Integrated false tooth fatigue test method and system

Abstract

The invention provides an integrated false tooth fatigue test method and system, and the method comprises the steps: obtaining the shape and size information, material characteristic information and constraint conditions of a to-be-tested false tooth, constructing a false tooth finite element model according to the shape and size information and the material characteristic information, and carrying out the fatigue test of the to-be-tested false tooth under the condition of the constraint conditions. Applying a dynamic load to the false tooth finite element model, solving the false tooth finite element model to obtain stress distribution data of each unit grid of the false tooth, and determining a false tooth fatigue test result according to the stress distribution data; according to the method, the limitation that only a static load or a single type of load can be applied in the false tooth anti-fatigue test process is overcome, the false tooth finite element model is solved under the conditions of constraint conditions and dynamic load application, the stress distribution data of each unit grid of the false tooth at different time nodes can be obtained, and the false tooth anti-fatigue test accuracy is improved. Therefore, the false tooth fatigue test result determined according to the stress distribution data is more accurate.

Description

Technical Field

[0001] This application relates to the field of denture testing technology, and in particular to an integrated denture fatigue testing method and system. Background Technology

[0002] Dentures are a general term in medicine for restorations made after partial or complete loss of upper and lower jaw teeth, aiming to restore the function and aesthetics of teeth.

[0003] In the actual use of dentures, fatigue resistance is a crucial performance indicator. Dentures need to withstand external forces such as chewing for extended periods; if their fatigue resistance is poor, they are prone to damage and breakage, affecting the patient's experience and oral health. Therefore, fatigue testing of dentures is necessary before use to ensure that they have good fatigue resistance in actual use.

[0004] Denture testing methods in related technologies often employ static loading tests and cyclic loading tests. Static loading tests involve fixing the denture to a specific fixture and then applying a constant force to it using a mechanical device. After a period of time, the denture is observed for damage such as cracks or deformation. However, this static loading test differs significantly from the actual stress conditions of a denture in the oral cavity (e.g., the frequency of chewing forces and occlusal forces), leading to substantial discrepancies between the test results and practical application. Cyclic loading tests simulate the actual stress conditions of a denture in the oral cavity by applying periodic dynamic loads. While this method is closer to reality to some extent than static loading tests, cyclic loading tests typically only simulate a single type of load and cannot account for the complex and variable stress environment in the oral cavity, thus affecting the accuracy of the denture test results.

[0005] Therefore, it is necessary to improve the denture fatigue testing methods in related technologies. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, this application provides an integrated denture fatigue testing method and system to solve the above-mentioned technical problems.

[0007] According to one aspect of the embodiments of this application, an integrated denture fatigue testing method is provided. The method includes: acquiring shape and size information, material property information, and constraint conditions of the denture to be tested; the constraint conditions include contact constraints and displacement constraints; constructing a finite element model of the denture based on the shape and size information and the material property information; applying a dynamic load to the finite element model of the denture under the constraint conditions, and solving the finite element model of the denture to obtain stress distribution data of each element mesh of the denture; the dynamic load is a load that varies with time in different directions; and determining the fatigue test result of the denture based on the stress distribution data.

[0008] In one embodiment of this application, the process of constructing a finite element model of a denture based on the shape and size information and the material characteristic information includes: constructing a preset dimension model of the denture to be tested according to the shape and size information; dividing the preset dimension model into meshes to obtain each unit mesh of the denture to be tested, and the interaction relationship between each unit mesh; determining the parameter information of each unit mesh according to the material characteristic information of each unit mesh; and obtaining the finite element model of the denture based on the parameter information of each unit mesh and the interaction relationship between each unit mesh.

[0009] In one embodiment of this application, if the preset dimensional model includes a clasp region, a denture base region, and a crown region, the process of meshing the preset dimensional model includes: meshing the clasp region to obtain a clasp region mesh; the clasp region mesh is a hexahedral mesh; meshing the denture base region to obtain a denture base region mesh; the denture base region mesh is a tetrahedral mesh; meshing the crown region to obtain a crown region mesh; the crown region mesh is a tetrahedral mesh; using the clasp region mesh, the denture base mesh, and the crown region mesh as all unit meshes of the denture to be tested; and obtaining the interaction relationship between each unit mesh based on the positional relationship between the clasp region mesh, the denture base mesh, and the crown region mesh.

[0010] In one embodiment of this application, if the stress distribution data includes principal stresses at different time points, and the material property information includes material yield strength, then the process of determining the denture fatigue test result based on the stress distribution data includes: calculating the equivalent stress of each unit grid of the denture at different time points based on the principal stresses at different time points; comparing the equivalent stress with the material yield strength in the order of the different time points; determining the denture fatigue life based on the comparison results at different time points; and using the denture fatigue life as the denture fatigue test result.

[0011] In one embodiment of this application, the process of determining the fatigue life of a denture based on comparison results at different time points includes: if there is no time point in the comparison results where the equivalent stress is greater than the yield strength of the material, then the denture deformation state is determined to be no deformation, and dynamic loads are continued to be applied to the finite element model of the denture until the equivalent stress calculated by subsequent stress fraction data is greater than the yield strength of the material; if there is a time point in the comparison results where the equivalent stress is greater than the yield strength of the material, then the denture deformation state is determined to be deformed, and the time points from no deformation to deformation are taken as the starting point of the deformation state, and the fatigue life of the denture is determined based on the time points located before the starting point of the deformation state.

[0012] In one embodiment of this application, the process of determining the fatigue life of the denture based on the time node located before the starting point of the deformation state includes: obtaining the load curve of the dynamic load; aligning the time node located before the starting point of the deformation state with the load curve to obtain the force load and the number of force applications at the time node located before the starting point of the deformation state; and using the force load and the number of force applications at the time node located before the starting point of the deformation state as the fatigue life of the denture.

[0013] In one embodiment of this application, the formula for calculating the equivalent stress of each element mesh of the denture at different time points is as follows: ,in, Indicates the first denture Each unit grid Equivalent stress at each time point Indicates the first Each unit grid The maximum principal stress at each time point Indicates the first Each unit grid The minimum principal stress at each time point, Indicates the first Each unit grid The intermediate principal stress at the time node, the Each unit grid The intermediate principal stress at the time node is located at the . Each unit grid The maximum principal stress at the first time node and the first Each unit grid Between the minimum principal stresses at each time point.

[0014] In one embodiment of this application, if the stress distribution data includes the maximum stress and minimum stress in each force direction, then the process of determining the denture fatigue test result based on the stress distribution data includes: calculating the stress amplitude and average stress of each denture unit grid in each direction based on the maximum stress and minimum stress in each force direction; and predicting the fatigue life of each denture unit grid in each direction based on the stress amplitude and average stress of each denture unit grid in each direction.

[0015] In one embodiment of this application, before obtaining the shape and size information, material property information, and constraint conditions of the denture to be tested, the method includes: obtaining the type information of the denture to be tested and the displacement constraint; determining the position information of the denture to be tested in the oral cavity based on the type information; determining the contact constraint of the denture to be tested based on the position information; scanning the denture to be tested to obtain the shape and size information of the denture to be tested; and using the displacement constraint and the contact constraint as the constraint conditions.

[0016] According to one aspect of the embodiments of this application, an integrated denture fatigue testing system is provided, comprising: an information acquisition module for acquiring shape and size information, material property information, and constraint conditions of the denture to be tested; the constraint conditions including contact constraints and displacement constraints; a model construction module for constructing a finite element model of the denture based on the shape and size information and the material property information; a model solving module for applying dynamic loads to the finite element model of the denture under the constraint conditions and solving the finite element model of the denture to obtain stress distribution data of each element mesh of the denture; the dynamic loads being loads that vary with time in different directions; and a result determination module for determining the fatigue test results of the denture based on the stress distribution data.

[0017] The beneficial effects of this application are as follows: This application obtains the shape and size information, material property information, and constraint conditions of the denture to be tested. Based on the shape and size information and material characteristic information, a finite element model of the denture is constructed. Under the constraint conditions, a dynamic load is applied to the finite element model of the denture, and the model is solved to obtain the stress distribution data of each element mesh of the denture. Based on the stress distribution data, the fatigue test results of the denture are determined. The above process, by applying a dynamic load to the denture to simulate the complex and variable stress environment in the oral cavity, overcomes the limitation that only static loads or single-type loads can be applied in the denture fatigue test. Furthermore, by solving the finite element model of the denture under constraint conditions and with the application of dynamic loads, the stress distribution data of each element mesh of the denture at different time points can be obtained, thus making the fatigue test results of the denture determined based on the stress distribution data more accurate.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic diagram illustrating an exemplary system architecture as shown in an exemplary embodiment of this application; Figure 2 This is a flowchart illustrating an exemplary embodiment of the fatigue testing method for an integrated denture, as shown in this application. Figure 3 This is an exemplary embodiment of the present application illustrating a flowchart for defining tooth fatigue life; Figure 4 This is a block diagram illustrating an integrated denture fatigue testing system, which is another exemplary embodiment of this application. Detailed Implementation

[0020] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0021] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0022] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.

[0023] Figure 1This is a schematic diagram illustrating an exemplary system architecture as shown in an exemplary embodiment of this application.

[0024] Reference Figure 1 As shown, the system architecture may include a storage device 101 and a data processing device 102. The data processing device 102 may be at least one of a desktop graphics processing unit (GPU) computer, a GPU computing cluster, or a neural network computer. Those skilled in the art can use the data processing device 102 to acquire the shape and size information, material property information, and constraints of the denture to be tested. Based on the shape and size information and material property information, a finite element model of the denture is constructed. Under the constraints, dynamic loads are applied to the finite element model of the denture, and the model is solved to obtain the stress distribution data of each element mesh of the denture. Based on the stress distribution data, the fatigue test results of the denture are determined. The storage device 101 is used to store the shape and size information, material property information, and constraints of the denture to be tested and provides them to the data processing device 102 for processing.

[0025] Indicatively, after acquiring the shape and size information, material properties information, and constraints of the denture to be tested from the storage device 101, the data processing device 102 constructs a finite element model of the denture based on the shape and size information and material properties information. Under the constraints, a dynamic load is applied to the finite element model of the denture, and the model is solved to obtain the stress distribution data of each element mesh of the denture. Based on the stress distribution data, the fatigue test results of the denture are determined. The above process, by applying a dynamic load to the denture to simulate the complex and variable stress environment in the oral cavity, overcomes the limitation that only static loads or single-type loads can be applied during the denture fatigue test. By solving the finite element model of the denture under constraints and with the application of dynamic loads, the stress distribution data of each element mesh of the denture at different time points can be obtained, thus making the fatigue test results of the denture determined based on the stress distribution data more accurate.

[0026] The implementation details of the technical solutions in the embodiments of this application are described in detail below: Figure 2 This is a flowchart illustrating an exemplary embodiment of the fatigue testing method for an integrated denture, as shown in this application. (Refer to...) Figure 2 As shown, the fatigue testing method for integrated dentures includes at least steps S210 to S240, which are described in detail below: In step S210, the shape and size information, material property information, and constraint conditions of the denture to be tested are obtained. In one embodiment of this application, the denture to be tested includes various types such as incisors, canines, and molars. Each type of denture has predetermined shape and size information, including crown shape and size, clasp shape and size, etc. The material property information refers to the property information of the material used to manufacture the denture to be tested. The materials used to manufacture the denture to be tested include acrylic resin, ceramics, etc., and the material property information includes material yield strength, material hardness, elastic modulus, thermal conductivity, Poisson's ratio, density, etc. The constraint conditions include contact constraints and displacement constraints. The displacement constraint includes: the vertical displacement of all points on the abutment tooth surface of the denture to be tested is 0. The contact constraint includes: frictional contact between the denture to be tested and the gingiva (e.g., the coefficient of friction between the denture to be tested and the gingiva is set to 0.3), and frictional contact between the denture to be tested and adjacent teeth (e.g., the coefficient of friction between the denture to be tested and adjacent teeth is set to 0.32).

[0027] In step S220, a finite element model of the denture is constructed based on shape and size information and material characteristic information. In one embodiment of this application, the process of constructing a finite element model of the denture based on shape and size information and material characteristic information includes: constructing a preset dimension model of the denture to be tested based on shape and size information; dividing the preset dimension model into meshes to obtain the meshes of each unit of the denture to be tested, and the interaction relationships between each unit mesh; determining the parameter information of each unit mesh according to the material characteristic information of each unit mesh; and obtaining the finite element model of the denture based on the parameter information of each unit mesh and the interaction relationships between each unit mesh. Through the above settings, the finite element model of the denture can accurately reflect the internal structure of the denture to be tested and the interaction relationships between the internal unit meshes, further improving the accuracy and reliability of the construction of the finite element model of the denture.

[0028] In step S230, under constrained conditions, a dynamic load is applied to the finite element model of the denture, and the finite element model is solved to obtain the stress distribution data of each element mesh of the denture. In one embodiment of this application, the finite element model of the denture is solved using a finite element model solver, including ABAQUS (Advanced Simulation for Engineering and Sciences), ANSYS, etc. The dynamic load is a load that varies with time in different directions, and the expression for the dynamic load is as follows: Equation (1) in, Indicates the first The load applied at each time point Indicates the first The biting force load applied at each time point Indicates the first The chewing force load applied at each time point Indicates the first Lateral force loads applied at each time point.

[0029] In one embodiment of this application, the expression for the bite force load is as follows: Equation (2) in, Indicates the first The biting force load applied at each time point Indicates the amplitude of the bite force. Indicates the bite frequency, Indicates the first Each time point This indicates the initial phase angle of the bite.

[0030] In one embodiment of this application, the expression for chewing force load is as follows: Equation (3) in, Indicates the first The chewing force load applied at each time point Indicates the amplitude of chewing force. Indicates chewing frequency. Indicates the first Each time point This represents the initial phase angle of chewing.

[0031] In one embodiment of this application, the lateral force load is used to simulate the force on the denture during lateral movement, and the expression for the lateral force load is as follows: Equation (4) in, Indicates the first Lateral force loads applied at each time point, Indicates the magnitude of the lateral force. Indicates the lateral loading frequency. Indicates the first Each time point This indicates the initial lateral phase angle.

[0032] In step S240, the fatigue test result of the denture is determined based on the stress distribution data. In one embodiment of this application, by acquiring the shape and size information, material property information, and constraint conditions of the denture to be tested, a finite element model of the denture is constructed based on the shape and size information and material characteristic information. Under the constraint conditions, a dynamic load is applied to the finite element model of the denture, and the finite element model of the denture is solved to obtain the stress distribution data of each element mesh of the denture. Based on the stress distribution data, the fatigue test result of the denture is determined. The above process, by applying a dynamic load to the denture to simulate the complex and variable stress environment in the oral cavity, overcomes the limitation that only static loads or single-type loads can be applied in the denture fatigue resistance test. Furthermore, by solving the finite element model of the denture under constraint conditions and with the application of a dynamic load, the stress distribution data of each element mesh of the denture at different time points can be obtained, thereby making the fatigue test result of the denture determined based on the stress distribution data more accurate.

[0033] In one embodiment of this application, solving the finite element model of the denture can yield strain data, displacement data, maximum deformation, maximum bending stress, maximum torsional stress, and maximum compressive stress for each element mesh at different time points. After obtaining the strain and displacement data for each element mesh at different time points, strain-stress curves and stress-displacement curves are obtained based on these data. The strain-stress curves reveal key mechanical properties of the denture material, such as its elastic stage, plastic stage, and yield point, allowing for assessment of whether the denture will undergo plastic deformation or even failure during normal use. The stress-displacement curves provide the stress magnitude experienced by the denture under different displacements, enabling evaluation of the denture's stability and reliability under various operating conditions.

[0034] In one embodiment of this application, the process of constructing a finite element model of a denture based on shape and size information and material characteristic information includes: Based on the shape and size information, a preset dimensional model of the denture to be tested is constructed. In one embodiment of this application, the preset dimensional model is a three-dimensional model, which is formed by three-dimensional model generation software, such as 3Shape Dental System or exocad DentalCAD ​​software.

[0035] The preset dimensional model is divided into grids to obtain the unit grids of the denture to be tested, as well as the interaction relationships between the unit grids. In one embodiment of this application, if the preset dimensional model includes a clasp region, a denture base region, and a crown region, the process of meshing the preset dimensional model includes: meshing the clasp region to obtain a clasp region mesh; the clasp region mesh is a hexahedral mesh; meshing the denture base region to obtain a denture base region mesh; the denture base region mesh is a tetrahedral mesh; meshing the crown region to obtain a crown region mesh; the crown region mesh is a tetrahedral mesh; using the clasp region mesh, denture base mesh, and crown region mesh as all unit meshes of the denture to be tested; and obtaining the interaction relationship between each unit mesh based on the positional relationship between the clasp region mesh, denture base mesh, and crown region mesh. The above process, using different mesh types according to the characteristics of different regions of the denture, can more accurately simulate the mechanical properties of each part of the denture. After obtaining each unit mesh and their interaction relationship, it is easier to determine whether there is friction, extrusion, etc., between each unit mesh, making the finite element model of the denture more realistically simulate the actual stress situation.

[0036] Based on the material characteristics of each unit grid, the parameter information of each unit grid is determined. In one embodiment of this application, when the retaining ring region is made of a metal material, the parameters of each unit grid in this region can be determined according to the selected metal material. For example, if the retaining ring region is made of a cobalt-chromium alloy, the elastic modulus of the cobalt-chromium alloy can be obtained from a technical manual as 200 GPa-230 GPa, Poisson's ratio as 0.28-0.3, and density as 8.3 g / cm³-8.9 g / cm³, which can be used as the parameter information of each unit grid in the retaining ring region. When the base region is made of a resin material, the parameters of each unit grid in this region can be determined according to the selected resin material. For example, if the base region is made of polymethyl methacrylate resin, the elastic modulus of polymethyl methacrylate resin can be obtained from a technical manual as 2.5 GPa-3.5 GPa, Poisson's ratio as 0.3-0.4, and density as 1.18 g / cm³-1.22 g / cm³, which can be used as the parameter information of each unit grid in the base region. When ceramic materials are used in the crown area, the elastic modulus of ceramics can be obtained by consulting the technical manual. The parameters are 100GPa-200GPa, Poisson's ratio is 0.2-0.3, and density is 3.5g / cm³-4.5g / cm³. These parameters can be used as the parameter information for each unit grid in the crown area.

[0037] A finite element model of the denture is obtained based on the parameter information of each element mesh and the interaction relationships between them. In one embodiment of this application, the process of obtaining the finite element model of the denture based on the parameter information of each element mesh and the interaction relationships between them includes: converting the parameter information of each element mesh and the interaction relationships between them into a preset format file (e.g., INP (Input File) format file, DAT (Data File) format file); importing the preset format file into finite element model generation software; and using the built-in modeling and analysis functions of the finite element model generation software to parse and process the data in the preset format file to obtain the finite element model of the denture. Finite element model generation software includes ABAQUS, ANSYS, OpenFOAM, etc.

[0038] In one embodiment of this application, the finite element model of the denture generated based on the parameter information of each unit mesh and the interaction relationship between each unit mesh not only considers the material properties of different areas of the denture, but also accurately simulates the mechanical relationship between each unit mesh. This model can more realistically reflect the mechanical behavior of the denture in actual oral use, thus making the denture fatigue test results more valuable.

[0039] In one embodiment of this application, if the preset dimensional model includes: a clasp region, a denture base region, and a crown region, then the process of meshing the preset dimensional model includes: The retaining ring region is meshed to obtain the retaining ring region mesh. In one embodiment of this application, the retaining ring region mesh is a hexahedral mesh. The hexahedral mesh has a regular geometric shape, which can provide high accuracy when simulating the mechanical properties of the retaining ring region. Moreover, the element structure of the hexahedral mesh is more uniform and accurate in transmitting stress and strain, and can better reflect the actual situation of the retaining ring region under stress.

[0040] The basement area is meshed to obtain the basement area mesh. In one embodiment of this application, the basement area mesh is a tetrahedral mesh. Tetrahedral meshes are highly flexible and can adapt well to the complex geometry of the basement area. Moreover, the basement area usually needs to conform to oral tissues, and its shape is irregular. Tetrahedral meshes can more accurately fit the basement area, thereby more accurately simulating the mechanical response of the basement area in the oral cavity. In addition, tetrahedral meshes can better capture the local mechanical changes that may occur in the basement area under stress when dealing with complex mechanical problems such as stress concentration.

[0041] The crown region is meshed to obtain the crown region mesh. In one embodiment of this application, the crown region mesh is a tetrahedral mesh. Tetrahedral meshes are highly flexible and can adapt well to the complex shape and structure of the crown region. Furthermore, the tooth region experiences forces from different directions during chewing, which may lead to stress concentration. Tetrahedral meshes perform well in handling such complex mechanical problems, accurately capturing the local mechanical changes that may occur in the crown region under stress. In addition, tetrahedral meshes have good computational performance and convergence in finite element analysis, improving computational efficiency and accuracy when performing mechanical analysis on the crown region, thus providing more reliable data support for denture fatigue testing.

[0042] The clasp region mesh, base region mesh, and crown region mesh are used as the unit meshes for the denture to be tested. In one embodiment of this application, by using a hexahedral mesh for the clasp region and a tetrahedral mesh for the base and crown regions, the mechanical behavior of the denture in the oral cavity can be comprehensively and accurately simulated, making the finite element model of the denture more consistent with reality, thereby improving the reliability and reference value of the denture fatigue test results.

[0043] Based on the positional relationships between the clasp area mesh, the base mesh, and the crown mesh, the interaction relationships between each unit mesh are obtained. In one embodiment of this application, the interaction relationships between each unit mesh include: the interaction between the clasp area mesh and the crown area mesh, the interaction between the base mesh and the crown area mesh, and the interaction between the clasp area mesh and the base mesh. The interaction between the clasp area mesh and the crown area mesh includes: the clasp arm mesh and the crown surface mesh generating contact pressure through elastic deformation, forming a retention friction. The magnitude of the retention friction depends on the elastic modulus of the clasp material, the surface roughness of the crown, and the contact area between the clasp area mesh and the base mesh; when the clasp enters the undercut area mesh of the crown, the dislocation direction forms a locking angle with the insertion path, resulting in a locking effect; and during chewing, the clasp area mesh absorbs part of the occlusal force through elastic deformation and transfers the remaining stress to the crown area mesh, resulting in a stress transfer effect. The interaction between the base area grid and the crown area grid includes: when the base area grid covers the alveolar ridge and palate, the crown area grid acts as an occlusal contact point, transferring stress to the base area grid, thus providing support and dispersing stress. The interaction between the clasp area grid and the base area grid includes: the clasp area grid is connected to the base area grid through connectors, forming a structural synergistic retention effect; the clasp area grid undergoes elastic deformation under stress, transferring some stress to the base area grid, thus forming stress transmission and buffering effects.

[0044] In one embodiment of this application, to ensure the correctness of the interaction relationships between the various unit meshes, the interaction relationships between the various unit meshes can be verified. For example, a pressure sensor can be used to measure the stress on different areas of the actual denture under different chewing actions, and the measured data can be compared with the stress simulated by the interaction relationships between the various unit meshes in the finite element model of the denture. If a large deviation is found between the simulated data and the actual measured data, it is necessary to adjust the interaction relationships between the various unit meshes by re-meshing, consulting technical documents, or conducting material performance tests. This allows for a more accurate simulation of the mechanical behavior of the denture in the oral cavity, thereby further improving the accuracy and reliability of the denture fatigue test results.

[0045] In one embodiment of this application, the clasp area, base area, and crown area may all use different shaped filling meshes and different manufacturing materials, which are not specifically limited here.

[0046] In one embodiment of this application, if the stress distribution data includes principal stresses at different time points, and the material property information includes the material yield strength, then the process of determining the denture fatigue test results based on the stress distribution data includes: Based on the principal stresses at different time points, the equivalent stress of each element mesh of the denture at different time points is calculated. In one embodiment of this application, the formula for calculating the equivalent stress of each element mesh of the denture at different time points is as follows: Equation (5) in, Indicates the first denture Each unit grid Equivalent stress at each time point Indicates the first Each unit grid The maximum principal stress at each time point Indicates the first Each unit grid The minimum principal stress at each time point, Indicates the first Each unit grid The intermediate principal stress at the time node, the Each unit grid The intermediate principal stress at the time node is located at the . Each unit grid The maximum principal stress at the first time node and the first Each unit grid Between the minimum principal stresses at each time point.

[0047] The equivalent stress is compared with the material yield strength in chronological order at different time points, and the fatigue life of the denture is determined based on the comparison results at different time points. In one embodiment of this application, the equivalent stress is arranged in chronological order, and the process of comparing the equivalent stress with the material yield strength is the process of comparing the equivalent stress with the material yield strength at each time point.

[0048] In one embodiment of this application, the process of determining the fatigue life of a denture based on the comparison results at different time points includes: if there is no time point in the comparison results where the equivalent stress is greater than the material yield strength, the denture deformation state is determined to be no deformation, and dynamic loads are continued to be applied to the finite element model of the denture until the equivalent stress calculated by subsequent stress fraction data is greater than the material yield strength; if there is a time point in the comparison results where the equivalent stress is greater than the material yield strength, the denture deformation state is determined to be deformed, and the time points from no deformation to deformation in all time points are taken as the starting point of the deformation state, and the fatigue life of the denture is determined based on the time points located before the starting point of the deformation state. The above process, by comparing the equivalent stress of each element mesh of the denture with the material yield strength, can scientifically determine the time point at which the denture begins to deform, thereby accurately obtaining the fatigue life of the denture.

[0049] The fatigue life of dentures is used as the result of denture fatigue testing. In one embodiment of this application, the fatigue life of dentures is an important indicator for measuring whether dentures can withstand repeated chewing forces in actual use without damage or failure. Obtaining the fatigue life test result can provide important reference for the design, manufacture, and clinical application of dentures.

[0050] In one embodiment of this application, the process of determining the fatigue life of a denture based on comparison results at different time points includes: If no time point in the comparison results shows that the equivalent stress is greater than the material yield strength, the deformation state of the denture is determined to be no deformation, and dynamic loads are continued to be applied to the finite element model of the denture until the equivalent stress calculated by subsequent stress fraction data is greater than the material yield strength. In one embodiment of this application, the process of continuing to apply dynamic loads to the finite element model of the denture can be carried out periodically according to the load magnitudes of formulas (1)-(4) until the equivalent stress calculated by subsequent stress fraction data is greater than the material yield strength. The comparison results at different time points can be the comparison results of the equivalent stress and corresponding material yield strength of all element meshes in the denture at different time points, or the comparison results of the equivalent stress and corresponding material yield strength of the key stress element meshes in the denture at different time points. The key stress element meshes include: the element meshes at the contact point between the clasp and the crown, the element meshes at the contact point between the denture base and the alveolar ridge, etc.

[0051] If any time point in the comparison results shows an equivalent stress greater than the material's yield strength, then the denture deformation state is determined to be deformed. The time point transitioning from no deformation to deformation is taken as the starting point of the deformation state. The fatigue life of the denture is determined based on the time points preceding the starting point of the deformation state. In one embodiment of this application, the process of determining the denture fatigue life based on the time points preceding the starting point of the deformation state includes: acquiring the load curve of the dynamic load; aligning the time points preceding the starting point of the deformation state with the load curve to obtain the force load and number of stresses at the time points preceding the starting point of the deformation state; and using the force load and number of stresses at the time points preceding the starting point of the deformation state as the denture fatigue life. The denture fatigue life determined in this way can intuitively reflect the magnitude and frequency of chewing forces that the denture can withstand in actual use, providing more detailed data reference for denture designers and manufacturers.

[0052] In one embodiment of this application, the process of determining the fatigue life of a denture based on a time point prior to the onset of deformation includes: Obtain the load curve of the dynamic load. In one embodiment of this application, the expression of the load curve of the dynamic load is shown in formulas (1)-(4).

[0053] By aligning the time nodes before the deformation start point with the load curve, the stress load and number of stresses experienced by the time nodes before the deformation start point can be obtained. In one embodiment of this application, time node alignment can be achieved by mapping the time nodes before the deformation start point to the corresponding time positions in the load curve. This operation helps to clarify the specific stress load magnitude corresponding to each time node. Furthermore, based on the number of time nodes before the deformation start point and the number of time nodes in one cycle of the load curve, the number of stresses experienced by the time nodes before the deformation start point can be determined. That is, the number of stresses experienced by the time nodes before the deformation start point is the ratio of the number of time nodes before the deformation start point to the number of time nodes in one cycle of the load curve. In this way, the stress conditions and number of stresses experienced by the denture before deformation can be accurately obtained.

[0054] The fatigue life of a denture is defined as the stress load and the number of stresses applied at time points prior to the onset of deformation. In one embodiment of this application, using the stress load and the number of stresses as the fatigue life provides strong data support for the quality assessment and performance optimization of dentures. For example, denture designers can adjust the structural design of dentures based on the fatigue life data, and denture manufacturers can select more suitable manufacturing materials, improve production processes, and enhance the overall quality and durability of dentures based on the fatigue life data.

[0055] In one embodiment of this application, if the stress distribution data includes the maximum and minimum stresses in each force direction, then the process of determining the denture fatigue test results based on the stress distribution data includes: Based on the maximum and minimum stresses in each force direction, the stress amplitude and average stress of each element mesh of the denture in each direction are calculated. In one embodiment of this application, each force direction includes the X-axis, Y-axis, and Z-axis of the coordinate system in which the denture is located. The coordinate system in which the denture is located includes the world coordinate system, the object coordinate system, etc. The formula for calculating the stress amplitude is as follows: Equation (6) in, Indicates the first denture Each unit grid The first time node Stress amplitude in each direction, Indicates the first denture Each unit grid The first time node Maximum stress in each direction, Indicates the first denture Each unit grid The first time node Minimum stress in each direction.

[0056] In one embodiment of this application, the formula for calculating the average stress is as follows: Equation (7) in, Indicates the first denture Each unit grid The first time node Average stress in each direction Indicates the first denture Each unit grid The first time node Maximum stress in each direction, Indicates the first denture Each unit grid The first time node Minimum stress in each direction.

[0057] In one embodiment of this application, the formula for calculating the maximum stress is as follows: Equation (8) in, Indicates the first denture Each unit grid The first time node Maximum stress in each direction, Indicates the first denture Each unit grid The first time node Maximum load in each direction Indicates the first denture Each unit grid The first time node The cross-sectional area subjected to force in each direction.

[0058] In one embodiment of this application, the formula for calculating the minimum stress is as follows: Equation (9) in, Indicates the first denture Each unit grid The first time node Minimum stress in each direction, Indicates the first denture Each unit grid The first time node Minimum load in each direction, Indicates the first denture Each unit grid The first time node The cross-sectional area subjected to force in each direction.

[0059] Based on the stress amplitude and average stress of each element mesh of the denture in each direction, the fatigue life of each element mesh in each direction is predicted. In one embodiment of this application, the calculation formula for the fatigue life of each element mesh in each direction is as follows: Equation (10) in, Indicates the first denture Each unit grid The first time node Stress amplitude in each direction, Indicates the first denture Each unit grid The first time node Average stress in each direction Indicates the first denture Fatigue limit coefficient of each element mesh, Indicates the first denture The overall bending strength coefficient of each element mesh. Indicates the first denture Each cell grid in the first The fatigue life in each direction, i.e., the first fatigue life of the denture. Each cell grid in the first The number of cycles of force load in each direction.

[0060] In one embodiment of this application, before obtaining the shape and size information, material property information, and constraint conditions of the denture to be tested, the fatigue testing method for integrated dentures includes: Obtain the type information and displacement constraints of the denture to be tested. In one embodiment of this application, the type information of the denture to be tested includes various types such as incisors, canines, and molars, and the displacement constraints include: the displacement of all points on the abutment tooth surface of the denture to be tested in the vertical direction is 0, etc.

[0061] Based on the type information, the position information of the denture to be tested in the oral cavity is determined; based on the position information, the contact constraints of the denture to be tested are determined. In one embodiment of this application, after determining the type information of the denture to be tested, the regional position of the denture to be tested in the oral cavity based on the type information is determined, and the installation area of ​​the denture to be tested based on the type information is determined. For example, when the type of the denture to be tested is a molar, the installation area of ​​the molar in the oral cavity is the area where the molar is located. After determining the area where the molar is located, the specific position of the molar in the area where the molar is located is determined according to the axial positioning, mesiodistal positioning, and occlusal surface positioning methods, i.e., the position information. The process of determining the contact constraints of the denture to be tested based on the position information includes: based on the position information, determining the teeth adjacent to the denture to be tested, and the contact area between the denture to be tested and the gingiva, and setting the friction value between the denture to be tested and the adjacent teeth (e.g., 0.32), and setting the friction value between the denture to be tested and the gingiva (e.g., 0.3).

[0062] The denture to be tested is scanned to obtain its shape and size information. In one embodiment of this application, the denture to be tested is scanned using a scanning device, including a laser scanner, a structured light scanner, etc. The shape and size information is three-dimensional model information.

[0063] Displacement constraints and contact constraints are used as constraint conditions. In one embodiment of this application, displacement constraints and contact constraints together constitute the mechanical boundary conditions of the denture in a simulated oral environment. Displacement constraints limit the displacement of certain parts of the denture, while contact constraints define the interaction between the denture and adjacent teeth, as well as between the denture and the gingiva. Using displacement constraints and contact constraints as constraint conditions can more accurately simulate the actual stress conditions of the denture in the oral cavity. After the constraint conditions are applied to the finite element model of the denture, they can more realistically reflect the mechanical behavior of the denture in the oral cavity.

[0064] Figure 3 This is a flowchart illustrating the fatigue life of a denture as shown in an exemplary embodiment of this application, such as... Figure 3 As shown, the process of determining the fatigue life of a denture includes: (1) comparing the equivalent stress with the yield strength of the material according to the order of different time nodes; (2) if there is no time point in the comparison result where the equivalent stress is greater than the yield strength of the material, the denture deformation state is determined to be no deformation, and dynamic load is applied to the finite element model of the denture until the equivalent stress calculated by subsequent stress fraction data is greater than the yield strength of the material; (3) if there is a time point in the comparison result where the equivalent stress is greater than the yield strength of the material, the denture deformation state is determined to be deformed, and the time node from no deformation to deformation in all time nodes is taken as the starting point of the deformation state, and the fatigue life of the denture is determined according to the time node located before the starting point of the deformation state.

[0065] The following describes an embodiment of the apparatus described in this application, which can be used to perform the integrated denture fatigue testing method described in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the integrated denture fatigue testing method described above in this application.

[0066] Figure 4 This is a block diagram illustrating an integrated denture fatigue testing system, as shown in an exemplary embodiment of this application.

[0067] like Figure 4 As shown, the exemplary integrated denture fatigue testing system 400 includes: The information acquisition module 401 is used to acquire the shape and size information, material properties information, and constraints of the denture to be tested.

[0068] The model building module 402 is used to build a finite element model of the denture based on shape and size information and material characteristic information.

[0069] The model solver module 403 is used to apply dynamic loads to the finite element model of the denture under constraints and solve the finite element model of the denture to obtain the stress distribution data of each element mesh of the denture.

[0070] The result determination module 404 is used to determine the fatigue test results of the denture based on the stress distribution data.

[0071] In one embodiment of this application, the denture to be tested includes various types such as incisors, canines, and molars. Each type of denture has predetermined shape and size information, including crown shape and size, root shape and size, etc. Material property information refers to the properties of the materials used to manufacture the denture, including acrylic resin, ceramics, etc., with material property information including yield strength, hardness, elastic modulus, thermal conductivity, Poisson's ratio, density, etc. Constraints include contact constraints and displacement constraints. The displacement constraint includes zero displacement in the vertical direction at all points on the abutment tooth surface of the denture. The contact constraint includes frictional contact between the denture and the gingiva (e.g., friction between the denture and the gingiva is set to 0.3), and frictional contact between the denture and adjacent teeth (e.g., friction between the denture and adjacent teeth is set to 0.32).

[0072] In one embodiment of this application, the process of constructing a finite element model of a denture based on shape and size information and material characteristic information includes: constructing a preset dimension model of the denture to be tested based on shape and size information; dividing the preset dimension model into meshes to obtain each unit mesh of the denture to be tested, as well as the interaction relationship between each unit mesh; determining the parameter information of each unit mesh according to the material characteristic information of each unit mesh; and obtaining the finite element model of the denture based on the parameter information of each unit mesh and the interaction relationship between each unit mesh. Through the above settings, the finite element model of the denture can accurately reflect the internal structure of the denture to be tested and the interaction relationship between each unit mesh, further improving the accuracy and reliability of the construction of the finite element model of the denture.

[0073] In one embodiment of this application, the finite element model of the denture is solved using a finite element model solver, including ABAQUS (Advanced Simulation for Engineering and Sciences), ANSYS, etc. The dynamic load is a load that varies with time in different directions. The expressions for the dynamic load are shown in formulas (1)-(4), which will not be elaborated here.

[0074] In one embodiment of this application, by acquiring the shape and size information, material property information, and constraints of the denture to be tested, a finite element model of the denture is constructed based on the shape and size information and material property information. Under the constraints, a dynamic load is applied to the finite element model of the denture, and the finite element model of the denture is solved to obtain the stress distribution data of each element mesh of the denture. Based on the stress distribution data, the fatigue test result of the denture is determined. The above process, by applying a dynamic load to the denture to simulate the complex and variable stress environment in the oral cavity, overcomes the limitation that only static loads or single-type loads can be applied in the denture fatigue test. Furthermore, by solving the finite element model of the denture under constraints and with the application of dynamic loads, the stress distribution data of each element mesh of the denture at different time points can be obtained, thereby making the fatigue test result of the denture determined based on the stress distribution data more accurate.

[0075] In one embodiment of this application, solving the finite element model of the denture can yield strain data, displacement data, maximum deformation, maximum bending stress, maximum torsional stress, and maximum compressive stress for each element mesh at different time points. After obtaining the strain and displacement data for each element mesh at different time points, strain-stress curves and stress-displacement curves are obtained based on these data. The strain-stress curves reveal key mechanical properties of the denture material, such as its elastic stage, plastic stage, and yield point, allowing for assessment of whether the denture will undergo plastic deformation or even failure during normal use. The stress-displacement curves provide the stress magnitude experienced by the denture under different displacements, enabling evaluation of the denture's stability and reliability under various operating conditions.

[0076] It should be noted that the integrated denture fatigue testing system and the integrated denture fatigue testing method provided in the above embodiments belong to the same concept. The specific operation methods of each module and unit have been described in detail in the method embodiments and will not be repeated here. In practical applications, the integrated denture fatigue testing system provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. This is not a limitation here.

[0077] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for testing the fatigue resistance of an integrated denture, characterized in that, The method includes: The shape and size information, material property information, and constraint conditions of the denture to be tested are obtained; the constraint conditions include contact constraints and displacement constraints. Based on the shape and size information and the material characteristic information, a finite element model of the denture is constructed; Under the aforementioned constraints, a dynamic load is applied to the finite element model of the denture, and the finite element model of the denture is solved to obtain the stress distribution data of each element mesh of the denture; the dynamic load is a load that varies with time in different directions; Based on the stress distribution data, the results of the denture fatigue test are determined.

2. The fatigue testing method for integrated dentures according to claim 1, characterized in that, The process of constructing a finite element model of a denture based on the shape and size information and the material characteristic information includes: Based on the shape and size information, a preset dimensional model of the denture to be tested is constructed; The preset dimension model is divided into grids to obtain the unit grids of the denture to be tested, as well as the interaction relationships between the unit grids; Based on the material characteristics of each element mesh, determine the parameter information of each element mesh; Based on the parameter information of each element mesh and the interaction relationship between each element mesh, the finite element model of the denture is obtained.

3. The fatigue testing method for integrated dentures according to claim 2, characterized in that, If the preset dimensional model includes: clasp area, denture base area, and crown area, then the process of meshing the preset dimensional model includes: The clasp region is divided into a mesh to obtain a clasp region mesh; the clasp region mesh is a hexahedral mesh. The basement region is divided into a mesh to obtain a basement region mesh; the basement region mesh is a tetrahedral mesh. The crown region is divided into a mesh to obtain a crown region mesh; the crown region mesh is a tetrahedral mesh. The clasp area grid, the base plate area grid, and the crown area grid are used as all the unit grids of the denture to be tested; Based on the positional relationship between the clasp region grid, the base plate region grid, and the crown region grid, the interaction relationship between each unit grid is obtained.

4. The fatigue testing method for integrated dentures according to claim 1, characterized in that, If the stress distribution data includes principal stresses at different time points, and the material property information includes the material yield strength, then the process of determining the denture fatigue test results based on the stress distribution data includes: Based on the principal stress at different time points, calculate the equivalent stress of each element mesh of the denture at different time points; The equivalent stress is compared with the yield strength of the material in chronological order of different time points, and the fatigue life of the denture is determined based on the comparison results at different time points. The fatigue life of the denture is used as the result of the denture fatigue test.

5. The fatigue testing method for integrated dentures according to claim 4, characterized in that, The process of determining the fatigue life of dentures based on comparisons at different time points includes: If there is no time point in the comparison results where the equivalent stress is greater than the yield strength of the material, the denture deformation state is determined to be no deformation, and dynamic load is continued to be applied to the finite element model of the denture until the equivalent stress calculated by subsequent stress fraction data is greater than the yield strength of the material. If there is a time point in the comparison results where the equivalent stress is greater than the yield strength of the material, then the denture is determined to be in a deformed state. The time point from no deformation to deformation is taken as the starting point of the deformation state. The fatigue life of the denture is determined based on the time points before the starting point of the deformation state.

6. The fatigue testing method for integrated dentures according to claim 5, characterized in that, The process of determining the fatigue life of the denture based on a time point prior to the onset of the deformation state includes: Obtain the load curve of the dynamic load; Align the time nodes before the starting point of the deformation state with the time points of the load curve to obtain the force load and the number of times the force is applied at the time nodes before the starting point of the deformation state. The stress load and number of stresses at time points prior to the onset of the deformation state are taken as the fatigue life of the denture.

7. The fatigue testing method for integrated dentures according to claim 4, characterized in that, The formulas for calculating the equivalent stress of each element mesh of the denture at different time points are shown below: ， in, Indicates the first denture Each unit grid Equivalent stress at each time point Indicates the first Each unit grid The maximum principal stress at each time point Indicates the first Each unit grid The minimum principal stress at each time point, Indicates the first Each unit grid The intermediate principal stress at the time node, the Each unit grid The intermediate principal stress at the time node is located at the . Each unit grid The maximum principal stress at the first time node and the first Each unit grid Between the minimum principal stresses at each time point.

8. The fatigue testing method for integrated dentures according to any one of claims 1-6, characterized in that, If the stress distribution data includes the maximum and minimum stresses in each stress direction, then the process of determining the denture fatigue test results based on the stress distribution data includes: Based on the maximum and minimum stresses in each direction of force application, calculate the stress amplitude and average stress of each element grid of the denture in each direction. Based on the stress amplitude and average stress of each denture unit grid in each direction, the fatigue life of each denture unit grid in each direction is predicted.

9. The fatigue testing method for integrated dentures according to any one of claims 1-6, characterized in that, Before obtaining the shape and size information, material property information, and constraint conditions of the denture to be tested, the method includes: Obtain the type information of the denture to be tested and the displacement constraints; Based on the type information, determine the position information of the denture to be tested in the oral cavity; based on the position information, determine the contact constraints of the denture to be tested. The denture to be tested is scanned to obtain its shape and size information. The displacement constraint and the contact constraint are used as the constraint conditions.

10. An integrated denture fatigue testing system, characterized in that, include: The information acquisition module is used to acquire information on the shape and size of the denture to be tested, material properties, and constraints. The constraints include: contact constraints and displacement constraints; The model building module is used to construct a finite element model of the denture based on the shape and size information and the material characteristic information; The model solving module is used to apply dynamic loads to the finite element model of the denture under the constraints, and solve the finite element model of the denture to obtain the stress distribution data of each element mesh of the denture; the dynamic loads are loads that vary with time in different directions; The result determination module is used to determine the denture fatigue test results based on the stress distribution data.

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