치주조직 재생을 위한 칼슘 포스페이트 글라스 분말이 백서 두개골 결손부의 골조직 재생에 미치는 영향

이용근,문현주,이상배,김광만,김경남,최성호 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

The treatment of the tone defects resulting from trauma, neoplasm, surgery, or infection is one of the major concern in dentistry. The major goal is the functional, esthetical regeneration of supporting structures already destructed by disease. Transplantation technique have been used to provide a scaffold for bone regeneration, to augment bony defects resulting from trauma or surgery, to restore bone loss caused by dental disease, to prevent the collapse the alveolar ridge in recent extraction sites, to replace bone loss by periodontal disease, to augment the alveolar ridge in implant surgery. There are autogeneous, allogenic, xenogenic and alloplastic bone-grafts in transplantation. Among the alloplastic bone-graft materials, calcium phosphates have been received the most attention. In this study, the critical size defects were surgically produced in the calvarial bone of Sprague-Dawley rats using the 8 ㎜ trephine bur. Calcium phosphate glass powders with mean diameter 400 ㎛ transplanted onto the produced detects in the experimental group, while sutured without grafting anything in the control group. Histomorphometric as well as radiodensitometric analyses were performed after sacrifice at 2, 4 and 8 weeks following operation. The prepared calcium phosphate glass powder with average size 400 ㎛ in CaO-CaF_2-P_2O_5-MgO-Al_2O_3 promoted new bone formation in the calvarial defects in the Sprague-Dawley rats. New bone was formed in the upper side of the detects as well as the defect margin and dura mater. Experimental group always exhibited higher values in the length, area and density of the newly formed bone than that of the control group. There were significant differences between the experimental and the control groups, except the density after 4 weeks (p<0.05).

Contact 경계조건을 이용한 CIB 패키지의 휨 수치모사

이상혁,김선경,박세훈,강남기 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

In this work, we have analyzed the warpage of em packages after processing. Geometric complexity is the main bottleneck in package simulation. Moreover, each layer has been modeled separately and then assembled together by the use of the contact boundary conditions between layers. Thus, modeling with full consideration of temperature-dependent properties and thermal cure is possible by nonlinear simulation with cure model but infeasible in terms of cost-effectiveness. Therefore, we have proposed to use the pseudo processing temperature (PPT) where the stress is free throughout the entire domain. As a result, warpage of CIB packages can be accurately simulated with a linear solver thanks to the use of PPT.

극놀이에서 나타난 유아의 상호 주관성 전개 과정 연구

이경남 서울여자대학교 1998 아동연구 Vol.2 No.-

[초록 없음]

대학생의 노인에 대한 태도에 관한 연구

이영희,권미경,김남선,김혜원,최미경,이규은,홍윤미 關東大學校 醫科大學 醫科學硏究所 2003 關東醫大學術誌 Vol.7 No.1

The purpose of this study is to identify the perception, the future and images, and prejudice toward old people. And to examine difference the group of gerontological education (educated group) with the non-educated group. 189 students in K university were participated in this study. The educated group was composed 101 students who enrolled liberal arts course that learned this title. Data were collected from May to June, 2002. The results are as follows; 1) Many students perceived the elderly that was started 60~64 years. 2) The perception, the future and images, and prejudice of both groups were some positively. 3) Each variables were not significantly difference. But the mean level of the educated group were more higher. 4) The educated group was found significantly related to the perception and prejudice(r=.303, p=.002). The non-educated group was found significantly related to the perception and the future and image(r=.421, p=.000), the perception and prejudice(r=.321, p=.003), the future, image and prejudice(r=.272, p=.012).

수종 직접충전용 광중합형 복합레진의 색변화와 물리적 성질

이서영,김경남 大韓齒科器材學會 1993 대한치과재료학회지 Vol.20 No.2

In the past thirty years, the use of light-cured composite resins for direct filling as an aesthetic restorative material has grown rapidly. But it has been proven this material has very poor color stability. The purposes of this study was to evaluate the color change, water sorption and solubility of two microfilled and three hybrid composite resins after storage for one week in distilled water at 37℃ and color change after thermocycled between 5℃ and 65℃. The results were as follows; 1. Among samples which immersed in 37℃ distilled water for 1 week, Clearfil-Photoposterior showed the lagest change. The others were almost same. 2. In the group of 5 to 65℃ thermocycling 5,000 times and 10,000 times, Silux-plus showed the largest color change and Z-100 had the smallest. Clearfil-Photoposterior and Herculite XR showed significant difference in discoloration between 5,000 and 10,000 times cycled group. 3. Bisfil-M and Silux-Plus showed more water sorption than Herculite XR, Z-100 and Clearfil-photoposterior. The reason for this is likely due to these materials are microfilled. Among the all tested materials, Silux-plus showed highest and Clearfill-Photoposterior showed the lowest water sorption. The may be attributed to filler content of the materials. 4. Silux-Plus which was microfilled showed the highest water solubility. Bisfil-M, Z-100, and Clesrfil-Photoposterior showed the lowest values. It was concluded that the filler content and type of the light cured composite materials had no effect on the discoloration of the tested materials. It also was proven that water sorption and solubility had no correlation.

금속강화형 글라스아이오노머 시멘트의 간접 인장강도

이서영,김경남 大韓齒科器材學會 1992 대한치과재료학회지 Vol.19 No.2

Glass ionomer cements possess certain properties that make them useful as a restorative filling material. These properties include (1) chemical bonding to tooth enamel and dentin, (2) the release of fluoride ions, and (3) biocompatibility. However glass ionomer cements are susceptible to fracture and exhibit a low resistance to abrasion. For improving their strength, the addition of metal powders has been directed. Two different formulas of glass ionomer cements have been developed to improve wear resistance and strength. One material is composed of a simple mixture of glass ionomer powder and amalgam alloy. The other is based on bonding of silver particles to glass particles by high temperature sintering and is called a cermet cement. The purpose of this study was to compare physical properties of one unreinforced glass ionomer cement and two metal reinforced glass ionomer cement. The physical property evaluated was diametral tensile strength. Specimens, 4㎜(diameter)×2.5㎜(heigth), were prepared and maintained in 100% humidity, 37℃. Then the diametral tensile strength was tested by the universal testing machine, with a cross head speed of 2㎜/min at 30minute and 24hrs after setting. All tested materials were increased in strength at 24hrs than at 30minutes. The cermet cement appeared to be significantly stronger in diametral tensile strength than either of Miracle Mix and unreinforced glass ionomer cement.

치과교정용 NiTi 합금계 선재의 탄성과 상변태 거동에 대한 열처리 효과

이진숙,김광만,김경남 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.1

Due to unique property of superelasticity, NiTi has been used widely since their introduction to the orthodontic specialty by Andreasen and Hillmann. But sufficent evaluation of superelasticity of domestic marketed wires has not yet been made. It has been known that heat treatment caused changes not only of elastic behavior but also of phase transformation behavior, an important factor of superelasticity. So, this study was investigated into varied ways of heat treatment of wires for orthodontic force proper for each clinical case. Each elastic behavior of 6 commercial NiTi alloy orthodontic arch wires(LG's ORTHOLLOY, G & H's Nickel Titanium arch wire, ORMCO's NI-TI and COPPER NI-TI, TOMY's SENTALLOY and 3M Unitek's Nitinol) were examined, and in order to study the effect of heat treatment on elasticity and phase transformation behavior, 3-point bending test, differential scanning calorimetry and X-ray diffraction with each wire heated at 350℃, 450℃ and 550℃ for 1hour were carried out compared with a as-recieved group. The results were as follows : 1. As a result of 3-point bending test in a control group, all wires had superelasticity and COPPER NI-TI showed the lowest maximum load as well as minimum(P<0.05). 2. As a result of 3-point bending est, except Nitinol and COPPER NI-TI, the wires in the group heated at 450℃ had lowest maximum and minimum load than that of a control group, and higher maximum and minimum load that of COPPER NI-TI in control group, and had superelasticity without and permanent deformation(P<0.05). 3. Phase transition temperature of all wires heated at 350℃ except COPPER NI-TI became higher but it became lower when they were heated at 450℃ and 550℃. 4. All wires in control group had austenite structure and when they were heated, martensite phase increased, and R phase appeared when heated at 550℃. The wires used in this study were changed in phase transition temperature, structure and elastic behavior as well by heat treatment. So this study showed that even the same kind of wire could be varied and used after heat treated, choosing proper load in accordance with each orthodontic clinic case.

세라믹스의 치과응용

이용근,김경남 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.4

치주조직 재생을 위한 칼슘 포스페이트 글라스가 MC3T3-E1 세포의 증식, 분화 및 석회화에 미치는 영향

이용근,송진,이상배,김경남,최성호 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

The purpose of this work was to exploring the influence of the prepared calcium phosphate glass on the proliferation, differentiation, and mineralization of the culture system of the pre-osteoblastic MC3T3-E1 cells. Polystytene was employed as a control in this experiment. Cells were cultured in a differentiated medium onto the calcium phosphate glass as well as polystyrene, and the number of cells and the protein contents were determined. To examine osteoblast differentiation, the alkaline phosphatase activity was measured. Mineralization was evaluated by staining the calcium deposit with Alizarin red. Culture onto the calcium phosphate glass exhibited no significant difference in cell proliferation compared with control group. The alkaline phosphatase activity in the experimental group, however. was enhanced In the calcium phosphate glass significantly at 10-18 days than that of the control group (p<0.05). Enhancement of bone-like tissue formation by the addition of the calcium phosphate glass was observed since 7 days. The results of the present study indicate that the prepared calcium phosphate glass promotes osteogenesis by increasing collagen synthesis and calcification of the extracellular matrix. It maybe due to greater calcium concentration in the culture medium released from the calcium phosphate glass.

바륨 페라이트를 함유한 알지네이트 자성 복합 입자의 제조

이덕연,오영일,김동현,김광만,김경남,이용근 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

Magnetic polymer composite materials with high coercivity have potential applications in medical diagnostic technologies, magnetic drug delivery, and hyperthermic cancer treatment. The purpose of this study was to prepare the magnetic composite particles by encapsulating barium ferrite powders with alginate and to investigate their physical and biological properties. 0.4 g of sodium alginate was dissolved in 20 ml of distilled water and different amount (0.4~4 g) of barium ferrite powder was dispersed in alginate solution using an ultrasonication method. The resulting barium ferrite-alginate slurry was added dropwise to a CaCl2 solution to form magnetic Ca-alginate composite beads. They were separated by filtration and washed several times with water and ethanol. The final product was then completely dried at 40℃ under vacuum to obtain brownish black powders (0.1~1 mm in size) with a high magnetic response when submitted to a small magnet. Average size of magnetic composite particles was dependent on the amount of barium ferrite and the viscosity of slurry . The morphological and dimensional analyses of magnetic composite particles were performed by optical microscopy and scanning electron microscopy. Magnetic polymer composite particle was found to maintain the high coercivity. The saturation magnetization value for magnetic Ca-alginate composites increased with the increase of the barium ferrite/alginate ratio. The amount of self-heating induced by hysteresis under an alternating magnetic field was measured as a function of barium ferrite/alginate ratio in distilled water. According to the results, the encapsulated magnetic composite is expected to be useful for hyperthermia and chemotherapy remarkably.