A method for manufacturing oral implant guide based on tetrahedron positioning

Abstract

A method for making an oral implant guide based on tetrahedron positioning, characterized in that its making steps are as follows: 1) making a digital model and determining a tetrahedron digital model; 2) measuring the distance between each point, using tetrahedron positioning technology, transferring the implant design digital model on CBCT to the dentition model, and making an implant guide. The present invention creatively uses tetrahedron positioning technology to transfer the implant design digital model on CBCT to the physical dentition model to make an implant guide, which is simple and easy to do, does not require special three-dimensional printing equipment, is low in cost, and is particularly suitable for single teeth and a small number of teeth. The accuracy of implantation with this implant guide is much better than free-hand implantation.

Description

Technical Field

[0001] The invention belongs to a method for manufacturing an oral implant guide plate. Background Art

[0002] The purpose of oral implant guides is to materialize the digital model of CBCT data. In recent years, implant guides based on cone beam computer tomography (CBCT) and 3D printing guide technology have been widely used in clinical practice, playing an important role in improving the accuracy of implantation and subsequent restoration. The existing technology for making dental implant guides mostly uses the digitalization of intraoral models and the overlap of CBCT data to design the guides and make them by 3D printing. However, the production of implant guides made by the existing 3D printing method commonly used in clinical practice is time-consuming and expensive, and requires special 3D printing equipment, which affects the promotion and popularization. For the implantation of single teeth and a few teeth (generally no more than 3 teeth), the proportion of dental implant guides to the cost of dental implants is large, and doctors and patients are reluctant to use such high-cost dental implant guides. Therefore, in clinical cases of single teeth and a few missing teeth, most of them are implanted by free hands based on the experience of doctors, which leads to a high risk of inaccurate 3D position of implants and contact with the roots of adjacent teeth.

[0003] After searching ZL201410228700.6 "A stereo positioning device and a method for making an oral implant guide using the device", its structure is as follows Figure 1 As shown, it includes an arc-shaped substrate 1, on which a first cylinder 2, a second cylinder 3 and a third cylinder 4 are arranged in parallel, and the center lines of the free ends of the first cylinder, the second cylinder and the third cylinder form a right triangle. The stereo positioning device is CT scanned to reconstruct a standardized three-dimensional model of the device, and the patient wears a radiographic guide with the device to take a CT, and the data is imported into the implant software to simulate the implantation, and the standardized three-dimensional model of the device is aligned to the patient's CT, and the implant space is measured on the basis of the standardized three-dimensional model of the device, and the three-dimensional relationship between the implant and the jaw is accurately transferred to the physical model, and then the oral implant guide is made by mechanical punching technology. There are two disadvantages of this stereo positioning device. First, a special device is required, and the CBCT shooting of the first cylinder, the second cylinder and the third cylinder of the device as the object has artifacts and magnification, which affects the accuracy of the guide design; second, the position of the patient wearing the radiographic guide with the device to take the CT and the position when the three-dimensional relationship between the implant and the jaw is transferred to the physical model later cannot guarantee absolute consistency, thereby affecting the accuracy of the guide in place. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects existing in the existing oral implant guide production process, and to provide a method for producing an oral implant guide based on tetrahedron positioning, which does not require special equipment, is simple and easy to operate, is less affected by the outside world, and has better implant quality than free-hand implantation.

[0005] The technical solution adopted by the present invention is a method for manufacturing an oral implant guide based on tetrahedron positioning, which is characterized in that its manufacturing steps are as follows: 1) manufacturing a digital model and determining a tetrahedron digital model; 2) measuring the distance between each point, and using tetrahedron positioning technology to transfer the implant design digital model on CBCT to the dentition model to manufacture an implant guide.

[0006] The present invention creatively uses tetrahedron positioning technology to transfer the digital model of implant design on CBCT to the physical dentition model. The production of implant guides is simple and easy, and no special three-dimensional printing equipment is required, which is low-cost.

[0007] The digital model making and tetrahedron digital model determination are as follows: the patient takes a CBCT scan at the first visit and makes an impression of the dental arch to be implanted; the CBCT data is analyzed to simulate the implant design; the doctor determines the implantation point P1 of the dental arch according to the CBCT data; two clear points are selected on the CBCT dental arch model as the vertices P3 and P4 of the tetrahedron; the implant direction is determined, and a ray is drawn along the central axis of the implant with P1 as the end point of the ray, and the direction of the implant is determined. The square is extended and point P2 is selected at a distance of 40±5 mm from P1 to form the four vertices of a tetrahedron.

[0008] Based on the analysis of the patient's CBCT data, the doctor designs the data of the three-dimensional position and length of the implant. How to reproduce the data design on the physical dental model is the key task of the present invention, that is, P1 and P2 are designed by the doctor, and then P3 and P4 are selected. The present invention uses two clear points that are easy to locate on the physical dental model as the vertices P3 and P4 of the tetrahedron, which provides convenience and guarantee for the physicalization of the digital model. P3 and P4 select the points, pits, and cusp vertices of the anatomical landmarks of the remaining teeth that are clearly visible on the CBCT and dental model. It is beneficial to improve the accuracy to disperse P1, P3 and P4 as much as possible on the dentition. The distance between P1 and P2 is designed to be 40±5mm, because normal The average width of the posterior segment of the upper and lower dental arches is 49.26mm and 43.27mm (Wang Xuan, Xie Xiaorui, Li Qin, Ren Liling. Normal Study on the correlation between vertical bone facial shape and dental arch width. Journal of Practical Stomatology ISSN: 1001-3733 Publication date: 2017 Issue number: Issue 6 Page number: 802-806), so the present invention selects P3 and P4 to disperse P1 as much as possible on the dentition to improve the accuracy of tetrahedron positioning, and at the same time the tetrahedron can be closer to a regular tetrahedron.

[0009] The transfer of the implant design digital model on the CBCT to the dentition model and the production of the implant guide plate refers to: a. Production of a guide post, the total length of which is equal to the distance between P1 and P2, the guide post is composed of two coaxial cylinders of large and small ends, the diameter of the small end is 0.1-0.5mm, the distance between the top and the large diameter root is 3-6mm, the two sections are connected by a conical surface, the height of the conical surface accounts for 1 / 3-2 / 3 of the distance, the diameter of the large diameter section is 2.5-3mm, and the length is 30- 40mm; b. Make a guide ring. The inner diameter of the guide ring and the outer diameter of the large diameter section of the guide post are transitional fit. The outer diameter of the guide ring is 4.5-5.5mm and the length is 6-8mm. The guide ring is sleeved on the large diameter section of the guide post; c. Find the corresponding points P3 and P4 of the digital model in the dental arch model, find the points P1 and P2 according to the measurement data in the digital model, and insert the guide ring into the guide post so that the guide post coincides with P1 and P2. The light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implant to form an implant guide.

[0010] The guide pin and guide ring of the present invention can be manufactured as universal parts. The length of the guide pin is: the small end is a fixed value, and the large end is selected as 40mm.

[0011] The guide ring is a titanium guide ring. The guide ring material can be varied, mostly titanium alloy materials, and also use harder ceramics such as zirconium oxide. Titanium alloy materials are used because they will not rust and are the same as implant materials. The tetrahedron design is as close to a regular tetrahedron as possible.

[0012] A center hole is arranged on the central surface of the large end of the guide pin. The center hole is a tapered hole with a depth of 0.3-0.5mm and a surface diameter of 0.3-0.5mm, which is conducive to the division and positioning.

[0013] The small end of the guide pin is needle-shaped, which ensures accurate positioning.

[0014] When the present invention is made, the corresponding points of P3 and P4 in the digital model are found in the dentition model, and the divider is taken to take P3 and P4 as the center of the circle, and the distance of P3-P1 and P4-P1 as the radius, and an arc is drawn at the intended implant position, and the intersection is P1. The guide ring is inserted into the guide post, and the tip of the small end of the guide ring is placed at P1. Two dividers are taken to take P3 and P4 as the center of the circle, and the distance of P3-P2 and P4-P2 is the radius. The other pin of the divider is at the center of the large end of the guide post at the same time, and the direction of the guide post is determined. The tetrahedron of the digital model is successfully moved to the dentition model, and the light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implant to form an implant guide plate with a guide ring. The implant guide plate can be made by the guide post, the guide ring and the two dividers without the need for special three-dimensional printing equipment. When implanting, the implant guide plate is placed in place on the patient's tooth, and the drill is positioned and oriented by the guide ring to perform drilling and implantation.

[0015] The advantages of the present invention are simple manufacturing and low cost, and it is particularly suitable for single teeth or a small number of teeth. The accuracy of implantation with the implant guide plate is much better than free-hand implantation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the existing oral implant guide structure

[0017] Figure 2 Schematic diagram of the structure of guide pillars and guide rings

[0018] Figure 3 Schematic diagram of fixed point P1

[0019] Figure 4 Schematic diagram of fixed point P2

[0020] Figure 5 Creating a schematic diagram for the implant guide

[0021] Wherein: 1 arc-shaped substrate 2 first cylinder 3 second cylinder 4 third cylinder 5 guide column 51 center hole 6 guide ring 7

[0022] Planting guide. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with the drawings so that those skilled in the art can better understand the present invention.

[0024] like Figure 2-5 As shown, a method for making an oral implant guide based on tetrahedron positioning, its production steps are as follows: 1) making a digital model and determining the tetrahedron digital model; 2) measuring the distance between each point, and using the tetrahedron positioning technology to transfer the implant design digital model on the CBCT to the dentition model to make the implant guide.

[0025] The patient takes a CBCT scan at the first visit and an impression of the dental arch to be implanted is made; the CBCT data is analyzed and the implant design is simulated; the doctor determines the implant point P1 based on the CBCT data, selects two clear points on the CBCT dental arch model as the vertices P3 and P4 of the tetrahedron, determines the implant direction, and uses P1 as the endpoint of the ray to draw a ray along the implant direction. The square is extended and point P2 is selected at a distance of 40±5 mm from P1 to form the four vertices of a tetrahedron.

[0026] P3 and P4 are selected from the points, cavities, and cusp vertices of the anatomical landmarks of the remaining teeth that are clearly visible on the CBCT and dentition model. Under this premise, P3 and P4 are dispersed as much as possible on the dentition. The closer the distance between P1 and P3 and P4 is to the distance between P1 and P2, the closer the tetrahedron is to a regular tetrahedron, which is beneficial to improving accuracy.

[0027] The transfer of the implant design digital model on the CBCT to the dentition model and the production of the implant guide plate refers to: a. Production of a guide post 5, the total length of the guide post is equal to the distance between P1 and P2, the guide post is composed of two coaxial cylinders of large and small ends, the diameter of the small end is 0.5-1mm, the tip is needle-shaped, the distance between the top and the root of the large diameter is 3-6mm, the two sections are connected by a conical surface, the height of the conical surface accounts for 1 / 3-2 / 3 of this distance, the diameter of the large diameter section is 2-3mm, the length is 30-40mm, and the surface of the large end of the guide post has a center hole 51; b. Production of a guide ring 6, the guide ring material can be varied, titanium alloy materials are mostly used, and harder ceramics such as zirconium oxide are also used. The inner diameter of the guide ring and the outer diameter of the large diameter section of the guide post are transitionally matched. The outer diameter of the guide ring is 4.5-5.5mm and the length is 6-8mm. The guide ring is sleeved on the large diameter section of the guide post; c. Find the corresponding points P3 and P4 of the digital model in the dental arch model, find the points P1 and P2 with the measurement data in the digital model, and insert the guide ring into the guide post so that the guide post coincides with P1 and P2. The light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implant to form an implant guide plate 7.

[0028] The guide column and guide ring of the present invention can be manufactured as universal parts. The length of the guide column is the same as the interval between P1 and P2, which can be in the range of 40±5mm. The diameter of the large section of the guide column is consistent with the diameter of the implant pilot drill.

[0029] When the present invention is made, the corresponding points of P3 and P4 of the digital model are found in the dental model, and the divider is taken to draw an arc with P3 and P4 as the center and the distance of P3-P1 and P4-P1 as the radius, and the intersection point is P1, the guide ring is inserted into the guide post, and the tip of the small end of the guide ring is placed at P1, and two dividers are taken to take P3 and P4 as the center and the distance of P3-P2 and P4-P2 as the radius, and the other pins of the divider are simultaneously at the center of the large end of the guide post, and the direction of the guide post is determined, and the tetrahedron of the digital model is successfully moved to the dental model, and the light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implanted tooth to form an implant guide plate with a guide ring, and the implant guide plate can be made by the guide post, the guide ring and the two dividers without the need for special three-dimensional printing equipment. When implanting, the implant guide plate is placed on the patient's tooth, the drill bit is positioned by the guide ring, and the direction is determined for drilling and implanting.

[0030] Embodiment 1, as Figure 3-5 As shown in the figure, the implant treatment of the missing mandibular first molar (tooth 46) is taken as an example, and the implant guide of tooth 46 is made. The patient takes a CBCT scan at the first visit and the mandibular impression is made. The CBCT data is imported into the software for analysis and the design of tooth 46 implant is simulated. The intersection point of the extended central axis of the tooth 46 implant and the gingival mucosa is set as a vertex P1 of the tetrahedron. The square was extended 40mm to take point P2 (P1 and P2 were obtained by the doctor according to the implant design), and a tetrahedral digital model was established with two clear points on the dental model that were easy to locate: such as the central fossa of tooth 37 as P3 and the distal fossa of tooth 34 as P4. The measured distances from P1 to P3 were 46.86mm, and the distance from P1 to P4 was 40.47mm. The lengths of P2-P3 and P2-P4 were 52.15mm and 45.46mm, respectively.

[0031] The implant design on CBCT was transferred to the mandibular model using tetrahedron positioning technology. First, a divider was used to draw an arc on the edentulous area of ​​tooth 46 on the mandibular plaster model, with the central fossa of tooth 37 (P3) and the distal fossa of tooth 34 (P4) as the center and the distances of P1-P3 and P1-P4 as the radius. The intersection point was the corresponding position of P1 on the model ( Figure 3 ). Grind a 0.5mm shallow groove at P1 of the model to fix the guide post. Slide the guide ring into the guide post, and place the tip of the small end of the guide post in the shallow groove. Then use one foot of the two dividers to fix it at P3 and P4 respectively. Figure 4 The angle lengths of the two dividers are set to P2-P3 and P2-P4 respectively. The other pin of the divider is at the center of the large end of the guide post at the same time. The direction of the guide post is determined, and the tetrahedron of the digital model is successfully moved to the dental arch model. The light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implant. The guide post is removed to form an implant guide plate 3 with a guide ring. The guide plate is completed by light curing ( Figure 5 ).

[0032] The total length of the guide post is equal to the distance between P1 and P2, which is 40.00 mm. The guide post is made of stainless steel, with a large end diameter of 2.80 mm and a length of 35.00 mm. A φ0.5 mm center hole 51 (i.e., P2) is drilled at the center of the large end surface. The center hole is a cone hole with a depth of 0.3 mm. The diameter of the small end is 0.50 mm, and the top is a needle tip. The distance between the top and the root of the large diameter is 5 mm. The two sections are connected by a conical surface with a height of 2 mm. The outer diameter of the guide ring is 5.00 mm, the length is 7.00 mm, and the inner diameter is 2.85 mm. Two dividers (H2030, Hero, Shanghai). CBCT (iCAT, KaVo, Germany). Electronic digital caliper (ARTPOL, Jiangsu Jingjiang Measuring Tools Co., Ltd., China). Light-cured temporary crown resin (Revotek LC, GC, Japan).

[0033] The remaining undescribed planting parts are the same as those in the prior art.

[0034] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any improvement and equivalent replacement made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for manufacturing an oral implant guide based on tetrahedron positioning, characterized in that Its production steps are as follows: 1) making a digital model and determining a tetrahedron digital model; 2) measuring the distance between each point, using tetrahedron positioning technology, transferring the digital model of the implant design on the CBCT to the dentition model, and making an implant guide; the making of the digital model and determining the tetrahedron digital model means: taking a CBCT scan of the patient at the first visit and making an impression of the dentition to be implanted; analyzing the CBCT data and simulating the implant design; The doctor determines the implant point P1 based on the CBCT data; selects two clear points on the CBCT dental arch model as the vertices P3 and P4 of the tetrahedron; determines the implant direction, takes P1 as the endpoint of the ray, draws a ray along the central axis of the implant, and The implant guide plate is made by transferring the implant design digital model on the CBCT to the dentition model and making the implant guide plate. The total length of the guide post is equal to the distance between P1 and P2. The guide post is composed of two coaxial cylinders of large and small sizes. The diameter of the small end is 0.5-1mm, the tip is needle-shaped, and the distance between the top and the large diameter root is 3-6mm. The two sections are connected by a conical surface. The height of the conical surface accounts for 1 / 3-2 / 3 of this distance. The diameter of the diameter section is 2-3mm and the length is 30-40mm; b. Make a guide ring, the inner diameter of the guide ring and the outer diameter of the large diameter section of the guide post are transitional fit, the outer diameter of the guide ring is 4.5-5.5mm, and the length is 6-8mm, and the guide ring is sleeved on the large diameter section of the guide post; c. Find the corresponding points P3 and P4 of the digital model in the dental arch model, find the P1 and P2 points according to the measurement data in the digital model, and put the guide ring into the guide post so that the guide post coincides with P1 and P2. The light-cured temporary crown resin fixes the guide ring on the fixed tooth adjacent to the implant to form an implant guide.

2. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1, characterized in that For P3 and P4, the anatomical landmarks of the remaining teeth, such as the gaps, pits, and cusp apex, which are clearly visible on the CBCT and dental arch models were selected.

3. A method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1 or 2, characterized in that P3, P4 and P1 should be dispersed as much as possible on the dentition.

4. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1, characterized in that The distance between P2 and P1 is 40±10mm.

5. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1, characterized in that The tetrahedron design is as close to a regular tetrahedron as possible.

6. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1, characterized in that The large end surface of the guide pin is provided with a center hole.

7. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 6, characterized in that The center hole is a tapered hole with a depth of 0.3-0.5mm and a surface diameter of 0.3-0.5mm.

8. The method for manufacturing an oral implant guide based on tetrahedron positioning according to claim 1, characterized in that The small end of the guide pin is needle-shaped.

Images