• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.2
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• pp.150-157
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• 2015

The purpose of this report is to suggest clinical managements of implant periapical lesions by presenting three clinical cases managed by either the infected form or the inactive form with the follow-up period of five to twelve years. One patient with no clinical symptom was regarded as inactive form. Two patients having pain were regarded as infected form and have been under the systemic antibiotic therapy. In one patient, the symptom subsided and the size of radiolucent lesion decreased. However, the other patient showed increased size of lesion causing the implant unstable, which leaded to remove the implant and to replace it. There was neither additional increase of the lesion nor functional problem for all three. It is important to detect implant periapical lesion in early stage before jeopardizing the stable implant and manage properly using systemic antibiotic therapy and surgical approach if needed, depending on infected form and inactive form.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.37-44
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• 1999

Because of bone resorption, wear of ultra-high molecular weight polyethylene(UHMWPE) in total knee arthroplasty has been recognized as a major factor in long-term failure of knee implant. The surface damage and the following harmful wear debris of UHMWPE is largely related to contact stress. Most of the previous studies focused on the contact condition only at the articulating surface of UHMWPE. Recently, contact stress at the metal-backing interface has been implicated as one of major factors in UHMWPE wear. Therefore, the purpose of the is study is to investigate the effect of the contact stress for different thickness, conformity friction coefficient, and flexion degree of the UHMWPE component in total knee system, considering the contact conditions at both interfaces. In this study, a two-dimensional non-linear plane strain finite element model was developed. The results showed that the maximum value of von-Mises stress occurred below the articulating surface and the contact stress was lower for the more conforming models. All-polyethylene component showed lower stress distribution than the metal-backed component. With increased friction coefficient on the tibiofemoral contact surface, the maximum shear stress increased about twofold.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.15-15
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• 2003

치과재료에 사용되는 금속재료는 주로 스테인리스강, 타이타늄, Ni-Ti, Co-Cr등과 같은 특수합금이 주로 사용되고 있다. 이들 재료는 치과 보철물과 교정재료 및 충전재료로 주로 사용되고 있으며 그 외 치과에서 사용되는 기기나 기구에도 많이 활용되고 있다. 특히 치과 보철물을 사용하여 치료를 원하는 환자가 최근에 급격히 증가하면서 임플란트 고정체와 나사 등을 이용한 치료법의 연구와 개발이 필요하게 되어 세계적으로 연구와 투자가 활발히 진행되고 있다. 그러나 재료의 설계나 합금의 설계 및 제품의 설계상의 문제로 인하여 생체조직과 결합하는데 많은 문제점이 임상적으로 발생되고 있다. 즉 임플란트 표면의 생체적합성부여, 고정체와의 결합시 파절이나 풀림현상, 골에 고정체로 사용하는 나사의 강도와 내마모성문제 등이 개선되어야 할 문제점으로 남아있다. 또한 총의치에 사용되는 자석 어태치먼트의erosion-corrosion문제, 교정선의 탄성 과 마모저항문제 등은 앞으로 계속적인 연구를 행하여야할 과제로 남아있다. 또한 국소의치에서 사용되는 frame은 정밀주조법을 통하여 제조하며 주조상의 결함 등으로 인한 클라스프의 파절 문제점이 발생되고 있다. 따라서 본 연구에서는 치과재료로 사용되는 임플란트 고정체, 나사, 교정용 선등의 문제점을 고찰하고, 지금까지 이루어진 연구를 중심으로 최적의 개선 조건을 찾고자하였다. 최근첨단소재 및 금속재료를 사용하여 치과재료 합금을 설계할 수 있는 연구가 활발히 진행된다면 수입에 의존하고 있는 고가의 치과재료를 값이 싼 고성능의 제품으로 대체할 수 있는 효과가 클 것으로 생각된다.>$\rho$$\sub$0/=1.8 %. As t$\sub$Co/ increases, a transition from the regime of co-existence of superparamagnetic and ferromagnetic behaviors to ferromagnetic behavior was observed. Tunneling barrier called "decay length for tunneling" for the films having the thickness of Co layer from 1.4 to 1.6 nm was measured to be ranged from 0.004 to 0.021 ${\AA}$$\^$-1/.문에 기업간 관계를 연구하는 측면에서는 탐험적 연구성격이 강하다. 더 나아가 본 산업의 주된 연구가 질적이고 기업내부만을 연구했던 것에 비교하면 시초적이라고 할 수 있다. 또한 관계마케팅, CRM 등의 이론적 배경이 되고 있는 신뢰와 결속의 중요성이 재확인하는 결과도 의의라고 할 수 있다. 그리고 신뢰는 양사 간의 상호관계에서 조성될 수 있는 특성을 가진 반면, 결속은 계약관계 초기단계에서 성문화하고 규정화 할 수 있는 변수의 성격이 강하다고 할 수가 있다. 본 연구는 복잡한 기업간 관계를 지나치게 협력적 측면에서만 규명했기 때문에 많은 측면을 간과할 가능성이 있다. 또한 방법론적으로 일방향의 시각만을 고려했고, 횡단적 조사를 통하고 국내의 한 서비스제공업체와 관련이 있는 컨텐츠 공급파트너

• Clinics in Shoulder and Elbow
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• v.12 no.1
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• pp.14-20
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• 2009

Purpose: This study examined the clinical results of the treatment of type 2 distal clavicle fracture with using a Wolter plate. Materials and Methods: Between 2004 and 2007, 16 patient treated for type 2 distal clavicle fracture using a Wolter plate were included in this study. Their average age was 32.6 years and the postoperative mean follow-up period was 22.9 months. The reduction and union were qualified according to the immediate post-operative and final radiographs. The functional outcome was evaluated by Kona's system and the Constant score Results: By Kona's functional evaluation, there were 12 cases with excellent results, 3 cases with good results and 1 case of fair results and the average Constant score was 90. All 16 cases showed bony union. As complications, there was 1 case in which the protruded hook of the plate could be palpated at the skin, and 1 case showed an acromial fracture, but all the cases dispalyed successful bony union and there was no acromioclavicular joint arthritis, infection or any other complications. Conclusion: Wolter plate fixation for type 2 distal clavicle fracture is a reliable surgical method for satisfactory reduction and rigid fixation, a lower incidence of nonunion and excellent clinical result.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1200-1206
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• 2006

The purpose of this study was to investigate the relation between NEAP (net rate of endogenous noncarbonic acid production) from dietary potassium and protein intakes, and bone mineral density and urinary deoxypyridinoline (DPD) in Korean women. The subjects were 276 women aged $18\sim81$, and they were asked about general characteristics and nutrient intake using 24-hr recall method. Also, their bone mineral density of spine and femoral neck were measured using DEXA. Urinary DPD analysis was done in 106 postmenopausal women. The average energy, protein and potassium intake were 1503.0 kcal, 57.7 g and 60.8 mEq, respectively. Mean NEAP [54.5$\times${protein intake (g)/potassium intake (mEq)}-10.2] was 44.6. NEAP showed a significantly negative correlation with spine bone mineral density of the subjects after controlling for confounding factors (age, height and weight) (p<0.05). The lowest quartile of protein intake had the highest spine bone mineral density after controlling for confounding factors (p<0.05). There was no significant correlation between urinary DPD and calculated NEAP. These results provided positive relation between a ratio of lower protein to higher potassium dietary intake and bone mineral density.

• Polymer(Korea)
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• v.33 no.2
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• pp.104-110
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• 2009

Demineralized boneparticle (DBP) has been widely used as and a powerful promoter of new bone growth. In this study, DBP sponges were chemically crosslinked and characterized for the potential application of tissue engineered scaffolds. The DBP sponges prepared by crosslinking with EDC. 0.1, 0.2 or 0.3% pepsin was applied to DBP dissolved in 3% (v/v) acetic acid aqueous solution for 48 hrs. The prepared sponges were crosslinked by 1, 5, 10, 50 or 100 mM of EDC solution concentration and then were lyophilized. The DBP sponges were characterized by SEM, FT-IR and DSC and analyzed in terms of their porosity and water absorption ability. The cellular viability and proliferation were assayed by MTT assay. Our investigation revealed that 0.2$\sim$0.3% of pepsin and 50$\sim$100 mM of EDC produced DBP sponges with good physical characteristics. In conclusion, DBP sponge prepared under these conditions is potentially useful for the applications of tissue construction.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.431-441
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• 2022

The digital facebow device records the trajectory of the mandibular movement where it is then reflected on the computer-aided design software, leading to an improvement on treatment outcomes of prosthetic restorations. In this clinical case, using a digital technology, an implant placement and prosthetic restoration were done in a patient who has lost maxillary and mandibular molars. Following an intraoral scan, a surgical stent for implant surgery was fabricated based on digital diagnostic wax-up, and implants were installed. After six months of sufficient osseointegration, customized abutments and the first temporary prostheses were delivered. Then two months later, at an abutment level, an intraoral scan and digital facebow transfer device were used to mount the intraoral scan data on a virtual articulator, and record the mandibular movements. Once the second temporary prostheses were fabricated and delivered on a basis of the mandibular movement, the definitive zirconia prostheses were designed and delivered based on a stabilized occlusion that was duplicated via double scan technique.

• Journal of Life Science
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• v.32 no.9
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• pp.698-705
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• 2022

Rice consumption in Korea is continuously decreasing; therefore, methods for reducing rice stocks are now being proposed. Increasing the consumption of rice and reduce these stocks will require that the rice processing industry be developed beyond simply using cooked rice as food. The Korean people's eating habits have also diversified recently, and the consumption of bread is increasing. Therefore, breeding a cultivar for rice flour is now necessary. Here, a line suitable for processing into rice flour was cultivated by deriving a mutant line by tissue culture of Ilpum. Mutant populations were investigated for major agricultural traits in the field, and grain characteristics and endosperm characteristics were investigated after harvest. Among the lines, line 29111 had similar agricultural characteristics to the background Ilpum, and excellent grain quality, and was selected for further analysis. The physicochemical properties that determine taste were similar or improved. However, unlike Ilpum, 29111 had a non-uniform starch structure and a characteristic powdery endosperm because large and male starch grains are evenly distributed. Therefore, 29111 was viewed as a breeding line suitable for processing and for excellent agricultural characteristics and taste. The added value can be increased by diversifying the uses of rice. The taste was improved and a method for breeding cultivars with grain characteristics for glutinous rice that would satisfy both producers and consumers was presented.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.113-124
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• 2023

Purpose. The purpose of this study is to help increase the success rate by analyzing the types and characteristics of implant prosthesis and the survival rate. Materials and methods. Among implants placed between 2011 and 2020 at Sanbon Dental Hospital, College of Dentistry, Wonkwang University, a case restored by a prosthetic surgeon was investigated for the characteristics and correlation of failure. The causes of failure were classified as failure of osseointegration, peri-implantitis, fixture fracture, abutment fracture, screw fracture, screw loosening, prosthesis fracture, and loss of prosthesis retention. Prosthetic method, cantilever presence, placement location, etc. were analyzed for their correlation with implant failure. Results analysis was derived through Chi-square test and Kaplan-Meier survival analysis using SPSS ver 25.0 (IBM, Chicago, IL, USA). Results. A total of 2587 implants were placed, of which 1141 implants were restored with Single Crown and 1446 implants with Fixed Partial Denture, and the cumulative survival rate was 88.1%. The success rate of SC was 86.2% (984) and the success rate of FPD was 89.6% (1295), showing statistically significant differences, among which factors that had significant differences were abutment fracture, screw fracture, and screw loosening (P < .05). Conclusion. As a result of the 10-year follow-up, more failures occurred due to biomechanical factors than biological factors. Further studies on the success of implants will be needed in the future.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.267-275
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• 2023

To obtain better esthetic results when immediately placing a dental implant, the soft tissue surrounding the implant must be conditioned during healing of the extraction socket. To this end, the emergence profile can be customized through immediate restoration of the provisional prosthesis, and good clinical results can be obtained at the time of definitive restoration in the future, resulting in high patient satisfaction. In this case, horizontal root fracture occurred after trauma to both maxillary central incisors. Immediate implant placement and loading was planned considering aesthetics and alveolar bone condition. By taking an impression using a digital intraoral scanner, a digital diagnostic wax-up was performed to make a more aesthetic prosthesis without applying external force to the traumatized teeth. Based on this, the ideal placement location was determined and immediate implant placement was performed using a 3D printed surgical guide. The provisional prosthesis was restored 5 days after placement, and the definitive zirconia crown was restored through soft tissue conditioning and customization using the shape of the provisional prosthesis for 3 months.