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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Acedemy of Dental Technology
Journal Basic Information
Journal DOI :
Korean Academy of Dental Technology
Editor in Chief :
Volume & Issues
Volume 31, Issue 3 - Sep 2009
Volume 31, Issue 2 - Jul 2009
Volume 31, Issue 1 - Mar 2009
Selecting the target year
Microstructure and Hardness of Ti-X%Cu(X=2,5,10) Alloys for Dental Castings
Jung, Jong-Hyun ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 9~14
This study evaluated the mechanical properties of Ti-Cu alloys with the hope of developing an alloy for dental casting with better mechanical properties than unalloyed titanium. Ti-Cu alloys with four concentrations of Cu(2,5,10wt%) were made in an argon-arc melting furnace. The microstructure and micro-Vickers hardness were determined. X-ray diffraction pattern test was performed on the polished specimens. The microstructure of 2%Cu and 5%Cu alloys are shown acicular
phase formed on the surfaces of previously formed
grains. The 10%Cu alloys has essentially a eutectoid structure; this structure includes lamella of
phase that transformed from
at the eutectoid temperature. The micro-Vickers hardness of CP Ti specimens was significantly(p<0.05) lower than that of any of the other alloys. Among the Ti-Cu alloys, the 10%Cu alloys exhibited a significantly(p<0.05) higher hardness value. but lower than that of Ti-6%Al-4%V alloy. From these results, it was concluded that new alloys for dental castings should be designed as Ti-Cu based alloys if other properties necessary for dental castings were obtained.
A Study on Metal-Porcelain Fusing Layer in Porcelain Fused to High Gold Alloy
Lee, Kee-Dae ; Kwak, Dong-Ju ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 15~20
The success of the porcelain fused to gold alloy restoration depends not only on the choice of materials but to a larger degree on the technical skills. The porcelain fused to metal(PFM) alloys containing gold are commonly use for dental purposes in dental laboratory. The gold-colored alloys contain primarily gold, platinum, palladium, and silver, with minimum amounts of such metals as tin, iridium, or titanium. The purpose of this study is on the metal-porcelain fusing layer in porcelain fused to high gold alloy Principal results are as follows. The hardness number(Hv) of PFG is respectively
in fired-treated. The formation of the fusing(intermediate) layer caused by components fusing the interface of porcelain and gold alloy. The main components of the fusing(intermediate) layer are Na, Al, Si, K, Zn, Zr and Ce. The intermediate layer formed by the 2nd firing is more larger than the intermediate layer formed by the 1st firing.
A Study on the Viability of Human Dermal Fibroblast Cell by Media for Ni-Cr alloy elution
Kim, Kap-Jin ; Choi, Sung-Min ; Kim, Chi-Young ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 21~26
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 Impacts of the Recasting of Non-precious Metal Alloy for Porcelain Fused to Metal Crowns on Strength
Chung, Hee-Sun ; Oh, Gyung-Jae ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 27~34
This study compared and analyzed changes to the mechanical characteristics to nonprecious metal alloy for porcelain fused to metal crowns when it's repetitively used without the addition of new alloy. Metal samples were made with the Verabond V nonprecious metal alloy. Those samples to measure tensile and yield strength were made in the standardized design(ISO 22674), those to measure bond strength in the
format, and those to measure hardness in the
format. A ceramic to measure bond strength was made at the center of the metal sample in the length of
by using Noritaker Super Porcelain EX-3. Ten samples were prepared for one, three and five repetitions of casting each. The test results were as follows: 1. The more casting was repeated, the more significantly tensile strength dropped. 2. The more casting was repeated, the more significantly yield strength dropped. 3. Repetitive casting didn't cause significant changes to bond strength. 4. The Vickers hardness significantly fell with increasing repetitions of casting. There were no changes to bond strength observed with the increasing number of repeating casting. But tensile strength, yield strength, and Vickers hardness decreased. Those results indicate that repeated casting can affect durability and that careful attention should be paid by avoiding repetitive use or excessive increase of uses when no new alloy is added.
Research about influence on the teeth health by the smoking - research intended for students of dental technology in Daegu -
Kim, Jeong-Sook ; Jung, Hyo-Kyung ; Lee, Jong-Do ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 35~45
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
, respondents who received scaling was
, respondents who regularly floss was
, respondents who brush more than three times a day was
and had better periodontal health. Bleeding during tooth brushing was more frequent in smoking group (
). Regarding mouth order, non-smoking group was
, after scaling was
, patients who regularly floss was
, patients who brush more than three times a day was
. Concerning the experience of dental caries treatment, smoking group was
, patients who do not floss was
, patients who brush once a day was
. With regard to dental prosthesis, non-smoking group was
, patients who received scaling was
, patients who regularly floss was
, patients who brush more than three times a day was
. 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.
Self-Leadership Strategy Styles of Dental Technicians - Focused on Gyeongnam region -
Nah, Jung-Sook ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 47~58
Self-leadership means a person's ability to make his thought or behavior in a right way by controlling it himself. Strategies of the same leadership can be largely categorized into three, behavior focused, natural reward and constructive thought strategies. In this study, the foresaid styles of self-leadership strategy are discussed from the perspective of dental lab laboratories' business environment of Gyeongnam region. And accordingly, this researcher examined such strategy styles that dental lab managers, chief technicians and assistant technicians usually have. Results of the study can be summarized as follows. First, out of the self-leadership strategy styles, most remarkably found among the professional of dental technology was constructive thought strategy, followed by behavior-focused and natural reward strategies in order. In general, therefore, the professionals strongly tend to make their thoughts that can a positive effect on their work performance or in a constructive way. In other words, professional dental technicians are more likely to make efforts to persuade or persuade themselves to change their own unreasonable confidence or negative process in more positive way. Second, the extent to which constructive thought strategy is perceived was not different among dental lab managers, chief technicians and assistant technicians. While, behavior-focused and natural reward strategies were found most strongly perceived by dental lab managers, followed by chief and assistant technicians in order. This may be attributed to the fact that the higher professional dental technicians are in position, the higher they are in self-leadership, or in the ability to overcome crises by themselves and make their thought or behavior in a right way. Dental lab managers usually have lots of experiences in relation to behavior-focused or natural reward strategy. Therefore, they are very strongly capable of controlling themselves in order to overcome crises or make their thought or behavior in a right way. In contrast, assistant technicians are still having lots of trials and errors because they are less experienced and skilled. This suggests that chief technicians should make themselves fully capable as a medium that connects between dental lab managers and assistant technicians.
Satisfaction and demand of the New Prosthesis Treatment according to the oral health condition of the geriatric patient in Daejeon City
Jung, Jae-Kwan ; Lee, Su-Ok ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 59~66
In this study 240 geriatric patients, aged 60 year and over were evaluated using a questionnaire and oral examination for their oral status, demand and satisfaction of prosthesis treatment. 1. The single main complaint was regarding from the existing removable prosthesis. When the complaints were catagorized into larger groups, complaints regarding existing prosthesis were 32% and followed by 30% in caries and endodontic problems. 2. DMFT index woman appeared the man the age when will increase more highly recording where highly and considered statistically. 3. According to the result from questionnaire, 48% of patients wearing removable prosthesis and 43% with fixed prosthesis were not satisfied with existing prosthesis. Thirty-seven percentages of patients were not satisfied with aesthetics and unable to chew food properly. 4. Thirty-nine percentage of patients were wearing removable prosthesis. More complete dentures were found on maxilla and partial dentures on mandible. 5. Seventy-seven percentage of patients requested for new prosthesis and the majority of these patients had complaints of difficulties in chewing and discomfort.
Assessment of Job stress and Psychosocial stress level using Psychosocial health measurement tool in dental technicians
Kim, Wook-Tae ; Han, Tae-Young ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 67~85
This study aims to provide the research for dental technician's stress prevention and management with basic materials by understanding dental technician's psychosocial stress level and examining relevant factors. The subject of this study is 255 dental technologists who work mainly in Seoul Gyeonggi district for a month of April of 2009 and I conducted cross-sectional study through self administered survey. The contents of survey include general feature, occupational feature, health behavior feature. I used Karasek's Job Content Questionnaire, JCQ and Psychosocial well-being index, PWI-SF as means of measurement. To compare the level of dental technician's psychosocial stress, I conducted t-test and ANOVA and I measured the factors that are related with psychosocial stress symptom with step by step multiple regressive analysis. According to the result of Cronbach's a value which is yielded to verify the reliability of means of measurement, the reliability of concept is sufficient. The detailed result of this study is as follows. 1. According to the result of analyzing the stress symptom in accordance with general feature and occupational feature, those dental technologists who are older and not married, graduate from junior college, have lower position, work at university hospital or general hospital show lower stress(p<0.05). There is no difference in the level of psychosocial stress with regard to duty related feature, period of service, daily average working hours, monthly average pay. 2. With regard to health behavior feature, those dental technologists who control weight better and have meal more regularly show lower stress(p<0.05). Those dental technicians who smoke, drink liquid and take a suitable sleep show low stress but the difference does not have significance statistically. 3. With regard to the factors of stress in the workplace, those dental technicians who have lower duty related requirement, have higher duty related control ability, have higher social support, have less instability of employment and have less workload and physical burden show lower stress(p<0.05). 4. According to the result of analyzing the factors that influence dental technologist's stress symptom, social support has the most enormous influence on stress symptom. Unstable employment, regular exercise, regular eating, daily average sleeping hours and technological capacity are also important in this order. According to the result of this study, those dental technicians who have higher social support, less instability of employment, do exercise more regularly, take enough sleep more soundly and have higher technological capacity show lower psychosocial stress symptom. Therefore, to adjust appropriately the dental technician's stress and properly maintain and improve the dental technician's mental health, effective management plan that enables dental technicians to maintain smooth human relationships for dental technicians should be sought. In addition, heath education and health management for dental technicians should be given more thoroughly so that they can establish desirable health behavior in daily life.
The Relationship between the Campus life satisfaction, the Major satisfaction and Life style type of Dental technology College Students'
Kim, Hee-Jung ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 87~103
The objective of the research which it sees life style of the individual and is the stroke engineering military merit satisfaction to examine the relationship. That Adler talked, it classified life style with the socially useful type, the ruling type, the getting type and the avoiding type. This governing form of the socially useful type sees, the ruling type grew the getting type and the avoiding type compared to military merit satisfactory boat song. Like this results military merit satisfactory degree of stroke engineering school lifestyle professionalism as dental technician company route period operates with the VIP who is important for is the thing. The research of the program development for the course map and the military merit duty selection map of restricted point and stroke engineering school lifestyle of the research which it sees discussed is necessary. The results are as following. 1. the types of Life-style ; the ruling type 31.3%, the getting type & the avoiding type 27.4%, the negative social type 26.6%, the socially useful type 14.8%. 2. the Major satisfaction ; the socially useful type 3.59, the ruling type 3.55, the negative social type 3.51, the getting type and the avoiding type 3.35. 3. the Campus life satisfaction ; the socially useful type 3.39, the ruling type 3.32, the negative social type 3.24, the getting type and the avoiding type 3.12.
다양한 시스템으로 제작할 수 있는 Mini-Cono-PM attachment
Sin, Jong-U ;
Journal of Korean Acedemy of Dental Technology, volume 31, issue 3, 2009, Pages 107~114