Digital forming method for immediate removable denture

Abstract

The application discloses a kind of digital production methods of activity instant restoration, it is related to denture repair technical field, to solve the technical problem that current activity instant restoration processing and production highly depend on personnel skills, process is complex and low in efficiency and precision is difficult to control, the method integrates intraoral scanning, CAD computer aided design, CAM cutting processing and 3D printing technology, carries exclusive algorithm and corresponding formula such as oral three-dimensional data reconstruction algorithm, base plate adaptive design algorithm, CAM tool path intelligent optimization algorithm, forms the whole process closed loop of "data acquisition-design optimization-fitting verification-precision cutting-finished product detection";The application realizes restoration full digitalization, intelligent preparation, improves processing precision and efficiency, reduces artificial dependence, adapts to different missing tooth scene, and can be widely applied to oral instant repair field.

Description

Technical Field

[0001] This invention relates to the field of dental prosthesis technology, specifically to a digital molding method for removable immediate prostheses. Background Technology

[0002] Removable immediate restorations are important restorative devices in the field of dental restorations, used to quickly restore chewing function and improve oral aesthetics after tooth loss. Their manufacturing precision and fit directly affect the patient's wearing comfort and usage effect. At present, there are still many technical bottlenecks in the processing and manufacturing of removable immediate restorations, which seriously restrict the efficiency and quality of restoration.

[0003] In current technologies, the fabrication of removable immediate prostheses largely relies on a combination of traditional manual techniques and basic digital technology. First, an intraoral impression is taken to obtain the patient's oral cavity morphology. Then, a prosthesis model is created through manual sculpting or simple CAD design, and finally, it is machined into shape. This method has the following core drawbacks: First, the processing is highly dependent on the technician's skills and experience. Significant differences in skill levels among technicians make it difficult to control the precision and consistency of the prosthesis, easily leading to problems such as poor fit between the base and oral tissues, and abnormal occlusion, affecting the patient's wearing experience. Second, the process is complex, from intraoral impression taking and model making to final cutting and shaping, the steps are cumbersome and time-consuming, failing to meet the needs of patients for immediate restoration and resulting in low efficiency. Third, the application of existing digital technology is relatively basic, lacking a fully intelligent control system. Intraoral scan data is prone to noise and omissions, and key parameters such as base thickness and tooth matching need to be manually adjusted during the design process, further reducing fabrication precision and efficiency. Fourth, material utilization is low; the lack of optimization in CAM toolpath design easily leads to waste of materials such as resin, increasing restoration costs. Therefore, developing a method for fabricating active immediate prostheses that can achieve full-process digitalization and intelligence, and is highly accurate, efficient, and reduces reliance on manual labor has become an urgent technical problem to be solved in the field of dental prosthodontics. Summary of the Invention

[0004] The purpose of this invention is to provide a digital molding method for removable immediate prostheses to solve the problems mentioned in the background art.

[0005] A digital molding method for removable immediate prostheses includes the following steps: S1: Obtain a digital model of oral soft tissues, mucosa and alveolar bone based on oral three-dimensional data reconstruction algorithm; S2: Based on the baseplate adaptive design algorithm, the data generated by the oral digital model is optimized to obtain the trial fitting model parameters; S3: CAM toolpath intelligent optimization layout is performed according to the wearing model parameters. The precise cutting and forming operation is used to cut and form the wearing model to obtain an immediate restoration.

[0006] Furthermore, the oral cavity three-dimensional data reconstruction algorithm is in the form of the following specific formula: ; in, The coordinates of the original scanned data points. The optimized data point coordinates are given by n, which represents the total number of data points scanned in a single region; missing data is filled using the formula. ,in, Missing data points For valid data points surrounding the missing point, The weights of the surrounding data points are denoted by k, which represents the number of valid surrounding data points, used to fill in missing data areas.

[0007] Furthermore, the Keithau adaptive design algorithm takes the form of the following specific formula: ; Where S represents the area of ​​the adaptation region, and D represents the three-dimensional region of the oral cavity scan data. For the adaptation region identification function, when the coordinates (x, y, z) belong to the adaptation region... =1, otherwise 0, automatically identifies the prosthesis fitting area, and calculates the formula within the area using virtual reserved space. Where H is the reserved space thickness, With a base thickness of 3mm, α being an adaptive coefficient of 0.5-1.0, and σ being the standard deviation of the mucosal undulation in the adaptation area, a virtual reserved space of 3-6mm thickness is precisely generated for adapting the prosthesis base; lingual thickness adaptive formula. Where t is the thickness of the tongue-side base plate. The baseline thickness is 2mm, and L is the actual width of the patient's tongue side. To achieve the standard lingual width, the lingual surface undergoes intelligent flattening. The thickness of the lingual base is adaptively adjusted based on the patient's oral lingual anatomy and occlusal force data to ensure wearing comfort and force stability. Subsequently, a dental CAD design software with a built-in tooth shape database, combined with a dentition matching algorithm, utilizes a tooth shape matching formula... ; Where M is the matching degree value, For the patient's oral dental arch characteristic parameters, The database contains tooth shape feature parameters, where n is the number of feature parameters. A smaller M value indicates a higher matching degree. The system automatically matches tooth size and shape to the patient's oral data and dental arch morphology, and supports custom tooth color. During simulated tooth arrangement, a calibration formula based on occlusal relationships is used. Where θ is the bite angle. , These are the normal vectors of the occlusal surfaces of the upper and lower teeth, respectively, which are used to calibrate the arch curvature, midline, and occlusal relationship in real time, so that they perfectly conform to the patient's oral anatomy and physiological function.

[0008] Furthermore, CAM technology is used with an intelligent toolpath optimization algorithm for toolpath calculation and layout. The intelligent toolpath optimization algorithm is in the form of the following formula: ; Where η is the material utilization rate, Let m be the volume of a single restoration, and m be the number of restorations. This refers to the total volume of the resin disc; ; Where L is the total length of the optimized toolpath, ( , , ) represents the coordinates of the nodes in the toolpath, and k represents the number of nodes.

[0009] Furthermore, based on the toolpath parameters calculated by the intelligent toolpath optimization algorithm, the resin disk is precisely cut. During the cutting process, a real-time monitoring algorithm for linkage accuracy is used. The real-time monitoring algorithm for linkage progress is in the form of the following specific formula: ; Where Δ is the deviation between the actual cutting and the design document, ( , , () represents the real-time coordinates for cutting. , , Using the coordinates of the design file, the cutting accuracy and restoration morphology parameters are monitored in real time to ensure that the thickness of the restoration base, tooth morphology, and occlusal relationship are completely consistent with the design file, and finally the fabrication of the removable immediate restoration is completed.

[0010] Furthermore, specific parameters of the oral soft tissues, mucosa, and alveolar bone were obtained using intraoral scanning. The intraoral scanning process employed a combination of sectional scanning and overall stitching. First, the anterior teeth, posterior teeth, and alveolar bone regions were scanned separately. Then, the data was stitched together using a seamless 3D data stitching algorithm built into the CAD software. This seamless 3D data stitching algorithm takes the form of the following specific formula: ; Where δ is the splicing deviation, ( , , ), ( , , ) represents the coordinates of the data points corresponding to adjacent partitions, and n represents the number of corresponding data points.

[0011] Furthermore, when simulating tooth arrangement using the digital oral model, the CAD software incorporates a built-in intelligent occlusal calibration algorithm, which takes the form of the following specific formula: ; Where d is the interocclusal space. The normal vector of the occlusal surface of the upper teeth. The algorithm uses any vector between the occlusal surfaces of the upper and lower teeth to collect and detect the occlusal gap after tooth alignment in real time. Based on oral physiological occlusion standards, it automatically fine-tunes tooth position and occlusal height to stably control the occlusal gap within 0.1-0.2mm, perfectly conforming to the physiological occlusal requirements of the human mouth throughout the process. The 3D printing utilizes photopolymerization technology, and a precise layer thickness control algorithm is implemented during the printing process. This precise layer thickness control algorithm takes the form of the following specific formula: ; in, This is the actual printed layer thickness. The layer thickness is set to 0.025-0.05mm, k is the temperature correction factor, and ΔT is the difference between the actual printing temperature and the standard temperature.

[0012] Furthermore, the CAM toolpath calculation adopts a layered cutting strategy and incorporates a partitioned cutting parameter adaptive algorithm, which is in the form of the following specific formula: ; Where v is the actual cutting speed. As the reference speed, The material density in the cutting region, To ensure the standard resin material density, the cutting speed and feed rate are automatically matched to the tissue surface, lingual surface, and tooth surface of the restoration base. The cutting speed for the tissue surface is 8000-10000 r / min, and the cutting speed for the lingual surface is 12000-15000 r / min. No manual adjustment of parameters is required, ensuring a smooth cutting surface without damaging the design shape.

[0013] Furthermore, after the cutting is completed, an intraoral scanner is used to perform a second scan of the finished restoration, and a data comparison and verification algorithm is used, which is in the form of the following specific formula: ; in, For overall deviation, For the deviation of a single data point, This represents the total number of data points.

[0014] Furthermore, the lingual surface of the immediate restoration base is smoothed using a gradient design. The area near the gingival margin is processed using an algorithm to generate a smooth transition segment of 1-2 mm. This algorithm takes the form of the following specific formula: ; Where t(x) is the thickness at any position of the transition section. The initial thickness of the transition section. L is the thickness at the end of the transition section, L is the length of the transition section, and x is the distance from the starting end.

[0015] By adopting the above technical solutions, the denture base thickness and tooth matching parameters can be adaptively adjusted according to different patients' tooth loss scenarios (such as unilateral posterior tooth loss, bilateral anterior tooth loss, multiple tooth loss, etc.) through algorithms, without the need for major modifications to the core process, and adaptable to various immediate dental restoration cases. At the same time, the fully digital process is easy to operate and can be widely used in various dental clinics, with strong promotion potential, which can promote the digital and intelligent development of immediate dental restoration technology.

[0016] Compared with the prior art, the beneficial effects of this invention are: the digital molding method for immediate restoration of dentures, Through a series of proprietary algorithms, such as oral 3D data reconstruction algorithm and base adaptive design algorithm, intelligent control of key aspects such as oral data optimization, prosthesis fitting area recognition, base design, tooth matching, tooth alignment calibration, and cutting path optimization is achieved. Technicians do not need to manually adjust key parameters, effectively avoiding manufacturing deviations caused by differences in the technical levels of different technicians. This solves the problem of difficulty in controlling the precision and consistency of prostheses in existing technologies, ensuring the quality stability of prostheses in different cases and batches. At the same time, it reduces the dependence on technician operating skills and reduces labor and training costs. A fully digital closed-loop process of "data acquisition - design optimization - trial fitting verification - precision cutting - finished product inspection" has been constructed, eliminating the need for tedious steps such as traditional manual mold taking and carving. The efficient connection of each link is achieved through algorithm optimization; intraoral scanning quickly acquires full-dimensional oral data, CAD design and CAM tool path optimization are completed simultaneously and efficiently, 3D printing trial fitting models are quickly formed, and the cutting process does not require manual intervention, which greatly shortens the production cycle of the prosthesis. It solves the defects of complex process and long time consumption in existing technologies, and can quickly respond to patients' immediate restoration needs and improve clinical diagnosis and treatment. Through precise control of various proprietary algorithms and specific formulas, the accuracy of oral scanning is controlled within ±0.05mm, the splicing deviation does not exceed 0.03mm, and the occlusal gap is stably controlled within 0.1-0.2mm. This ensures that the prosthesis base fits closely to the oral soft tissues, mucosa, and alveolar bone, and that the arch curvature, midline, and occlusal relationship fully conform to the physiological and anatomical characteristics of the human oral cavity. At the same time, the gradually flat design on the lingual side of the base avoids the problem of mucosal pressure, and the precise control of the 3D printing layer thickness ensures that there is no foreign body sensation during the trial fitting. This effectively solves the problems of poor fit, abnormal occlusion, and discomfort in existing technologies, significantly improving the patient's wearing comfort and usage effect. By using the CAM toolpath intelligent optimization algorithm, combined with the resin disc material utilization formula, the restoration is intelligently arranged to maximize the use of resin disc material and reduce material waste. Compared with traditional toolpath design, the material utilization rate is improved by more than 15%. At the same time, a closed-loop management system is formed through real-time accuracy monitoring algorithm and data comparison and verification algorithm to avoid rework waste caused by unqualified accuracy, further reducing the cost of restoration materials and processing costs, and improving the economics of clinical application. Attached Figure Description

[0017] Figure 1 This is an overall flowchart of the present invention; Figure 2 This is a physical diagram of the cutting process of the present invention; Figure 3 This is a physical image of the finished product of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-3 This invention provides a technical solution: a digital molding method for removable immediate prostheses. The core of this digital fabrication method for removable immediate prostheses is the integration of three core technologies: intraoral scanning, CAD design, and CAM cutting. It incorporates proprietary algorithms such as a three-dimensional oral data reconstruction algorithm, a baseplate adaptive design algorithm, and a CAM toolpath intelligent optimization algorithm. Through specific algorithmic formulas, it achieves precise control at each stage, forming a closed-loop process of "data acquisition - design optimization - trial fitting verification - precise cutting." The three-dimensional oral data reconstruction algorithm utilizes noise removal formulas... in, The coordinates of the original scanned data points. The optimized data point coordinates are defined by n, which represents the total number of data points scanned in a single region. This is used to remove scanning noise and fill in missing data using the formula. ,in, Missing data points For valid data points surrounding the missing point, The weights of surrounding data points are defined, where k is the number of valid surrounding data points. This fills in missing data areas, optimizes intraoral scan data, and ensures data integrity and accuracy. The basement adaptive design algorithm includes a formula for identifying the prosthesis fitting area. Where S is the area of ​​the adaptation region, and D is the three-dimensional region of the oral cavity scan data. For the adaptation region identification function, when the coordinates (x, y, z) belong to the adaptation region... =1, otherwise 0; Virtual reserved space calculation formula Where H is the reserved space thickness, The base thickness is 3mm, α is the adaptive coefficient of 0.5-1.0, σ is the standard deviation of the mucosal undulation in the adaptation area, and the adaptive formula for tongue side thickness is given. Where t is the thickness of the tongue-side base plate. The baseline thickness is 2mm, and L is the actual width of the patient's tongue side. Formulas for standard lingual width and tooth profile matching Where M is the matching degree value, For the patient's oral dental arch characteristic parameters, Here, n represents the number of tooth shape feature parameters in the database, and the occlusal relationship calibration formula is used. Where θ is the bite angle. , These are the normal vectors of the occlusal surfaces of the upper and lower teeth, enabling intelligent design of the denture base, tooth matching, and tooth alignment; the seamless 3D data stitching algorithm uses a stitching deviation calibration formula. Where δ is the splicing deviation, ( , , ), ( , , () represents the coordinates of data points corresponding to adjacent partitions, and n represents the number of corresponding data points, reducing splicing errors; the intelligent calibration algorithm for bite relationship uses the bite gap calculation formula Where d is the interlocking interval. The normal vector of the occlusal surface of the upper teeth. For any vector between the occlusal surfaces of the upper and lower teeth, the occlusal gap can be precisely controlled; the 3D printing layer thickness precision control algorithm uses a layer thickness error correction formula. ,in, This is the actual printed layer thickness. To set the layer thickness to 0.025-0.05mm, k is the temperature correction coefficient, and ΔT is the difference between the actual printing temperature and the standard temperature, ensuring stable printing layer thickness; the CAM toolpath intelligent optimization algorithm includes a resin disk material utilization formula. Where η is the material utilization rate. Let m be the volume of a single restoration, and m be the number of restorations. Formulas for optimizing the total volume of the resin disk and the toolpath Where L is the total length of the optimized toolpath, ( , , () represents the coordinates of the toolpath nodes, and k represents the number of nodes, achieving efficient material utilization and improved cutting efficiency; the zoned cutting parameter adaptive algorithm matches the cutting speed using the cutting speed matching formula. Where v is the actual cutting speed, The reference rotational speed is ρ, and the material density in the cutting zone is ρ. The cutting parameters are automatically matched to the standard resin material density; the real-time accuracy monitoring algorithm calculates the accuracy deviation using the formula. Where Δ is the deviation between the actual cutting and the design document, ( , , () represents the real-time coordinates for cutting. , , The coordinates in the design file ensure cutting accuracy; the data comparison and verification algorithm uses the overall deviation evaluation formula. ,in, For overall deviation, For the deviation of a single data point, where n is the total number of data points, accurate detection of the finished product is achieved; the transition section thickness gradient algorithm uses the transition section thickness gradient formula. Where t(x) is the thickness at any position of the transition section, The initial thickness of the transition section. L represents the thickness at the end of the transition segment, L represents the length of the transition segment, and x represents the distance from the starting end, achieving a gradual, flat design on the lingual side of the denture base. The specific process is as follows: First, a full-dimensional data of the patient's oral cavity is acquired using an intraoral scanner. A 3D oral data reconstruction algorithm is used to remove noise and fill in missing data, resulting in a precise digital model of the oral cavity. Then, using CAD-aided design software, an adaptive design algorithm for the denture base is activated to complete the identification of the prosthesis fitting area, design of the denture base thickness, tooth matching, and tooth alignment calibration, generating design files. A trial model is then created using 3D printing to verify whether the function and shape meet the requirements. Next, CAM technology, coupled with a toolpath intelligent optimization algorithm, completes toolpath calculation and layout optimization, maximizing material utilization and shortening cutting time. Finally, the resin disc is precisely cut according to the optimized toolpath parameters, with a real-time accuracy monitoring algorithm ensuring cutting precision. After cutting, a data comparison and verification algorithm is used for finished product inspection to ensure the prosthesis meets design requirements, ultimately completing the fabrication of the removable immediate prosthesis. The entire process requires minimal manual intervention, is highly automated, has controllable precision, and significantly improves efficiency.

[0020] Example 1 This embodiment addresses a patient with unilateral maxillary posterior tooth loss, using the method of this invention to fabricate a removable immediate restoration. The specific steps are as follows: The 3Shape Trios 5 intraoral scanner was used to perform a comprehensive scan of the patient's maxillary oral cavity, focusing on the areas of missing posterior teeth, remaining alveolar bone, oral soft tissues and mucosa. During the scan, the scanner's built-in oral 3D data reconstruction algorithm was activated to optimize the original scan data, remove scanning noise, and fill in missing data areas. Finally, a complete digital model including maxillary soft tissues, mucosa and alveolar bone was obtained. The scanning accuracy was measured to be ±0.04mm, completely replicating the patient's oral physiological and anatomical morphology. Using Exocad dental CAD-aided design software, the optimized oral digital model was imported, and the base design adaptive algorithm was activated for fine editing. This algorithm automatically identifies the fitting area for the prosthesis in the missing maxillary posterior teeth area and accurately generates a 3-6mm thick virtual reserved space within the area to fit the prosthesis base. The algorithm simultaneously locks the tissue surface of the base, preserving the original morphology of the oral mucosa, and intelligently smooths the lingual surface, adaptively adjusting the thickness of the lingual base to ensure wearing comfort. Subsequently, the built-in tooth shape database of the CAD software is called, and the posterior teeth matching algorithm is used to automatically match the tooth body that matches the patient's oral data. The tooth body color is customized to natural tooth color (shade A2). During the simulated tooth arrangement process, the occlusal relationship is calibrated through the occlusal relationship calibration algorithm to ensure that it meets the physiological occlusal requirements of the human oral cavity. The design file is imported into the Formlabs Form 3B+ 3D printer, and a prosthesis trial model is printed using biocompatible resin material (model Formlabs Dental SG). After printing, the surface is polished to a surface roughness Ra of 0.6μm. A Roland DWX-52D CAM cutting machine was selected. Based on the final design documents mentioned above, an intelligent toolpath optimization algorithm was activated to calculate and arrange the toolpath. This algorithm intelligently arranged multiple restorations, maximizing the use of resin disc material and reducing material waste. At the same time, it optimized the cutting toolpath, avoiding toolpath jamming and repeated cutting, and shortening the overall cutting time. In this arrangement, two restorations were prepared (one for the patient and one as a spare), achieving a material utilization rate of 80%, and the total toolpath length was shortened by 15% compared to traditional toolpaths. Based on the optimized toolpath parameters, the resin disc (model 3M Lava Ultimate) was precisely cut. During the cutting process, a real-time precision monitoring algorithm was used to monitor the cutting accuracy and ensure that the shape of the restoration was consistent with the design documents. After the cutting was completed, an intraoral scanner was used to scan the finished restoration a second time. A data comparison and verification algorithm was used to compare the data to ensure that the restoration met the requirements. Finally, the fabrication of the immediate removable restoration for the missing maxillary unilateral posterior tooth was completed. After the trial fitting, the patient reported that the restoration fit well, there was no foreign body sensation, and the bite was normal.

[0021] Example 2 This embodiment addresses a patient with bilateral mandibular anterior tooth loss, using the method of this invention to fabricate a removable immediate restoration. The specific steps are as follows: The Itero Element 5D intraoral scanner was used to perform a sectional scan of the patient's mandibular oral cavity, specifically scanning the anterior tooth loss area, the left and right posterior tooth areas, and the alveolar bone area. After scanning, a combination of sectional scanning and overall stitching was used. The data was stitched together using the 3D data seamless stitching algorithm built into the CAD software. During the scanning process, an oral 3D data reconstruction algorithm was activated to optimize the data, remove noise, and fill in missing data to obtain a complete digital model of the oral cavity. The scanning accuracy was ±0.03mm. During the stitching process, the 3D data seamless stitching algorithm was used to calibrate deviations to ensure that the data stitching was continuous and without deviation. Crown & Bridge CAD dental design software was used to import the optimized digital oral model, and the adaptive design algorithm for the denture base was activated. This algorithm identifies the suitable area for the missing mandibular anterior teeth and generates a virtual reserved space that meets the requirements. The tissue surface of the denture base retains the original mucosal morphology, and the lingual thickness is adaptively adjusted by the algorithm to ensure wearing comfort. A tooth shape database was accessed, and a tooth alignment matching algorithm was used to match the anterior teeth. The tooth color was customized to a natural tooth color (shade A3). During simulated tooth arrangement, an intelligent occlusal calibration algorithm was used to monitor the occlusal gap, ensuring it met the physiological requirement of 0.1-0.2mm and guaranteeing normal occlusion. The design file was imported into a Prusa i3 MK3S+ 3D printer, and a trial model was printed using biocompatible resin material. During printing, a precise layer thickness control algorithm was used to stably control the printed layer thickness. After printing, the surface was polished to a roughness Ra of 0.7μm. A Zirkonzahn M1 CAM cutting machine was selected, and a toolpath intelligent optimization algorithm was initiated based on the design files. This algorithm achieved efficient utilization of resin disk material and optimization of toolpath path. In this layout of two restorations, the material utilization rate reached 85.7%, and the total toolpath length was optimized to reduce the cutting time by 20%. The resin disc is cut according to the optimized toolpath parameters. During the cutting process, a real-time accuracy monitoring algorithm is used to ensure that the cutting accuracy meets the requirements. After cutting, a second scan is performed, and the data is compared and verified using a data comparison algorithm to confirm that the restoration is qualified. When the restoration is tried on, the base fits tightly, there is no pressure on the lingual side, and the bite is smooth, meeting the patient's immediate restoration needs.

[0022] Example 3 This embodiment addresses a patient with multiple missing maxillary teeth (3 anterior teeth + 2 posterior teeth), and uses the method of this invention to fabricate a removable immediate restoration. The specific steps are as follows: The Planmeca Emerald S intraoral scanner was used to perform a comprehensive scan of the patient's maxillary oral cavity, focusing on the areas of missing teeth, remaining teeth, oral soft tissues, and alveolar bone. The oral cavity 3D data reconstruction algorithm was activated to optimize the data, remove noise, and fill in missing data to obtain a complete digital model of the oral cavity. The scanning accuracy was ±0.04mm. A partitioned scanning + stitching method was adopted, and the stitching deviation was calibrated by a seamless 3D data stitching algorithm to ensure data integrity and continuity.

[0023] Dental System CAD software was used to import the optimized digital oral model. The adaptive design algorithm for the denture base was activated. This algorithm identifies the fitting area and generates virtual reserved space. The tissue surface of the denture base retains the original mucosal morphology. The thickness of the lingual side is adaptively adjusted by the algorithm. In the area of ​​the lingual side of the denture base near the gingival margin, a smooth transition segment of 1.5mm is generated through the transition segment thickness gradient algorithm to achieve thickness gradient and avoid mucosal compression. The tooth shape database is called and the tooth structure of the anterior and posterior teeth is matched with the tooth structure. The tooth color is customized to natural tooth color (shade A2.5). During the simulated tooth arrangement, the occlusal relationship intelligent calibration algorithm monitors the occlusal gap and controls it within a reasonable range to ensure occlusal stability. The design file is imported into the AnycubicPhoton Mono X 3D printer. A trial model is printed using biocompatible resin material. The layer thickness is controlled by a precise layer thickness control algorithm. After polishing, the surface roughness Ra is 0.5μm. The Sirona inLab MC X5 CAM cutting machine was selected, and the toolpath intelligent optimization algorithm was activated. This algorithm achieves efficient utilization of resin disk material and optimization of toolpath. In this layout of one restoration, the material utilization rate reached 80%, and the total toolpath length was optimized to improve cutting efficiency by 18%. At the same time, a layered cutting strategy was adopted, equipped with a partitioned cutting parameter adaptive algorithm, which automatically matched the cutting speed and feed rate of different areas of the restoration. No manual adjustment of parameters was required, ensuring a smooth cutting surface without damaging the design shape. Based on the optimized toolpath parameters and cutting speed, the resin disc is precisely cut. During the cutting process, a real-time accuracy monitoring algorithm is used to monitor the process and ensure that the cutting accuracy meets the requirements. After the cutting is completed, a second scan is performed, and the data is compared and verified by a data comparison algorithm to confirm that the restoration is qualified. After the restoration is tried on, the patient reports that the fit is high, there is no mucosal pressure, and the occlusal function is normal, which can meet the needs of immediate restoration.

Claims

1. A digital molding method for removable immediate prostheses, characterized in that, Includes the following steps: A digital model of the oral cavity, including soft tissues, mucosa, and alveolar bone, is obtained based on an oral cavity three-dimensional data reconstruction algorithm. Based on the adaptive design algorithm for dental trays, the data generated by the aforementioned digital oral model is optimized to obtain the parameters of the trial fitting model; Based on the parameters of the wearing model, CAM toolpath intelligent optimization and layout are performed. The precise cutting and shaping operation is used to cut and shape the wearing model to obtain an immediate restoration.

2. The digital molding method for removable immediate prostheses according to claim 1, characterized in that, The algorithm for reconstructing three-dimensional oral cavity data is in the form of the following specific formula: ； in, The coordinates of the original scanned data points. The optimized data point coordinates are given by n, which represents the total number of data points scanned in a single region; missing data is filled using the formula. ,in, Missing data points For valid data points surrounding the missing point, The weights of the surrounding data points are denoted by k, which represents the number of valid surrounding data points, used to fill in missing data areas.

3. The digital molding method for removable immediate prostheses according to claim 1, characterized in that, The Keith adaptive design algorithm is in the form of the following specific formula: ； Where S represents the area of ​​the adaptation region, and D represents the three-dimensional region of the oral cavity scan data. For the adaptation region identification function, when the coordinates (x, y, z) belong to the adaptation region... =1, otherwise 0, automatically identifies the prosthesis fitting area, and calculates the formula within the area using virtual reserved space. Where H is the reserved space thickness, With a base thickness of 3mm, α being an adaptive coefficient of 0.5-1.0, and σ being the standard deviation of the mucosal undulation in the adaptation area, a virtual reserved space of 3-6mm thickness is precisely generated for adapting the prosthesis base; lingual thickness adaptive formula. Where t is the thickness of the tongue-side base plate. The baseline thickness is 2mm, and L is the actual width of the patient's tongue side. To achieve the standard lingual width, the lingual surface undergoes intelligent flattening. The thickness of the lingual base is adaptively adjusted based on the patient's oral lingual anatomy and occlusal force data to ensure wearing comfort and force stability. Subsequently, a dental CAD design software with a built-in tooth shape database, combined with a dentition matching algorithm, utilizes a tooth shape matching formula... ; Where M is the matching degree value, For the patient's oral dental arch characteristic parameters, The database contains tooth shape feature parameters, where n is the number of feature parameters. A smaller M value indicates a higher matching degree. The system automatically matches tooth size and shape to the patient's oral data and dental arch morphology, and supports custom tooth color. During simulated tooth arrangement, a calibration formula based on occlusal relationships is used. Where θ is the bite angle. , These are the normal vectors of the occlusal surfaces of the upper and lower teeth, respectively, which are used to calibrate the arch curvature, midline, and occlusal relationship in real time, so that they perfectly conform to the patient's oral anatomy and physiological function.

4. The digital molding method for removable immediate prostheses according to claim 3, characterized in that, CAM technology is used with an intelligent toolpath optimization algorithm for toolpath calculation and layout. The intelligent toolpath optimization algorithm is in the form of the following formula: ； Where η is the material utilization rate, Let m be the volume of a single restoration, and m be the number of restorations. This refers to the total volume of the resin disc; ； Where L is the total length of the optimized toolpath, ( , , ) represents the coordinates of the nodes in the toolpath, and k represents the number of nodes.

5. The digital molding method for removable immediate prostheses according to claim 4, characterized in that, Based on the toolpath parameters calculated by the intelligent toolpath optimization algorithm, the resin disc is precisely cut. During the cutting process, a real-time monitoring algorithm for linkage accuracy is used. The real-time monitoring algorithm for linkage progress is in the form of the following specific formula: ； Where Δ is the deviation between the actual cutting and the design document, ( , , () represents the real-time coordinates for cutting. , , Using the coordinates of the design file, the cutting accuracy and restoration morphology parameters are monitored in real time to ensure that the thickness of the restoration base, tooth morphology, and occlusal relationship are completely consistent with the design file, and finally the fabrication of the removable immediate restoration is completed.

6. The digital molding method for removable immediate prostheses according to claim 1, characterized in that, Specific parameters of oral soft tissues, mucosa, and alveolar bone were obtained using intraoral scanning. The intraoral scanning process employed a combination of sectional scanning and overall data stitching. First, the anterior teeth, posterior teeth, and alveolar bone regions were scanned separately. Then, the data was stitched together using a seamless 3D data stitching algorithm built into the CAD software. This seamless 3D data stitching algorithm takes the form of the following specific formula: ； Where δ is the splicing deviation, ( , , ), ( , , ) represents the coordinates of the data points corresponding to adjacent partitions, and n represents the number of corresponding data points.

7. The digital molding method for removable immediate prostheses according to claim 1, characterized in that, When simulating tooth arrangement using the digital oral model, the CAD software incorporates an intelligent occlusal calibration algorithm, which takes the form of the following specific formula: ； Where d is the interocclusal space. The normal vector of the occlusal surface of the upper teeth. The algorithm uses any vector between the occlusal surfaces of the upper and lower teeth to collect and detect the occlusal gap after tooth alignment in real time. Based on oral physiological occlusion standards, it automatically fine-tunes tooth position and occlusal height to stably control the occlusal gap within 0.1-0.2mm, perfectly conforming to the physiological occlusal requirements of the human mouth throughout the process. The 3D printing utilizes photopolymerization technology, and a precise layer thickness control algorithm is implemented during the printing process. This precise layer thickness control algorithm takes the form of the following specific formula: ； in, This is the actual printed layer thickness. The layer thickness is set to 0.025-0.05mm, k is the temperature correction factor, and ΔT is the difference between the actual printing temperature and the standard temperature.

8. The digital molding method for removable immediate prostheses according to claim 4, characterized in that, CAM toolpath calculation employs a layered cutting strategy, incorporating a partitioned cutting parameter adaptive algorithm. This algorithm is defined by the following specific formula: ； Where v is the actual cutting speed. As the reference speed, The material density in the cutting region, To ensure the standard resin material density, the cutting speed and feed rate are automatically matched to the tissue surface, lingual surface, and tooth surface of the restoration base. The cutting speed for the tissue surface is 8000-10000 r / min, and the cutting speed for the lingual surface is 12000-15000 r / min. No manual adjustment of parameters is required, ensuring a smooth cutting surface without damaging the design shape.

9. The digital molding method for removable immediate prostheses according to claim 5, characterized in that, After the cutting is completed, an intraoral scanner is used to perform a second scan of the finished restoration, and a data comparison and verification algorithm is used. The algorithm is in the form of the following specific formula: ； in, For overall deviation, For the deviation of a single data point, This represents the total number of data points.

10. The digital molding method for removable immediate prostheses according to claim 1, characterized in that, The lingual surface of the immediate restoration base is smoothed using a gradient design. Near the gingival margin, a smooth transition segment of 1-2 mm is generated using an algorithm, which is expressed by the following formula: ； Where t(x) is the thickness at any position of the transition section. The initial thickness of the transition section. L is the thickness at the end of the transition section, L is the length of the transition section, and x is the distance from the starting end.

Images