• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.158-158
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• 2017

Titanium and its alloys have been used in the field dental and orthopedic implants because of their excellent mechanical properties and biocompatibility. Despite these attractive properties, their passive films were somewhat bioinert in nature so that sufficient adhesion of bone cells to implant surface was delayed after surgical treatment. Recently, plasma electrolyte oxidation (PEO) of titanium metal has attracted a great deal of attention is a comparatively convenient and effective technique and good adhesion to substrates and it enhances wear and corrosion resistances and produces thick, hard, and strong oxide coatings. Silicon(Si), Zinc(Zn), and Manganese(Mn) have a beneficial effect on bone. Si in particular has been found to be essential for normal bone and cartilage growth and development. And, Zn has been shown to be responsible for variations in body weight, bone length and bone biomechanical properties. Also, Mn influences regulation of bone remodeling because its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. The objective of this work was research on bone-like apatite morphology on Si-Zn-Mn-hydroxyapatite coating on Ti-6Al-4V alloy by plasma electrolytic oxidation. Anodized alloys were prepared at 280V voltage in the solution containing Si, Zn, and Mn ions. The surface characteristics of PEO treated Ti-6Al-4V alloy were investigated using XRD, FE-SEM, and EDS.

• Structural Engineering and Mechanics
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• v.86 no.4
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• pp.487-501
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• 2023

Nanoparticles have lower size and larger specific surface area, good stability and less toxic and side effects. In recent years, with the development of nanotechnology, its application range has become wider and wider, especially in the field of biomedicine, which has received more and more attention. Bone defect repair materials with high strength, high elasticity and high tissue affinity can be prepared by nanotechnology. The purpose of this paper was to study how to analyze and study the composite materials for sports bone injury based on multifunctional nanomaterials, and described the electrospinning method. In this paper, nano-sized zirconia (ZrO₂) filled micro-sized hydroxyapatite (HAP) composites were prepared according to the mechanical properties of bone substitute materials in the process of human rehabilitation. Through material tensile and compression experiments, the performance parameters of ZrO₂/HAP composites with different mass fraction ratios were analyzed, the influence of filling ZrO₂ particles on the mechanical properties of HAP matrix materials was clarified, and the effect of ZrO₂ mass fraction on the mechanical properties of matrix materials was analyzed. From the analysis of the compressive elastic modulus, when the mass fraction of ZrO₂ was 15%, the compressive elastic modulus of the material was 1222 MPa, and when 45% was 1672 MPa. From the analysis of compression ratio stiffness, when the mass fraction of ZrO₂ was 15%, the compression ratio stiffness was 658.07 MPa·cm³/g, and when it was 45%, the compression ratio stiffness is 943.51MPa·cm³/g. It can be seen that by increasing the mass fraction of ZrO₂, the stiffness of the composite material can be effectively increased, and the ability of the material to resist deformation would be increased. Typically, the more stressed the bone substitute material, the greater the stiffness of the compression ratio. Different mass fractions of ZrO₂/HAP filling materials can be selected to meet the mechanical performance requirements of sports bone injury, and it can also provide a reference for the selection of bone substitute materials for different patients.

• Journal of Life Science
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• v.30 no.11
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• pp.983-989
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• 2020

The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is key to bone health. An imbalance between osteoclasts and osteoblasts leads to various bone-related disorders, such as osteoporosis, osteomalacia, and osteopetrosis. However, the bone-resorption inhibitor drugs that are currently used may cause side effects. Natural substances have recently received much attention as therapeutic drugs for the treatment of bone health. This study was designed to determine the effect of Tenebrio molitor larvae ethanol extract (TME) on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. To measure the effect of TME on osteoclast differentiation, RAW264.7 cells were treated with RANKL with or without TME for 5 days. The tartrate-resistant acid phosphatase (TRAP) activity was significantly inhibited by treatment of TME without cytotoxicity up to 2 mg/ml. In addition, TME effectively suppressed expression of osteoclast differentiation-related marker genes and proteins such as TRAP, NFATc1, and c-Src. TME also significantly inhibited the p38 mitogen-activated protein kinase (MAPK) signaling pathway without affecting ERK and JNK signaling in RANKL-induced RAW264.7 cells. Consequently, we conclude that TME suppresses osteoclast differentiation by inhibiting RANKL-induced osteoclastogenic genes expression through the p38 MAPK signaling pathways. These results suggest that TME and its bioactive components are potential therapeutics for bone-related diseases such as osteoporosis.

• Molecules and Cells
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• v.24 no.2
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• pp.177-184
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• 2007

Approximately 200 individual skeletal elements, which differ in shape and size, are the building blocks of the vertebrate skeleton. Various features of the individual skeletal elements, such as their location, shape, growth and differentiation rate, are being determined during embryonic development. A few skeletal elements, such as the lateral halves of the clavicle and parts of the skull are formed by a process called intramembranous ossification, whereby mesenchymal cells differentiate directly into osteoblasts, while the majority of skeletal elements are formed via endochondral ossification. The latter process starts with the formation of a cartilaginous template, which eventually is being replaced by bone. This requires co-regulation of differentiation of the cell-types specific for cartilage and bone, chondrocytes and osteoblasts, respectively. In recent years it has been demonstrated that Wnt family members and their respective intracellular pathways, such as non-canonical and the canonical $Wnt/{\beta}$-catenin pathway, play important and diverse roles during different steps of vertebrate skeletal development. Based on the recent discoveries modulation of the canonical Wnt-signaling pathway could be an interesting approach to direct stem cells into certain skeletal lineages.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.127-138
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• 2012

This study is to assess the effect of preload level on the stress development at the marginal cortical bone surrounding implant neck. A finite element model was created for a single implant placed in the lower jaw bone. An external load of 100N was applied on the top of abutment at 30 degree with the implant axis in lingo-buccal direction. Five different preloads, i.e. 0, 200, 400, 600, 800N were applied to the abutment stem to investigate if and/or how the preload affects on the marginal bone stress. Differences in the marginal bone stress were recorded depending on the level of preload. On the other hand, the tensile stress on the marginal cortical bone decreased in models of higher preload. Preloads between abutment/fixture can increase compressive stresses in the marginal cortical bone although the amount may be insignificant as compared to those generated by functional forces.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.5
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• pp.331-336
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• 2013

Maxillary sinus membrane elevation and bone graft have been performed routinely in alveolar bone with insufficient residual bone height. There are a number of causes for development of maxillary sinusitis after these procedures. When maxillary sinusitis is caused by sinus membrane elevation, bone graft, and implant placement, various treatment such as medication, incision and drainage (I&D), implant removal, and the Caldwell-Luc procedure can be considered. Removal of an implant or the Caldwell-Luc procedure can be harmful if inflammation is not present in the oral cavity and survival of grafted bone and implant osseointegration can be expected despite the presence of maxillary sinusitis. In this case, functional endoscopic sinus surgery, which was often used in the otorhinolaryngology department, was performed without removal of the implant for a patient with maxillary sinusitis after one month following implant placement. Thus, we report on this case with a review of the literature.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.725-734
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• 1996

The present study has been performed to revise the forms of early-onset periodontitis(EOP) into the homogeneous phenotypic subsets by cluster analysis using sets of clinical parameters. Retrospective radiographic interproximal alveolar bone levels were measured from cemento-enamel junctions on patients who have previously been diagnosed as having one of EOP during last 5 years. Mean interproximal bone levels(BL) and mesial bone level(Ratio) of 1st molars relative to mean interproximal bone levels of adjacent teeth(lst and 2nd premolars and canines)were calculated on each patient. Using parameters BL and Ratio(BR group) or BL, Ratio and age(BRA group), cluster analysis was performed to revise EOP patients into homogeneous subsets. At least three or four cluster could be homogeneously formed both in BR or BRA groups with statistically significant differences in parameters used among clusters as evidenced by MANOVA test. It was shown that the greater the BL, the smaller the Ratio was. It was also evident that mean interproximal bone levels were lowest aroud 1st molars and/or incisors regardless of cluster types. The results has provided cluster-based studies for identifying laboratory markers responsible for the development of EOP subsets.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.162-169
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• 2005

The functional external fixator system fur bone deformity near joints in legs using the worm gear was developed for curing the difference angles in fracture bone and the lengthening bar for curing the difference length in fracture bone. Both experiments and FE analysis were performed to compare the elastic stiffness in several loading modes and to improve the functional external fixator system for the bone deformity. The FE model using the compressive and bending FE analysis was applied to the FE analysis due to the angle differences. The results show that the compressive stiffness value in experiment was 175.43N/mm; the bending stiffness value in experiment was 259.74N/mm; compressive stiffness value in FEM was 188.67N/mm; bending stiffness value in FEA was 285.71N/mm. The errors between experiments and FEA were less than 10%. The maximum stress (157MPa) to the angle of clamp was lower than the yield stress (176.4MPa) of SUS316L. The stiffnesses in both axial compressive and bending of the new fixator are about 2 times higher than other products except EBI (2003).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1248-1251
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• 2004

The functional external fixator system for bone deformity near joints in legs using the worm gear was developed for curing the difference angles in fracture bone and the lengthening bar for curing the difference length in fracture bone. Both experiments and FE analysis were performed to compare the elastic stiffness in several loading modes and to improve the functional external fixator system for bone deformity near joints in legs. The FE model using the compressive and bending FE analysis was applied the FE analysis due to the angle differences. The results show that the compressive stiffness value in experiment was 175.43N/mm, the bending stiffness value in experiment was 259.74N/mm, compressive stiffness value in FEM was 188.67N/mm, bending stiffness value in FEA was 285.71N/mm. The errors between experiments and FEA were less than 10％. The maximum stress (157MPa) to the angle of clamp was lower than the yield stress (176.4MPa) of SUS316L. The stiffnesses in both axial compressive and bending of the new fixator are about 2 times higher than other products except EBI (2003).

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.609-610
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• 2017

국내 외에서 잘못된 생활습관으로 대사증후군 환자가 급증하고 있다. 최근 대사증후군 환자들을 위한 웨어러블 디바이스를 이용하여 생활습관정보를 수집 분석하여 피드백하는 연구가 진행되고 있다. 생활습관 정보를 수집하는 대표적인 방법은 온라인/오프라인 설문지 또는 웨어러블 디바이스를 활용하여 수집하는 형태로 구분된다. 그러나 기존 설문지 방법은 연속적인 데이터를 얻기 어렵고, 웨어러블 디바이스를 이용하는 방법은 신뢰성 있는 데이터를 수집하기에는 한계가 있다. 따라서 본 논문에서는 대사증후군 환자를 대상으로 생활습관 정보 수집을 위한 병원의 설문지를 앱을 기반으로 개발하여 수집하고 스마트 폰과 밴드와 같은 웨어러블 디바이스를 이용하여 실시간 활동정보를 수집하여 환자 생활 습관에 따른 맞춤 별 예방정보를 제공하는 시스템을 제안하고자 한다.