• Journal of Technologic Dentistry
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• v.14 no.1
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• pp.23-43
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• 1992

Corrosion characteristics of four commerial gold-based dental alloys(C-1; Au75%, Ag13.9%, Pd3%, Cu & etc.,8.1%, C-2 ;Au 52.08, Ag 24%, Pd 5%, Cu & etc.,18.92, C-3 ; Au 53%, Ag 22%, Pd 5%, Pt 3% Cu & etc.,17%, C-4 ; Au 53%, Pd4, Pt1.5%, Ag & Cu & etc.,41.5%) and four experimental ternary Au-Ag-Cu alloys(E-1 ; Au 50%, Ag 30%, Cu 20%, E-2 ; Au 50%, Ag 20%, Cu 30%, E-3 ; Au 50%, Ag 10%, Cu 40%, E-4 ; Au 50%, Ag 40%, Cu 10%) were investigated by potentiodynamic polarization analysis and the structure was examined by optical microscope and SEM. All corrosion testing was conducted in 1% NaCl solution. The main results are as follows : 1. The corrosion resistence of commercial alloys was decreased in the order of C-1, C-3, C-4, C-2. C-2. 2. The E-1 and E-3 ternary alloys exhibits the higher corrosion resistence than E-2 and E-4 alloys. 3. The cast microstructure of alloys reveals dendrite morphology which shows the significant microsegregation caused by the difference in the diffusion rate between liquid and solid. 4. It is found that the surface corrosion products were mainly AgCl by X-ray diffraction results.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.399-407
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• 2014

The purpose of this study was to provide basic data necessary for improving the oral health of the elderly and quality of their lives by analyzing the relationship among the geriatric denture-related characteristics, denture satisfaction, and geriatric oral health assessment index. For this study, the elderly aged 65 or higher who resided in Euseong-gun, Yeongju-si, Andong-si, Gyeongsangbuk-do were surveyed from March 25, 2013 to May 9 of the same year. The results of this study showed that the denture satisfaction had high correlation with the 'satisfaction with denture attachment', 'satisfaction with aesthetic function of pronunciation', and satisfaction with masticatory function. Moreover, the causative relation was found to exist among the geriatric denture-related characteristics, denture satisfaction, and geriatric oral health assessment index. Thus, it is considered necessary to establish the institutional system and take measures that can improve the awareness towards the geriatric oral health education and geriatric oral health state with respect to effective use and management of denture.

• Journal of Korean society of Dental Hygiene
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• v.5 no.2
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• pp.185-199
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• 2005

The purpose of this research is to suggest a new desirable direction to a positive educational program for dental hygeine students, through the analysis of the degrees of observation and performance practice and the student satisfaction. This researched 471 senior dental hygien students from 5 separate universities. SPSS 10.0 for Windows was used to transform the results data analysis into statistics. The students' degree of satisfaction and length of observational/performance practice level were measured. For statistical anlysis the Mean and Standard Deviation were computed and the t-test and ANNOVA were carried out. The significant level of these statistics was a=0.05. 1. 12 weeks practice is the highest in the satisfaction of observation practice was the highest in clinical settings, followed by 16 weeks practice, and 8 weeks practice. 2. 12 weeks practice is the highest in the satisfaction of performance practice, followed by 16 weeks practice, and 8 weeks practice. 3. 8 weeks practice is the highest in the satisfaction of performance practice, followed by 12 weeks practice, and 16 weeks practice. 4. According to the frequency of clinical practice and satisfaction 12 week program of observation/performance practice is the most desirable, followed by 16 weeks practice, and 8 weeks practice.

• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.69-76
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• 2004

The objective of this finite element method study was to analyze the stress distribution induced on a supporting bone by 3.75mm, 4.0mm, 5.0mm diameter of dental implant fixture(13mm length). 3-dimensional finite element models of simplified gold alloy crown(7mm height) and dental implant structures(gold cylinder screw, gold cylinder, abutment screw, abutment, fixture and supporting bone(cortical bone, cancellous bone) designs were subjected to a simulated biting force of 100 N which was forced over occlusal plane of gold alloy crown vertically. Maximum von Mises stresses(MPa) under vertical loading were 9.693(3.75mm diameter of fixture), 8.885(4.0mm diameter of fixture), 6.301(5.0mm diameter of fixture) and the highest von Mises stresses of all models were concentrated in the surrounding crestal cortical bone. The wide diameter implant was the good choice for minimizing cortical bone-fixture interface stress.

• Journal of Technologic Dentistry
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• v.22 no.1
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• pp.79-88
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• 2000

The objective of this finite element method study was to analyze the stress distribution induced in a maxillary central incisor Ni-Cr base metal coping ceramic crowns with various margin design. Margin designs of crown in this experiment were knife-edge metal margin on chamfer finishing line of tooth preparation(M1), butt metal margin on shoulder finishing line(M2), reinforced butt metal margin on shoulder finishing line(M3), beveled metal margin on bevelde shoulder finishing line(M4). Two- dimensional finite element models of crown designs were subjected to a simulated biting force of 100N which was forced over porcelain near the lingual incisal edge. Base on plane stress analysis, the maxium von Miss stresses(Mpa) in porcelain venner was 0.432, in metal coping was 0.579, in dentin abutment was 0.324 for M1 model, and M2 model revealed in porcelain was 0.556, in metal coping was 0.511, in dentin was 0.339, and M3 model revealed in porcelain was 0.556, in metal coping was 0.794, in dentin was 0.383 for M4 model. All values of each material in metal-ceramic crown were much below the critical failure values.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.21-26
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• 2009

Purpose: Standards of alloy for porcelain fused to metal crown be classified by metallic factor and biological factor. Metallic factors consist of stability of alloy composition and mechanical strength and surface characteristics for chemical bond. Biological factors be considered properties of metallic elements and problems originated by toxicity and hypersensitive reaction. Alloys considered such controversial points are the most suitable alloy for dental instrument. Method: Alloys added Be and Nb using Ni-Cr alloy which has been widely used for dental instrument be selected and classified experimental group. Non-addition Be and Nb to Ni-Cr alloy classify control group and addition Be alloy is Be-experimental group, addition Nb alloy is Nb-experimental group. Specimens for cytotoxicity analysis gave effect to washing and sterilization. and then made an experiment on elution with cell medium after disinfection. It conducted specimens within cell medium with 24hours, 48hours, 72hours, respectively. It cultured human dermal fibroblast(HDF) using cell medium for cytotoxicity test and then investigated elution rate through spectroscopic analysis by MTT-assay. Result: As results of cytotoxicity test by MTT-assay, cultured cell rate of VII measured more low numerical value within elution medium for 24hours focused on control group. Also, cultured cell rate of K3 alloys observed low value for 48hours, 72hours than value of control group. Conclusion: According to final result that synthesize above results, Ni-Cr alloy added Be and Ni has little difference in Cytotoxicity by MTT-assay.

• The Korean Journal of Health Service Management
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• v.5 no.2
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• pp.53-62
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• 2011

This study is to inquire into the correlation between patients' knowledge and attitude about the implant denture, as well as to provide exact information for patients. The results are expected to be basic data to make patients have positive attitudes to the implant denture. The study was conducted on patients who visited dental hospitals located in South Gyeongsang Province, South Korea, from 1 November to 31 December, 2009, the answer sheets from 198 patients analyzed. The results showed that 24.2% of respondents had implant dentures put in. Hereat, the t-test and the analysis of variance (ANOVA) were performed to analyze respondents' knowledge and attitude about the implant denture according to general characteristics. In relation to knowledge about the implant denture, respondents showed differences according to what levels of education they had and whether they had the implant dentures put in. The results of a correlation analysis showed that respondents' knowledge and attitude about the implant denture had a significant correlation with each other. In other words, respondents, who had a high degree of knowledge about the implant denture, had a more positive attitude to it. With the generalization of implant dentures, dental care providers have need to provide exact information about the implant denture for dental patients in order that they may comprehend it and have positive attitudes to it. In addition, there is a need to establish a system to provide the general public with exact information about the implant denture.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.191-199
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• 2020

This study conducted a self-written questionnaire survey on the correlation between job satisfaction, emotional labor, and turnover intention of dental hygienists according to the gender of dental medical institutions. Job satisfaction was high smoking cessation, emotional labor was low age. Turnover intention was low in over 35 years old, number of employees was 11-20, was high in smoking. For women, job satisfaction was high 10 years experience, university, 20 employees. Emotional labor was low age, drinking. Intention to turnover was high in college, single, drinking. Men's emotional labor was 0.22 times less than women's, but their turnover intention was 3.9 times higher. The number of employees was 2.7 times higher than 10 employees. Therefore, efforts to raise job satisfaction and reduce emotional labor and turnover intentions should be made systematically in consideration of gender differences.

• Journal of Korean society of Dental Hygiene
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• v.12 no.4
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• pp.793-800
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• 2012

Objectives : The purpose of this study was to examine the relationship between the DISC behavioral type of dental hygienists and their job satisfaction in an effort to provide some information on the efficiency of human-resources management. Methods : The subjects in this study were 278 dental hygienists who worked in dental clinics in Seoul. A self-administered survey was conducted from February 10 to March 30, 2011, and the statistical package SPSS WIN 12.0 was employed to analyze the collected data. Results : As for differences among the dental hygienists in DISC behavioral type according to their general and job-related characteristics, there were statistically significant differences in dominance type according to age, and statistically significant differences were found in steadiness type according to martial status. There were statistically significant differences in conscientiousness type according to career, and statistically significant differences were found in steadiness type according to the daily mean number of outpatients. Concerning differences in job satisfaction according to DISC behavioral type, the group of influence type was most satisfied with the job itself, and those who were of dominance type expressed the best satisfaction with pay. The group of influence type was most satisfied with boss ties, and those who were of influence type expressed the best satisfaction with colleague relationships as well. Conclusions : The above-mentioned findings indicate that in order to ensure the job satisfaction of dental hygienists in terms of human-resources management, both of their DISC behavioral type and job satisfaction should accurately be grasped, which is expected to make a contribution to the efficient human-resources management of dental institutions.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.35-45
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• 2009

This survey study was conducted on dental technician school students in April 2008 to investigate the effects of smoking on oral health. 110 male and 39 female students were surveyed and cross analysis was performed to examine the relationship between oral health status and smoking-related and oral health maintenance characteristics of smoking and non-smoking group. T-test and one-way ANAVA was used to analyze the average difference verification of two independent samples(smoking group and non-smoking group) and followings are the results. In general characteristics, 74 male students(74.7%) and 25 female(25.3%) students smoked and the percentage of male students were higher in smoking group. Regarding class grade, 2nd-year students(37 students, 37.4%) and 1st-year students(18 students, 36.0%) took the highest percentage of smoking and non-smoking group, respectively. Concerning the experience of drinking, smoking group consumed more alcoholic beverages(94 students, 94.9%) With respect to the frequency of between-meal consumption, respondents who eat between-meal once or twice smoked more. Respecting preferences of sweet food, respondents who enjoyed sweet food smoked more. Concerning smoking characteristics, many of smoking group had been smoked fo a long time(two to five years) and it was worrisome. About the amounts of smoking, 50 respondents(52.6%) of smoking group smoked 20 cigarettes a day with the highest proportion. With regard to the awareness of harmfulness, 70 respondents(70.7%) considered smoking as very harmful and showed that smoking group were aware of its harmfulness but it was habitualized. Respecting smokers in family members, father was more common as smokers(58 respondents, 58.6%) in family and showed that the influence of father. Main reasons of poor periodontal health were alchoholic consumption, smoking, and oral parafunctional habit(57 respondents, 56.7%) in smoking group and neglect of oral hygiene(21 respondents, 42.0%) in non-smoking group. With regard to the scaling, 80 respondents of smoking group(80.8%) didn't received scaling and showed that more oral health education was required. Regarding the periodontal status, non-smoking group was $1.26{\pm}0.44$, respondents who received scaling was $1.43{\pm}0.50$, respondents who regularly floss was $1.50{\pm}0.52$, respondents who brush more than three times a day was $1.38{\pm}0.49$ and had better periodontal health. Bleeding during tooth brushing was more frequent in smoking group ($1.51{\pm}0.70$). Regarding mouth order, non-smoking group was $2.34{\pm}0.62$, after scaling was $2.02{\pm}0.76$, patients who regularly floss was $1.50{\pm}0.52$, patients who brush more than three times a day was $1.81{\pm}0.87$. Concerning the experience of dental caries treatment, smoking group was $1.20{\pm}0.40$, patients who do not floss was $1.30{\pm}0.46$, patients who brush once a day was $1.29{\pm}0.45$. With regard to dental prosthesis, non-smoking group was $3.78{\pm}1.62$, patients who received scaling was $1.43{\pm}0.50$, patients who regularly floss was $1.40{\pm}0.51$, patients who brush more than three times a day was $1.24{\pm}0.43$. From these results, oral health education and smoking has correlation and more oral health education needs to be carried out to educate students with non-health related majors about harmfulness of smoking on oral health. Also more study are required.