Search

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: In oral implant repair, soft tissue level implants are different from bone level implants, which adopt non-embedded surgical methods. A good neck design can promote bone bonding or reduce marginal bone absorption and facilitate the formation of stable soft tissue sealing. Therefore, the neck structure design of implants is one of the key factors for the success of implant repair. OBJECTIVE: To simulate and analyze the stress distribution of implant components and implant-bone interface during the restoration of mandibular molars with four different smooth collar implants using three-dimensional modeling and finite element analysis software. METHODS: The cone-beam CT image data of a patient undergoing mandibular first molar implantation were selected, and the mandible model was established by Mimics 21.0 software. The mandible model was imported into Solidworks 2018 software. Smooth neck implant models were constructed as follows: the standard conventional cervical implant (2.8 mm in height, 4.8 mm in diameter), standard wide cervical implant (2.8 mm in height, 6.5 mm in diameter), aesthetic conventional neck implant (1.8 mm in height, 4.8 mm in diameter), and aesthetic wide neck implant (1.8 mm in height, 6.5 mm in diameter). The four models were repaired with pure titanium base table and zirconia full-crown screw fixation. The von-Mises stress distribution of implant components and the implant-bone interface in four groups of different smooth collar implants were compared and analyzed under vertical and oblique loadings. RESULTS AND CONCLUSION: (1) Whether it was vertical loading or oblique loading, the peak values of von-Mises stress were located in the neck region of the implant, and the peak values of von-Mises stress at the implant-bone interface were located in the cortical bone region of the neck region of the implant. (2) When using the same smooth collar implant, compared with the vertical loading group, the peak values of Von-Mises stress were greater in the four different smooth collar implants in the oblique loading group. (3) Under vertical or oblique loading, the maximum von-Mises stress of the standard implant group was greater than that of the standard implant group, and the maximum von-Mises stress of the aesthetic implant group was lower than that of the aesthetic implant group. (4) The maximum von-Mises stress on the implant-bone interface in the wide-neck standard implant group was lower than that in the other smooth cervical implant groups, regardless of vertical or oblique loading. (5) The results showed that the stress distribution of implant components and implant-bone interface was different with different smooth collar implants. [ABSTRACT FROM AUTHOR]

BACKGROUND: In oral implant restoration, patients with single missing maxillary anterior teeth often have alveolar bone absorption and defect due to different reasons. To avoid the risk of bone grafting, inclined implants are often used to avoid the alveolar bone absorption area. The angle abutment is used to restore the normal overcovering relationship of patients. The size and distribution of the influence of different abutment materials on the occlusal force transfer of the implant and the surrounding bone were studied. OBJECTIVE: To compare the influence of time on the peak value of bone stress around the implant with three abutment materials under simulated dynamic loading under three implantation conditions. METHODS: Cone beam CT data of a healthy adult undergoing implant restoration of maxillary central incisor were selected. Minics software was used to cut the jaw bone. Solidworks 2018 was used to establish the implant, jaw bone, and angle abutment (angle 0°, 15°, and 25°). Base stations materials included pure titanium, zirconium dioxide, and alumina), central screw, and zirconium dioxide full porcelain crown model. Assembly was complete, for embedded in the original maxillary fang root cutting direction 0° angle, then simulated palate to tilt 15° and 25°, no implanted implant thread exposure. According to different implant angles, they were divided into 0°, 15°, and 25° groups. Dynamic loading was performed for 0.2 seconds, to obtain the time-dependent relationship between the peak value of equivalent stress of bone around the implant prosthesis of each material abutment. RESULTS AND CONCLUSION: (1) All abutment implant restorations had the same peak distribution of surrounding bone stress when they were subjected to occlusal force, all of which were located in the bone cortex of the implant neck. The fastest time period for the increase of bone stress around abutment implant restorations of each material was within 0.025-0.05 seconds. The range of high stress value of cortical bone in the 15° group was larger than that in the 0° group. The initial stress value of cortical bone of implant in the 25° group was significantly higher than that of the other two groups. The residual stress value of cortical bone was higher after loading. After titanium abutment implantation, the bone stress around the prosthesis had the largest increase, and the range of high stress value was relatively concentrated. (2) In the 15° group, the peak value of bone stress around the implanted prosthesis on the abutment of the three materials was located in the neck of the implant. The increase in bone stress around the titanium abutment implanted prosthesis was relatively large but not obvious, and the distribution range of high stress was relatively consistent. Compared with the other two groups, the high stress value of the 25° group was more concentrated; the initial stress value was higher and the range of change was greater, among which the bone stress around the implanted prosthesis on the dialumina abutment increased the most within 0-0.1 seconds. At 0.2 seconds, the peak value of bone equivalent stress of zirconia abutment decreased to 0, and high residual stress remained in the bone around the implants of the other two abutments. (3) It is concluded that based on the analysis of the distribution of different influences of the implant angle and abutment material on the bone interface, the bone stress of the implants using zirconia abutment was relatively stable at all time points in the three groups. [ABSTRACT FROM AUTHOR]

BACKGROUND: Stroke has become one of the thorny diseases facing the world due to its high morbidity, high mortality, high disability rate, and high recurrence rate. However, traditional rehabilitation methods, characterized by slow effect, low efficiency, and dull training, elicit little effects in the treatment of stroke. With the development of science and technology, virtual reality technology which has the characteristics of simplicity, high efficiency, high security, strong interest, low price, and real-time feedback can solve the imbalance of doctor-patient ratio, promote the development of remote rehabilitation medicine, and has extremely important practical significance for the rehabilitation of stroke patients. OBJECTIVE: To study the research hotspots and progress of virtual reality technology in stroke treatment using Citespace V knowledge graph software, and to clarify the structural model of this field and predict the possible development trends of virtual reality technology worldwide in the future. METHODS: A total of 1 374 core articles addressing virtual reality technology published since 2007 were retrieved from Web of ScienceTM, CNKI, CSSCI, and CSCD database and used as data sources. Citespace V knowledge graph software was used to analyze the research status of virtual reality technology in stroke treatment. In addition, the domestic and foreign differences in disciplines, countries, authors, institutions, and research hotspots were compared. Then, the possible development trend in the future was predicted. RESULTS AND CONCLUSION: The foreign countries have formed a multi-disciplinary and multi-domain comprehensive group, focusing on neuroscience, computer science, and biomedical engineering. Domestic disciplines are relatively monotonous, and no obvious discipline group has formed. There is a network of close exchanges and cooperation that has formed between foreign countries/regions, authors, and institutions, forming a high school mentality of countries, authors, and institutions. The cooperation among domestic authors, groups and institutions is poor, with geographical restrictions, and there is a lack of influential academic groups and institutions. There are differences in research contents at home and abroad, and there have been four development stages of this technology in foreign countries. The possible trends of future research abroad are the research, development and evaluation of remote rehabilitation medicine, robot-assisted therapy, and virtual rehabilitation system, highlighting the screening of virtual rehabilitation therapy. The possible future research topics in China may be the effect and evaluation of the combined treatment of specific parts with virtual reality technology and other methods, and the introduction and development of advanced technology. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Despite three-dimensional (3D) finite element model is helpful for the analysis of the injury mechanism and mechanical characteristics of knee joint, there are few researches on dynamic movement simulation of knee joint. OBJECTIVE: A 3D finite element model of normal male knee joint was established to dynamically simulate the movement of knee joint and analyze the biomechanical characteristics and relative movement of the tibio-femoral joint under different flexion angles, so as to provide a 3D finite element model for the investigation of knee biomechanics, and provide basis for the design of personalized knee prosthesis and 3D printing. METHODS: The knee joint from a healthy male adult was scanned by CT. Then, a normal 3D finite element model of knee joint was constructed by Mimics, Hypermesh and Abaqus. Simulation and stress analysis of knee joint were carried out under different loads. RESULTS AND CONCLUSION: (1) The constructed finite element model of knee joint could accurately reflect the geometrical structure and biomechanical characteristics of the knee joint, and could simulate multiple movements of knee joint and was effective for biomechanical research of the knee joint. (2) In the process of simulating knee flexion at 0°-60°, the range of knee valgus angle was 3.34°-6.13°, and the range of internal rotation angle was 1.56°-29.17°. The femur had a significant posterior shift relative to tibia, and the shifted distance was from 4.36 mm to 7.23 mm. (3) At knee flexion 0°, the maximum contact stresses of femur cartilage, tibial cartilage and meniscus were 1.45, 1.03 and 2.59 MPa, respectively, and 6.41, 6.73 and 8.65 MPa, respectively at knee flexion 60°. (4) Our findings indicate that in the process of simulating knee flexion at 0°-60°, the range of knee valgus angle is relatively small, and stable, while the range of internal rotation angle is relatively large. In the process of simulating knee flexion at 0°-60°, the contact stress of femoral and tibial cartilage gradually increased with the varied flexion angle, while the changes of contact stress of medial and lateral menisci are different, the changes of medial meniscus are much great, and the contact stress of lateral meniscus is relatively stable. The contact stress of medial meniscus is greater than that of lateral menisci. [ABSTRACT FROM AUTHOR]

BACKGROUND: The edge load contact caused by joint separation causes great stress concentration and then produces a large amount of wear. The edge contact caused by hip joint separation is a dynamic process of femoral head touching the rim of the acetabulum and sliding into the acetabulum quickly, so a dynamic contact mechanical model is needed. OBJECTIVE: To obtain the dynamic mechanical simulation model of ceramic acetabulum under the edge load contact, so as to provide the contact mechanics foundation for the wear analysis of hip joint under the condition of edge load, and provide theoretical basis for prosthesis design and surgeon operation. METHODS: By using 3D modeling software SolidWorks and dynamic simulation software ADAMS, edge load contact dynamics simulation model of ceramic femoral head and acetabular cup was established to verify the edge load contact deformation by numerical method. The effects of acetabular abduction angle and initial separation distance on edge load contact were analyzed. RESULTS AND CONCLUSION: (1) The contact stiffness coefficient used in the model is reasonable and effective. This model can be used to study the parameters that influence the edge load contact of hip joints. (2) The excessive cup inclination angle and initial separation distance will increase the severity of the edge load. (3) Acetabular cup inclination angle and initial separation distance are two important factors that affect the edge load contact. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)