Design method of nanocrystalline pure titanium implant
By deforming the crude crystal pure titanium implant into a nanocrystal pure titanium implant and optimizing the implant model using finite element simulation, the problems of low strength and poor biocompatibility of traditional implants are solved, and higher mechanical properties and biocompatibility are achieved.
Patent Information
- Application Number
- CN202411489655.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-02-25
AI Technical Summary
Traditional pure titanium implants have low mechanical strength, while titanium alloy implants have defects in their biocompatibility due to the addition of alloy reinforcement elements.
The raw materials of crude crystal pure titanium implants are severely plastically deformed to form nanocrystalline materials, and the nanocrystalline pure titanium implant materials are prepared by continuous equal-channel angle extrusion technology. The implant model is optimized using finite element simulation software to improve its mechanical properties and biocompatibility.
The mechanical properties of nanocrystal pure titanium implants are improved, their stability and durability in the oral cavity are enhanced, and the risk of complications after implantation surgery is reduced, while maintaining good biocompatibility.
Smart Images
Figure CN119498993A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of implant design methods, and in particular to a design method for a nanocrystalline pure titanium implant. Background Art
[0002] Oral implant restoration technology is an important development in the field of modern dentistry. It provides patients with missing teeth with an alternative that is close to the function and appearance of natural teeth. Traditional implants are mostly made of commercially pure titanium or titanium alloy materials, which are widely accepted for their good biocompatibility, corrosion resistance and ability to integrate with bone tissue.
[0003] Traditional pure titanium implant treatment is a common method of oral restoration, but traditional pure titanium implants have low mechanical strength, and titanium alloy implants have biocompatibility defects due to the addition of alloy strengthening elements. Therefore, in order to further improve the long-term stability and mechanical properties of implants and reduce possible complications after implant surgery, it is urgent to develop a new implant material and design method. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a design method for a nanocrystalline pure titanium implant, which solves the problems of low strength of existing pure titanium implants and poor biocompatibility of titanium alloy implants.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A design method of a nanocrystalline pure titanium implant comprises the following steps:
[0006] Step 1: subjecting the coarse-grained pure titanium implant material to severe plastic deformation to form a nanocrystalline material, and preparing the nanocrystalline pure titanium implant material using a continuous equal channel angular extrusion technology;
[0007] Step 2: Using the mechanical property parameters of nanocrystalline pure titanium obtained, a cylindrical implant model with a diameter of 3.9 mm and a height of 13 mm was established using finite element simulation software with the Swiss Nobel pure titanium implant as the implant model. The difference in stress distribution of the implant model was described using the static analysis module in the ANASYS finite element software database;
[0008] Step 3: Based on the optimized model of Swedish Nobel pure titanium implant, optimize the morphological parameters of the implant model.
[0009] Preferably, the specific parameters of the continuous equal channel angular extrusion technology described in step 1 are: the outer angle is 120°; the extrusion temperature is 300° C.; the extrusion path is the BC path; and the number of extrusion passes is 4.
[0010] Preferably, the specific operation of step 2 is to use the mechanical property parameters of the obtained nanocrystalline pure titanium to establish a cylindrical implant model with a diameter of 3.9 mm and a height of 13 mm using the Swiss Nobel pure titanium implant as the implant model through finite element simulation software, import the cylindrical implant model into ANASYS finite element software in XT format, and divide the model into 30,000 units and 45,000 nodes; fix the bottom of the implant model to ensure the stability of the model, and perform finite element analysis on the room temperature tensile stress-strain curve of the nanocrystalline pure titanium material and the implant model structure;
[0011] The static analysis system of ANASYS finite element software was used to simulate the difference in stress distribution of the implant model. A vertical load of 100N and a buccolingual load of 50N were applied to the upper plane of the implant model base for 3s to simulate the stress conditions of the implant model in the oral cavity.
[0012] Preferably, the buccolingual load direction is 30° to the long axis direction of the implant.
[0013] Preferably, the step three is specifically configured as follows:
[0014] The equivalent stress distribution of the bone structure around the implant model was used as the criterion for judging the results of implant structure optimization. The bone block was simplified into a rectangular block with cancellous bone inside and 1.3 mm thick cortical bone outside. The buccal and lingual width of the model was 16 mm, the height was 26 mm, and the length was 36 mm. At the same time, the established cylindrical implant model with a diameter of 3.9 mm and the jaw model were imported into the ANASYS finite element software in XT format for analysis, and the default automatic meshing of the Meshing module of the software was used. In order to ensure the stability of the model, it was assumed that the implant and the jaw were in fixed contact, and there was no separation or relative dislocation between the implant and the jaw interface. The contact relationship between the components was defined as "bonded" in the ANASYS finite element software. In order to simulate the constraint effect and the influence of chewing force during chewing, a fixed support was used to constrain the bottom of the jaw. At the same time, restrictions were imposed on the jaw section to simulate the constraint effect of the rest of the jaw on this part.
[0015] Under the action of vertical load and buccal-lingual load, the morphological parameters of the implant model were optimized based on the equivalent stress peak of the bone environment around the implant model.
[0016] Beneficial Effects
[0017] The present invention provides a design method for a nanocrystalline pure titanium implant, which has the following beneficial effects:
[0018] 1. The present invention uses severe plastic deformation to make the implant material obtain large strain, refines the coarse-grained metal or coarse-grained alloy into a material with a grain size of nanometer level, and can improve the mechanical properties of the material: the obtained nanocrystalline pure titanium has a grain size of 700nm, a Vickers hardness of 260HV, and a tensile strength of 721MPa, which are 61% and 48% higher than those of coarse-grained pure titanium respectively;
[0019] 2. The implant made of nanocrystalline pure titanium in the present invention has a maximum equivalent stress of 289 MPa after being loaded in the vertical and buccal-lingual directions, which is only 39% of the strength limit of the nanocrystalline pure titanium material of 741 MPa. Compared with the coarse-crystalline pure titanium implant whose maximum equivalent stress is 56% of the strength limit of the implant material, the nanocrystalline pure titanium implant has been significantly improved;
[0020] 3. The present invention is based on the design method of nanocrystalline pure titanium implants based on ANASYS simulation software. A cylindrical implant model is established with Swiss Nobel pure titanium implants as the model of the implant, and the implant diameter is optimized using ANASYS finite element software. The optimized implant model has a diameter of 3.3 mm, a height of 13 mm, a screw height of 0.4 mm, and a screw pitch of 0.5 mm. The maximum equivalent stress of the bone tissue around the oral implant is 52.3 MPa, which has not exceeded the stress limit of bone absorption of 60 MPa, and is fully sufficient to meet the needs of an oral implant. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a schematic diagram of the structure of the oral implant model established by the present invention based on the Swedish Nobel implant.
[0022] Figure 2 This is a schematic diagram of the metallographic observation photograph of the present invention after four ECAP deformations.
[0023] Figure 3 This is a schematic diagram of the grain size distribution after four ECAP deformations of the present invention. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] Example: See Figure 1-3 The present invention is a design method of a nanocrystalline pure titanium implant, which comprises the following steps:
[0026] Step 1: subjecting the coarse-grained pure titanium implant material to severe plastic deformation to form a nanocrystalline material: using continuous equal channel angular extrusion technology to prepare the nanocrystalline pure titanium implant material, the specific parameters of the continuous equal channel angular extrusion technology are as follows: the outer angle is 120°; the extrusion temperature is 300°C; the extrusion path is the BC path; the extrusion passes are 4 times;
[0027] like Figure 2 , 3 As shown in the figure, the nanocrystalline pure titanium obtained by 4-pass BC path equal channel angular extrusion has a grain size of 700nm, a Vickers hardness of 260HV, and a tensile strength of 721MPa, all of which meet the mechanical property standards of dental implants in the national standard GB / T13810-2017.
[0028] Step 2: Using the mechanical property parameters of nanocrystalline pure titanium obtained, an implant model is established through finite element simulation software: The oral implant model established in the present invention is a cylindrical implant model with a diameter of 3.9 mm and a height of 13 mm, such as Figure 1 As shown, a cylindrical implant model was established using Solid Works 2022 software, and imported into ANASYS finite element software in XT format to divide the model into approximately 30,000 units and 45,000 nodes; the bottom of the implant-optimized model was fixedly constrained to ensure the stability of the model, and the room temperature tensile stress-strain curve of nanocrystalline pure titanium material was combined with the implant model structure for finite element analysis: the maximum destructive strength of the implant model optimized based on the Swedish Nobel implant was estimated to exceed 300N, meeting the loading requirements for withstanding the maximum bite force of human teeth.
[0029] In addition, the static analysis system of ANASYS finite element software was used to simulate the difference in stress distribution of implants. A vertical load of 100N and a buccolingual load (30° to the long axis of the implant) of 50N were applied simultaneously to the upper plane of the implant base for 3s to simulate the stress conditions of the implant in the oral cavity. According to the finite element analysis results, the maximum equivalent stress of the implant made of nanocrystalline pure titanium after being loaded vertically and buccolingually was 289MPa, which is only 40% of the strength limit of the nanocrystalline pure titanium material.
[0030] Step 3: Based on the optimization model of Swedish Nobel pure titanium implant, optimize the implant morphology parameters. The optimized nanocrystalline pure titanium implant has a smaller diameter while meeting the basic strength requirements.
[0031] The present invention uses the equivalent stress distribution of the bone structure around the implant as the criterion for judging the implant structure optimization results, and simplifies the bone block into a rectangular block with cancellous bone inside and 1.3mm thick cortical bone outside. The buccal and lingual width of the model is 16mm, the height is 26mm, and the length is 36mm. At the same time, the established 3.9mm diameter cylindrical implant and jaw model are imported into the ANASYS finite element software in XT format for analysis, and the default automatic meshing of the software Meshing module is used. In addition, in order to ensure the stability of the model, the present invention assumes that the implant and the jaw are in fixed contact, and there is no separation and relative dislocation between the implant and the jaw interface. The contact relationship between the components is defined as "bonded" in the ANASYS finite element software. In order to simulate the constraint effect of the chewing process and the influence of the chewing force, this study uses fixed support to constrain the bottom of the jaw. At the same time, restrictions are imposed on the jaw section to simulate the constraint effect of the remaining jaw on this part.
[0032] Under the action of vertical load, the peak value of equivalent stress of the bone environment around the implant increases with the reduction of diameter and height, and the maximum is 8.6MPa, which is still far from the stress limit of 60MPa of overload bone absorption. Under the action of buccal and lingual load, the peak value of equivalent stress of the bone environment around the implant increases with the reduction of diameter and height. The maximum equivalent stress in the bone tissue around the implant model with a diameter of 3.2mm and a height of 13mm is 59.5MPa, and the stress peak value is slightly lower than the overload threshold, and there is still a potential risk of bone overload. Based on this point, the present invention decides to select an implant model with a diameter of 3.3mm and a height of 13mm as the optimization result based on the Swedish Nobel pure titanium implant model. After being loaded vertically and buccal and lingually, the peak values of equivalent stress of the bone tissue are 7.2MPa and 52.3MPa respectively, which do not exceed the overload bone absorption stress.
[0033] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".
[0034] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A design method for a nanocrystalline pure titanium implant, characterized in that: The following steps are involved: Step 1: subjecting the coarse-grained pure titanium implant material to severe plastic deformation to form a nanocrystalline material, and preparing the nanocrystalline pure titanium implant material using a continuous equal channel angular extrusion technology; Step 2: Using the mechanical property parameters of nanocrystalline pure titanium obtained, a cylindrical implant model with a diameter of 3.9 mm and a height of 13 mm was established using finite element simulation software with the Swiss Nobel pure titanium implant as the implant model. The difference in stress distribution of the implant model was described using the static analysis module in the ANASYS finite element software database; Step 3: Based on the optimized model of Swedish Nobel pure titanium implant, optimize the morphological parameters of the implant model.
2. The design method of a nanocrystalline pure titanium implant according to claim 1, characterized in that: The specific parameters of the continuous equal channel angular extrusion technology described in step 1 are: the outer angle is 120°; the extrusion temperature is 300°C; the extrusion path is the BC path; and the number of extrusion passes is 4.
3. The design method of a nanocrystalline pure titanium implant according to claim 2, characterized in that: The specific operation of step 2 is to use the mechanical property parameters of nanocrystalline pure titanium obtained to establish a cylindrical implant model with a diameter of 3.9 mm and a height of 13 mm using Swiss Nobel pure titanium implant as the implant model through finite element simulation software, import the cylindrical implant model into ANASYS finite element software in XT format, and divide the model into 30,000 units and 45,000 nodes; fix the bottom of the implant model to ensure the stability of the model, and perform finite element analysis on the room temperature tensile stress-strain curve of nanocrystalline pure titanium material and the implant model structure; The static analysis system of ANASYS finite element software was used to simulate the difference in stress distribution of the implant model. A vertical load of 100N and a buccolingual load of 50N were applied to the upper plane of the implant model base for 3s to simulate the stress conditions of the implant model in the oral cavity.
4. The design method of a nanocrystalline pure titanium implant according to claim 3, characterized in that: The buccolingual load direction is 30° with respect to the long axis direction of the implant.
5. The design method of a nanocrystalline pure titanium implant according to claim 4, characterized in that: The step three is specifically configured as follows: The equivalent stress distribution of the bone structure around the implant model was used as the criterion for judging the results of implant structure optimization. The bone block was simplified into a rectangular block with cancellous bone inside and 1.3 mm thick cortical bone outside. The buccal and lingual width of the model was 16 mm, the height was 26 mm, and the length was 36 mm. At the same time, the established cylindrical implant model with a diameter of 3.9 mm and the jawbone model were imported into the ANASYS finite element software in XT format for analysis, and the default automatic meshing of the Meshing module of the software was used. In order to ensure the stability of the model, it was assumed that the implant and the jawbone were in fixed contact, and there was no separation or relative dislocation between the implant and the jawbone interface. The contact relationship between the components was defined as "bonded" in the ANASYS finite element software. In order to simulate the constraint effect and the influence of chewing force during chewing, a fixed support was used to constrain the bottom of the jawbone. At the same time, restrictions were imposed on the jawbone section to simulate the constraint effect of the rest of the jawbone on this part. Under the action of vertical load and buccal-lingual load, the morphological parameters of the implant model were optimized based on the equivalent stress peak of the bone environment around the implant model.