Method for manufacturing an integrated post and core based on a single tooth impression, integrated post and core and post and core system

Abstract

The application relates to a manufacturing method of an integrated post core based on a single tooth impression, an integrated post core and a post core system, and relates to the technical field of dental post core repair. The method can solve the problems of poor post core positioning and poor suitability. The method comprises the following steps: performing tooth preparation on a diseased tooth according to the requirements of full crown repair, and performing root canal post channel preparation on the diseased tooth by using a reaming drill; performing a single tooth impression on the diseased tooth to obtain a post core impression of the diseased tooth, scanning the post core impression of the diseased tooth to obtain a digital single tooth impression, and then performing intraoral dentition scanning on the patient; performing digital design and processing and manufacturing of the integrated post core according to the digital single tooth impression and the intraoral dentition scanning result, to obtain an initial integrated post core; performing model trial fitting and adjustment on the initial integrated post core to obtain a target integrated post core, and performing clinical trial fitting and adhesion on the target integrated post core.

Description

Technical Field

[0001] The present application relates to the technical field of dental post and core restoration, and in particular to a method for manufacturing an integrated post and core based on a single tooth impression, an integrated post and core, and a post and core system. Background Art

[0002] Residual roots and crowns caused by caries and trauma are relatively common in clinical practice. Post-core-crown restoration is the main treatment method for preserving residual roots and crowns. The post and core are used to restore the defective tooth tissue and provide support and retention for crown restoration. It is the basis for the success of post-core-crown restoration. Common post and core systems include cast metal post and core and prefabricated fiber post + resin core.

[0003] Cast metal posts and cores have good mechanical properties, high strength, and are not easy to break. They can be used for root canals with irregular shapes and have high adaptability. However, they have the following disadvantages: (1) The elastic modulus of cast metal posts and cores is 100-200 GPa, which is much higher than that of dentin (19-29 GPa), and can easily cause root fractures; (2) Cast metal posts and cores can cause discoloration of the gums, which is not conducive to the aesthetics of the affected teeth, especially the post and core restorations of the upper front teeth; (3) Cast metal posts and cores (except pure titanium materials) can interfere with magnetic resonance imaging, so patients need to remove the metal posts and cores before undergoing MRI, which brings inconvenience to patients. The elastic modulus of the prefabricated fiber post is close to that of dentin, which is not easy to cause root fracture, has good aesthetics, and does not affect magnetic resonance imaging. However, the clinical operation of the prefabricated fiber post + resin core is complicated and technically sensitive. It is prone to risks such as fiber post shedding and crown shedding caused by core rupture. Especially for root canals with irregular morphology, there is a clear gap between the prefabricated fiber post and the root canal, which needs to be filled with resin cement. The resin will shrink during curing and easily cause microleakage, which reduces the retention force of the post and core.

[0004] With the widespread application of digital technology in the field of dentistry, CAD / CAM integrated fiber post and core has been widely used in the field of dentistry. It takes into account the excellent adaptability of cast metal post and core and the appropriate elastic modulus and aesthetics of prefabricated fiber post, which is conducive to the preservation of residual roots and crowns. In the production process of CAD / CAM integrated fiber post and core, the accurate preparation of the digital post and core model of the affected tooth is the basis and key to its success. At present, the acquisition of digital post and core models is mainly through the following methods: (1) CBCT method: take CBCT and extract root canal morphological data from it; (2) scanning rod method: use scanning rod to obtain post and core data through intraoral scanning; (3) silicone rubber impression method: make silicone rubber impression of the post and core and perform digital scanning to obtain post and core data. The steps of extracting root canal morphology by CBCT method are more complicated, there may be artifacts, the accuracy is low, and it will also increase the patient's medical expenses and radiation dose. The scanning rod method requires a special scanning rod, which increases the complexity of clinical operation and is not applicable to root canals with irregular morphology. The silicone rubber impression method is simple and easy to perform, does not increase the cost and radiation exposure of CBCT, is suitable for irregular root canals, and has the widest application range. Clinically, a partial tray is commonly used to create a silicone rubber impression of at least three teeth, including the affected tooth. However, in rare cases, deformation of the post and core model can lead to poor post and core seating, necessitating re-impression and rework, which increases the number and time of patient visits. Summary of the Invention

[0005] Based on this, it is necessary to provide a method for manufacturing an integrated post and core based on a single tooth impression, an integrated post and core, and a post and core system to address the above technical problems.

[0006] In a first aspect, the present application provides a method for fabricating an integrated post and core based on a single tooth impression, comprising:

[0007] Prepare the affected tooth according to the requirements of full crown restoration, and prepare the root canal post of the affected tooth using a reamer;

[0008] Taking a single tooth impression of the affected tooth, obtaining a post and core impression of the affected tooth, scanning the post and core impression of the affected tooth to obtain a digital single tooth impression, and then performing an intraoral dentition scan on the patient;

[0009] Performing digital design and processing of an integrated post and core based on the digital single tooth impression and intraoral dentition scan results to obtain an initial integrated post and core;

[0010] The initial integrated post and core are subjected to a model trial fitting and adjustment to obtain a target integrated post and core, and the target integrated post and core are subjected to a clinical trial fitting and bonding. In one embodiment, the tooth preparation according to the requirements of full crown restoration includes:

[0011] For the affected tooth that meets the indications for post and core crown and excludes contraindications, the apical filling is removed to expose the root canal opening according to the pulp cavity and root canal morphology of the affected tooth X-ray; the tooth is prepared according to the requirements of full crown restoration, the thin-walled weak tip and the concave tissue in the pulp cavity are removed, the gap between the apical surface and the adjacent surface is at least 0.8mm, the axial convergence degree is 2°-5°, and the thickness of the remaining tooth tissue is at least 0.6mm.

[0012] In one embodiment, the step of preparing the root canal post of the affected tooth using a reamer includes:

[0013] The root canal post of the affected tooth is prepared using a reamer, requiring 4-5 mm of root filling material to be retained at the root apex, the length of the post to be greater than the clinical crown height, the length of the intraosseous post to be greater than 1 / 2 of the intraosseous root length, and the diameter of the post to be 1 / 4-1 / 3 of the root diameter.

[0014] In one embodiment, before taking a single tooth impression and digital scanning of the affected tooth, the method further includes:

[0015] Use a K file wrapped with an alcohol cotton ball to clean the post channel, and use a moisture-absorbing paper tip to remove the residual liquid in the post channel. Adjust the length of the prefabricated reinforcement nail used for molding to match the length of the root canal, remove the reinforcement nail, and place it next to the chair for use.

[0016] In one embodiment, taking a single tooth impression and digital scanning of the affected tooth includes:

[0017] Prepare a silicone rubber weight, and use a silicone rubber light gun + a fine gun head to inject the silicone rubber light into the post channel to completely cover the post channel, pulp cavity and side wall edge; place the screw conveyor on a low-speed mobile phone, insert it into the post channel and rotate it at a low speed to empty the gas in the post channel, place the reinforcement nail in the post channel, and place one reinforcement nail in each post channel, and inject the silicone rubber light again to completely cover the reinforcement nail and the edge of the affected tooth; take the prepared silicone rubber weight and place it on the silicone rubber light, completely surround the affected tooth in the buccal and lingual direction and have a thickness of at least 3mm, extend to the adjacent tooth in the mesiodistal direction, and do not exceed 1 / 2 of the mesiodistal length of the adjacent tooth. Take out the silicone rubber impression after 5 minutes; the silicone rubber impression can be dislocated from the buccal root direction, or from the buccal root direction and lingual direction; use an intraoral scanner to scan the silicone rubber impression, and export the scanned data as PLY (Polygon File Format, a data format for storing three-dimensional graphic objects) format, named "Data 1-Single Tooth Impression".

[0018] In one embodiment, performing an intraoral dentition scan on a patient includes:

[0019] The intraoral scanner is used to scan the upper and lower dentitions and the occlusal relationship of the patient, and the scanned data is exported into the PLY format and named "Data 2 - Denture".

[0020] In one embodiment, the digital design and processing of an integrated post and core are performed based on the single tooth impression, digital scanning, and intraoral dentition scanning, including:

[0021] Select the affected tooth position, select "onlay" as the design type, mark the opposing tooth, and reverse the post and core impression into a positive post and core mold; select 1-3 reference points on the crown of the affected tooth to match and merge the "Data 1 - Single Tooth Impression" and the "Data 2 - Teeth", draw the edge line of the restoration on the merged model, and make fine adjustments; design the placement direction of the restoration. If it is a single post channel or two parallel post channels, the placement channel is parallel to the post channel direction; if there are two or more post channels and they are not parallel to each other, select the post channel closest to the long axis of the root of the affected tooth as the main one The post channel and the other post channels that deviate from the long axis of the tooth root are pin posts. In this case, the direction of the placement channel is parallel to the main post channel. According to the undercut information prompted by the placement channel direction, the design model is trimmed and the undercut is manually filled to make it less than 0.15mm. The bottom of the inlay is generated and the bonding gap is designed to be 0.04-0.05mm. The teeth are arranged and the tooth position is adjusted to coordinate with the adjacent teeth and the opposing teeth. The crown is generated and the post and core edge, adjacent and occlusal space are adjusted through the "free shaping" operation. For single post channels or double post channels parallel to each other, the restoration is merged and saved. Use the "Free Shaping" operation to smooth the surface of the post and core, remove the thin-walled weak tip, select "Free Shaping of Restoration", select the attachment, add the handle, complete the design, and export the data to STL format; for posts with two or more that are not parallel to each other, it is necessary to design a pin post. Export the design to STL format and load it into Magics software (version 20 and above). Click the "Cut or Punch" option and select the "Circle" option. Set the parameters as follows: the center of the circle is the center of the root apex of the post, and the cutting radius is 0.1-0.2mm larger than the radius of the pin post. The tolerance design is 0.04-0.050mm, no notch is designed, the gap is 0.04-0.05mm, the cutting of the pin post is completed, the data is saved as an STL file, and re-imported into the exocad software. The surface of the post and core is smoothed through the "free shaping" operation, and the thin-walled weak tip is removed. The handle of the pin post is added through the "add accessories" function to complete the design and export the data to STL format; the designed file is transferred to a digital cutting device or a 3D printing device, and the integrated post and core is made using a glass fiber reinforced resin block as a raw material.

[0022] In one embodiment, performing a clinical trial fitting and bonding of the target integrated post and core comprises:

[0023] Clinically, the target integrated post and core are disinfected with alcohol, tried on, and the positioning, fit and retention of the target integrated post and core are checked; the post channel, the affected tooth and the target integrated post and core are disinfected, the crown of the affected tooth and the target integrated post and core are blown dry, the liquid in the post channel is absorbed by a moisture-absorbing paper tip, the target integrated post and core are bonded with resin cement, the resin is completely light-cured, the excess adhesive is removed, the tooth is re-prepared, and the crown restoration is performed.

[0024] In a second aspect, the present application further provides an integrated post and core, which is prepared according to the method for making an integrated post and core based on a single tooth impression as described in the aforementioned embodiment.

[0025] In a third aspect, the present application also provides a post and core system, comprising the above-mentioned integrated post and core.

[0026] The above-mentioned method for making an integrated post and core based on a single tooth impression, an integrated post and core, and a post and core system are used to make a post and core impression by developing the concept and technology of a single tooth impression. The impression range includes the affected tooth and a small number of adjacent teeth. When the impression is dislocated, the resistance of the adjacent teeth is small. It can be dislocated not only in the buccal direction but also in the buccal and lingual direction, ensuring that the impression is not deformed and improving the suitability of the post and core. At the same time, this impression technology not only does not require the use of a tray, saving materials, but also significantly reduces the silicone rubber impression material used, reducing costs. In addition, based on the accuracy of a single tooth impression, the present application provides a digital design method for an integrated post and core, which is suitable for situations such as a single post channel and two or more post channels, and solves the problem of poor positioning and poor suitability of the integrated post and core. In summary, the present application can not only be used for secondary post and core restoration with poor post and core positioning, but also can detect the location and degree of post and core deformation through digital means, improve the clinician's ability to identify deformation of the post and core impression, reduce or even avoid the probability of deformation of the post and core impression, reduce the rework rate, and save medical and patient diagnosis and treatment time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 1 is a schematic diagram of a process for fabricating an integrated post and core based on a single tooth impression in one embodiment;

[0029] Figure 2 Schematic diagram of a single tooth impression in one embodiment; wherein A is the apical view, B is the buccal and lingual view, and C is the mesiodistal view;

[0030] Figure 3 Figure 1 is a flow chart of the CAD / CAM integrated post and core fabrication process based on a single tooth impression in one embodiment; wherein, (A) a new project is created using Exocad software (version 3.0), with the design type selected as "onlay," to fabricate an integrated post and core; (B) intraoral dentition scan data is imported; (C) a single tooth impression scan data is added; (D) the single tooth impression scan data is inverted to a positive post and core mold; (E) the dentition data and the single tooth positive mold data are matched, replaced, and merged; (F) the merged design data is replaced; (G) the post and core margin line is drawn; (H) the seating path is set, and undercut information is displayed; (I) the crown is placed; (J) the post and core shape is designed; (K) the occlusion of the post and core is displayed; (L) a handle is added; (M) the designed post and core is displayed; (N) the integrated post and core is digitally cut; (O) the integrated post and core crown is tried on the model, and the placement is smooth and the margins are tightly fitted;

[0031] Figure 4 Schematic diagram of the process of secondary post and core design and processing steps based on a single tooth impression in one embodiment; wherein, (A) a silicone rubber impression of the lower left dentition is made using a partial tray, a digital impression is obtained by intraoral scanning, and an integrated post and core is made by CAD / CAM. The post and core of the lower left second molar can be fully seated, but the post and core of the lower left first molar is poorly seated; (B) a single tooth impression of the lower left first molar is made using silicone rubber material; (C) a digital scan of the single tooth impression; (D) the partial impression and the single tooth impression are matched using exocad software, and the post channels of the two cannot match, indicating that the partial tray has an impression deformation; (E) a post and core are designed using the patented technology The designed integrated post and core shape; (F) Magics software circularly cuts the distal post track, apical view; (G) Magics software circularly cuts the distal post track, apical view; (H) The cut-out pin post; (I) The cut-out main post and core; (J) The designed main post and core and pin post; (K) The main post and core designed based on the local impression (right) and the main post and core designed based on the single tooth impression (left), the two have different post and core angles; (L) The main post and core designed based on the local impression is poorly seated; (M) The main post and core designed based on the single tooth impression is well seated and the edges are tightly fitted; (N) The pin post designed based on the single tooth impression is smoothly seated and tightly fitted. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0034] In one embodiment, Figure 1 As shown, a method for making an integrated post and core based on a single tooth impression is provided, comprising the following steps:

[0035] Step 1: Tooth preparation for the crown and root canal preparation:

[0036] For teeth that meet the indications for post-core crowns and exclude contraindications, the apical filling is removed based on the pulp cavity and root canal morphology on X-rays, exposing the root canal orifice. The tooth is then prepared according to the requirements for a full crown restoration, removing the thin-walled weak apex and undercut tissue within the pulp cavity. The apical and interproximal clearance is at least 0.8mm, the axial convergence is 2°-5°, and the remaining tooth tissue thickness is at least 0.6mm. A reamer is used to prepare the root canal post tract, requiring 4-5mm of root filling material to remain at the root apex. The post length is greater than the clinical crown height, the intraosseous post length is greater than 1 / 2 of the intraosseous root length, and the post diameter is 1 / 4-1 / 3 of the root diameter.

[0037] Step 2: Single tooth impression and digital scan, intraoral dentition scan:

[0038] Use a K-file wrapped with an alcohol cotton ball to clean the post channel, remove the residual liquid in the post channel with a moisture-absorbing paper tip, adjust the length of the prefabricated reinforcement nail used for molding to match the length of the root canal, remove the reinforcement nail, and place it next to the chair for use; prepare the silicone rubber heavy body, and use a silicone rubber light body gun + a fine gun head to inject the silicone rubber light body into the post channel to completely cover the post channel, pulp cavity and side wall edge; place the spiral conveyor on a low-speed mobile phone, insert it into the post channel and rotate it at a low speed to empty the gas in the post channel, place the reinforcement nail in the post channel, place one reinforcement nail in each post channel, and inject the silicone rubber light body again to completely cover the reinforcement nail. The prepared silicone rubber weight was placed on the silicone rubber light weight. The silicone rubber weight was required to be plastic and kneadable, completely surrounding the affected tooth buccal-lingually and at least 3 mm thick, extending mesiodistal to the adjacent tooth, and not exceeding 1 / 2 the mesiodistal length of the adjacent tooth. The silicone rubber impression was removed after 5 minutes. The impression could be dislocated lateral to the buccal root, lateral to the buccal root, and lingually. The silicone rubber impression was scanned with an intraoral scanner. The scan was required to be clear, continuous, and complete. The scan data was exported in PLY format and named "Data 1 - Single Tooth Impression." The patient's upper and lower dentition and occlusion were scanned using an intraoral scanner. The scan data was exported in PLY format and named "Data 2 - Dentition."

[0039] Step 3: Digital design and processing of integrated pile and core:

[0040] Open exocad software (version 3.0 and above), create a new project, select the affected tooth, choose "Onlay" as the design type, and mark the opposing teeth. Click "Design" in the operation bar, import "Data 2 - Dentition," click "Tools," select "Add / Remove Mesh," select "Additional Scan Model" as the mesh type, and load "Data 1 - Single Tooth Impression." Select "Data 1 - Single Tooth Impression," right-click, and select "Edit Mesh." Right-click, select "Show Triangle Mesh Positioning," and right-click, select "Invert Triangle Mesh Positioning." Click "OK." This step inverts the post and core impression into a positive model, facilitating subsequent post and core design. Right-click, select "Match Scan," select one to three reference points on the crown of the affected tooth, and match "Data 1 - Single Tooth Impression" and "Data 2 - Dentition." Click "OK" and select "Replace All Scans" to complete the data matching and merging. Draw the restoration margins on the merged model and make fine adjustments, ensuring a smooth transition between the margins and the remaining tooth tissue. Design the placement path direction of the restoration. If it is a single post path or two parallel post paths, the placement path is parallel to the post path direction. If there are two or more post paths and they are not parallel to each other, select the post path closest to the long axis of the root of the affected tooth as the main post path, and the other post paths that deviate from the long axis of the root are pin posts. In this case, the placement path direction is parallel to the main post path. According to the undercut information prompted by the placement path direction, trim the design model and manually fill the undercut to make it less than 0.15mm. Generate the bottom of the inlay and design the bonding gap to be 0.04-0.05mm. Arrange the teeth and adjust the tooth position to coordinate with the adjacent teeth and the opposing teeth. Generate the crown and adjust the post and core edge, adjacent and occlusal space through the "free shaping" operation. For single pile channel or double pile channels parallel to each other, merge and save the restoration, use the "free shaping" operation to smooth the surface of the post and core, remove the thin-walled weak tip, select "free shaping of restoration", select the attachment, add the handle, complete the design, and export the data to STL format; for pile channels with two or more that are not parallel to each other, it is necessary to design a pin pile, export the design to STL format, load it into Magics software (version 20 and above), click the "cut or punch" option, select the "circular" option, and refer to the STL format. The data were set as follows: the center of the circle was the center of the apical area of ​​the post channel, the cutting radius was 0.1-0.2 mm larger than the radius of the plug post channel, the tolerance was designed to be 0.04-0.050 mm, no notch was designed, and the gap was 0.04-0.05 mm. The plug post was cut and the data was saved as an STL file. It was re-imported into the exocad software and the post and core surface was smoothed through the "free shaping" operation to remove the thin-walled weak tip. The handle of the plug post was added through the "add accessory" function to complete the design and export the data to the STL format.The designed file is transferred to a digital cutting device or 3D printing device, and a CAD (Computer-aided design) / CAM (Computer-aided manufacturing) integrated fiber post and core is produced using a glass fiber reinforced resin block as the raw material.

[0041] Step 4: Try out the model of the integrated post and core:

[0042] The digital processing process can cause errors, leading to slight deformation of the post and core, necessitating adjustments on the plaster model. A sterilized silicone rubber impression of the single tooth was cast, and a plaster model was created. The integrated post and core was trial-fitted onto the plaster model, and any undercuts were removed. The post and core surface was then sandblasted and disinfected with alcohol before delivery to the clinic.

[0043] Step 5: Clinical trial fitting and bonding of the integrated post and core:

[0044] Clinically, the integrated post and core are disinfected again with alcohol, and the post and core are trial-fitted to check for proper seating, fit, and retention. The post channel, affected tooth, and post and core are disinfected, the crown, and post and core are air-dried, and the liquid in the post channel is absorbed with a moisture-absorbing paper tip. The post and core are then bonded with resin cement, the resin is fully light-cured, and excess adhesive is removed. The tooth is then re-prepared and the crown restoration is performed.

[0045] In the above-mentioned method for making an integrated post and core based on a single tooth impression, the concept and technology of a single tooth impression is developed to make a post and core impression. The impression range includes the affected tooth and a small number of adjacent teeth. When the impression is dislocated, the resistance of the adjacent teeth is small. It can be dislocated not only in the buccal direction but also in the buccal and lingual direction, ensuring that the impression is not deformed and improving the suitability of the post and core. At the same time, this impression technology not only does not require the use of a tray, saving materials, but also significantly reduces the silicone rubber impression material used, reducing costs. In addition, based on the accuracy of the single tooth impression, the present application provides a digital design method for an integrated post and core, which is suitable for single pile channels and two or more pile channels, etc., and solves the problems of poor positioning and poor suitability of the integrated post and core. In summary, the present application can not only be used for secondary post and core restoration with poor post and core positioning, but also can detect the location and degree of post and core deformation through digital means, improve the clinician's ability to identify the deformation of the post and core impression, reduce or even avoid the probability of deformation of the post and core impression, reduce the rework rate, and save medical and patient diagnosis and treatment time.

[0046] In one embodiment, digital design and processing of an integrated post and core is performed based on a single tooth impression (the residual root of the upper right second molar, which has undergone complete root canal treatment for more than one week, has no discomfort or looseness when percussed, and meets the indications for a post and core crown after examination. The tooth and post channel preparation are performed, the thin-walled weak apex and the undercut tissue in the pulp cavity are removed, the interproximal gap is approximately 0.8 mm, the remaining tooth tissue thickness is at least 0.6 mm, the root canal post channel is prepared using a reamer, and 5 mm of root filling material is retained at the root apex). The specific steps include:

[0047] 1) Single tooth impression:

[0048] Use a K-file wrapped with an alcohol cotton ball to clean the post channel, use a moisture-absorbing paper tip to remove the residual liquid in the post channel, adjust the length of the reinforcement nail to match the length of the root canal, remove the reinforcement nail, and place it next to the chair for use. Prepare the silicone rubber weight, and use a silicone rubber light gun + fine gun head to inject the silicone rubber light body into the post channel so that it completely covers the post channel, pulp cavity and side wall edge. Place the spiral conveyor on a low-speed handpiece, insert it into the post channel and rotate it at a low speed to empty the gas in the post channel, place the reinforcement nail in the post channel, and inject the silicone rubber light body again to completely cover the reinforcement nail and the edge of the affected tooth. Take the prepared silicone rubber weight and place it on the silicone rubber light body, completely surrounding the affected tooth in the buccal and lingual directions with a thickness of about 4mm, extending to the adjacent teeth in the mesiodistal direction, and not exceeding 1 / 2 of the mesiodistal length of the adjacent teeth. After 5 minutes, remove the silicone rubber impression, dislocate it in the ulnar direction, and obtain a single-tooth silicone rubber impression ( Figure 2 AC). The silicone rubber impression was scanned with an intraoral scanner and the scanned data was exported in PLY format and named "Data 1 - Single Tooth Impression".

[0049] 2) Intraoral dentition scan:

[0050] Use an intraoral scanner to scan the patient's upper and lower dentition and occlusal relationship, and export the scanned data in PLY format and name it "Data 2-Dentition".

[0051] 3) Digital design and processing of integrated post and core:

[0052] Open exocad software (version 3.0), create a new project, select the affected tooth, select the design type as "onlay", mark the opposing tooth ( Figure 3 A). Click the "Design" option in the operation bar, import "Data 2-Dentition", click "Tools", select "Add / Remove Mesh", select the mesh type as "Additional Scan Model", and load "Data 1-Single Tooth Impression" ( Figure 3 C). Select "Data 1 - Single Tooth Impression", right-click, select "Edit Mesh"; right-click, select "Show Triangular Mesh Positioning"; right-click, select "Invert Triangular Mesh Positioning", click "OK" to invert the post and core impression into a positive post and core mold ( Figure 3D). Right-click and select "Match Scan", select a reference point on the crown of the affected tooth to match "Data 1 - Single Tooth Impression" with "Data 2 - Dentition" ( Figure 3 E), click "OK", select "Replace all scan data", complete the data matching and merging ( Figure 3 F). Draw the margin line of the restoration on the combined model and make fine adjustments to ensure a smooth transition between the margin line and the remaining tooth tissue ( Figure 3 G). Design the placement direction of the restoration to be parallel to the post path direction. According to the undercut information indicated by the placement direction, trim the design model and manually fill the undercut to make it less than 0.15mm ( Figure 3 H). Generate the bottom of the inlay and design the bonding gap to be 0.05mm. Arrange the teeth and adjust the tooth position to coordinate with the adjacent teeth and the opposing teeth ( Figure 3 I). Generate the crown and adjust the post and core margins, proximal joints and occlusal space through the "free shaping" operation ( Figure 3 J, K). Merge and save the restoration, smooth the surface through the "Free Forming" operation, remove the thin wall and weak tip, select "Free Forming of Restoration", select the attachment, add the handle, complete the design, and export the data to STL format ( Figure 3 L, M). The designed file is transferred to the digital cutting equipment, and the glass fiber reinforced resin block is used as the raw material to make the CAD / CAM integrated fiber post and core ( Figure 3 N).

[0053] 4) Model trial wearing of integrated post and core:

[0054] The silicone rubber impression of the single tooth was disinfected and a plaster model was cast. The integrated post and core were tried on the plaster model and the inspection showed that the integrated post and core were smoothly positioned, the edges were tightly fitted, and the retention was good ( Figure 3 O). The surface of the post and core was cleaned by sandblasting, and the post and core were disinfected with alcohol before being sent to the clinic.

[0055] 5) Clinical trial fitting and bonding of integrated post and core:

[0056] Clinically, the integrated post and core are disinfected again with alcohol, and the post and core are trial-fitted to check for proper seating, fit, and retention. The post channel, affected tooth, and post and core are disinfected, the crown, and post and core are air-dried, and the liquid in the post channel is absorbed with a moisture-absorbing paper tip. The post and core are then bonded with resin cement, the resin is fully light-cured, and excess adhesive is removed. The tooth is then re-prepared and the crown restoration is performed.

[0057] In this embodiment, based on the single tooth impression technology, the integrated fiber post and core are digitally designed and produced, which can effectively avoid the deformation of the post and core during the preparation of multiple tooth impressions, improve the suitability of the integrated post and core, and is particularly suitable for post and core repairs with irregular root canal morphology and secondary post and core repairs with poor post and core positioning.

[0058] In one embodiment, a single tooth impression is combined with digital technology to identify local tray impression deformation, and to design and manufacture a secondary post and core for poorly positioned teeth (the left lower first and second molars have large tooth defects, and after complete root canal treatment, they meet the indications for post and core crowns. After tooth preparation and post channel preparation, a silicone rubber impression is made using a local tray and digitally scanned to obtain a digital impression ( Figure 4 A) The scanned data was exported to PLY format and named "Data 0 - Partial Tray Impression" to produce a CAD / CAM integrated post and core. During the clinical trial, it was found that the lower left second molar was poorly seated, with a gap of about 2-3 mm between the post and core and the abutment tooth. To identify the deformed part of the impression and re-produce the post and core, the following steps were performed using this embodiment:

[0059] 1) Single tooth impression:

[0060] Use a K-file wrapped with an alcohol cotton ball to clean the post channel, use a moisture-absorbing paper tip to remove the residual liquid in the post channel, adjust the length of the reinforcement nail to match the length of the root canal, remove the reinforcement nail, and place it next to the chair for use. Prepare the silicone rubber weight, and use a silicone rubber light gun + fine gun head to inject the silicone rubber light body into the post channel so that it completely covers the post channel, pulp cavity and side wall edge. Place the spiral conveyor on a low-speed handpiece, insert it into the post channel and rotate it at a low speed to empty the gas in the post channel, place the reinforcement nail in the post channel, place 1 impression post on each of the mesial and distal roots, and inject the silicone rubber light body again to completely cover the reinforcement nail and the edge of the affected tooth. Take the prepared silicone rubber weight and place it on the silicone rubber light body, completely surrounding the affected tooth in the buccal and lingual directions with a thickness of about 4mm, extending to the adjacent teeth in the mesial and distal directions, and not exceeding 1 / 2 of the adjacent teeth in the mesial and distal directions. Take out the silicone rubber impression after 5 minutes, dislocate it from the buccal and lingual directions, and obtain a single-tooth silicone rubber impression ( Figure 4 B). Scan the silicone rubber impression with an intraoral scanner to obtain a digital single tooth impression ( Figure 4 C) Export the scanned data to PLY format and name it "Data 1 - Single Tooth Impression". Open exocad software (version 3.0), import "Data 0 - Partial Tray Impression" and "Data 1 - Single Tooth Impression" and perform data matching. The results show that the post paths of the two cannot be matched. The mesial root post path has a significant deviation, while the distal root post path has a smaller deviation ( Figure 4 D).

[0061] 2) Intraoral dentition scan:

[0062] Use an intraoral scanner to scan the patient's upper and lower dentition and occlusal relationship, and export the scanned data in PLY format and name it "Data 2-Dentition".

[0063] 3) Digital design and processing of integrated post and core:

[0064] Open exocad software (version 3.0), create a new project, select the affected tooth, choose "Onlay" as the design type, and mark the opposing teeth. Click "Design" in the operation bar, import "Data 2 - Dentition," click "Tools," select "Add / Remove Mesh," select "Additional Scan Model" as the mesh type, and load "Data 1 - Single Tooth Impression." Select "Data 1 - Single Tooth Impression," right-click, and select "Edit Mesh." Right-click, select "Show Triangle Mesh Positioning," and right-click, select "Invert Triangle Mesh Positioning." Click "OK" to invert the post and core impression into a positive post and core model. Right-click, select "Match Scan," select three reference points on the crown of the affected tooth, and match "Data 1 - Single Tooth Impression" and "Data 2 - Dentition." Click "OK" and select "Replace All Scans" to complete the data matching and merging. Draw the restoration margins on the merged model and make fine adjustments to ensure a smooth transition between the margins and the remaining tooth tissue. Design the placement direction of the restoration, select the mesial root as the main post, and design the distal root as a pin post. The placement direction is parallel to the mesial root. According to the undercut information prompted by the placement path, manually fill the undercut to make it less than 0.15mm, generate the bottom of the inlay, and design the bonding gap to be 0.05mm. Arrange the teeth and adjust the tooth position to make it coordinated with the adjacent teeth and the opposing teeth. Generate the crown, adjust the post and core edges, adjacent and occlusal space through the "free shaping" operation, and generate an integrated post and core ( Figure 4 E). Export the design to STL format, load it into Magics software (version 20), click the "cut or punch" option, select the "circle" option, and set the parameters as follows: the center of the circle is the center of the apex of the distal post channel, the cutting radius is 0.1mm larger than the radius of the plug post channel, the tolerance is designed to be 0.050mm, no notch is designed, and the gap is 0.05mm. The cutting of the distal plug post is completed ( Figure 4 FI), the data was saved as an STL file and re-imported into exocad software. The surface of the post and core was smoothed by the "free shaping" operation, and the thin wall and weak tip were removed. The handle of the pin pile was added through the "add accessories" function to complete the design ( Figure 4 J), the data was exported to STL format. The designed file was transferred to the digital cutting equipment, and the glass fiber reinforced resin block was used as the raw material to make the CAD / CAM integrated fiber post core. Comparing the appearance of the new and old main posts, it was found that the curvature of the old post was larger than that of the new post, and the two were not consistent ( Figure 4 K).

[0065] 4) Model trial wearing of integrated post and core:

[0066] The silicone rubber impression of the single tooth was disinfected and a plaster model was cast. When the old integrated post and core were tried on the plaster model, it was found that there was a significant gap between the two and the post and core could not be fully seated ( Figure 4L), while the new integrated post and core can be fully positioned, and the two fit tightly and have good retention ( Figure 4 M), the pin pile trial showed that it was fully seated and fit tightly ( Figure 4 N). The surface of the post and core was cleaned by sandblasting, and the post and core were disinfected with alcohol before being sent to the clinic.

[0067] 5) Clinical trial fitting and bonding of integrated post and core:

[0068] Clinically, the integrated post and core are disinfected again with alcohol, and the post and core are trial-fitted to check for proper seating, fit, and retention. The post channel, affected tooth, and post and core are disinfected, the crown, and post and core are air-dried, and the liquid in the post channel is absorbed with a moisture-absorbing paper tip. The post and core are then bonded with resin cement, the resin is fully light-cured, and excess adhesive is removed. The tooth is then re-prepared and the crown restoration is performed.

[0069] In this embodiment, based on the single tooth impression technology, the integrated fiber post and core are digitally designed and produced, which can effectively avoid the deformation of the post and core during the preparation of multiple tooth impressions, improve the suitability of the integrated post and core, and is particularly suitable for post and core repairs with irregular root canal morphology and secondary post and core repairs with poor post and core positioning.

[0070] In one embodiment, an integrated post and core is further provided, which is prepared according to the method for preparing an integrated post and core based on a single tooth impression as described in the above embodiment.

[0071] In one embodiment, a post and core system is provided, comprising the integrated post and core.

[0072] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0073] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for making an integrated post and core based on a single tooth impression, characterized in that: The method comprises: Prepare the affected tooth according to the requirements of full crown restoration, and prepare the root canal post of the affected tooth using a reamer; Prepare a silicone rubber heavy body, and use a silicone rubber light body gun + a fine gun head to inject the silicone rubber light body into the post channel so that it completely covers the post channel, pulp cavity and side wall edge; place the screw conveyor on a low-speed mobile phone, insert it into the post channel and rotate it at a low speed to empty the gas in the post channel, place the reinforcement nail in the post channel, and place one reinforcement nail in each post channel, and inject the silicone rubber light body again so that it completely covers the reinforcement nail and the edge of the affected tooth; take the prepared silicone rubber heavy body and place it on the silicone rubber light body, completely surround the affected tooth in the buccal and lingual directions and have a thickness of at least 3mm, extend to the adjacent tooth in the mesiodistal direction, and do not exceed 1 / 2 of the mesiodistal length of the adjacent tooth. Take out the single tooth silicone rubber impression after 5 minutes; the single tooth silicone rubber impression can be taken from Toward dislocation, or from the buccal root direction Lingual dislocation; using an intraoral scanner to scan the single tooth silicone rubber impression, and exporting the scanned data into PLY format, named "Data 1 - Single Tooth Impression"; using the intraoral scanner to scan the patient's upper and lower dentition and occlusal relationship, and exporting the scanned data into PLY format, named "Data 2 - Dentition"; Based on the digital single tooth impression and intraoral dentition scanning results, the integrated post and core are digitally designed and processed to obtain the initial integrated post and core; The initial integrated post and core are subjected to a model trial fitting and adjustment to obtain a target integrated post and core, and the target integrated post and core are subjected to a clinical trial fitting and bonding.

2. The method according to claim 1, characterized in that The tooth preparation is carried out according to the requirements of full crown restoration, including: For the teeth that meet the indications for post and core crown and exclude contraindications, remove the pulp cavity and root canal morphology according to the X-ray film of the teeth. Surface filling, exposing the root canal orifice; Prepare the affected tooth according to the requirements of full crown restoration, remove the thin-walled weak tip and the undercut tissue in the pulp cavity, The interproximal and interproximal gaps should be at least 0.8 mm, the axial convergence should be 2°-5°, and the remaining tooth tissue thickness should be at least 0.6 mm.

3. The method according to claim 1, characterized in that The step of preparing the root canal post of the affected tooth by using a reamer comprises: The root canal post of the affected tooth is prepared using a reamer, requiring 4-5 mm of root filling material to be retained at the root apex, the length of the post to be greater than the clinical crown height, the length of the intraosseous post to be greater than 1 / 2 of the intraosseous root length, and the diameter of the post to be 1 / 4-1 / 3 of the root diameter.

4. The method according to claim 1, wherein Before taking a single tooth impression and digital scanning of the affected tooth, the method further includes: Use a K file wrapped with an alcohol cotton ball to clean the post channel, and use a moisture-absorbing paper tip to remove the residual liquid in the post channel. Adjust the length of the prefabricated reinforcement nail used for molding to match the length of the root canal, remove the reinforcement nail, and place it next to the chair for use.

5. The method according to claim 1, wherein Based on the digital single tooth impression and intraoral dentition scan results, the integrated post and core are digitally designed and processed, including: Select the affected tooth, choose "onlay" as the design type, mark the opposing tooth, and reverse the post and core impression to a positive post and core mold; Select 1-3 reference points on the crown of the affected tooth to match and merge the "Data 1 - Single Tooth Impression" and the "Data 2 - Dentition", draw the margins of the restoration on the merged model, and make fine adjustments; Design the placement path direction of the restoration. If there is a single post path or two parallel post paths, the placement path should be parallel to the post path direction. If there are two or more post paths and they are not parallel to each other, the post path closest to the long axis of the root of the affected tooth should be selected as the main post path, and the other post paths that deviate from the long axis of the root should be selected as pin posts. In this case, the placement path direction should be parallel to the main post path. According to the undercut information prompted by the placement path direction, the design model should be trimmed and the undercut should be manually filled to reduce the undercut to less than 0.15mm. Generate the inlay base, design the bonding gap to be 0.04-0.05mm, arrange the teeth, and adjust the tooth position to make it coordinated with the adjacent teeth and the opposing teeth; Generate the crown and adjust the post and core margins, adjacencies, and occlusal space using the "Free Shaping" operation. For single or parallel post channels, merge and save the restoration. Use the "Free Shaping" operation to smooth the post and core surface and remove thin walls and weak apexes. Select "Free Shaping of Restoration," select the attachments, add the handle, complete the design, and export the data to STL format. For piles with two or more non-parallel channels, a pin pile needs to be designed. Export the design to STL format and load it into Magics software (version 20 and above). Click the "Cut or Punch" option and select the "Circle" option. Set the parameters as follows: the center of the circle is the center of the root apex of the channel, the cutting radius is 0.1-0.2mm larger than the radius of the pin pile channel, the tolerance is 0.04-0.050mm, no notch is designed, and the gap is 0.04-0.05mm. After cutting the pin pile, save the data as an STL file and re-import it into exocad software. Use the "Free Form" operation to smooth the post and core surface and remove the thin-walled weak tip. Use the "Add Accessory" function to add the handle of the pin pile. Complete the design and export the data to STL format. The designed file is transferred to a digital cutting device or a 3D printing device, and the integrated post and core is manufactured using a glass fiber reinforced resin block as a raw material.

6. The method according to any one of claims 1 to 5, characterized in that Performing clinical trial fitting and bonding of the target integrated post and core, including: Clinically, the target integrated post and core is disinfected with alcohol, the target integrated post and core is tried on, and the positioning, fit, and retention of the target integrated post and core are checked; Disinfect the post channel, the affected tooth and the target integrated post and core, blow dry the crown of the affected tooth and the target integrated post and core, absorb the liquid in the post channel with a moisture-absorbing paper tip, bond the target integrated post and core with resin cement, completely light-cure the resin, remove excess adhesive, re-prepare the tooth, and perform crown restoration.

7. An integrated post and core, characterized in that: It is prepared according to the method for making an integrated post and core based on a single tooth impression according to any one of claims 1 to 6.

8. A post-core system, characterized in that: Including the integrated post and core as described in claim 7.

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