수종의 내부연결형 임플란트에서 연결부의 형태에 따른 응력분포의 유한요소 분석

정병현,이경제,강동완 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.2

Purpose: This study was performed to compare the stress distribution pattern of abutment-fixture connection area using 3-dimensional finite element model analysis when 5 different implant systems which have internal connection. Materials and methods: For the analysis, a finite element model of implant was designed to locate at first molar area. Stress distribution was observed when vertical load of 200 N was applied at several points on the occlusal surfaces of the implants, including center, points 1.5 mm, 3.0 mm away from center and oblique load of 200 N was applied 30º inclined to the implant axis. The finite element model was analyzed by using of 3G. Author (PlassoTech, California, USA). Results: The DAS tech implant (internal step with no taper) showed more favorable stress distribution than other internally connected implants. AS compare to the situations when the loading was applied within the boundary of implants and an oblique loading was applied, it showed higher equivalent stress and equivalent elastic strain when the loading was applied beyond the boundary of implants. Regardless of loading condition, the abutments showed higher equivalent stress and equivalent elastic strain than the fixtures. Conclusion: When the occlusal contact is afforded, the distribution of stress varies depending on the design of connection area and the location of loading. More favorable stress distribution is expected when the contact load was applied within the diameter of fixtures and the DAS tech implant (internal step with no tapering) has more benefits than the other design of internally connected implants. 연구 목적: 본 연구는 3차원 유한요소분석을 통해 특징적인 내부연결구조를 갖는 5종의 임플란트의 고정체와 지대주의 연결방식에 따른 응력분산을 알아보고자 하였다. 연구 재료 및 방법: 본 실험을 위한 유한요소모델은 하악 제1대구치부에 임플란트가 식립되고 상부구조물로 3형 금합금을 사용하는 것으로 가정하였다. 응력분산은 200 N의 하중이 교합면의 중심, 중심에 1.5 mm 외측, 중심에서 3.0 mm 외측에 수직으로 가해지고 임플란트의 장축과 30º의 각도로 경사하중이 가해지도록 하여 분석하였다. 유한요소모델에 대한 해석작업은 3G.Author (PlassoTech, California, USA)를 사용하여 이뤄졌다. 결과: 경사가 없는 내부계단 구조를 가지는 DAS tech의 임플란트의 경우, 내부연결구조를 갖는 다른 임플란트에 더 유리한 응력분산을 보였다. 하중이 임플란트 고정체의 외형선 이내에 가해지는 경우와 비교하여 외형선 바깥이나 경사력으로 전해지는 경우 더 높은 응력을 보였으며 하중조건과 관계없이 임플란트 고정체보다는 지대주에 더 큰 응력이 집중되었다. 결론: 교합력이 가해졌을 때 응력분산은 임플란트의 연결부의 형태와 하중이 가해지는 위치에 따라 달라졌으며 내부계단 구조를 가지는 DAS tech의 임플란트를 사용한 경우와 고정체의 외형선 이내에 하중이 가해졌을 경우에 더 유리한 응력분산을 보였다.

Stainless steel crown 순면위에 레진피복을 이용한 전치부 심미적 수복

안수현,김재곤,백병주,박종하 大韓小兒齒科學會 1997 大韓小兒齒科學會誌 Vol.24 No.4

Despite dentistry's attempts to improve the dental health of the public and to minimize the effects of caries, many children still present with extensive destruction of primary anterior teeth. One of dentistry's most challenging tasks is to repair these teeth with restoration which are durable, retentive, and esthetic. Esthetic restoration can often be achieved with polycarbonate crowns, strip crowns, conventional S-S crowns, open-faced S-S crowns, commercially veneered S-S crowns. But, all of these have limitation. Advances in restorative materials and metal-bonding procedures have made possible new restorative techniques that combine the advantages of S-S crowns with the cosmetics of composite restoration methods. The described technique of bonding composite to trimmed and fitted S-S crowns offers many advantages over other techniques currently used to restore primary anterior teeth. 1. If S-S crowns are accurate trimmed and contoured, good retention of crowns is achieved. 2. The patient time required is similar to that of conventional S-S crowns. 3. Good esthetics and high bond strengths are achieved. 4. It is possible to use this veneering technique intraorally on crowns that have fractured veneers.

Habermas에 있어서 解放의 意味

文顯丙 新羅大學校 1986 論文集 Vol.21 No.-

This study aims to illustrate the meaning of emancipation in Habermas`s thought. In order to construct an adequate model for critical social theory Habermas introduced the theory of cognitive interests which intrinsically connected with anthropologially deepseated systems of action. In them the emancipatory interest takes us to the center of Habermas`s thought. This emancipatory interest or interest in emancipation, according to Habermas, which is invested in the self-formative process of the species and penneates the movement of reflection, aims at realizing those conditions of symbolic interaction and instrumental action, and to this extent, it corresponds to or guides the critical and selfreflective sciences. In this way critical theory pursues self-reflection out of an interest in emancipation. Futhermore Habermas claims that ultimately a radicalized critique of knowledge can only be carried out in the form of a reconstruction of the history of the species. Thus Habermas wanted to reconstruct the historical materialism. Habermas organizes his discussion of historical materialism around two basic concepts-and two basic assumptions-the theory of base and superstructure and the dialectic of forces and relations of production. But through his analysis of society Habermas supposes that all previous history has been a history of distorted communication. Such a claim ultimately only be justified through a general theory of language, a theory of language which would have to be a theory of undistorted as well as of distorted communication. In this respect Habermas established the theory of communicative competence and universal pragmatics. The task of universal pragmatics is to identifiy and reconstruct universal conditions of possible understanding. With the achievement of that task Habermas presents an ideal speech situation which could make possible mutually validity claims. In spite of such a project of Habermas, however, his critical theory has some problems which fundamentally to be criticized.

브라켓 간접부착술식시 레진 베이스의 표면처리가 전단결합강도에 미치는 영향

임병철,황현식 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.5

본 연구는 브라켓 간접부착식시 레진 베이스의 표면처리에 따른 전단결합강도와 파절양상을 비교함으로써 레진 베이스 표면처리의 효과를 평가해 보기 위하여 시행되었다. 소의 하악 중절치를 포매하여 만든 90개 시편의 석고모형에 광중합형 레진 접착제를 이용하여 금속 브라켓을 위치시킨 후 대조군은 표면처리하지 않은 반면 실험군은 레진 베이스를 Plastic Conditioner와 sandblasting으로 각각 표면처리하여 시편에 옮겨 부착한 다음 만능물성 시험기를 이용하여 전단결합강도를 측정하고, 파절양상을 관찰하여 다음과 같은 결과를 얻었다. 1. 레진 베이스를 표면처리하지 않은 경우에 비하여 Plastic Conditioner와 sandblasting으로 각각 처리한 경우 평균 전단결합강도가 높게 나타났으며 통계적으로 유의한 차이를 보였다. 2.Plastic Conditioner로 처리한 군과 sandblasting으로 처리한 군 간의 전단결합강도는 통계적 유의차를 보이지 않았다. 3. 각 군의 파절양상을 접착제 잔류지수를 통하여 비교 관찰한 결과 세 군 간에 통계적 유의차를 보이지 않았다. 4. 전단결합강도와 접착제 잔류지수 간의 상관검정 결과 전단결합강도가 높은 경우 레진 베이스와 브라켓 경계부에서의 파절이 빈번한 경향을 보였으나 그 통계적 유의성은 보이지 않았다. 이상의 실험결과는 브라켓 간접부착술식에서 결합강도 증가를 위하여 레진 베이스의 표면처리가 필요함을 시사하였다. The purpose of this study was to evaluate the effects of the surface treatments of resin bases in indirect bracket bonding technique by study of shear bond strengths and failure patterns. Ninety metal brackets were bonded to the stone models of specimens involving bovine lower incisor with light-cured adhesive(Light-Bond). After removal of brackets with the resin base from the stone models, the surfaces of resin bases in thirty brackets were treated with Plastic Conditioner and the surfaces of resin bases in another thirty brackets were treated with sandblaster and remaining thirty brackets were served as controls. All brackets were transferred to the specimens and bonded using sealant. The shear bond strength was tested on universal testing machine, and failure pattern was assessed with the adhesive remnant index(ARI). The results were as follows: 1. Surface treatments of resin bases with Plastic Conditioner or sandblasting showed statistically higher shear bond strengths than no treatment group. 2. No significant difference in shear bond strength was found between Plastic Conditioner treatment and sandblasting treatment groups. 3. No significant difference in ARI scores was found among the three groups. 4. As the result of correlation analysis between shear bond strength and ARI scores, failure at adhesive/bracket base interface tends to increase when the shear bond strength was high, but it was not significant statistically. The above results suggest that improvement of bond strength can be obtained by surface treatment of resin base in the indirect bonding technique.

브라켓 간접부착술식시 레진 베이스의 표면처리가 진단결합강도에 미치는 영향

임병철,황현식 전남대학교 치과대학 1998 전남치대논문집 Vol.10 No.1

The purpose of this study was to evaluate the effects of the surface treatments of resin bases in indirect bracket bonding technique by study of shear bond strengths and failure patterns. Ninety metal brackets were bonded to the stone models of specimens involving bovine lower incisor with light-cured adhesive(Light-Bond). After removal of brackets with the resin base from the stone models, the surfaces of resin bases in thirty brackets were treated with Plastic Conditioner and the surfaces of resin bases in another thirty brackets were treated with sandblaster and the remaining thirty brackets were served as controls. All brackets were transferred to the specimens and bonded using sealant. The shear bond strength was tested on universal testing machine, and failure pattern was assessed with the adhesive remnant index(ARI). The results were as follows: 1. Surface treatments of resin bases with Plastic Conditioner or sandblasting showed statistically higher shear bond strengths than no treatment group. 2. No significant difference in shear bond strength was found between Plastic Conditioner treatment and sandblasting treatment groups. 3. No significant difference in ARI scores was found among the three groups. 4. As the result of correlation analysis between shear bond strengths and ARI scores, failure at adhesive/bracket base interface tends to increase when the shear bond strength was high, but it was not significant statistically. The above results suggest that improvement of bond strength can be obtained by surface treatment of resin base in the indirect bonding technique.

소아에서 발생한 비치성 양성종양에 관한 임상적 연구

백병주,김문현,김재곤,허선,김영신 大韓小兒齒科學會 1998 大韓小兒齒科學會誌 Vol.25 No.2

Non-odontogenic tumors can be classified as malignant or benign. Most oral tumors in children are benign. In the Belfact series only 7.5 percent of soft tissue tumors were malignant and Bhaskar(1963) found only 9 percent of 293 oral tumors of all kinds to be malignant. Benign tumors may be classified as epithelial and mesenchymal. The most common tumor of surface epithelium is the squamous papilloma. These are easily recgnized clinically as cauliflower-like lesions. Fibrous lesions are very common in children's mouths. Many of these are not true neoplasms but are related to fibrous hyperplasia. Another common oral tumor in children is angiomatous tumor. Hemangioma occurred more frequently than lymphangioma. Cy stic hygroma, a cystic subtype of lymphangioma, is a developmental tumor of lymphatic origin. It is a considered to be a relatively rare lesion. about 50 precent of cystic hygroma are present at birth, and most of the remaining 50 percent appear in the early years of life during the period of active lymphatic growth. The preferred treatment for these lesions, except for hemangioma, is complete surgical excision. With proper surgical techniques, recurrence is not expected.

산부식전 소와 열구 처리법에 따른 치면 열구 전색재의 변연 봉쇄성에 관한 연구

安帥炫,金秀也,白秉周 全北大學校 齒醫學硏究所 1993 전북치대논문집 Vol.11 No.1

The purpose of this study was to evaluate the marginal sealing of pit & fissure sealant according to the treatment of pit & fissure prior to acid etching in permanent premolar & molar. 20 premolars & 30 molars were used for experiment. They were classified into 5 experimental group at random : Group 1 was not treatment and Group 2, 3, 4, 5 were respectively treatment with pumice, small round steel bur of low speed handpiece, pointed diamond bur of high speed handpiece, Murakami R.I. No. 1-2. All the specimens were then thermocycled in a range of 4℃∼54℃ and immersed in 2% methylene blue dye solution for 24 hours and sectioned with low speed diamond cutter into two part under water condition. All the specimens were observed at pit & fissure-sealant interface with light microscope & statistical analysis was performed. The obtained results were as follows ; 1. There were significant increase in marginal sealing of high speed handipiece-pointed diamond bur group in contrast to pumice group at significant level α=0.05 when compared by dye penetration score(P<0.05). 2. There were significant increase in marginal sealing of low speed handpiece-small round steel bur group, high speed handpiece-pointed diamond bur group and Murakami R.I. No 1-2 group in contrast to pumice group at significant level α=0.01 when compared by dye penetration score(p<0.01.) 3. There were significant increase in marginal sealing of low speed handpiece-small round steel bur group, high speed handpiece pointed diamond bur group and Murakami R.I. No. 1-2 group in contrast to pumice bur group and Murakami R.I. No. 1-2 group in contrast to pumice group at significant level α=0.01 when compared by dye penetration length(p<0.01). 4. When compared by dye penetration score, it is lowest in high speed handpiece-pointed diamond bur group and lower in low speed handpiece-small round steel bur group, Murakami R.I. No. 1-2 group, pumice group, no treatment group in sequence. 5. There were better penetration force of pit and fissure sealant in low speed handpiece-small round steel bur group and high speed hdndpiece-pointed diamond bur group than no treatment group, pumice group and Murakami R.I. No. 1-2 group.

批判理論에 있어서 哲學의 機能

文顯丙 新羅大學校 1985 論文集 Vol.19 No.-

To speak of Critical Theory as a systematically elaborated account of social reality is possible only by understanding the concept of critique in Critical Theory. The concept of Critical Theory derives from the traditions of Kantian critical philosophy and of Marxian critique of ideology. But the concept of Critical Theory is not on the same level with such traditions. Thus it is necessary to draw an exact line not only between the meaning of critique in such traditions and in Critical Theory, but also between traditional theory and Critical Theory. In this respect Horkheimer for the first time, Adorno, Marcuse, and Habermas engaged in a detailed critique both of the objects of traditional scientific theory and of its method. The task of Critical Theory, especially according to Horkheimer, is to penetrate the world of things to show underlying relations between persons, and to see the human bottom of nonhuman things and to demystify the surface forms of equality. Consequently the social function of philosophy lies in the criticism of what is prevalent. This study was written for the purpose of describing the function of philosophy in Critical Theory as mentioned above.

Video-on-Demand 시스템에 관한 연구

안현석,최병석 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-

VOD (Video on Demand) service, is a kind of multimedia services which provides the transfer of digitally compressed and encoded video information from a server to a client. Since the various multimedia services such as distance education, news on demand, and games, can be deployed over VOD network, the VOD service play the key role for the multimedia services in the future. Emerging the video compression technology and broadband network, the VOD service and be realizing in the near future. In this paper, we discuss the system elements of VOD system and the features of VOD system using ATM network.

現代社會에 있어서의 公開性回復의 問題 : Remarks on Habermas' Critical Theory Habermas의 社會批判理論을 中心으로

文顯丙 新羅大學校 1984 論文集 Vol.16 No.-

Habermas investigated two tendencies of development which are characteristic of advanced capitalism with a view to the depoliticization of the public. He referred in the first place to the cumulative grouwth, on the part of the state, of interventionist activity which is designed to secure the stability and growth of the economic system; and secondly, the growing interdependence of research, technology, and governmental administration, which has converted the system of the sciences into a primary force of production. As a result of these tendencies following problems are occurred. on the one hand, the priorities set under economic imperatives cannot be allowed to depend on a general discursive formation of the public will, therefore politics today assumes the appearance of technocracy. On the other hand, the exclusion of consequential practial questions from dissussion by depoliticized public becomes increasingly difficult. In this regard Habermas was to seek the recovery of 「Offentlichkeit」in contemporary society which was systematically distorted by the rationally goal-directed organization of means and invisible compulsion. Thus Habermas aimed to reconstruct the ideal speech situation and developed the thesis that anyone acting communicatively must, in performing any spech action, raise universal validity claims and suppose that they can be vindicated. Consequently in spite of his superiority which claim for the emancipation from domain and suppression, the conclusion of Habermas' Critical Theory is too ideal to be realized in actuality.