design prototype of the post preparation guide device 200.

[0067] The post preparation guide device made according to the above preferred embodiment has a cover plate 220, which facilitates the wearing of the entire device on the target tooth position 100 and its effective fixation, so as to further facilitate the physician to perform post preparation through the guide structure 213.

[0068] Based on the above preferred design, in order to design a cover plate 220 that is more suitable for the target tooth position 100, combined with Figure 4 As shown, the specific design process of the prototype of the cover plate 220 in step S4 is as follows:

[0069] B1. Based on the digital model of the tooth crown, determine the mesial border 131 and distal border 132 of the buccal and lingual surfaces of the target tooth position 100, as well as the observation line 133; the observation line 133 is the line connecting the outermost contour lines of the buccal surface 141 and the outermost contour lines of the lingual surface 142 of the tooth along the circumferential direction when the placement direction 113 is used as the observation direction; typically, the observation line 133... The area on the gingival side is the non-inverted area, while the area on the gingival side is the inverted area;

[0070] B2. The theoretical morphology of the cover plate tissue surface 221 is designed, which includes the mesiodistal margin and the buccal-lingual margin; the mesiodistal margin is based on the teeth. The buccal and lingual margins are defined by the observation line 133, mesial margin 131, and distal margin 132. The buccal and lingual margins are defined by the intersection of the observation line 133 with the buccal and lingual margins 141 and 142 of the tooth, respectively, after the observation line 133 is lowered by 0.5-1.0 mm along the placement direction 113. In this step, if the lowering of the observation line 133 is less than 0.5 mm, the margin may enter the undercut too shallowly, and for the target tooth position 100 with a large defect area, the resulting retention force may not be sufficient to maintain the stability of the device during use. If the lowering of the observation line 133 is greater than 1.0 mm, the clasp arm of the removable denture may enter the undercut too deeply, which may cause deformation during insertion and removal. In addition, if the margin enters the undercut too deeply, it may also damage the abutment tooth during removal. Therefore, the lowering amount is limited to 0.5-1.0 mm to protect the abutment tooth and ensure the stability of the denture.

[0071] B3. Offset the theoretical shape of the cover plate structure surface 221 outward along its normal direction by 0 to 0.2 mm to obtain the design prototype of the cover plate structure surface 221; thicken the design prototype of the cover plate structure surface 221 outward along its normal direction by a distance c, where c is 3 to 5 mm, to obtain the design prototype of the cover plate 220.

[0072] In cases where the crown defect is too large, in order to increase retention, combined with Figure 3 , Figure 4 and Figure 5 As shown, step B3 further includes designing a lingual retention arm 222 and a labial-buccal retention arm 223 on the lower buccal-lingual side of the cover plate 220, respectively. Both the lingual retention arm 222 and the labial-buccal retention arm 223 are used to connect and fix to the adjacent teeth of the target tooth position 100. The lingual retention arm 222 and the labial-buccal retention arm 223 are usually fixed 0.5 to 1.0 mm below the observation line 133 of the adjacent teeth of the target tooth position 100.

[0073] Specifically, to further facilitate the design and fabrication of the pile preparation guide device 200, it is preferable to use:

[0074] In step A3, the extended distance is D;

[0075] In step A4, the design prototype of the guide structure 213 is subtracted from the design prototype of the main body of the retainer 210 by Boolean operation to obtain the design prototype of the retainer 210.

[0076] In step S5, the design prototype of the fixed body 210 and the design prototype of the cover plate 220 are added by Boolean operation to obtain the design prototype of the pile road preparation guide device 200.

[0077] The design prototype of the pile preparation and guidance device 200 is output as design data in STL format, and then manufactured into a finished product by 3D printing equipment.

[0078] The present invention also provides a pile preparation guide device 200 that can guide physicians to accurately and easily achieve the direction preparation and depth control of a predetermined pile path, which is manufactured by the above-mentioned pile preparation guide device manufacturing method.

[0079] like Figure 2As shown, the post preparation guide device includes a retainer 210 and a cover plate 220. The upper part of the retainer 210 is integrally connected to the central part of the cover plate 220, and the part not connected to the cover plate 220 can be embedded in the target pulp chamber 120. A guide structure 213 is provided inside the retainer 210 along the guide direction 112. The upper opening of the guide structure 213 is a guide inlet 214 on the top surface of the cover plate 220, and the lower opening of the guide structure 213 is a guide outlet 212 on the bottom surface 211 of the retainer. When the retainer 210 is embedded in the target pulp chamber 120, the guide outlet 212 corresponds to the target root canal orifice 111. The bottom surface of the cover plate 220 can be aligned with the buccal surface 141, the lingual surface 142, and the tooth. The cover plate 221 is connected to surface 143.

[0080] Preferred, such as Figure 3 , Figure 4 and Figure 5 As shown, the buccal and lingual lower edges of the cover plate 220 are respectively provided with a lingual retention arm 222 and a labial-buccal retention arm 223, both of which are used for connection and fixation with the adjacent teeth of the target tooth position 100. This structure of the cover plate 220 enables the post preparation guide device 200 to be stably worn on the target tooth position 100 even when the crown defect volume is too large.

[0081] For the retainer 210 of the above-mentioned post preparation guide device 200, the dentist can choose different placement directions 113 according to the different spatial positions of the target tooth position 100 itself, and use this as the observation direction to determine the observation line 113 of the target tooth position 100. When the edge of the cover plate 220 and the retainer arm enter the undercut area below the observation line 133, a greater retention force can be obtained. At the same time, the sidewall of the retainer 210 is usually adapted to the shape of the pulp chamber wall of the target pulp chamber 120, and the friction between the two can also serve as the main source of retention force to ensure the stability of the entire device during the post preparation process.

[0082] The aforementioned pre-guided pile driver 200 has the following advantages:

[0083] 1) The guide structure 213 can limit the direction and depth of the pile preparation needle during the pile preparation process, which solves the problems of pile deviation and insufficient or excessive preparation depth caused by limited vision during pile preparation.

[0084] 2) The guide structure 213 with reasonable length and direction can better restrict the direction of the far end of the pre-stud in the pile path, effectively solving the problem of low accuracy at the far end of other similar guide plates.

[0085] 3) The device is secured by a retainer 210 that can be embedded in the target pulp chamber 120, a cover plate 220 that can enter the edge of the tooth undercut, and a lingual retainer arm 222 and a labial / buccal retainer arm 223 that can enter the undercut of adjacent teeth. This effectively reduces the displacement of the device during use and enhances its stability.

[0086] 4) The preoperative digital three-dimensional design is transferred to the intraoral cavity through the post preparation guide device 200, so that the preoperative expectations can be fully realized. This can reduce unnecessary hard tissue damage caused during equipment preparation, ensure sufficient hard tissue resistance of the remaining tooth root, and extend the service life of the post and core crown.

[0087] 5) The use of this pile preparation guide device 200 can greatly reduce the difficulty of pile preparation, which is conducive to beginners to master it quickly, and can also improve work efficiency and greatly reduce the clinical working time of doctors.

[0088] 6) The preparatory guide device 200 for the pile channel is relatively small in size, providing a better user experience and avoiding the problem of poor patient treatment experience caused by the excessive size of previous guide plates.

[0089] Example 1

[0090] A post and thread preparation guide 200 was designed and fabricated for a maxillary first molar with no or minor tooth defects. Because its structure is relatively intact and its retention is sufficient, a labial or lingual retention arm is not required. Figure 1 As shown, the specific production process is as follows:

[0091] S1. Acquire three-dimensional data of the target tooth position 100 and its adjacent teeth to generate a digital crown model including data of the target root canal 110 and the target pulp chamber 120. The digital crown model is generated by fitting the first digital model and the second digital model. The first digital model is obtained by acquiring three-dimensional data of the target tooth position 100 and its adjacent teeth through CBCT and importing it into reverse engineering software in DICOM format. The second digital model is obtained by acquiring three-dimensional data of the target tooth position 100 and its adjacent teeth through an intraoral scanner to ensure that the structure of the pulp chamber wall and floor of the target pulp chamber 120 and the target root canal orifice 111 is clear and imported into reverse engineering software in STL format.

[0092] S2. Based on the digital model of the crown, the guiding direction 112 is determined according to the direction of the target root canal 110, and the placement direction 113 of the post preparation guide device 200 is determined according to the undercut structure of the target tooth position 100 and its adjacent teeth.

[0093] S3. Design the prototype of the retainer 210 according to the following steps;

[0094] A1. Based on the digital model of the crown, a matching abutment bottom surface 211 is designed according to the bottom surface of the target pulp chamber 120 and the morphology of the target root canal orifice 111 of the target root canal 110. A guide outlet 212 is designed on the abutment bottom surface 211, and the projection of the guide outlet 212 along the guide direction 112 is located inside the target root canal orifice 111. The process of designing the guide outlet 212 is as follows: when the post preparation bur to be used is arranged along the guide direction 112 and its end faces the position on the abutment bottom surface 211 corresponding to the target root canal orifice 111, the outline of its projection on the abutment bottom surface 211 corresponding to the target root canal orifice 111 is the theoretical guide outline. The outline formed on the abutment bottom surface 211 after the theoretical guide outline is shifted outward by 0.06mm is the outline of the guide outlet 212.

[0095] A2. Stretch the guide opening 212 in the opposite direction of the guide direction 112 by a distance D = 11 mm to obtain the design prototype of the guide structure 213; D = b - a + c, where: a represents the length from the target root canal orifice 111 to the apex of the target root canal 110 measured along the guide direction 112, a = 10 mm; b represents the working length recorded during root canal preparation, b = 16 mm; c represents the reserved apical closure length, c = 5 mm;

[0096] A3. Using the bottom surface 211 of the fixation body as the base surface, extend in the opposite direction of the placement direction 113 to form the main body of the fixation body 210. The extension distance is D, thus obtaining the design prototype of the main body of the fixation body 210.

[0097] A4. Subtract the design prototype of the guide structure 213 from the design prototype of the main body of the retainer 210 through Boolean operation to obtain the design prototype of the retainer 210.

[0098] S4. Based on the digital model of the dental crown, a cover plate 220 that can be worn on the target tooth position 100 was designed, resulting in a design prototype of the cover plate 220. The specific design process of the design prototype of the cover plate 220 is as follows:

[0099] B1. Based on the digital model of the crown, determine the mesial margin 131 and distal margin 132 of the buccal and lingual surfaces of the target tooth position 100, as well as the observation line 133. The observation line 133 is the line connecting the outermost contour line of the buccal surface 141 and the outermost contour line of the lingual surface 142 of the tooth along the tooth circumference when the placement direction 113 is taken as the observation direction.

[0100] B2. The theoretical morphology of the cover plate tissue surface 221 is designed, which includes the mesiodistal margin and the buccal-lingual margin; the mesiodistal margin is based on the teeth. The buccal and lingual margins are defined by the observation line 133, the mesial margin 131, and the distal margin 132. The buccal and lingual margins are defined by the intersection of the observation line 133 with the buccal surface 141 and the lingual surface 142 of the tooth after the observation line 133 is moved down 1.0 mm along the positioning direction 113.

[0101] B3. Offset the theoretical shape of the cover plate structure surface 221 outward by 0.2mm along its normal direction to obtain the design prototype of the cover plate structure surface 221; thicken the design prototype of the cover plate structure surface 221 outward by a distance c along its normal direction to obtain the design prototype of the cover plate 220.

[0102] S5. After adding the design prototype of the fixed body 210 and the design prototype of the cover plate 220 through Boolean operation, the design prototype of the pile preparation guide device 200 is obtained.

[0103] S6. Output the design data of the prototype of the pile preparation guide device 200 in STL format, and then use 3D printing equipment to make it into a finished product.

[0104] Combination Figure 4 , Figure 5 and Figure 6 As shown, the fabricated post preparation guide device 200 includes a retainer 210 and a cover plate 220. The upper part of the retainer 210 is integrally connected to the central part of the cover plate 220, and the part not connected to the cover plate 220 can be embedded in the target pulp chamber 120. A guide structure 213 is provided inside the retainer 210 along the guide direction 112. The upper opening of the guide structure 213 is a guide inlet 214 on the top surface of the cover plate 220, and the lower opening of the guide structure 213 is a guide outlet 212 on the bottom surface 211 of the retainer. When the retainer 210 is embedded in the target pulp chamber 120, the guide outlet 212 corresponds to the target root canal orifice 111. The bottom surface of the cover plate 220 can be aligned with the buccal surface 141, the lingual surface 142, and the tooth. The cover plate tissue surface 221 is connected to the surface 143; the post preparation guide device 200 is suitable for single posterior teeth with no tooth defects or minor defects, such as rotated teeth or misaligned teeth.

[0105] When preparing the tooth path for the target tooth position 100 using the aforementioned post preparation guide device 200, the operator places the post preparation guide device 200 on the target tooth position 100 along the placement direction 113, such as... Figure 4 As shown; the retention force is generated by the friction between the retainer 210 and the pulp chamber wall of the target pulp chamber 120, and by the edge of the cover plate 220 entering the undercut area below the observation line 133, to maintain the stability of the entire device during the post preparation process, as shown. Figure 6As shown; a slow-speed dental handpiece equipped with a post preparation bur is inserted into the guide structure 213 through the guide inlet 214 in the guide direction 112 and exits through the guide outlet 212 to probe near the target root canal orifice 111. The operator controls the dental handpiece to lift the prepared post along the guide direction 112 using the conventional operating method, using the edge of the guide inlet 214 as a depth marker to indicate the post preparation depth, until it matches the preoperative measurement length. The post preparation bur is then changed, and the above operation is repeated until the preparation is complete. This post preparation method ensures that the preparation direction is not deviated while maximizing the preservation of healthy tooth structure and the length of gutta-percha sealing within the root canal.

[0106] Example 2

[0107] Combination Figure 7 As shown, a post preparation guide device 200 is designed and fabricated for a target tooth position 100 with a large area of ​​tooth defect. This embodiment differs from the aforementioned Embodiment 1 in that, due to the excessively large area of ​​tooth defect, the retainer 210 and cover plate 220 alone are insufficient to provide the retention force required for the post preparation guide device 200 during use. Therefore, the following design steps are added based on the aforementioned Embodiment 1:

[0108] In step S1, when obtaining initial data using the aforementioned method, the extraction and scanning range is expanded to include mesial and distal adjacent teeth;

[0109] Step B3 also includes the process of designing a lingual retention arm 222 and a labial-buccal retention arm 223 on the buccal-lingual lower edge of the cover plate 220, respectively. Both the lingual retention arm 222 and the labial-buccal retention arm 223 are used to connect and fix with the adjacent teeth of the target tooth position 100. The lingual retention arm 222 and the labial-buccal retention arm 223 can be extended into the undercut area of ​​the mesial and distal adjacent teeth of the target tooth position 100 to increase retention. The thickness and length of the lingual retention arm 222 and the labial-buccal retention arm 223 are determined according to the different undercut areas of different teeth and no fixed size is set.

[0110] In addition, the relevant design parameters of this embodiment are as follows: the theoretical guiding contour is offset outward by 0.05 mm; D = 10 mm, a = 9 mm, b = 15 mm, c = 4 mm; the buccal and lingual edges are moved down 0.9 mm along the positioning direction 113 with the observation line 133; the theoretical shape of the cover plate tissue surface 221 is offset outward by 0.1 mm along its normal direction; the rest of the design and manufacturing process is the same as in embodiment 1.

[0111] Example 3

[0112] Combination Figure 8As shown, a post preparation guide device 200 is designed and fabricated for an anterior tooth with residual root and crown structure at a target tooth position 100. The difference between this embodiment and the aforementioned embodiment 2 is that, due to the special anatomical shape of the anterior tooth and adjacent teeth, it is difficult for the labial surface of the anterior tooth to have undercuts. Therefore, the labial and buccal retention arms 223 are removed, leaving only the lingual retention arms 222 to enter the lingual undercut area of ​​the adjacent tooth to increase retention.

[0113] In addition, the relevant design parameters of this embodiment are as follows: the theoretical guide contour is offset outward by 0.07 mm; D = 12 mm, a = 13 mm, b = 20 mm, c = 5 mm; the buccal and lingual edges are moved down 0.6 mm along the positioning direction 113 with the observation line 133; the theoretical shape of the cover plate tissue surface 221 is offset outward by 0.15 mm along its normal direction; the rest of the design and manufacturing process is the same as in embodiment 2.

Claims

1. A method of manufacturing a pile channel preparation guide, comprising the step of manufacturing a design prototype of a pile channel preparation guide (200) as a finished product; characterized in that: The design prototype of the pile channel preparation guide device (200) includes a design prototype of the retainer (210); The design process of the design prototype of the pile channel preparation guide device (200) is as follows: S1, obtaining the three-dimensional data of the target tooth site (100) and its adjacent teeth, and generating a digital crown model including the target root canal (110) and the target pulp chamber (120); S2, based on the digital crown model, determining the guide direction (112) according to the direction of the target root canal (110), and determining the in-place direction (113) of the pile channel preparation guide device (200) according to the undercut structure of the target tooth site (100) and its adjacent teeth; S3, the design prototype of the retainer (210) is designed as follows: A1, based on the digital crown model, the retainer bottom surface (211) is designed to match the bottom surface of the target pulp chamber (120) and the shape of the target root canal orifice (111) of the target root canal (110), and the guide through hole (212) is designed on the retainer bottom surface (211), the projection of the guide through hole (212) along the guide direction (112) is in the target root canal orifice (111); A2, the guide through hole (212) is stretched in the opposite direction of the guide direction (112) by a distance D to obtain the design prototype of the guide structure (213); D=b-a+c, in the formula: a represents the length from the target root canal orifice (111) to the root apex of the target root canal (110) measured along the guide direction (112), b represents the working length recorded during root canal preparation, and c represents the reserved root apex sealing length; A3, the retainer main body is extended in the opposite direction of the in-place direction (113) based on the retainer bottom surface (211), and the extension distance needs to ensure that the retainer main body can at least completely cover the peripheral wall of the guide structure (213), thereby obtaining the design prototype of the retainer main body (210); A4, the design prototype of the guide structure (213) is implanted into the design prototype of the retainer main body (210), and the guide entry port (214) at the upper end of the guide structure (213) is located on the top surface of the retainer main body (210), thereby obtaining the design prototype of the retainer (210).

2. A method of manufacturing a pile channel preparation guide according to claim 1, characterised in that: The digital crown model in step S1 is mainly fitted by a first digital model and a second digital model; The first digital model is obtained by CBCT to obtain the three-dimensional data of the target tooth site (100) and its adjacent teeth, and is imported into the reverse engineering software in DICOM format; The second digital model is obtained by an intraoral scanner to obtain the three-dimensional data of the target tooth site (100) and its adjacent teeth, and is imported into the reverse engineering software in stl format.

3. The method of claim 1, wherein: In step A1, the process of designing the guide access hole (212) is as follows: the pile channel preparation vehicle needle to be used is arranged along the guide direction (112), and the end thereof is directed to the position corresponding to the target root canal orifice (111) on the abutment bottom surface (211), and the projection contour of the end on the position corresponding to the target root canal orifice (111) on the abutment bottom surface (211) is the theoretical guide contour; the contour formed on the abutment bottom surface (211) after the theoretical guide contour is outwardly shifted by 0-0.1 mm is the contour of the guide access hole (212).

4. A method of manufacturing a pile channel preparation guide according to any one of claims 1 to 3, characterised in that: The design prototype of the pile channel preparation guide device (200) further comprises a design prototype of a cover plate (220); The design process of the design prototype of the pile channel preparation guide device (200) further comprises steps S4 and S5; S4, based on the digital crown model, a cover plate (220) capable of being worn on the target tooth site (100) is designed, and a design prototype of the cover plate (220) is obtained; S5, the design prototype of the abutment (210) and the design prototype of the cover plate (220) are combined together when they are fitted and installed on the digital crown model, and a combined body design prototype is obtained, and a reverse concave structure capable of exposing the guide access hole (214) is formed on the top surface of the combined body design prototype, and a design prototype of the pile channel preparation guide device (200) is obtained.

5. A method of manufacturing a pile channel preparation guide according to claim 4, characterised in that: In step S4, the specific design process of the design prototype of the cover plate (220) is as follows: B1, based on the digital crown model, the mesial edge line (131) and the distal edge line (132) of the buccal and lingual surfaces of the target tooth site (100) are determined, and an observation line (133) is determined; the observation line (133) is a connecting line of the most outer contour line of the buccal surface (141) and the most outer contour line of the lingual surface (142) along the tooth circumference when the in-place direction (113) is taken as the observation direction; B2, a theoretical form of the cover plate tissue surface (221) is designed, which comprises mesial and distal side edges and buccal and lingual side edges; The mesial-distal side edges are bounded by the tooth The mesial edge line (131) and the distal edge line (132) are bounded by the facial surface (143), and the buccal-lingual side edges are respectively bounded by the intersection lines on the tooth buccal surface (141) and the lingual surface (142) after the observation line (133) is moved 0.5-1.0 mm downward along the seating direction (113). B3, the theoretical form of the cover plate tissue surface (221) is outwardly shifted by 0-0.2 mm along its normal direction to obtain a design prototype of the cover plate tissue surface (221); the design prototype of the cover plate tissue surface (221) is thickened by a distance c along its normal direction to obtain a design prototype of the cover plate (220), and c is 3-5 mm.

6. A method of manufacturing a pile channel preparation guide according to claim 5, characterised in that: Step B3 further comprises the process of designing a lingual retention arm (222) and a labial and buccal retention arm (223) on the buccal and lingual lower edges of the cover plate (220), respectively; the lingual retention arm (222) and the labial and buccal retention arm (223) are used to be connected and fixed with adjacent teeth of the target tooth site (100).

7. A method of manufacturing a pile channel guide according to claim 4, wherein: In step A3, the extension distance is D; In step A4, the design prototype of the guide structure (213) is subtracted from the design prototype of the main body of the abutment (210) through Boolean operation to obtain the design prototype of the abutment (210); In step S5, the design prototype of the abutment (210) is added to the design prototype of the cover plate (220) through Boolean operation to obtain the design prototype of the pile channel preparation guide device (200); The design prototype of the pile channel preparation guide device (200) is outputted in stl format to output design data, and then a 3D printing device is used to manufacture a finished product.

8. Pile channel preparation guiding device, characterized in that: The pile channel preparation guide device is manufactured by the manufacturing method of any one of claims 1 to 7.

9. A pile channel preparation guide according to claim 8, characterised in that: The pile channel preparation guide device comprises a retaining body (210) and a cover plate (220). The upper part of the retaining body (210) is connected to the central part of the cover plate (220) as a whole, and the part of the retaining body (210) not connected to the cover plate (220) can be embedded in the target dental pulp chamber (120). A guide structure (213) is arranged in the retaining body (210) along the guide direction (112), the upper end opening of the guide structure (213) is a guide inlet (214) on the top surface of the cover plate (220), and the lower end opening of the guide structure (213) is a guide outlet (212) on the bottom surface (211) of the retaining body (210); when the retaining body (210) is embedded in the target dental pulp chamber (120), the guide outlet (212) corresponds to the target root canal opening (111). The bottom surface of the covering plate (220) is a covering plate tissue surface (221) capable of being connected with the tooth buccal surface (141), the tooth lingual surface (142) and the tooth facial surface (143). The bottom surface of the covering plate (220) is a covering plate tissue surface (221) capable of being connected with the tooth buccal surface (141), the tooth lingual surface (142) and the tooth facial surface (143).

10. A pile channel preparation guide according to claim 9, characterised in that: Buccal and lingual side retaining arms (222) and (223) are arranged on the lower edges of the buccal and lingual sides of the cover plate (220), respectively, and the buccal and lingual side retaining arms (222) and (223) are used to be connected and fixed with adjacent teeth of the target tooth (100).

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