1.Microleakage and water stability of resin cements.
Sun Young CHOI ; Sun Hyung LEE ; Jae Ho YANG ; Jung Suk HAN
The Journal of Korean Academy of Prosthodontics 2003;41(3):369-378
STATEMENT OF PROBLEM: Recently, resin cements have become more widely used and have been accepted as prominent luting cements. Current resin cements exhibit less microleakage than conventional luting cements. However, the constant contact with water and exposure to occlusal forces increase microleakage even in resin cements inevitably. Most bonding resins have been modified to contain a hydrophilic resin such as 2-hydroxyethylmethacrylate (HEMA) to overcome some of the problems associated with the hydrophobic nature of bonding resins. By virtue of these modifications, bonding resins absorb a significant amount of water, and there may also be significant stresses at bonding interfaces, which may adversely affect the longevity of restorations. Therefore the reinforcement of water stability of resin cement is indispensable in future study. PURPOSE: This study was conducted to examine the influence of water retention on microleakage of two resin cements over the period of 6 months. MATERIALS AND METHODS: 32 ex acted human teeth were used to test the microleakage of a single full veneer crown. Two resin cements with different components and adhesive properties - Panavia F (Kuraray Co., Osaka, Japan) and Super-Bond C&B (Sun Medical Co., Kyoto, Japan)- were investigated. The storage medium was the physiological saline solution changed every week for 1 month, 3 months, and 6 months. One group was tested after storage for 1 day. At the end of the each storage period, all specimens were exposed to thermocycling from 5.C to 55.C of 500 cycles and chewing simulation of 50,000 cycles, and then stained with 50% silver nitrate solution. The linear penetration of microleakage was measured using a stereoscopic microscope at x 40 magnification and a digital traveling micrometer with an accuracy of +/-3 um. Values were analyzed using two-way ANOVA test, Duncan's multiple range tests (DMRT). RESULTS: Statistically significant difference of microleakage was shown in the 3-month group compared with the 1-day or 1-month group in bot systems (p<0.05) and there were statistically significant differences in microleakage between the 3-month group and the 6-month group in both systems (p<0.05). The two systems showed different tendency in the course of increased microleakage during 3 months. In Panavia F, microleakage increased slowly throughout the periods. In Super-Bond C&B, there was no significant increase of microleakage for 1 month, but there was statistically significant increase of microleakage for the next 2 months. For the mean microleakage for each period, in the 3-month group, microleakage of Super-Bond C&B was significantly greater than that of Panavia F. On the other hand, in the 6-month group, microleakage of Panavia F was significantly greater than that of Super-Bond C&B (p<0.05). CONCLUSION: Within the limitation of this study, water retention of two different bonding systems influence microleakage of resin cements. Further studies with the longer observation periods in viro are required in order to investigate water stabilty and the bonding durability of the resin cement.
Adhesives
;
Bite Force
;
Crowns
;
Hand
;
Humans
;
Longevity
;
Mastication
;
Resin Cements*
;
Silver Nitrate
;
Sodium Chloride
;
Tooth
;
Virtues
;
Water*
2.Intramuscular Lipoma of the Frontalis Muscle.
Yoon Sun CHUN ; Kyeong Han YOON ; Hyun Joo CHOI ; Lee Sun KIM
Annals of Dermatology 1999;11(2):98-100
Intramuscular lipomas are benign soft-tissue mesenchymal tumors which rarely occur in the region of the head. These tumors present as slow-growing, generally painless masses and are easily misdiagnosed initially as epidermal inclusion cysts. We describe a 44-year-old woman who presented with an intramuscular lipoma of the frontalis muscle.
Adult
;
Female
;
Head
;
Humans
;
Lipoma*
3.The Relationship of Perceived Stress, Ways of Coping, and Stress Response of Nursing Students.
Na Sun HA ; Kuem Sun HAN ; Jung CHOI
Journal of Korean Academy of Nursing 1998;28(2):358-368
This was designed to identify the relationship of perceived stress, ways of coping, and stress response in student nurses. The subjects of this study were 320 student nurses from two universities and three junior colleges located in Seoul. The data were collected from November 28 to December 10, 1997 by a questionnaire survey method. The instruments for this study were the perceived stress scale developed by Levenstein(1993), ways of coping scale developed by Lazarus and Folkman(1984), and the stress response scale developed by Choi(1991). The data were analyzed by SAS program, using descriptive statistics, Pearson correlation coefficient, and ANOVA. The results are summarized as follows : 1. The mean score for the level of perceived stress was 2.55. 2. The mean score for the level of problem oriented coping was 1.61 and the mean score for the level of emotional oriented coping was 1.37. 3. The mean score for the level of stress response was 3.74. Stress was classified into nine factors and the order of scoring for the most frequent was; assignments(3.98), as a nurse(3.97), interpersonal relationship(3.88). 4. The relationship between perceived stress and stress response revealed a positive significant correlation(r=0.23, p=0.0001). 5. The relationship between emotional oriented coping and stress response revealed a positive significant correlation(r=0.22, p=0.0001). 6. The relationship between perceived stress and emotional oriented coping revealed a positive significant correlations(r=0.13, p=0.020). In conclusion, this study revealed that the level of perceived stress and ways of coping were important factors influencing the stress response of student nurses. Therefore, in consideration of perceived stress, ways of coping should be included in the development of a stress management program for student nurses. Further research with an expanded area and subjects is recommended.
Surveys and Questionnaires
;
Humans
;
Nursing*
;
Seoul
;
Students, Nursing*
4.Effects of major blood components on CT number: an experimental study.
Sun Seob CHOI ; Sang Hee CHOI ; Seoung Oh YANG ; Yung Il LEE ; Jin Yeong HAN ; Jung Man KIM
Journal of the Korean Radiological Society 1992;28(4):559-564
The study was undertaken to evaluate the effect of major blood components on the CT number. The CT numbers according to the various levels of hematocrit, total protein and cholesterol were checked and analysed by the dilution of pack cell, plasma and 184 complete blood cell count samples under same scanning conditions. In case of normal protein and cholesterol level(33 samples), the CT number was increased about 5.5 hounsfield unit according to 10% increase of hematocrit level: and In case of normal hematocrit and cholesterol level(39 samles), the CT number was increased about 3.5 hounsfield unit according to 1gm% increase of protein level. CT number changes were not predictable according to the changes of cholesterol level(34 samples). From these results, we concluded that major blood components should be considered in the CT number analysis of tissue.
Blood Cell Count
;
Cholesterol
;
Hematocrit
;
Plasma Cells
5.MRI Evaluation of the Vascular Pattern in Intracranial Meningioma.
Mi Hye KIM ; Kyung Sub SHINN ; Hyo Sun CHOI ; Kyu Ho CHOI ; Il Gwon YANG ; Han Jin LEE
Journal of the Korean Radiological Society 1994;30(2):225-229
PURPOSE: The purpose of this study was to assess the usefulness of MRI in the evaluation of vascular changes of the meningioma. MATERIALS AND METHODS: We retrospectively studied the MRI findings in 20 cases of intracranial meningiomas. The images were assessed for vascular hilum, vascular rim, sinus invasion, and vascular encasement. Cerebral angiograms were obtained in 15 cases and compared with MRI findings. RESULTS: MRI was as accurate as angiography in detection of vascular hilum(MRl=8/20, Anglogram=9/15), vascular rim(MRl=14/20, Angiogram=9/15) and dural sinus invasion(MRl=4/6, Angiogram=5/6). MRI was superior to angiography in detection of vascular encasement(MRl=2/3, Angiogram=0/2) and cavernous sinus invasion(MRI=3/3, Angiogram=0/2). CONCLUSION: MRI is an excellent noninvasive imaging modality in evaluating vascular changes of omas.
Angiography
;
Cavernous Sinus
;
Magnetic Resonance Imaging*
;
Meningioma
;
Retrospective Studies
6.Defense Mechanisms in the Specialty Choice of Medical Students.
Han Yong JUNG ; Sun Ho HAN ; Eui Jung CHOI ; Dong Wook KIM
Journal of Korean Neuropsychiatric Association 1999;38(6):1412-1420
OBJECTIVES: To determine differences of common personality profiles and coping mechanisms of medical students who prefer specific specialties (medicine and surgery), the authors evaluated the defense mechanisms of the medical students by using Ewha Defense Mechanisms Test. METHODS: The authors compared the defense mechanisms between two groups (medicine selection group and surgery selection group) who are in the senior year of the Soonchunhyang University School of Medicine. RESULTS: There were no significant differences in mean scores of the each defense mechanism and 4 groups of defense mechanisms divided by maturity level between the groups of students who selected medicine and surgery. But, frequency of major defense mechanisms were as follows; For the surgery selection group, the passive-aggression in the Immature defense mechanism and show-off in the Neurotic defense mechanism were significantly higher than in the medicine selection group. Contrarily, in the medicine selection group, humor in the mature defense mechanism as the major defense mechanism was significantly higher than in the surgery selection group. CONCLUSION: After analysis of the differences of frequency of major defense mechanisms between the two groups, there were no significant differences between the two groups in personality. However, the students of the medicine selection group used humor of the mature defense mechanism as a major defense mechanism in higher frequency than the surgery selection group. In situations of complications, anxiety and suffering, the use of the humor defense mechanism gave the students strength to endure these situations. Among these students, there is a high probability that many of them possess strong ego strength. Contrarily, the students of the surgery selection group did not express aggression directly, rather, they expressed these feelings indirectly through passive opposition. There was a high frequency of passive-aggression defense mechanism in dealing with feelings of aggression. Also, in the neurotic defense mechanism, compared to ability, excessive goals were set as was the resulting behavior. Especially, behavior was extremely sensitive to how others would evaluate those actions resulting in using show-off mechanism as a major defense mechanism in higher frequency by the surgery selection group. The results seem to be useful in understanding the student's optimal character for specific specialities that were selected by evaluating the differences of the common characteristics and coping mechanisms of each specialty group.
Aggression
;
Anxiety
;
Defense Mechanisms*
;
Ego
;
Humans
;
Students, Medical*
7.Decompressive Craniectomy for Acute Cerebral Infarction.
Heung Sun LEE ; Won Han SHIN ; Soon Kwan CHOI ; Bark Jang BYUN ; In Soo LEE
Journal of Korean Neurosurgical Society 1991;20(10-11):854-859
We present a series of 10 Patients(Seven men and three women with an average age of 53 years) who underwent decompressive craniectomy for treatment to massive brain swelling following acute cerebral infarction. Clinical signs of cerebral herniation(anisocoria or fixed and dilated pupil, and/or hemiplegia with decerebrate righidity) were present in all patients. Computed tomography and magnetic resonance imaging showed the mass effect by cerebral edema through midline shift. All patients were treated with an extensive craniectomy and duroplasty. Among them, one recovered without neurological deficit, three were moderately disabled but functionally dependent, three remained in a persistent vegetative state and three died within 9 days after surgery(good recovery=1, moderate disability=3, persistent vegetative state=3, death=3). The results suggest that decompressive craniectomy can be an useful lifesaving procedure for massive cerebral edema following widespread hemispheric infarction.
Brain Edema
;
Cerebral Infarction*
;
Decompressive Craniectomy*
;
Female
;
Hemiplegia
;
Humans
;
Infarction
;
Magnetic Resonance Imaging
;
Male
;
Persistent Vegetative State
;
Prognosis
;
Pupil
8.Colonization Rate of Methicillin-resistant Staphylococcus aureus in Neonates: A Single Center Experience.
Soo Young CHOI ; Sang Woo HAN ; Hye Sun YOON ; Moran KI
Korean Journal of Pediatric Infectious Diseases 2012;19(3):111-120
PURPOSE: The aim of this study is to investigate the colonization rate of Methicillin-resistant Staphylococcus aureus (MRSA) in neonates by different clinical characteristics, to presume the origin of MRSA acquisition, and to identify the risk factors associated with MRSA colonization. METHODS: We retrospectively reviewed the medical records of 1,733 neonates admitted to Seoul Eulji hospital Neonatal Intensive Care Unit between January 2008 and December 2011. Nasal, inguinal and rectal swab specimens were obtained upon admission and each week until discharge. We classified the route of MRSA acquisition as; hospital associated (HA-MRSA) and community associated (CA-MRSA) according to the case definition. RESULTS: Among 1,733 neonates, 415 (23.9%) were colonized with MRSA. Gestational age, birth weight, delivery type, maternal antibiotics usage before delivery, birth place and care place before admission were influencing factors in colonization of MRSA. The colonization rate was significantly high in neonates without maternal prophylactic antibiotics use before delivery than in the other group (relative risk 2.77, 95% CI 1.88-4.07; P<0.01), and outborns showed higher MRSA colonization rate compared to inborns (relative risk 2.28, 95% CI 1.17-4.42; P=0.015). CONCLUSION: We identified the neonatal MRSA colonization rate to be 23.9%. We estimated HA-MRSA colonization rate to be 10% (51/511) and CA-MRSA colonization rate to be 36% (309/858). We ascertained that risk factors in MRSA colonization in neonates were prophylactic use of antibiotics in mothers and the birth place.
Anti-Bacterial Agents
;
Birth Weight
;
Colon
;
Gestational Age
;
Humans
;
Hypogonadism
;
Infant, Newborn
;
Intensive Care, Neonatal
;
Medical Records
;
Methicillin Resistance
;
Methicillin-Resistant Staphylococcus aureus
;
Mitochondrial Diseases
;
Mothers
;
Ophthalmoplegia
;
Residence Characteristics
;
Retrospective Studies
;
Risk Factors
;
Staphylococcus aureus
9.Two Cases of Multiple Pilomatricoma.
Yi Sun KIM ; Kyeong Han YOON ; Hyun Joo CHOI ; Il Joo LEE
Korean Journal of Dermatology 1998;36(5):950-952
Pilomattiaoma, aften called calcifying epithelioma of Malherbe, is a benign tumor originating from the outer root sheath cell of the hair follicle and extending into the hair matrix, Pilomatricoma usually occurs as a single, asymptomatic dermal or subcutaneous nodule. Multiple lesions are quite unueuel, comprising only 2-3.5% of cases. We report two patients with multiple pilomatricoma.
Hair
;
Hair Follicle
;
Humans
;
Pilomatrixoma*
10.Dysembryoplastic Neuroepithelial Tumor: CT and MR Findings A Case Report.
Sun Wha LEE ; Hye Young CHOI ; Yoo Mi HAN ; Hea Soo GOO ; Myung Hyn KIM
Journal of the Korean Radiological Society 1995;32(6):981-984
Dysembryoplastic neuroepithelial tumor(DNET) is a recently described rare tumor that occurs most frequently in the temporal lobe of the brain and is characterized by long-standing, intractable complex partial seizures in children. The authors experienced one case of DNET occurring in a 13-year old boy, who had refractory complex partial seizure for 7 years. CT scan revealed nonenhancing low density mass in the left temporal lobe. MR images demonstrated a well-marginated cortical mass with very low signal intensity on TIWI and multinodular appearance of high signal intensity on T2WI. A few small enhancing foci within the mass were noted on contrast enhanced MR images. DNET, a rare tumor, should be considered in the differential diagnosis of neoplasm which causes seizure and is distinguished from other tumors because of its benign course. Differentiation between DN ETand other tumors by CT and MR findings is very difficult. But, our case showed the multinodular pattern on T2W image, which may be helpful feature in the differential diagnosis.
Adolescent
;
Brain
;
Child
;
Diagnosis, Differential
;
Humans
;
Male
;
Neoplasms, Neuroepithelial*
;
Seizures
;
Temporal Lobe
;
Tomography, X-Ray Computed