6 . 「 내훈 」 소고 - 그 표기법을 중심으로 -

이청희 문창어문학회 1969 문창어문논집 Vol.9 No.-

포스트 및 코어 수복시 레진 세멘트가 파절 저항에 미치는 영향

이청희 慶北大學校 齒科大學 1993 慶北齒大論文集 Vol.10 No.2

손상이 심한 근관치료된 치아를 포스트 및 코어로 회복할 때에 포스트 세멘트의 기계적 및 화학적 성질이 치근 파절저항에 어떠한 영향을 주는지 알아보기 위해서, 발거된 소구치를 사용하여 법랑-백아질 경계선 상에서 치아장축에 수직되게 절단한 후 기성품인 평행한 Para-post를 샌드브라스팅하여 깊이 7mm로, Ⅰ군에는 Z,P,C., Ⅱ군에는 Panavia, Ⅲ군에는 All-bond로 세멘트한 후 복합레진 코어를 형성하고 치질 1mm 포함하는 금관을 니켈-크롬계 비귀금속으로 주조하여 각치아에 Z.P.C.로 세멘트 하였다. 인스트론 만능 시험기에 시편을 거상하고 치아 장축에 45˚가 되게 압축하중을 가하여 파단하중을 측정하고 치근내부를 주사전자현미경으로 관찰한 결과 다음과 같을 결과를 얻었다. 1. 파절저항이 Panavia 군에서는 175.8±54.5kg, Z.P.C.군에서는 146.8±36.8kg, 그리고 All-bond 군에서는 144.6±25.8kg의 순서로 나왔으나 통계적으로 유의성있는 차이를 나타내지 않았다.(P>0.05). 2. 파절 후의 주사전자현미경(SEM) 관찰에서 Panavia 군은 상아질 세관 내로 레진의 침투가 거의 관찰되지 않았으며, All-bond 군에서는 일부 관찰되었다. The purpose of this study was to evaluate root failure loads of teeth in which posts were cemented with various cements. Thirty-three recently extracted, intact premolars were used and stored in a physiologic saline solution from the time of extraction. The crown of each tooth was removed with a water-cooled diamond disk at the cemento-enamel junction. Then, the teeth were endodontically treated and post spaces were prepared to 7mm in depth with a Para-post drill(P-42-5). The teeth were divided into three groups of eleven teeth per each group. Prefabricated parallel Para-Posts(PD-K-5, Φ1.25mm) were sandblasted and used in each group. Group Ⅰ; Posts were cemented with zinc phosphate cement. Group Ⅱ; posts were cemented with Panavia cement. Group Ⅲ; Posts were cemented with All-Bond and Composite luting cement. A composite resin core was built to the height of 4.5mm above the tooth and sunk to the depth of 1mm and was involved the substance of the tooth because of the ferrule effect. Thereafter, a complete cast crown was made with nickel-chrome alloy and cemented with zinc phosphate cement on each tooth. The failure loads of the specimens were measured by an Instron Universal testing machine. The mean values of failure loads for the three groups were statistically compared by Duncan's multiple range test. There was an examination by scanning electron microscopy in order to evaluate the mechanical bonds of resin on the internal root surface in each teeth. The results were as follows; 1. There was not a statistically significant difference between the failure loads of each group(P>0.05). 2. In examination of SEM, there were no resin tags in dentinal tubules in group Ⅱ(Panavia). In group Ⅲ(ALL-Bond), there were resin tags in dentinal tubules, though sometimes, there were no resin tags.

연쇄이동 반응을 이용한 Ag/PVP 나노복합체 제조에 관한 연구

이청희,최세은,김주영,인교진 한국공업화학회 2008 한국공업화학회 연구논문 초록집 Vol.2008 No.-

불포화레시틴을 이용한 나노베지클의경피흡수에 관한 연구 : 모델 활성물질 - 알부틴, 토코페릴아세테이트

이청희,왕수환,서정민,강기춘,이천일,표형배 한국공업화학회 2004 한국공업화학회 연구논문 초록집 Vol.2004 No.1

시스템별 기능 및 취약점을 분석하라

이청희,Lee, Cheong-Hui 한국데이터베이스진흥원 1999 디지털콘텐츠 Vol.11 No.-

인터넷의 개방성으로 인하여 발생되는 전자상거래의 취약점을 최소화하기 위하여 우리는 보안 기술을 사용하게 된다. 그러나 보안 기술을 사용함으로 인하여 서비스 속도가 느려지거나 사용자에게 불편을 주지 않아야 한다. 현재 가장 이슈가 되고 있는 인터넷 쇼핑몰의 실례를 보면서 보안 적용 방안을 제시하고자 한다.

자당지방산에스텔을 이용한 액정 제조 및 화장품 응용에 관한 연구

이청희,김성호,이정순,이천일,표형배 한국공업화학회 2007 한국공업화학회 연구논문 초록집 Vol.2007 No.-

Stabilization of Ascorbic acid Using Anhydrous emulsification

이청희,서정민,김태훈,강기춘,표형배 한국공업화학회 2009 한국공업화학회 연구논문 초록집 Vol.2009 No.1

PVP 라디칼중합과정에서 연쇄이동반응을 통한 은 나노 입자의 제조

이청희,인교진 한국고분자학회 2008 한국고분자학회 학술대회 연구논문 초록집 Vol.33 No.2

접착성가공의치에서 세멘트 종류가 전단결합강도에 미치는 영향

이청희,Lee, Cheong-Hee 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.4

교정치료을 위해 발거된 소구치를 사용하며 레진에 고정한 후 직경 4mm이상의 법랑질 평면을 얻었다. 직경 4mm의 아크릴릭 봉을 길이 5mm로 해서 Ni-Cr 비귀금속 합금으로 주조한 후, 사용될 표면을 전기화학적 식각처리 하였다. 각 실험군당 시편 42개를 I군은 Panavia 21, II군은 Superbond, III군은 All-Bond로 세멘트 한 후 1일, 15일, 그리고 30일에 각 군당 14개의 시편을 임의로 취득하여 인스트론 만능시험기에 특별히 만든 Jig를 사용하여 거상하고 cross-head speed 1mm/min으로 전달결합강도를 측정하였다. 세멘팅한 후 1일에 측정한 전달결합강도는 Panavia-21의 I군에서 $32.7{\pm}9.9kg$중, Super-bond의 II군에서 $25.9{\pm}5.9kg$중, 그리고 All-Bond의 III군에서 $23.5{\pm}7.2kg$중의 순으로 나타났으며, I군이 II군과 III군에 대하여 통계학적인 유의성이 있었다(P<0.01). 세멘팅후 15일에 측정한 전단결합강도는 II군이 $34.6{\pm}10.4kg$중, I군에서 $23.1{\pm}8.7kg$중, 그리고 III군에서 $10.9{\pm}7.2kg$중으로 II군이 I과 III군에 대해, I군은 III군에 대해 통계학적 유의성이 있었다(P<0.01) 세민팅후 30일에 측정한 전달결합강도는 II군에서 $33.0{\pm}12.9kg$중, I군에서 $31.0{\pm}8.6kg$중, 그리고 III군에서 $13.6{\pm}6.6kg$중으로 II군과 I군이 III군에 대해 통계학적인 유의성이 있었다(p<0.01). 저장기간에 따른 전달결합강도 비교에서 III군에서 1일에서의 전단결합강도가 15일과 30일에서의 전단결합강도보다 통계학적으로 유의성 있게 높았다(P<0.01). The purpose of this study was to compare the shear bond strength of adhesion bridge by various resin cements. One hundred and foully 1st premolars were used. The teeth were cut below 2mm from CEJ and the coronal portions were used. The coronal portions were embeded with the acrylic resin and trimmed with sic paper until the flat plane with ${\phi}$ 4mm above acrylic resin sticks in height 5mm were casted with nonprecious metal and the using surfaces were treated with sic paper from #200 to #1200 and polished with alminum oxide paste. And then, the using surfaces were sandblasted and treated with the electrochemical etching. The teeth were divided into three groups of fourty two each. In group I, teeth and specimens were cemented with Panavia 21 In group II, teeth and specimens were cemented with Superbond In group I, teeth and specimens were cemented with All-Bond & composite resin cement Each group was subdivided into three subgroups according to the storage period ; one-day storage, fifteen-day storage, and thirty-day storage. The special jig was made. Then, the specimen and jig were mounted to Instron Universal Testing Machine and the failure were measured. The results were as follows. 1. There was statisfically significant difference between the failure loads of group I and group II and III after one day storage(P<0.01), 2. There was statisfically significant difference between the failure loads of group II and group I and III and between group I and group III at fifteen day storage(P<0.01). 3. There was statisfically significant difference between the failure loads of group I and II and group III after thirty day storage(P<0.01). 4. There was statisfically significant difference between the failure loads of one day storage and fifteen and thirty days storages in group III (P<0.01).

위상이동 형상측정법을 이용한 도재 소성시의 도재 수축률의 측정

이청희,Lee, Cheong-Hee 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.6

To compare several porcelains made by various manufacturers in shrinkage after firing and investigate the effect of condensation on shrinkage, specimens were prepared and the volume of each body was measured by the phase-shifting profilometry. Baseplate wax was cut by $2.5cm{\times}2cm$ and cast in nonprecious metal(Verabond, U.S.A.), then any surfaces of specimens were abrased and polished on the SiC abrasing papers, preparing 120 specimens. Specimens were divided into six groups according to the porcelain used, and the porcelain used in each group were as follows. Group I : Ceramco dentin porcelain Group B : Creation dentin porcelain Group III : Creation margin porcelain Group IV : Vintage margin porcelain Group V : Vita dentin porcelain Group VI : Vintage dentin porcelain Porcelain was built up on the metal plates using a small spoon and then solution matching to each porcelain was added. The six groups are subdivided into a and b. In subgroup a, only excessive solution was absorbed with tissue and in subgroup b, porcelain was condensed sufficiently. When build-up was completed, the shape was measured using the phase-shifting profilometry. After that, specimens were fired in the furnace programed for each porcelain and then their changed shape were measured again. Using the difference between the two above measurements, the ratio of shrinkage was calculated. Obtained results were as follows ; 1. Regardless of condensation, the volume of fired specimens were not different significantly between the two subgroups a and b in the same group. 2. The ratios of shrinkage were significantly higher in the groups porcelain built-up was condensed than in the groups not condensed 3. The ratios of shrinkage were in the range of 36.81-27.19% in the groups porcelain built up was condensed and 44.52-37.54% in the other groups not condensed.