• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.357-367
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• 1993

The purpose of this study was to evaluate the fracture strength of class II restored premolars with amalgam, posterior composite, amalgam - Ketac silver, resin - Ketac silver restorations at marginal ridge. Fifty extacted maxillary and mandibular premolar teeth that were caries free, fracture free, and restoration free were selected and randomly divided into five groups : Group 1 : 10 intact teeth, Group 2 : 10 teeth with class II cavities and restored with, amalgam, Group 3: 10 teeth with class II cavities and restored with posterior resin, Group 4 : 10 teeth with class II cavities and restored with amalgam - ketac silver, Group 5 : 10 teeth with class II cavities and restored with resin - Ketac silver. All teeth were mounted in base of dental stone within metal rings of 2cm diameter, exposing only the crown portion. Class II mesio - occlusal or disto - occlusal cavities were prepared into specimens of Group 2 through 5 by using a No. 710 fissure bur. The occlusal portion was prepared to a faciolingual width of 1.5mm and a pulpal depth of 1.5mm. The proximal protion was prepared to a faciolingual width of 4mm, a occlusogingival height of 4mm, and a gingival floor of 1.5mm. The teeth in Group 2 and 3 were resotored with silver amalgam apd posterior resin respectively. In Group 4 and 5, proximal portions were first filled with Ketac silver 1.5mm gingivally and remaining cavities were restored with amalgam and posterior resin respectively. All specimens were stored in 100 % relative humidity at $37^{\circ}C$ for 48 hours before testing. All teeth were subjected to a compressive load in a Universal Instron Testing Machine at marginal ridges. The loads required to fracture the restorations were recorded in killograms and the data obtained were subjected to statisticall analysis. The results were all follows : 1. The fracture strength of Group 1 which were unprepared were $100{\pm}10.1\;kg$ and the higher values than Group 2, 3, 4, 5 which were prepared and resotred. 2. In restored groups, Group 2 had the higher fracture strength($81.8{\pm}12.4\;kg$) than other groups and Group 4 had the lowest fracture strength($66.8{\pm}9.2kg$). 3. There were significant differences between fracture strength of between Group 1 and Group 3, 4, 5(P<0.05), but not significant difference between fracture strength of Group 2, 3, 4, 5(P>0.05).

• 치위생과학회지
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• 제8권4호
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• pp.375-380
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• 2008

본 연구는 초등학교 구강보건사업에 대한 유용성을 제시하고자 안양시에 소재한 B초등학교의 학교구강보건사업의 사업군과 대조군을 대상으로 구강건강상태 및 구강보건지식, 태도, 행동 그리고 이와 관련된 변수들의 연관성을 조사 분석한 바 다음과 같은 결론을 얻었다. 1. 조사 대상자의 일반적 특성에 따른 성별, 학년, 부모의 직업, 부모의 교육수준과 영구치우식경험도의 차이를 보면 성별과 학년에서 두 집단 간에 유의한 차이가 있었다(p < 0.05). 2. 학교구강보건실 구강보건사업의 사업군과 대조군의 구강보건 지식, 태도, 행동 수준을 비교해 본 결과 행동과 태도에서 두 집단 사이에 유의한 차이를 나타냈으며(p < 0.05), 지식에서는 유의한 차이가 없었다. 3. 학교구강보건실 구강보건사업의 사업군과 대조군의 구강건강인지도, 구강건강상태만족도, 구강치료필요도에 따른 차이를 비교해 본 결과 두 집단 사이에 유의한 차이가 없었다(p > 0.05). 4. 주관적 구강건강인지도, 건강상태만족도, 치료필요도, 구강보건지식, 태도, 행동, 영구치우식경험도간의 상호연관성에 대한 분석결과 구강보건에 대한 지식이 높을수록 구강보건에 대한 태도와 행동이 적극적이었으며(P < 0.01), 구강보건태도가 좋을수록 행동에 적극적이었다(p < 0.05). 5. 구강보건에 대한 태도가 양호할수록 영구치우식경험도는 낮게 조사되었으나 통계적으로 유의한 차이는 없었고(p > 0.05), 구강보건행동과 영구치우식경험도와는 약간의 음의 연관성이 있었다(p < 0.05). 6. 주관적 구강건강인지도와 구강건강상태만족도는 강한 양의 상관관계가 있었고, 영구치우식경험도가 높을수록 구강건강인지도가 낮아지는 것으로 나타났다(p < 0.05). 또한 영구치우식경험도가 높을수록 구강병치료가 필요하다고 느끼는 것으로 나타났으며, 구강보건지식이 높고 태도가 좋을수록 구강치료가 필요없다고 느끼는 것으로 나타났다(p < 0.05).

• 암석학회지
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• 제6권2호
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• pp.96-110
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• 1997

원동 칼데라의 화산작용은 화도에서 어떤 외부물과 상호작용되는 수증기마그마성 분출작용으로 시작하여 점차 물의 유입이 차단됨으로써 저플리언 분출작용으로 전환되었으며 이는 다시 회류분출로 전환되었다. 이 회류분출은 초기에는 중앙화구로부터 일어났으며 후기에는 환상 열극화구로 전환되었다. 이러한 환상 열극화구로부터 회류분출의 방출율이 급격히 커짐으로써 원동 칼데라가 형성되고 뒤이어 환상단열대를 따라 석영반암이 관입되어 환상암맥을 형성하였다. 그리고 이 칼데라 모우트에는 오랬동안 응회질 퇴적물이 채워지면서 반상유문암 용암이 초기 소생도움으로부터 분류되었으며, 환상단열대의 다른 틈을 따라 소량의 회류응회암이 분출되었다. 그리고 소생도움이 더 커지면서 세립질 화강섬록암이 관입되었으며, 마지막으로 지속적 소생작용으로 칼데라 중앙부에 각섬석 흑운모 화강암이 정치되어 완전한 소생도움을 형성하는 과정을 겪었다.

• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.107-119
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• 1990

The purpose of this study was to evaluate the marginal adaptability of the amalgam restorations in applying the cavity varnish (Copalite$^{(R)}$) and dentin bonding agent (Scotchbond 2$^{(R)}$) under the scanning electron microscope. For this study, eighteen sound extracted human molars were selected. Class I cavities in 12 teeth and class V cavities in 6 teeth were prepared using an air turbine with No. 701 tungsten carbide bur and finished using a low speed handpiece with No. 557 fissure bur. The prepared specimens were then divided into three groups including 4 class I cavities and 2 class V cavities in each group and restored as follows ; Group I. All the prepared cavities were restored with amalgam only (Control). Group II. Two layers of Copalite$^{(R)}$ cavity varnish were applied to the cavities with a gentle stream of air after each application and cavities were restored with amalgam. Group III. The enamel cavity margins were etched with 37% phosphoric acid gel for 60 sec., rinsed for 30 sec. and dried. One layer of visible lightcured Scotchbond Dental Adhesive$^{(R)}$ was applied and immediately cured for 20 seconds with visible light-cure unit and cavities were restored with amalgam. All the specimens were cut at the neck of the teeth and the occlusal halves of specimens were sectioned buccolingually in the longitudinal axis centering the amalgam restorations, using the disk. The cut specimens were ground with sandpapers (400, 600, 800, 1000 grit), and cleaned for 5 minutes in the ultrasonic cleaner (Brason Co. U.S.A.). In the cut surfaces, the amalgam - tooth interfaces were examined under the scanning electron microscope (JSM, 35C type, JEOL). The obtained results were as follows ; 1. The amalgam-tooth interfaces were reduced more significantly in the Copalite$^{(R)}$ and Scotchbond 2$^{(R)}$ application group than in the control group. 2. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed the findings similar to the Copalite$^{(R)}$ application group in the cavity floor, and the marginal adaptability was better in the side wall than in the cavity floor. 3. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed better marginal adaptability in the occlusal margin than in the gingival margin. 4. The marginal adaptability was in the order of the Scothbond 2$^{(R)}$ application group, the Copalite$^{(R)}$ application group and the control group.

• 식물분류학회지
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• 제42권2호
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• pp.141-149
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• 2012

분류학적 식별형질이 모호한 국내에 분포하는 작살나무와 좀작살나무(마편초과) 두 분류군에 대한 외부형태학적 형질 및 미세형태학 형질(잎, 약, 열매. 특히 내과피의 표면 및 구조, 화분)을 상세히 관찰하고, 기재하였다. 결과적으로 줄기 단면 윤곽, 동아 형태 및 길이, 화관 통부 길이와 열편 길이, 약의 길이와 열개유형, 내과피의 형태가 두 분류군을 구별하는데 유용한 식별형질임을 확인하였다. 특히 다음의 세 가지 형질들이 이들 분류군의 동정에 더 유용한 것으로 나타났다: (1) 작살나무의 화관통부의 길이(2.5-4.6 mm)는 좀작살나무(0.7-1.0 mm)에 비해 길고; (2) 약의 열개 유형은 작살나무가 개화기 초반에 상부의 끝에서 구멍모양으로 열개하고, 반면 좀작살나무는 개화기 시작부터 상부에서 하부까지 세로로 열개한다; 그리고 (3) 작살나무의 경우 측면에서 볼 때 내과피의 가장자리가 부분적으로 오목하고, 좀작살나무의 경우에는 편평하다. 반면에 엽연에 나타나는 거치의 위치 및 화서의 형성위치는 좋은 진단형질은 아닌 것으로 평가되었다. 추가적으로 현재까지 알려진 한국산 작살나무속 분류군의 검색표를 제시하였다.

• 대한소아치과학회지
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• 제29권1호
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• pp.69-75
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• 2002

치과치료를 위하여 마취를 시행할 때 아동들의 주사기나 주사바늘에 대한 불편감을 감소시키기 위한 여러 방법들이 있다. 도포마취제의 사용이 한 가지 방법이다. 도포마취는 많은 임상과정, 즉 주사침 자입부위, 간단한 유치발치, 구토반응이 심한 환자에서 치과용 구내 방사선 촬영시, 인상채득 전 구토반응의 감소 목적 등으로 사용되어 왔다. 또한 소아에서 치면열구전색술과 예방심미수복술시 치아격리를 위한 러버댐 clamp의 장착은 불편감을 유발할 수 있는데, 도포마취는 이런 목적으로 러버댐 장착시 도움이 된다. 모든 구강내 도포마취제는 점막에 동등한 효과가 있다고 제안되었으나, 1980년대 개발되어 피부의 표면마취에 사용되는 EMLA(acronym for eutectic mixture of local anaesthetics)가 기존의 도포마취제보다 부착치은에 사용시 더 효과가 있다고 보고되고 있다. 본 증례에서는 침윤마취가 필요한 몇 증례에서 EMLA cream을 이용하여 국소마취를 하기 전단계, 유치 발거시, clamp 장착시, 기성관 수복 등에서 동통을 감소시킴으로써 환아의 치과 치료에 대한 불안감을 감소시키는데 매우 효과적이었기에 보고하는 바이다.

• IUGG한국위원회:학술대회논문집
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• IUGG한국위원회 2003년도 정기총회 및 학술발표회
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• pp.20-20
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• 2003

In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

• Journal of Genetic Medicine
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• 제7권1호
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• pp.37-44
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• 2010

목적: Kabuki 증후군은 정신 지체를 동반하는 선천성 다발성 기형 증후군이다. 우리나라에서는 현재까지 6례의 Kabuki 증후군 증례가 산발적으로 보고 된 바 있다. 본 연구에서는 저자들이 경험한 Kabuki 증후군 환자 6명의 임상 및 유전학적 특징을 조사하고, 이를 외국 문헌들과 비교 분석해 보고자 하였다. 대상 및 방법: 2003년부터 2009년까지 아주대학교 병원 유전질환 전문센터에서 Kabuki 증후군으로 진단되어 추적 중인 6명의 한국인 여아를 대상으로 하였으며, 의무기록을 후향적으로 검토하여 이들의 임상 및 검사 소견을 수집하고 분석하였다. 결 과: 6명의 환자 모두가 특징적인 얼굴 모습 및 발달 지연 소견을 보이고 있었고, 손끝의 태아 패드 또한 모든 환자에서 확인되었다. 이외에도 대부분의 환자가 생후 성장 지연(83.3 %) 및 근력 저하(83.3%) 소견을 보였다. 안과적인 이상 또한 흔하게 동반되었는데, 특히 사시(83.3%)가 가장 흔한 안과적 이상 소견이었다. 선천성 심장 기형은 50%의 환자에서 동반되었으며, 골격계통의 증상으로는 짧거나(83.3%) 굽은(50%) 5번째 손가락, 관절의 과신전(50%) 및 고관절 탈구(16.7%) 등으로 다양하였다. Kabuki 증후군의 가족력을 가진 환자는 없었으며, 핵형 분석 및 array CGH를 포함한 세포유전학적 분석에서 Kabuki 증후군의 원인으로 생각되는 이상 소견은 발견되지 않았다. 결 론: 한국인 Kabuki 증후군 환자들이 보이는 임상 양상은 매우 광범위하며 다양한 신체 기관을 침범하고 있다. 비록 Kabuki 증후군의 임상적특징들이 비교적잘 알려져 있기는 하지만, 아직질환의 원인으로 추정되는 유전적 이상은 확실히밝혀지지 않았다. 적절한 질환의 관리및 유전상담이 이루어지기 위해서는 Kabuki 증후군의 자연 경과 및 유전적 배경에 대한 추가적인 연구가 필요하다고 생각된다.

• 한국치위생학회지
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• 제6권4호
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• pp.455-467
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• 2006

Demand for appropriate health care has gradually increased in Korea. In addition, developments of community- and school-based oral health programs have also focused oral health care for the oral health promotion. Especially, school-based oral health programs are the underpinnings of promoting oral health and preventing oral diseases among schoolchildren. School-based oral health programs have had three major components: oral health education, oral health services, and a healthful environments. These included oral health education(one-to-one communication, group communication, and use of mass communication), oral examination, fluoride mouthrinsing, pit-and-fissure sealants, fluoride gel application, mechanical plaque control, and chewing xylitol candy. In this study, we evaluate the effects of oral health programs among primary schoolchildren by comparing the oral health knowledge, oral health behaviors, and perception of caries prevention procedures. Data for this study were obtained from 699 primary schoolchildren at the two primary school in Daegu, Korea. One is experimental group, N primary school, that was established school-based oral health center under supervision of Nam-gu Public Health Center, the other is control group, N' primary school, that was yet to establish school-based oral health center. We surveyed children's oral health knowledge and behaviors, and perception of caries prevention procedures using self-administrated questionnaire and then analyzed differences of each item among two groups. The brief findings of this study were summarized as follows. There are several advantage to a comprehensive school-based oral health program. (1) School-based oral health programs facilitate and increase the effectiveness of teaching oral health subjects. (2) Schoolchildren are available for prevention or treatment procedure. (3) School-based oral health center may be less threating than private dental clinic. (4) With comprehensive school-based oral health programs the decayed, missing, and filled teeth(DMFT) of schoolchildren should demonstrate a substantial and steady decrease over time(Choi et al, 2004). In conclusion, treatment is not the answer to solving children's oral health programs; rather primary prevention is the key. Many countries and communities are focusing on hoe millions of underprivileged children can be provided with health care. Schoolchildren gain the knowledge and behaviors to attain and maintain good oral health in schools. For these reasons, the role of school-based oral health center is not only important but also a necessity.

• 한국치위생학회지
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• 제15권2호
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• pp.271-278
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• 2015

Objectives: The aim of this study was to investigate the effect of water fluoridation program(WFP) on dental caries prevention in Ulsan, Korea. Methods: The data of control group were extracted from 2012 Korean National Oral Health Survey(KNOHS). Since 1998, WFP was implemented in Ulsan. The subjects were 670 subjects including 10 to 12-years old children in 2009. The control subjects were 4,871 people in non-fluoridated metropolitan cities comparable to Ulsan. The control subjects were selected from 2012 KNOHS. A self-reported questionnaire was completed by the variables including oral health behaviors on daily frequency of toothbrushing, eating snacks and beverages. Oral health examination was carried out by two dentists who received a training in KNOHS with an inter-examiner-agreement. Caries preventive fraction was calculated by the difference of DMFT and DMFS index. The preventive effects of the WFP program were focused on gender, number of fissure sealed teeth, daily frequency of toothbrushing, eating snacks and beverages. Data were analyzed using SPSS $19.0^{(R)}$(SPSS Inc., Chicago, IL, USA) statistical package. Results: DMFT indices of 12-year-old subjects(n=670) in WFP and control population(n=4,871) were 2.11 and 1.23, respectively with an estimated prevention effect of 41.7%. Conclusions: WFP in Ulsan reduced the prevalence of dental caries. WFP should be recommended for the public oral health program in other metropolitan cities.