• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.169-181
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• 2003

Statement of problem : The survival rate of wide diameter implants was lower than of 3.75-mm implants in some clinical researches. Purpose : The purpose of this study was to investigate the influence of implant diameter on the osseointegration of implants in the rabbit femoral condyle and tibial metaphyses by means of removal torque measurements and histomorphometric analysis. Material and Method : Ten adult New Zealand White rabbits were used in this study Two 3.75-mm diameter implants were inserted through one cortical layer in the tibial metaphyses and one 3.75-mm diameter implant was inserted in the femoral condyle. 5.0-mm diameter implants were inserted in the other leg in the same manner. A total of 60 implants (3.75-mm diameter implants:30 : 5.0-mm diameter implants:30) were installed. After a healing time of 4 and 12 weeks, the peak removal torque values required to shear off the implants were recorded. From the removal torque values (Ncm) obtained, the mean shear stress ($N/mm^2$) was calculated. And the percentage of direct bone-to-implant contact and the percentage of bone area inside the thread were measured by Kappa Image Base-metreo. The Student's t-test was undertaken for statistical analysis (p<0.05). Results : The removal torque value of 5.0-mm diameter implants was higher than of 3.75-mm diameter implants (p<0.05). The difference of shear stress value between 3.75-mm and 5.0-mm diameter implants was not statistically significant (p>0.05). The percentage direct bone-to-implant contact had no statistical difference between two groups (p>0.05). The percentage of bone area inside the thread had no statistical difference between two groups (p>0.05). Conclusion It is concluded that the quality f osseointegration is not influenced by increasing implant diameter.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.342-350
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• 2003

Statement of problem. Titanium-Nickel alloy might be used in various prosthetic restorations since it has a unique property such as super-elasticity and high fatigue resistance. However, little is known about the casting ability of this alloy. Purpose. This in vitro study compared the casting accuracy and the porosity made with different investments and various sprue designs to ascertain what casting condition would be better for the fabrication of Ti-Ni cast restorations. Material and methods. A total of 70 Ti-Ni alloy crowns were made and divided into 7 groups of 10 copings on a metal master die. For measuring the effect of the sprue numbers, two groups with one and two 8-gauge sprues were compared. Moreover, the results of the conventional sprue and the double thickness sprues were compared. Three investments were used; carbon free phosphate bonded investment, titanium investment and gypsum bonded investment. The cast restorations were evaluated at 48 points on the entire circumferential margin with a stereomicroscope measuring in micrometers. Each crown was radiographically examined for casting defects and porosity. Data on casting accuracy were analyzed using two-way and Post hoc Scheffe's comparison to determine whether significant differences existed at the 95% confidence level. Student-Newman-Keuls test were performed to identify significant differences in the number of voids. Results. The double sprueing group and double thickness group had significantly less marginal discrepancy than the single sprueing group (P<.05 and P<.01, respectively). The castings with phosphate bonded investment showed the least marginal discrepancy and the smoothest surface. The castings invested in the gypsum bonded investment had the greatest gaps in margin and the largest failure rate. The double sprueing group and phosphate bonded investment group had significantly smaller void numbers and smaller void size than the other groups. Conclusion. Within the limitations of this in vitro study, the casting accuracy of the groups using thicker, double sprue design and the phosphate bonded investment was significantly superior. Moreover, void number and size were less than other groups.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.849-857
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• 2007

Purpose: The purposes of this study were to compare and quantify the expressions of RANK and RANKL in the gingival tissues of non-periodontitis patient and patients with chronic periodontitis, in order to understand the contribution of these proteins to periodontal destruction. Material and methods: Gingival tissue samples were obtained during periodontal surgery or tooth extraction. According to the patient's systemic condition & clinical criteria of gingiva, each gingival sample was divided into two groups. Group 1 (n=8) is clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from non-periodontitis patients. Group 2 (n=8) is inflammed gingiva from patients with chronic periodontitis. Tissue samples were prepared and analyzed by Western blotting. The quantification of RANK and RANKL were performed using a densitometer and statistically analyzed by Student's t-Test. Results: The expression of RANK were similar in group 1 and 2. The difference between group 1 and 2 was not statistically significant. And the mean amount of RANKL was more increased in group 2 than group 1. The difference between group 1 and group 2 was statistically significant. Conclusion: The expression level RANK didn't show any significant difference between healthy tissue from non-periodontitis patients and inflamed tissue from chronic periodontitis, but the expression level of RANKL in inflammed tissue from chronic periodontitis showed significantly increased tendency compared to healthy gingiva from non-periodontitis patients. Therefore, characteristics of RANK and RANKL in progress of chronic periodontitis would be basis of further studies in diagnostic method and treatment index of the disease.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.1
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• pp.15-26
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• 2016

Based on a survey done recently in Japan, 30 percent of the serious accidents occurred in oral implant surgery were concerned with the mandibular canal and 3/4 of them were related to drilling. One of the reasons lies in the lack of the education system. To overcome this problem, a new educational system focusing on drilling the mandibular trabecular bone has been developed mainly for dental college students in the form of an oral implant surgery training simulator that enables student to sense the reaction force during drilling. On the other hand, the conventional system uses polymeric model. Based on these systems, two approaches were proposed; the evaluation by experienced clinicians using the simulator, and experimental works on the polymeric model. Focusing on the combination of the drilling force sensed and drilling speed obtained through both approaches, the results were compared. It was found that the polymeric models were much softer especially near the mandibular canal. In addition, the study gave us an insight of the understanding in bone quality through tactile sensation of the drilling force and speed. Furthermore, the clinicians positively reviewed the simulator as a valid tool.

• Journal of Gifted/Talented Education
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• v.19 no.1
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• pp.25-46
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• 2009

The purpose of this study was to investigate gifted students' gender difference in ego state and personality, the characteristics of the functional types and the temperable types in personality traits and relations between gifted students' ego state and their personality traits by Ego-gram test based on Borne's personality theory and MMTIC test based on Jung's psychological theory. The subjects of this study were 230 of gifted students of K Gifted Center, The data analyzed by chi-square, t-test, one-way anova in accordance with each research question. The results of this study can be used as the material data for academic and career counseling and for guidance in students' human relationships. The results showed that there were gender differences in the ego state and personality traits in two dimensions. Second, gifted students showed significant difference from Korean standardization in the functional types and the temperable types of personality. These results showed that there were solid relations between the types of ego-gram and personality of gifted students.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.1
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• pp.513-532
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• 2016

The purpose of this study is to gain a better understanding of undergraduate citation behavior and to measure the contribution which an academic library makes in the academic writing of students. Citations in 80 student papers submitted in the academic paper competition was analyzed for types of items cited and the number of items in the library collection, etc. The findings indicate: 1) the level of undergraduates' citation knowledge is very low, 2) undergraduates prefer web resources (44.9%) to such academic resources as books, journal articles, theses or dissertation, and 3) undergraduates find academic resources in their academic library. Upon these findings, this study suggests that academic library staff should intervene to enhance undergraduate academic writing skills and to develope of educational material, including how to search for and cite reliable resources.

• Korean Journal of Clinical Pharmacy
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• v.23 no.1
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• pp.57-64
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• 2013

Purpose: Drug can be hazardous for people if misused although they are useful for their indication. In urgent incidences such as overdose, proper treatment for intoxication can save patients' lives. In emergent case regarding drug overdose, pharmacists should know how to provide correct information including antidote to other healthcare providers. However, in Korea, there is neither regular class nor education material regarding detoxification. Therefore, the object of our study is to investigate the perception of pharmacists about it. Method: We surveyed hospital pharmacists by means of self-reporting questionnaire in order to investigate the pharmacists' perception of detoxification treatments from May $12^{th}$ 2012 to August $10^{th}$ 2012. The questionnaire comprised of demographic information, interest in detoxification treatment (inquiry from patients and education about antidote), knowledge of antidote, effective drug search route and perception of the need for education and stocking materials about antidotes). Results: It included total 281 hospital pharmacists from 30 hospitals in S. Korea. Of them, only 16.7% have been questioned about drug overdose from patient or representative and 35% have learned about antidotes in case of drug overdose through education program of Korean association of hospital pharmacist or university. About 98% thought that education and stocking materials about frequently overdosed drug and antidotes are helpful for patients in emergent case. Also, the percentage of correct answer of each questions about antidotes were higher in educated group ($p{\leq}0.001$). The more work years are, the percentage of correct answer of each questions are higher ($p{\leq}0.001$). Conclusion: In conclusion, it will be helpful for reducing damage by drug overdose that pharmacists take regular education about antidote for all pharmacist and pharmacy student. In addition, preparing and keeping booklet for Korean Style-antidote in pharmacy is needed currently for protecting public health.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.523-532
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• 2011

Objectives : The purpose of this study was to measure the effect of factors analyes the associated by the dental treatment fear of level dental hygiene and non-dental hygiene students, and then to provide basic material which can help to improveoral health and effective dental treatment. Methods : The subject in this study were 275 students in Jeolla region. The data were collected from March through April 2010, by way of the self-reported questionnaire. Results : 1. Subjects, who correspond to 'high fear level' which is more than 60 points in the scale of Dental Fear Survey, were indicated to be larger in collegians of general-related departments(38.9%) than collegians of health-related department(36.3%).2. Among three detailed factors, the treatment-stimulator response factor showed the higher fear sense than other 2 factors. In the physiological response, 'muscular tension' was 2.72 points, there by having been indicated to be the highest.3. The more belonging to the group with high fear was indicated to lead to the more in direct pain experience, in non-anesthesia pain experience, and in indirect pain experience through brothers and sisters. Even the symptom and syndrome in oral disease were indicated to be much. 4. As a result of comparing difference in dental fear level depending on pain experience, it was indicated that the more belonging to the group with high fear leads to the more in direct pain experience, in non-anesthesia pain experience, and in indirect pain experience through brothers and sisters. Conclusions : Dental fear must be controlled carefully in order to promote oral health and effective dental treatment.

• Hwankyungkyoyuk
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• v.21 no.2
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• pp.51-67
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• 2008

The purpose of this study is to develop and applicate the elementary environmental textbook in order to solve its problem and to improve attitude related to the Asian dust. The results in this research are as follows. First, it was showed that three groups who composed of teachers, parents and students in the elementary school had recognized the serosities and problems caused by the Asian dust form TV, and that such problems was associated with increase of the desertification and the global warming. Especially the student group insist that the cause in Asian dust is due to the natural phenomena or industrialization. Second, as a result in analysis on the Asian dust through both textbooks on the 7th elementary curriculum and subsidiary textbooks, contents concerning Asian dusts was little or noting. In addition, in the subjects of Science, Society and Health for the 5th and 6th grade students in the elementary school, they were explained partially as one of the air pollutants. Third, the elementary environmental textbook on the Asian dust was developed for the 5th and 6th grade students. The textbook is composed of four contents on the material which is harmful of the human health and life in Asian dust, the special news of Asian dust, and the best answer to solve Asian dust as well as the cause and the source of Asian dust. Forth, as a result in classes using the environmental textbook developed by four themes about the Asian dust, its application is meaningful in the level of p value in the view of knowledge, awareness and attitude of the experiment group. They was more improved in 37%, 14%, and 15%, respectively, than the comparative group. In conclusion, the environmental textbook related to Asian dust will play an important role in useful tool to understand the right knowledge, awareness, and attitude which makes an effort on its effective management in the elementary school.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.845-854
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• 1998

Background: S-2-(3 aminoprophlamino) ethylphosphorothioic acid(WR-2721) is one of the radical scavenging thiols. We tested its protective effects in the reperfused heart. Material and Method: The experimental setup was the constant pressure Langendorffs perfusion system. We investigated the radical scavenging properties of this compound in isolated rat hearts which were exposed to 20 minutes ischemia and 20 minutes reperfusion. Four experimental groups were used:group I, control, Amifostine 50 mg(1 mL) peritoneal injection 30 minutes before ischemia(group II), Amifostine 10 mg(0.2 mL) injection during ischemia through coronary artery(group III),and Amifostine 50 mg(1 mL) peritoneal injection 2 hrs before ischemia(group IV). The experimental parameters were the levels of latate, CK-MB, and adenosine deaminase(ADA) in frozen myocardium, the quantity of coronary flow,and left ventricular developed pressure, and it's dp/dt. Statistical analysis was performed using repeated measured analysis of variance and student t-test. Result: The coronary flow of group II and IV were less than group I and III at equilibrium state but recovery of coronary flow at reperfusion state of group II, III, and IV were more increased compared with group I. The change of systolic left ventricular devoloping pressure of group II and IV were less than control group at equilibrium state, which seemed to be the influence of the pharmacological hypotensive effect of amifostine. But it was higher compared with group I at reperfusion state. The lactic acid contents of group II were less than control group in frozen myocardium.(Group I was 0.20 0.29 mM/g vs Group II, which was 0.10 0.11 mM/g). The quantity of CK-MB in myocardial tissue was highest in group IV (P=0.026 I: 120.0 97.8 U/L vs IV: 242.2 79.15 U/L). The adenosine deaminase contents in the coronary flow and frozen myocardium were not significantly different among each group. Conclusion: Amifostine seemed to have significant cardioprotective effect during ischemia and reperfusion injuries of myocardium.