단계별 광중합 방식이 복합레진 수복물의 수축 응력과 변연 접합도에 미치는 영향

박종휘,이난영,이상호 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.2

본 연구는 단계별 광중합 방법이 복합레진의 중합 및 수축 응력에 미치는 효과를 비교, 평가하고자 자연치를 대상으로 와동을 형성하고 할로겐 광중합기와 LED 광중합기의 통법에 의한 연속 조사 및 단계별 조사법으로 각각 복합레진을 중합시킨 후 수축 응력을 측정하고 주사전자현미경을 통해 수복물과 와동의 계면부에서 접착 상태를 관찰하여 다음과 같은 결과를 얻었다. 1. 모든 군에서 광중합 직후에는 일시적으로 팽창되었다가 초기에는 급격한 수축 응력의 증가를 보였고 시간이 경과될수록 수축 응력의 증가가 완만해지는 경향을 보였다(P<0.05). 2. 동일한 광조사 군내에서는 hybrid형인 Filtek Z-250™군보다는 flowable형인 Filtex flow™군이 더 적은 수축 응력을 보였다. 3. Filtek Z-250™군에서는 LED 단계별 조사군이 수축 응력이 가장 적게 나타났다.(P<0.05). 4. Filtek flow™군 역시 LED 단계별 조사군이 수축 응력이 가장 작게 나타났으나(P<005) Filtek Z-250군에서와 같이 다른 조사군에 비해 많은 차이를 보여주지는 못했다. 5. 주사전자현미경으로 관찰한 복합레진과 와동벽과의 접합 상태는 긴밀한 상태를 보였으나 LED 조사군에서 일부 틈이 관찰되었다. 이상의 결과를 종합해 보면 hybrid형 복합레진의 경우 단계별 중합방식을 사용할 경우 단일광도의 중합방식에 비해 수축응력을 감소시킬 수 있고 적절한 변연 적합상태를 유지시킴으로써 임상적으로 고광도 LED 광중합기의 경우 단계별 중합방식의 사용이 유리하다고 사료된다. The purpose of this study was to inverstigate the effect of step-curing mode on polymerization shrinkage and contraction of composite resion restoration. Class I cavities were prepared on the extracted human premolars. The cavities were filled with Filtek Z-250™(hybrid resin, 3M ESPE, USA) and Filtek flow™(flowable resin, 3M ESPE, USA) and cured with one of the following irradiation modes; Halogen 40sec with continuous curing, LED 10sec with continuous curing, and LED 13sec with step-curing. Contraction stress was measured with strain gauge which was connected to TML Datalogger™(TDS-102, SOKKI, Japan) and resion-dentin interfaces were observed by scanning electron microscope. The results of present study can be summarized as follows: 1. Composite resion restoration showed transient expansion just after irradiation of curing light. Contraction stress was increased rapidly at the early phase of polymerization and reduced slowly as time elapsed(P<0.05). 2. Filtek flow™ showed lower contraction stress than Filtek Z-250™ regardless of curing modes. 3. LED step-curing mode showed lowest contraction stress in Filtek Z-250™ compared with other curing modes(P<0.05). 4. LED step-curing mode showed lowest contraction stress in Filtek flow™ compared with other curing modes(P<0.05), but difference in contraction stress was not go greate as in Filtek Z-250™. 5. Polymerization of composite resion by LED light with step-curing mode and halogen light with continuous mode resulted in better marginal sealing than LED light with continuous mode.

9세 소아에서 나타난 비구개낭의 치험례 : CASE REPORT

이상호,모경희,박종휘,이난영,이창섭,윤정훈 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.3

비구개낭은 절치관낭이라고도 불리우며 가장 흔한 비치성낭이다. 발육성으로 비구개관내에서 태생 상피잔사가 증식하여 낭변성을 일으킴으로써 발생한다. 비구개낭은 악골낭의 약 1.7-11.9%를 차지하며 남자에게서 약 3배 정도 호발한다. 연령분포는 매우 광범위하나 대개 40대에서 60대 사이에서 발견되며 10세 이전에 발견되는 경우는 매우 드물다. 비구개낭을 위한 적절한 치료는 적출이며 비구개신경에 손상을 가하지 않도록 해야 한다. 낭이 커서 치아의 생활력에 영향을 주거나 비구강누공이나 구강 상악동 누공을 형성할 우려가 있을 경우에는 조대술로 치료할 수 있다. 본 증례의 환아는 구개부의 무통성 종창을 주소로 내원하여 임상 및 방사선 검사를 실시한 결과 소아에서 매우 드물게 나타나는 비구개낭으로 방사선사진에 32×25.5mm크기를 나타내었으며, 매우 팽창되어 순측 피질골판을 관통하고 상순소대 하방과 전정부위까지 종창되어 있었다. 병소와 인접한 상악 4전치 치근은 심하게 이개되어 있었다. 낭의 크기가 매우 커서 조대술을 시행하였으며 obturator를 장착하고 있으며 향후 계속 관찰이 요한다. Nasopalatine duct cyst(NPDC) is the most common non-odontogenic cyst in the oral area and is thought to be originated from the epithelial remnants of the nasopalatine duct. Many etiologic factors have been proposed for the NPDC; trauma to the region during mastication of from ill fitting dentures, bacterial infection, and spontanious proliferation of tissue. The majority of cases are seen between the ages of 40th and 60th and it is rare in children. Surgical enucleation is the recommended treatment for NPDC, usually under general anaesthesia. A 9-year-old boy was refered to the chosun university pedodontics clinic that this child who has anterior palatal swelling is in routine check. In this case, swelling was presented at the bottom of the anterior nasal cavity as well as in the labial aspect of the upper alveolar ridge. It was so large that we treated it by marsupialization and obturator was put. This patient is on the continuous observation. We treated the child who had NPDC by marsupialization, and got the successful results such as rapid bone regeneration and the consistency of incisor vitality.

葡萄汁加酸棗仁湯의 스트레스 해소효과에 대한 臨床的 硏究

李仲徽,崔昇勳,吳旼錫,김재식,윤상원 대전대학교 한의학연구소 2003 한의학연구소 논문집 Vol.12 No.1

Clinical studies were carried out 29 cases through administration of Sanjointang added Grape Juice(ST+GJ) from December 1st 2002 to December 30th 2002. The results were summarized as follows; 1. There were significant decreases in physical symptoms of fatigue from 4.34±2.70 to 2.34±1.78 by administration of ST+GJ. 2. There were significant decreases in mental symptoms of fatigue from 5.10±2.74 to 3.76±2.23 by administration of ST+GJ. 3. There were significant decreases in neuro-sensory symptoms of fatigue from 3.66±2.13 to 2.69±2.07 by administration of ST+GJ. 4. There were significant decreases in total subjective symptoms of fatigue from 13.14±6.18 to 8.79±4.63 by administration of ST+GJ. 5. There were significant decreases in VAS of fatigue ratio, but not significant changes in VAS of concentration ratio by administration of ST+GJ. According to the results, we could suggest that ST+GJ is able to be applied to the relaxion of stress.

경부 낭성종양의 전산화 단층촬영 소견 : 선천성 낭종을 중심으로 Congenital Cystic Masses

이연희,성기준,김영주,김명순,홍인수,조휘율,김응조 최신의학사 1991 最新醫學 Vol.34 No.11

각종 치과레이저의 Streptococcus mutans에 대한 증식 기능억제 효과

한강석,국중기,유소영,김화숙,박종휘,박현동,이상훈 大韓小兒齒科學會 2003 大韓小兒齒科學會誌 Vol.30 No.3

레이저의 구강내 산 생성 세균인 S. mutans에 대한 증식 및 기능 억제효과를 평가하기 위하여 S. mutans KCTC 3065가 포함된 세균 pellet에 Er:YAG 레이저와 Nd:YAG 레이저를 비접촉식 방법으로, 조사세기 50mJ, 조사시간 5초, 그리고 pulse repetition rate를 각각 10Hz와 30Hz로 하여 조사하고 세균 군락수, 산 생성능, 불용성 세포외다당류의 합성량을 측정하여 다음과 같은 결과를 얻었다. 1. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 S. mutans의 증식을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 증식을 억제하였다. Chinese ink를 사용하지 않고 ND:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 증식을 억제하지 못하였다. 2. Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우가 일정기간 동안 S. mutans의 산생성능을 가장 많이 억제하였으며 Er:YAG 레이저 조사도 산 생성능을 억제하였다. Chinese ink를 사용하지 않고 Nd:YAG 레이저를 단독으로 조사한 경우는 S. mutans의 산 생성능을 억제하지 못하였다. Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후 Nd:YAG 레이저를 조사한 경우는 pulse repetition rate가 클수록 전반적으로 세균의 산생성능을 더 많이 억제하였다. 3. 레이저 조사는 S. mutans의 불용성 세포외다당류의 합성에 영향을 미치지 못하였다. 이상의 결과로 보아 Er:YAG 레이저와 Chinese ink로 photosensitization을 시행한 후의 Nd:YAG 레이저 조사는 일정시간 동안 S. mutans의 증식과 산 생성능을 억제시키므로써 치아우식증 예방효과를 얻을 수 있다고 사료되나 억제효과가 오래가지 않아 임상적으로 효과를 얻기 위해서는 자주 조사를 해주어야 한다는 문제점을 안고 있어 임상적으로 치아우식증 예방이란 단독 목적으로 사용하기에는 실용성이 크지 않다고 사료된다. This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd:YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiatioin of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prenent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.

A Direction of the 21st Century Distance Education for the Gifted: Case of the KAIST Education Center for the Scientifically Gifted

Sung Min Bae,Jae Heon Park,Whi Kang Kim,Sang Chan Park,Koon Hyun Lee 한국스쿨넷학회 1998 학술발표 논문집 Vol.1998 No.1

Bank Mergers and Acquisitions: The Use of Collar Offers and Lockup Options

Sang Whi Lee 한국무역학회 2008 Journal of Korea trade Vol.12 No.1

As finance literature suggests, an option is valuable. The major finding of this study is that lockup options and collar offers in bank merger transactions are important terms in determining the bid premiums offered to the target, after controlling for the salient financial and deal-specific variables. The findings are somewhat consistent with Burch (2001) and Fuller (2003). This paper also finds that synergy is positively related to merger premiums, but the effect is significant only in intrastate mergers when large banks takeover relatively smaller banks. The structure of the deal (pooling vs. purchase) and the credit quality of the target bank s portfolio seems to affect the target s value in bank takeover markets.

The Maturity of Syndicated Loans Originated in Japan

Sang Whi Lee 한국무역학회 2006 Journal of Korea trade Vol.10 No.1

I estimated a model that addresses the maturity of syndicated loans originated in Japan, employing a sample of 126 facilities. I found a negative relationship between maturity and the existence of credit rating and loan size, consistent with the Diamond s (1991b) liquidity risk hypothesis that firms that face potential inefficient liquidation lengthen the maturity of their debt. I also found evidence that the national identity of the arranging bank influences the maturity of syndicated loans. As the arranging bank is a local (i.e. Japanese) bank, its maturity is lengthened. I also found that loan maturity increases with the number of lenders within a syndicate, implying that Japanese borrowers prefer to have longer-term loans when the prospect for loan re-negotiability is reduced. Finally, I found that loan type and loan purpose influence the loan maturity.

Arterial stiffness in patients with cilostazole after percutaneous coronary intervention (초)

( Sang Young Cho ),( Kye Hwan Kim ),( Ji Hyun Min ),( Jong Hwa Ahn ),( Eun Ju Lee ),( Yong Whi Park ),( Choong Hwan Kwak ),( Jin Yong Hwang ),( Jeong Rang Park ) 대한내과학회 2012 대한내과학회 추계학술대회 Vol.2012 No.1

Reduction of adult hippocampal neurogenesis is amplified by aluminum exposure in a model of type 2 diabetes

Sung Min Nam,Jong Whi Kim,Daeyoung Yoon,Hyo Young Jung,최정훈,In Koo Hwang,Je Kyung Seong,Yeo Sung Yoon 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.1

In the present study, we investigated the effects of chronic aluminum (Al) exposure for 10 weeks on cell proliferation and neuroblast differentiation in the hippocampus of type 2 diabetic rats. Six-week-old Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were selected and randomly divided into Al- and non-Al-groups. Al was administered via drinking water for 10 weeks, after which the animals were sacrificed at 16 weeks of age. ZDF rats in both Al- and non-Al-groups showed increases in body weight and blood glucose levels compared to ZLC rats. Al exposure did not significantly affect body weight, blood glucose levels or pancreatic b-cells and morphology of the pancreas in either ZLC or ZDF rats. However, exposure to Al reduced cell proliferation and neuroblast differentiation in both ZLC and ZDF rats. Exposure to Al resulted in poor development of the dendritic processes of neuroblasts in both ZLC and ZDF rats. Furthermore, onset and continuation of diabetes reduced cell proliferation and neuroblast differentiation, and Al exposure amplified reduction of these parameters. These results suggest that Al exposure via drinking water aggravates the impairment in hippocampal neurogenesis that is typically observed in type 2 diabetic animals.