골내 고정 장치용 초내식성 오스테나이트 및 듀플렉스 스테인리스강 가공재의 특성

오근택,강국진,박용수,김경남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3

Nickel is one of the most common causes of allergic contact dermatitis and hypersensitivity. In case of stainless steel as biomaterials, the higher the corrosion resistance and the lower the nickel content, the better it is or the human body. However, because nickel plays an essential role in the stabilization of the austenitic phase and the corrosion resistance of stainless steel, it is difficult to remove the nickel from the constituents of stainless steels completely. Therefore, the purpose of this study was to investigate corrosion resistance, cytotoxicity, and mechanical property of super stainless steels, which had high corrosion resistance by synergistic effect of Mo(or W) and N, with respect to nickel content and to evaluate their potential for orthodontic applications. Super austenitic stainless steel(SR-50A) had high nickel content of 22% and super duplex stainless steels nickel contents of 6~10%. Super austenitic and duplex stainless steels had nitrogen contents of above 0.2%. Also, these steels had high Mo or W contents which were able to increase the localized corrosion resistance. In terms of hardness, super stainless steels, which had Vickers hardness values of 374~400 Hv in cold-rolled state and 186~285 Hv in annealed state, exhibited higher values than 316L S. S.. Duplex stainless steels exhibited higher mechanical properties than austenitic stainless steels. In terms of corrosion resistance, super stainless steels exhibited lower passive current density(2.3~3.8 ㎂/cm^2) than pure Ti(6.6㎂/cm^2) in the body-simulated solution and similar potentiodynamic polarization behaviors. Pitting corrosion occurred in 316L S. S. but not in the others. Thus these steels were considered to have high corrosion resistance in the human body. In terms of cytotoxicity, SR-5OA and SAF2507 exhibited none cytotoxicity and the others slight. This results indicated that the cytotoxicity of alloys containing nickel had no relation with nickel content because SR-5OA with the highest nickel content exhibited none cytetoxicity In conclusion, it is considered that super stainless steels with high corrosion resistance and good biocompatibility can be used for orthodontic applications because of the enhanced passive film by high addition of Mo, W, N, etc.

초기 유방암 환자에서 피하 유방 절제술후 즉시 유방 재건술에 대한 고찰

오경석,김해진,정재호,설정현 大韓成形外科學會 2001 Archives of Plastic Surgery Vol.28 No.5

중국 다문화 교육 탐색 : 중학교 음악교과서를 중심으로

왕금령,오경희 한국문화교육학회 2010 문화예술교육연구 Vol.5 No.3

본 연구는 중국 중학교 음악교과서에서 다문화주의의 반영 정도를 알아보는데 목적을 두고 있다. 이에 중국 중학교 음악과 악보 교과서를 분석하였다. 분석 대상은 중학교 전 학년(1, 2, 3학년) 악보 교과서에 실린 모든 음악과 삽화이다. 음악의 경우, 장르 구별 없이 예를 들면, 민족음악, 대중음악, 종교음악 등 교과서에 실려 있는 모든 곡들을 대상으로 중국 내부 소수 민족별로, 외국별로 분석하였다. 삽화의 경우, 삽화에 나타난 외국의 대표적 작곡가, 음악 등에 대한 소개, 외국의 전통 복장, 외국의 대표적 건물, 풍경, 바다 등, 중국 소수민족, 외국 악기에 대한 소개를 중심으로 분석하였다. 분석결과 첫째, 음악의 경우, 중국 자국 내에 소수민족 음악은 교과서에 어느 정도 반영되어 있으나 55개의 소수민족 음악 중에서 주로 신강 위구르족, 몽골족, 카자흐족, 티베트족, 포이족, 묘족, 백족, 태족, 이족, 요족, 납서족인 11개 민족에 편중되어 있었다. 그리고 외국 음악은 5대륙 지역의 음악이 모두 실려 있으나 분포가 균형적이지 않았으며 특히 유럽 지역의 음악을 중심으로 편중되어 나타났다. 둘째, 삽화의 경우, 외국 작곡가에 대한 소개는 총 13회, 외국의 상징적 물건 총 27희, 소수민족 인물상 종 14회로 나타났다. 이와 같은 분석들을 통해, 무엇보다 다민족으로 이루어진 중국 내에서의 다양한 문화의 공존을 존중하는 배움의 기희가 학생들에게 제공되어져야 함을 촉구하고자 한다. The purpose of this study is to explore the degree of multicultural education reflected in music textbooks of Chinese middle school. The analytic objects are all the music and illustrations appeared in three textbooks. The case of music, ethnic music and foreign music were analyzed. The case of illustrations, representatives of foreign writers, representative works, traditional clothing, and other landmark buildings, natural scenery, China's ethnic minorities, foreign musical instruments. The results are as follows: the first, the case of music, although Chinese minority music were reflected to some degree, focus mainly on the Uygur, Mongolian, Tibetan, Buyi and Miao ethnic music. Regarding foreign music, although the music of five continents appeared in the textbooks, very unevenly distributed and put emphasis on the European music. The second, the case of illustrations, the introduction of foreign musicians appeared 13 times in total; The symbolic construction of foreign appeared 27 times, China's 14 ethnic minority figure appeared. Through these analysis, it can help students understand the cultural diversity of China in music textbooks.

초내식성 스테인리스강 선재와 브라켓의 내식성 및 금속 이온 용출 특성

오근택,정경진,황충주,박용수,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Metallic orthodontic appliances are known to release metal ions in an oral cavity. It is not advisable that toxic corrosion products derived from the appliances is absorbed into the body. Metal ions release from orthodontic appliances is known to have large effects on the result of orthodontic treatment and systemic health. Metal bracket and wire were made of super stainless steel(S32050) with high corrosion resistance. The corrosion resistance and ion release property of S32050 and conventionally used appliances were examined. Four types of wire were ligated in either super stainless steel(SB) or Tomy bracket(TB) with O-ring, and then each group was immersed in an artificial saliva at 37℃ for 12 weeks. Amount of released metal ions was measured with immersion time by graphite furnace atomic absorption spectroscopy and surface morphology was investigated. S32050 showed the low passive current density of about 1 μA/㎠ and the stable passive region to a high potential in artificial saliva. S32050 appliances did hardly release nickel ions in artificial saliva. S32050 wire(SRW) and NiTi wire(NW) didn't show significant difference of Ni ion release with immersion time, meanwhile, Remanium wire(RW) showed significant difference in 12 weeks. Ni ion releasce from the brackets didn't show any significant difference with immersion time and between SB and TB. Amounts of Ni ion released from TB-SRW showed significant difference in 12 weeks, those from TB-RW showed significant difference from 4 weeks later and highest release among all groupsin12weeks. TB-NW released little Ni ion for all immersion time and showed significant difference from 4 weeks later, TB-TW(TMA wire) showed significant difference in 12 weks. SB-SRW didn't show any significant difference and SB-RW signigicant difference in 12 weeks,but lower compared with TB group. SB-NW and SB-TW didn't show any significant difference. Corrosion products didn't be observed in mostly groups during the immersion time, except that in TB-RW, they were observed on the bracket surface between O-ring and wire from 8 weeks later. Super stainless steel wire had good corrosion resistance compared with stainless steel wire, and it is believed that it can be used as orthodontic material for bracket and wire.

교정학적 적용을 위한 초내식성 스테인리스강의 특성

오근택,김금진,황충주,박용수,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.3

Various kinds of orthodontic appliances have been developed for ideal tooth movement during orthodontic treatment. The orthodontic appliances made of metals are bands, arch wires, brackets and miniscrews as orthodontic anchorage. Generally, these appliances are made of stainless steel, pure titanium, Ni-Ti and TMA with the proper biocompatibility. However, localized corrosion of these materials can frequently occur in the particular environment. Super stainless steels, recently developed, have good corrosion resistance to reduce metal ion release induced by many kinds of corrosion. Recently, it has been reported that nickel ion release from orthodontic appliances affect the prevalence of nickel sensitization; however, there has been some controversy about nickel hypersensitivity to orthodontic appliances containing nickel. The purpose of this study was to evaluate and compare the microhardness, nickel ion release, corrosion resistance and cytotoxicity of 4 types of super stainless steels and 316L stainless steel as the control group according to nickel contents, and to determine the acceptability as the new material for various kinds of orthodontic appliances. All super stainless steels showed higher microhardness than 316L stainless steel, SR-3Mo showed especially the highest microhardness. In anodic polarization test, corrosion resistance was high in order of SR-50A, SFSS, SR-6DX, 316L stainless steel, SR-3Mo. There was no increase in nickel ion release from SR-50A, SR-6DX, 316L stainless steel with immersion time in artificial saliva; whereas there was some increase from SFSS and SR-3Mo with immersion time. All super stainless steels showed very low cytotoxicity regardless of nickel contents although SR-3Mo showed relatively higher cytotoxicity than the others. It is concluded that SR-50A among super stainless steels has the highest corrosion resistance and biocompatibility. It is undesirable to consider the alloys with high nickel content to release lots of nickel ion.

Chlorhexidine 처리가 상아질 접착제의 미세인장결합강도에 미치는 영향

오은화,최경규,김종률,박상진 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

본 연구는 상아질 혼성층의 교원섬유를 가수분해하는 효소인 MMPs (Matrix metalloproteinses) 억제제로 알려진 chlorhexidine (CHX)을 적용 후 결합강도를 측정하였으며, 이를 각각 열순환 처리 후 결합강도를 측정하였다. 또한 주사전자현미경으로 접착계면메서의 파괴 양상을 비교 분석하였다. 우식이 없는 발거한 32 개의 제 3 대구치의 교합면 상아질을 노출시키고 GI그룹에서는 dentin conditioner를 처리 후 2% chlorhexidine을 적용시키고, 산부식 접착제 그룹에서는 인산 산부식을 시행하고 2 % chlorhexidine을 적용 후 3단계 산부식형 상아질 접착제 (Scotchbond Multipurpose, SM), 2단계 산부식형 상아질 접착제 (Single Bond, SB)를 도포하고, 자가부식 접착제 그룹에서는 2 % chlorhexidine 적용 후 자가부식 상아질 접착제 (Clearfil Tri-S, TS)를 도포한다. 이후 복합 레진 (Z-250)과 GI (Fuji-II LC)를 충전한 시편을 1 ㎟의 단면을 갖는 beam으로 제작하여 열순환 하지 않거나, 10,000 회 열순환 (5 ~ 55 ℃)하였다. Universal testing machine (EZ-test: Shimadzu, Japan)에서 cross head speed 1 mm/min로 인장력을 가하여 , 미세인장결합강도를 측정하였다. 실험 결과는 유의수준 0.05 1evel에서 two-way ANOVA를 이용하여 통계분석하였다. 그 후 파절된 시편의 파괴 양상을 현미경 (SEM)으로 관찰하여 다음과 같은 갈론을 얻었다; 1. 2 % CHX을 적용한 모든 실험군에서 상아질과의 미세인장결합강도가 증가하였고, 열순환은 상아질과의 미세인장 결합강도를 감소시켰다 (P>0.05). 2. CHX 적용 후 열순환 한 군은 CHX을 적용하지 않고 열순환한 군에 비하여, 상아질과의 미세인장결합강도가 높았으며 , 특히 GI와 TS군에서 유의한 차이를 나타내었다 (P<0.05). 3. 파괴 양상 분석 결과, 혼성층에서의 접착성 파괴를 보이며, CHX을 적용하면 혼성층 기저부에서 상부로 파괴 부위가 옮겨가는 양상을 나타내었다. 이상의 연구 결과를 토대로, MMPs 억제제인 2 % CHX은 글래스 아이오노머 시멘트와 상아질 접착제의 초기 미세인장결합강도에는 영향을 미치지 않으며 ,CHX 적용이 접착 내구성을 유지하는데 도움이 되었다. The purpose of this study was to evaluate the effect of chlorhexidine (CHX) on microtensile bond strength (μTBS) of dentin bonding systems. Dentin collagenolytic and gelatinolytic activities can be suppressed by protease inhibitors. indicating that MMPs (Matrix metalloproteinases) inhibition could be beneficial in the preservation of hybrid layers. Chlorhexidine (CHX) is known as an inhibitor of MMPs activity in vitro. The experiment was proceeded as follows : At first, flat occlusal surfaces were prepared on mid-coronal dentin of extracted third molars. GI(Glass lonomer) group was treated with dentin conditioner, and then, applied with 2 % CHX. Both SM (Scotchbond Multipurpose) and SB (Single Bond) group were applied with CHX after acid-etched with 37% phosphoric acid. TS (Clearfil Tri-S) group was applied with CHX, and then, with adhesives. Hybrid composite Z-250 and resin-modified glass ionomer Fuji-II LC was built up on experimental dentin surfaces. Half of them were subjected to 10,000 thermocycle, while the others were tested immediately. With the resulting data, statistically two-way ANOVA was performed to assess the μTBS before and after thermocycling and the effect of CHX. All statistical tests were carried out at the 95 % level of confidence. The failure mode of the testing samples was observed under a scanning electron microscopy (SEM). Within limited results, the results of this study were as follows; 1. In all experimental groups applied with 2 % chlorhexidine, the microtensile bond strength increased, and thermocycling decreased the microtensile bond strength (P > 0.05). 2. Compared to the thermocycling groups without chlorhexidine, those with both thermocycling and chlorhexidine showed higher microtensile bond strength, and there was significant difference especially in GI and TS groups.

중·고등학교 아랍어 교재 집필 및 교재 내용에 관한 연구 보고서

오명근,송경숙,전완경,사희만,이규철,조희선,정규영,최진영 한국아랍어아랍문학회 1999 아랍어와 아랍문학 Vol.3 No.1

웹을 이용한 건축설계 협업시스템 구축을 위한 정보 플로우에 관한 연구

오경진,오건수 남서울대학교 2005 남서울대학교 논문집 Vol.11 No.1

The main problem of the architectural design process using web is a lack of proper collaboration system. The lack of proper collaboration system can occur the serious problems because of difficulty of sharing the opinions of participants and exchanging information each other. Therefore, to progress the architectural design in effective way, standardized and objective collaboration process is necessary. We develope the efficient communication to support the process. The main purpose of this study is to analyze the existing architectural design process, list the information according to the steps, and develope the collaborative system which can be saved as database and help the decision making.

조직공학적 연골생성에 있어서 연골막의 필요성

오경석,김해진,이동준,정재호,최준혁 大韓成形外科學會 2001 Archives of Plastic Surgery Vol.28 No.4

외상후 혈뇨환자에서 응급 초음파검사의 의의

임경수,이강현,황성오,이진웅 대한응급의학회 1996 대한응급의학회지 Vol.7 No.2

The Ultrasonography is rapid, mobile, and noninvasive diagnostic tool in emergency center. As a result, we estimate it`s value as an advocated primary diagnostic modality in the immediate evaluation of patients with multiple trauma. We investigated 60 patients with traumatic hematuria(microscopic hematuria or gross hematuria) who visited our emergency department from 1995, July to 1996, March. To evaluate the injury of urinary systems, emergency physician examined patients with hematuria by ultrasonography, and comapared the results with those of excretory urography and computed tomography. We demonstrated 21 positive findings for abnormal fluid collection and renal parenchymal injury and bladder rupture on ultrasonography. All bladder injuries were diagnosised by ultrasonography, and all major renal injury(grade Ⅲ,Ⅳ,Ⅴ) were also diagnosised by that. The accuracy of emergency ultrasound examination in traumatic hematuria was 97.0%, and sensitivity was 95.0% with specificity of 97.4%. The ultrasonography was an accurate diagnostic adjunct in detecting renal injury and bladder injury in traumatic hematuria patients. Ultrasonography provides an excellent noninvasive diagnostic tool for the initial screening study of patients with traumatic hematuria.