The Influence of AH-26 and Zinc Oxide-Eugenol Root Canal Sealer on the Shear Bond Strength of Composite Resin to Dentin

Cho, Ju-Yeon,Jin, Myoung-Uk,Kim, Young-Kyung,Kim, Sung Kyo 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.3

AH-26 근관실러가 상아질에 대한 복합레진의 전단결합강도에 미치는 영향을 평가하기 위하여 144개의 발거된 대구치를 실린더형의 몰드에 매식한 다음 치관부의 상아질 표면을 노출시킨 후 편평하게 연마하고 AH-26을 도포한 군, ZOE paste를 도포한 군 및 실러를 도포하지 않은 대조군으로 나누어 One-step 상아질 접착제를 처리한 후에 Charisma (Heraeus Kulzer, Germany) 복합레진을 적용하고 광중합시켰다. 시편을 분리하여 37℃ 항온조에 24시간 보관후 Instron test machine (Model 4202, Instron Corp., USA)을 이용하여 시편의 전단 결합 강도를 측정하고 one-way ANOVA 및 Tukey's studentized rank test로 통계 분석하였다. AH-26 근관실러로 처리한 군과 대조군은 ZOE 근관실러 처리군에 비해 유의하게 놓은 접착강도를 나타내었다 (p<0.05). AH-26 근관실러 처리군과 아무 처리하지 않은 대조군 사이에는 결합강도에 있어 유의한 차이를 나타내지 않았다 (p>0.05). 본 연구의 조건에서는 ZOE 근관실러는 상아질에 대한 복합레진의 전단결합강도를 저하시키는 반면 AH-26 근관실러는 유의한 영향을 미치지는 않는 것으로 보인다. 따라서 임상에서 근관실러로 AH-26을 사용한 근관충전 후에는 즉시 복합레진 코어를 해 주어도 결합력에 저해가 없을 것으로 여겨진다. The purpose of this study was to evaluate the influence of the AH-26 root canal sealer on the shear bond strength of composite resin to dentin. One hundred and forty four (144) extracted, sound human molars were used. After embedding in a cylindrical mold, the occlusal part of the anatomical crown was cut away and trimmed in order to create a flat dentin surface. The teeth were randomly divided into three groups; the AH-26 sealer was applied to the AH-26 group, and zinc-oxide eugenol (ZOE) paste was applied to the ZOE group. The dentin surface of the control group did not receive any sealer. A mount jig was placed against the surface of the teeth and the One-step dentin bonding agent was applied after acid etching. Charisma composite resin was packed into the mold and light cured. After polymerization, the alignment tube and mold were removed and the specimens were placed in distilled water at 37℃ for twenty four hours. The shear bond strength was measured by an Instron testing machine. The data for each group were subjected to one-way ANOVA and Tukey's studentized rank test so as to make comparisons between the groups. The AH-26 group and the control group showed significantly higher shear bond strength than the ZOE group (p<0.05). There were no significant differences between the AH-26 group and the control one (p>0.05). Under the conditions of this study, the AH-26 root canal sealer did not seem to affect the shear bond strength of the composite resin to dentin while the ZOE sealer did. Therefore, there may be no decrease in bond strength when the composite resin core is built up immediately after a canal filling with AH-26 as a root canal sealer.

문학,문화 : 디지털 시대 도시의 생태학적 전망

이경래 ( Kyung Lae Lee ),박규현 ( Kyou Hyun Park ),조연정 ( Yeon Jung Cho ) 경희대학교 비교문화연구소 2012 비교문화연구 Vol.26 No.-

City`s Ecological Landscape in the Digital Age Lee Kyung-Lae, Park Kyou-Hyun, Cho Yeon-Jung We all know how beautiful our wild and it`s importance to our living planet Earth. But did you realise the speed at which man himself is damaging it`s unique natural habitat. We are well on our way to destroy our forests, plants, wetlands. We are polluting our oceans and seas. This way, we`re driving numerous animal species, plant species and many others into extinction. Everyone should be aware of the importance of our natural environment. We live in the period of echocide. Why we need nature to survive and how we can deal with the environmental problems we face. This paper has the purpose to reform city`s environment. Because, Metropolis and megalopolis are the principal cause of environmental disruption. To reform the city is needed to consider digital technology in our age. In the face of economic and cultural globalization, many have argued that we live an increasingly placeless world. However, as a growing number of cities participate and compete in key marketplaces of advanced capitalism, the spectacle of the city is more than ever a significant medium of communication in its own right. In doing so, this work is focused specifically on the dimension of city`s media environment. To that end, the paper examined U-City and U-Eco city. In this study, we will introduce the study on model of U-Eco City as one way for the eco-freindly future city.

급성기 뇌경색 환자에서 화열 관련 증상과 증후의 변화에 관한 연구

곽승혁,박수경,우수경,이은찬,박주영,정우상,문상관,조기호,조승연,박성욱,고창남,Kwak, Seung-hyuk,Park, Su-kyung,Woo, Su-kyung,Lee, Eun-chan,Park, Joo-young,Jung, Woo-sang,Moon, Sang-kwan,Cho, Ki-ho,Cho, Seung-yeon,Park, Sung-wook,Ko, Ch 대한중풍순환신경학회 2011 대한중풍.순환신경학회지 Vol.12 No.1

Objective : Fire and heat related symptoms and signs are considered common in acute stage of diseases. The purpose of this study is to evaluate the occurrences and changes of fire and heat related symptoms and signs in acute cerebral infarction patients. Method & subjects : 40 acute cerebral infarction patients hospitalized in Oriental medicine hospital, Kyung-Hee University, who had examined and diagnosed 2 or 3 times based on oriental medical diagnosis were selected. We chose 23 as fire and heat related symptoms and signs from 94 diagnostic articles, and we added all those scores together of each patient. We analysed the scores of fire and heat related symptoms and signs as the time passed, and depending on oriental medical diagnosis. Result : In acute cerebral infarction patients of this study, 4 of fire and heat related symptoms and signs were took 1st, 2nd, 4th and 8th places in most changeable 10 articles of total 94 articles. The mean score of fire and heat related symptoms and signs of all patients were decreased significantly over the 3 times of measurements. The 8 patients diagnosed as fire and heat diagnosis at visit1 were samely diagnosed as fire and heat diagnosis at visit2, and at visit3 5 patients of them except for 3 patients excluded between visit2 and visit3, were still diagnosed as fire and heat diagnosis. At all of 3 measuring times, the scores of fire and heat related symptoms and signs of fire and heat diagnosis group were higher than non-fire and heat diagnosis group. Conclusion : This study indicated that fire and heat related symptoms and signs were very changeable phenomenon in acute cerebral infarction patients. And they decreased as time goes on.

FDTD Modeling for the Accurate Electromagnetic Wave Analysis of Graphene

Yeon‑Hwa Kim,Hongjin Choi,Jeahoon Cho,Kyung‑Young Jung 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

We develop a fnite-diference time-domain (FDTD) method suitable for the electromagnetic (EM) analysis of graphene. In this work, we employ the modifed Lorentz model for dispersion modeling, the two-dimensional (2-D) sheet model for geometrical modeling, and the complex-frequency-shifted (CFS)-perfectly matched layer (PML) for the absorbing boundary condition. In specifc, the accurate complex-conjugate pole-residue (CCPR) dispersion model is frst adapted for the electrical modeling of graphene by using the robust vector ftting. Next, the CCPR parameters are converted to the modifed Lorentz parameters and then the modifed Lorentz-based dispersive FDTD formulation is used to enhance the computational efciency. In FDTD cell modeling, the 2-D sheet cells are allocated for graphene rather than the conventional FDTD cell-based modeling. Finally, CFS-PML are employed for terminating the computational domain to avoid the late-time instability. The presented FDTD approach is validated in numerical examples for graphene-based parallel plate waveguides.

보육시설 과학 특별활동 프로그램의 개발과 적용

조복희,곽혜경,한유미,양연숙,손경화 한국영유아보육학회 2003 한국영유아보육학 Vol.0 No.32

The purpose of this study was to develop early childhood science activities, which could be utilized as an extracurricular program in the day-care center. The program is based on the Constructivist theory(Piaget and Vygotsky) and the nation-wide survey data on the extracurricular programs and science activities in the day-care center. After the manuals for the program was monitored and corrected by the professionals, the application of each activities was empirically tested by the teachers in the day-care setting. The effects of the sample program(6 activities) were conducted using Tegano, Sawyers & Moran(1989)'s Scientific problem-solving scale and Lee(2001)'s Scientific attitude scale. Subject of thirty nine children were administered by the pre-test and post-test and experimental group participated the program for six weeks. The results showed that the program was effective for enhancement of scientific problem-solving ability and scientific attitude of young children in day-care setting.

증기압 멸균 소독에 의한 치과용 석고의 물성변화

김연웅,이용근,김광만,김경남,조리라,정경호 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.1

Gypsum products have potential contamination by infectious human pathogens, which could be transmitted from patient to the gypsum model via impression materials. Therefore disinfection and sterilization of gypsum products are recommended. Steam sterilization: namely autoclaving is widely available in dentistry. The aim of this study was to investigate degradation of mechanical properties for dental gypsum after steam sterilization. The effect of autoclaving on compressive strength, weight loss and dimensional accuracy of specimens of commercial die stone such as Crystal Rock(CR : Maruishi), Die Keen(DK : Columbus Dental), Resin Rock(RR : Whip Mix), Tuff Rock(TR : Talladium) were estimated, and experimental gypsums{(EP) : 0.5wt% accelerator, 0.02wt% retarder, 0.1wt% surface agent, 0.1wt% Poly Vinyl Acetate} were also measured the above properties after autoclaving. For each group, five cylindrical(6㎜ in diameter and 12㎜ long) specimens made with manufactures water:powder ratio. All specimens were dried in oven until reaching the constant mass. After dried, they were autoclaved at 121℃ for 20 minute, dried again. Compressive strength was measured before and after autoclaving using mechanical testing machine at a cross-head speed of 0.5㎜/min. The dimensional accuracy was estimated by length change of specimens with digital caliper before and after autoclaving. For statistical analysis, ANOVA Tukeys Studentized Range(HSD) test and T test were used. Compressive strength and weight were decreased in all samples after autoclaving. There is significant difference between CR, DK and RR, TR in after autoclaving(p<0.05). EP exhibited the highest compressive strength after autoclaving. The weight was significantly decreased in all group except RR after autoclaving(p<0.05). The dimensional accuracy was not significantly increased in all group except CR. As this result, we found that resin-containing dental stone is more appropriate for autoclaving in dentistry.

조직구성 수성망상증 2예

최연수,박일,죄희충,김원식,양태영,허경,안기완,정춘해 조선대학교 1993 The Medical Journal of Chosun University Vol.18 No.2

Histiocytic medullary reticulosis (HMR) is a malignant noeplastic process, with tumor cells belonging to the histiomonocytic line, and originally described by Scott and Robb-Smith in 1939 characterized by its acute onset, progression to death within a few months and its clinical features are fever, lymphadenopathy, hepatosplenomegaly, jaundice, and purpura common laboratory findings are characterized by severe anemia, leukopenia, thrombocytopenia and histologically by systemic progressive invasion of morphologically atypical histiocytes or of their precursor. 61 and 37-year-old males were admitted with camplaints of high fever and chilling sensation and were treated by cyclophosphamide, vincristine, prednison and antiobiotics, but patients all died 17 and 14 days after admission due to probably sepsis and respiratory failure.

광조사 시간에 따른 복합레진과 Ormocer의 중합수축에 관한 연구

정연정,민경산,이해형,조경모,조용범 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.4

Ormocer has organic-inorganic compound polymers. One of advantages of ormocer is reduced polymerization shrinkage. The purpose of this study was to compare the amount of contraction shrinkage of composite resins and ormocers. Additionally, the time of each material when there is no further change of contraction shrinkage was analysed. Four brands of composite resins (P-60, Surefil, Z-250 and Denfil) and two brands of ormocers (Definite and Admira) were used. 20 seconds, 40 seconds and 60 seconds of curing times were given. Contraction shrinkage of them were measured using a linometer for 80 seconds. The effect of material and curing time to contraction shrinkage at the time of 80 seconds was analysed by two-way ANOVA. The effect of time to contraction shrinkage was analysed by one-way ANOVA, and the time when there was no further change of the contraction shrinkage was analysed. The results are as follows : 1. P-60, Dfinite, Z-250 and Denfil had no further change of contraction shrinkage from the time of 20 seconds, and Surefil and Admira had no further change of contraction shrinkage from the time of 10 seconds. 2. Statistical analysis revealed volumetric shrinkage varied among material (p<0.05). No significant difference of contraction shrinkage among different curing times was found, and there was no effect of interaction between materials and curing times to contraction shrinkage. 3. Dfinite and Admira showed the statistically same contraction shrinkage with those of Z-250 and P-60, which is higher than that of Surefil and lower than that of Denfil (p<0.05).

미세 패턴에서 공정 여유도를 고려한 선폭 분석

정연운,조선영,오진경,오혜근 漢陽大學校 工學技術硏究所 1997 工學技術論文集 Vol.6 No.1

The linewidth variation with different process variables, such as exposure dose, thickness of PR, thickness of thin film, and the optical property of thin film, was studied for deep UV light and resist developed 0.25 μm isolated line pattern. We found that the PR thickness which gave minimum linewidth showed larger exposure latitude and smaller linewidth variation compared to the PR thickness which gave maximum linewidth. Thus it will provide better process latitude and smaller linewidth variation if we use this PR thickness.

급성 호흡곤란으로 내원한 성대기능이상 1례

함초롬,박경일,박혜연,황철웅,김종연,김태년,진재용,이성순 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Vocal cord dysfunction (VCD) is a respiratory disorder characterized by the abnormal adduction of the vocal cords upon inspiration, expiration, or both, leading to a diverse array of acute obstructive airway signs and symptoms (wheezing, chest tightness, shortness of breath, and cough). VCD frequently mimics or confounds asthma. Misdiagnosis as asthma has led to inappropriate treatment, most notably with high-dose corticosteroids. Mistaken for anaphylaxis or angioedema, VCD has led to intubation and tracheostomy. VCD should be suspected in patients who are treated aggressively for asthma but continue to experience dyspnea. The diagnosis of VCD is made from direct visualization of the vocal cords during an attack. Inspiratory, anterior vocal cord closure with a posterior glottic chink is seen. On pulmonary function testing, a pattern of "saw-toothing", or fluttering of the inspiratory limb, representing fluctuations in the abnormal cord motion is seen in VCD patient. Treatment includes discussion of the diagnosis with the patients, discontinuing unnecessary medications, using of a helium-oxygen mixture in acute attack. Speech therapy and psychotherapy are the mainstays of long-term treatment. Here in we report a case of VCD in company with asthma.