엔진구동형 NiTi 파일의 근관성형능력 비교

김보혜,최경규,박상혁,최기운 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.2

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using “single length”technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan’s test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time. 이 연구의 목적은 4가지 엔진구동형 NiTi 기구의 근관성형력을 비교하는 것이다. 32개의 투명레진모형을 사용하여 파일의 단면도가 S자 형태이고“single length”방법으로 근관성형을 시행하는 Mtwo와 crown-down 방법으로 근관성형을 하는 Profile, ProTaper Universal 및 K3로 근관성형을 하였다 (n = 8). 모든 근관은 한사람의 술자가 근단공 크기가 #30이 될때까지 성형하였다. 기구 사용 전과 후 근관 모양을 디지털 영상을 기록하였고, 컴퓨터 영상 분석 프로그램(Expression Scanner와 Adobe Photoshop CS)으로 평가하였다. 다음과 같은 결론을 얻었다. 근첨으로부터 1, 2, 3, 4, 5, 6, 7 mm 떨어진 부위의 내측과 외측으로 삭제된 레진 양을 측정하였고, 자료는 SPSS법으로 비교 분석하였다. 1. 근관형성 시간은 Mtwo가 84.50초로 가장 짧았으며, 총 작업시간은 K3가 269.37초로 가장 길었다(p < 0.05). 2. 기구의 변형과 파절은 모든 구동형 NiTi 파일에서 발생하지 않았다. 3. 근관 내측 폭경의 변화는 Profile이 1, 2 mm 부위를 제외한 다른 부위에서 가장 적었으며, ProTaper Universal은 모든 부위에서 가장 많았다(p < 0.05). 4. 근관 외측 폭경의 변화는 Mtwo이 1 mm 부위를 제외한 모든 부위에서 가장 적었으며, Profile은 3, 4 mm 부위에서 가장 많았다(p < 0.05). ProTaper Universal와 K3는 1, 2, 6, 7 mm 부위에서 가장 많았다(p < 0.05). 5. 근관중심변위율(centering ratio)은 Profile이 1, 4, 5, 6 mm 부위에서 가장 적었다(p < 0.05). 이상의 결과, 구동성 NiTi 파일을 이용한 만곡 근관의 근관형성은 치경부는 ProTaper와 같은 삭제력이 높은 파일을 사용하는 것이 근관 입구를 효과적으로 넓히고 더 나은 taper를 형성하며, 근단부는 Profile과 같은 근관 중심 변위가 적은 파일을 사용하는 것이 근관형성 시간을 단축하고 근단부의 근관 변형(transportation)을 줄일 수 있다고 판단된다.

Flow-Cell의 개발 및 응용: 1.2.4-Trichlorobenzene 전기화학적인 탈염소화 반응에 관한 연구

이보영,박혜옥,이인숙 서울여자대학교 자연과학연구소 2000 자연과학연구논문집 Vol.12 No.-

Polychlorinated organic pollutants such as polychlorobenzenes (PCBs) hat,·e been causing environmental problems because of their toxicity, persistence and bioaccumulation in aquatic organisms. Therefore, several methods including electrochemical techniques have been developed for degradation of PCBs. This work describes an electrolytic system for the reduction of chlorinated aromatic hydrocarbons to their parent hydrocarbon using reticulated vitreous carbon (RVC) electrodes in several electrolytes. First, for the electrolytic degradation of PCBs, a RVC electrode in DMF solution was used and stepwise dechlorination was observed. Also, degradation of mono- and di-chlorobenzens was tested for the elucidation of reaction mechanism. Results obtained from cyclicvoltammetry (CV), chronoamperometry (CA), and chronocoulometry (CC) are presented.

광중합 Glass lonomer Cement의 결합 강도에 대한 실험적 연구

김보혜,손흥규 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

The purpose of study was to compare bond strength of Light-cured Glass Ionomer Cement with those of Chemically-cured Glass Ionomer Cement and Composite Resin to enamel and dentin surface. Each extracted molars, the buccal surfaces of which were flattened, were divided into two groups, so that 40 teeth their enamel exposed and the other 40 had their dentin exposed. The materials used were: 1) FujiⅡ LC(Light-cured Glass Ionomer Cement) 2) FujiⅡ&Shofu G.I typeⅡ(Chemically-cured Glass Iomomer Cement) 3) Silux Plus(Composite Resin) Each of the materials was applied to the exposed surface of 10 teeth by insertion into a cylindericalshaped matrix which is 3mm diameter and 2mm in height. The completed specimens were stored at 37。c under 100% humidity for 24 hours: then the shear bond strength of each material to enamel and dentin surface were measured with Instron universal testing machine. The following results were obtained: 1. Bond strength to enamel surface increased in order of Shofu G.I typeⅡ, FujiⅡ, FujiⅡLC, and Silux Plus. Statistical significance was obserbed except for Shofu G.I typeⅡ and FujiⅡ, which are chemically-cured materials(p<0.01). 2. Bond strenght to dentin surface increased in order of Shofu G.I typeⅡ, FujiⅡ, Silux Plus, FujiⅡLC. There was statistical significance(p<0.05). 3. Bond strength to enamel surface was greater than that to dentin. There was statistical significance(p<0.01). From such results, it can be concluded that when Glass Ionomer Cement is used for esthetic restoration, light-cured type, which has greater bond strenth to tooth structure, is preferred to chemically-cured type.

서울시내 일부 고등학교 학생들에서 학업성취도가 우울 증상에 미치는 영향

박혜숙,최경희,이보은 韓國學校保健學會 2001 韓國學校保健學會誌 Vol.14 No.2

Depression is one of the most common psychologic disorder and dealt as a major public health concern. School students have heavy school work loads and stress from various evaluations representing school performance. In this study, to examine the effect of school performance and stress on depressive symptoms, we assessed the frequency of risk factors for depressive symptoms among 2,717 high school students. From April 2001 to May 2001, using a self-reported questionnaire, we collected data on the frequency of occurrence of depressive symptoms and potential risk factors for depressive symptoms. Depressive symptoms were measured using Center Epidemiologlc Studies Depression (DES-D) index. Thirty-seven percent of high school students reported having high depressive symptoms for a week Female students had a higher prevalence of depressive symptoms than males (OR=1.44, 95% CI 1.22-1.70). In a multiple logistic regression model, we found that good perceived school performance (OR=0.43, 95% CI 0.31-0.60) had a negative association with depressive symptoms. On the contrary, we also found that stress from school performance (OR=2.03, 95% CI 1.69-2.44) associated with high depressive symptoms. In conclusion, high school students had a relatively high prevalence of depressive symptoms. Students with stress from school performance had the higher risk far depressive symptoms. Key words : Depression, risk factors, prevalence, performance, youths

난소 기형종에 동반된 직장후방 기형종

오보영,이령아,구혜수,문혜성 이화여자대학교 의과학연구소 2012 EMJ (Ewha medical journal) Vol.35 No.2

황사 기간 동안에 어린이, 성인, 노인에서의 자각증상과 예방행동에 대한 조사연구

이보은,하은희,박혜숙,권지숙,신경림 韓國學校保健學會 2005 韓國學校保健學會誌 Vol.18 No.1

Purpose: Recently there are scientific evidences for the health effects of Asian dust-storms. Particularly in 2002, the daily average of PM_(10) exceeded 600 and 700 ㎍/㎥ in March and April respectively. We examined the effects of Asian dust-storms on perceived symptoms and preventive behaviors among children, adults, and elders. Method: The subjects of this study were 425 children, 444 adults and 60 elders. A questionnaire survey was carried out on the children and the adults by teachers and on the elders by interviewers to obtain information on demographic variables, perceived symptoms and preventive behaviors, previous respiratory disease, environmental tobacco smoke, and proximity between the house and the road during Asian dust-storms. We analyzed using descriptive statistics, X_(2) test and multiple logistic regression models. After adjustment for potential confounders, we estimated the odds ratios and 95% confidence intervals of the children and the elders for perceived symptoms and preventive behaviors. Result: The elders had a significantly higher prevalence of respiratory symptoms than the other groups. The children had a significantly higher prevalence than the adults in getting URI (1.51), coughing (1.68), rhinorrhea (1.46), fever (2.39) and medication for allergy or asthma (1.90). The children had better behaviors than the elders in closing windows (3.57), taking less outdoor recreational activity (2.59) and staying home (2.60).

거대 자궁 근종의 1예

전혜숙,강경화,이보연,이선경,허주엽,김승보 경희대학교 2000 慶熙醫學 Vol.16 No.3-4

대학생의 취업스트레스와 자아존중감, 자아효능감, 외모관리행동의 관계

김보라,김유진,김지희,노혜진,오승희,홍지혜,황윤희,박선아 水原大學校 2016 論文集 Vol.30 No.-

Purpose: Many university students are under a lot of job-seeking stress because the employment rate is low. This study sought to determine the relationship between job-seeking stress, self esteem, self efficacy and appearance management behavior amongst university students focusing on nursing. Methods: This descriptive correlational study evaluated the relationships between job-seeking stress, self esteem, self efficacy and appearance management behavior of 340 university students was conducted between September 1 and October 5, 2015. Results: The correlational analysis between job-seeking stress, self esteem, self efficacy and appearance management behavior revealed a negative correlation between job-seeking stress, self esteem and self efficacy and a positive correlation between job-seeking stress and appearance management behavior. In addition, age also correlated with self esteem, self efficacy and appearance management behavior. Conclusion: Stress correlated with self esteem and self efficacy and appearance management behavior. Therefore job-seeking stress may be reduced through not only self esteem and self efficacy enhancement programs but also management according to age.

단기순환형 정동장애 3례

김은혜,최보문,유태열,백인호 大韓神經精神醫學會 1988 신경정신의학 Vol.27 No.4

Three cases of rapid cycling affective disorders were examined from a clinical perspective. We presented several different etiologies to the rapid cycling pattern in these patients. It was revealed that the rapid mood swings were due to natural expression of the affective disorder, tricyclic induced, lithium induced, and a combination of the aforementioned etiologies. Brief reviews on factors considered to induce rapid cycling, its etiopathogensis, clinical features and treatment strategies were also presented.

소아의 변색된 치아에서 Vital Bleaching을 이용한 치료 증례

김보혜,손흥규,이종갑 大韓小兒齒科學會 1992 大韓小兒齒科學會誌 Vol.19 No.2

Discoloration of teeth, especially maxillary incisor, that appears in various types and severties causes a major problem in esthetic aspect. The attributing factors can be classified into extrinsic and intrinsic factors : chewing tabacco, coffee, and tea are some example of the former, and intake of tetracycline, fluorosis, pulpal necrosis, iatrogenic agents, systemic condition, genetic factors, and aging process are, the latter. Treatment of a discolored vital tooth include full crown restoration, direct or indirect venner restoration, vital bleaching, and so on. Several vital bleaching techniques have been developed since Capple first introduced a bleaching case using oxalic acid in 1877. Nowadays, the technique that utilizes both hydrogen peroxide and bleaching light is most preferred. The pulpal effect of vital bleaching medicaments and lights have been controversal, but it has been also noted that 98℉~141℉, 30~35% hydrogen peroxide causes only mild reversible inflammation. In these cases, 12 and 10-year-old sisters showed generalized brown discoloration of teeth. Their primary dentitions were normal color, and there were no history of discolored teeth. The exact cause could not be found, but tooth color was improved by vital bleaching of four times. For the better esthetic results, combination therapy of repeated bleaching and veneering restoration is recommended.