• 대한치과기공학회지
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• 제36권4호
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• pp.257-266
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• 2014

Purpose: This report intend to provide basic materials of Musculoskeletal diseases prevention program development and preventive measures establishing by surveying Musculoskeletal symptoms. Musculoskeletal disease and Musculoskeletal disease prevention act about dental technician in Daegu. Methods: From October. 2012 to November. 2012 by conducting self - survey using questionnaire and use unit490 final analysis data. Results: In dental Technicians, as the musculoskeletal symptoms back or waist pain rate appear such as 28.2% and as the musculoskeletal disorders, the shoulder region pain complaint rate appear highly such as 87.4%. Musculoskeletal disease prevention act was highly appeared man more than women, the married than the unmarried, over 10 years dental experience, fewer working hours per day, the average monthly income is greater regular medical check-up dental technician than technician who do not. As working environment, In case working in laboratory whch dust is well ventilated and with a barrier, Musculoskeletal disease prevention act rate was highly appeared more than another technician who do not. Conclusion: We must prepare an effective preventive measures. To development Musculoskeletal disease prevention program suitable for dental technic working and make obliged to practice.

• 대한치과기공학회지
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• 제23권1호
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• pp.45-53
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• 2001

This study was performed to investigate the effect of vent on the marginal discrepancy of PFM base metal castings. Eighteen identical wax patterns of a maxillary 3 unit anterior bridge were fabricated. Nine cases out of them were vented with $\phi$2.5mm sprue wax, for direct comparison as to the marginal discrepancy of the castings with the other non vented 9 ones. The mean value of marginal discrepancies of the vented castings was $85.02{\pm}25.57{\mu}m$, and that of the non vented was $163.21{\pm}69.88{\mu}m$ respectively. Statistical analysis revealed that marginal discrepancy of the vented casting was significantly reduced(p<0.05).

• 대한치과기공학회지
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• 제42권3호
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• pp.248-253
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• 2020

Purpose: This study aimed to verify whether blended learning is worth alternating with traditional face-to-face learning for some dental technology students in practice teaching. Methods: A total of 68 students were included in this study. They were divided into two groups to compare blended learning and traditional face-to-face learning. The experiment had been carried out over 15 weeks. The following tests were performed: test of instructional quality, test of learning satisfaction, test of perceived usefulness, and test of learning flow. The IBM SPSS software was used to analyze the data. Results: The learning satisfaction and the perceived useful of blended learning by students appeared to be higher than that of traditional face-to-face learning. However, there was no significant difference in the variables of traditional face-to-face learning and those of blended learning (p<0.05). Conclusion: Blended learning is an alternative to traditional face-to-face learning for some dental technology students in practice teaching.

• 대한치과기공학회지
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• 제14권1호
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• pp.81-90
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• 1992

1. The dental technicians are worn to a frazzle by a hard work. Therfore, the term of manufacturing denture should be prolonged as 4$\sim$5 days. 2. The dental technicians work under the harmful environments. It should be improved the working conditions for the dental technicians. 3. In case of the women dental technicians, they feel like being treated discriminality. It should be take over a portion of the work in dental laboratory as the accountant' section and the technical section. 4. It should be abolished a pressent instruction dentist system.

• 대한치과기공학회지
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• 제39권1호
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• pp.43-52
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• 2017

Purpose: Physical and chemical properties of gold is most suitable to be restored of teeth to its original state. Recently zirconia was used instead of gold because of esthetical and intimacy of human body. Because of high strength and high abrasion resistance of zirconia, all zirconia artificial tooth lead to wear the original tooth of opposite site. To preserve this original tooth, zirconia artificial tooth covered with dental ceramic glass was used. When joining the zirconia core and dental ceramic glass, difference of their thermal expansion coefficient and wetting ability is generated the residual stress at interface lead to crack. In order to solve this problem, intermediate layer what is called zir-liner was imported to decrease the residual stress and increase the bonding strength. Methods: In this study, to identify the optimum conditions for manufacturing process, various methods to rough the surface of zirconia core were adopted, and vary the thickness of interlayer, and analyzed bond strength. Results: Bond strength of sanding specimens group showed higher than that of non-sanding specimens group, and once applied intermediate layer with sanding specimens showed highest bond strength with 28 MPa. SEM photomicrographs of zirconia cores fired at $1500^{\circ}C$ showed parallel straight lines in sanding and pockmarked surface in blasting surfaces as abrasion traces. Observation of the destruction section after shear test by SEM were carried out. Liner applied non-sanding group and non-liner applied sanding group all showed interfacial crack. Sandblasting group with non-liner showed remained dental ceramic glass on the surface of zirconia. Sandblasting group with once applied liner showed partially remained liner and dental ceramic glass on the surface of zirconia. XRD analysis revealed that sandblasting group showed higher monoclinic peaks than other specimens group and this result was due to the high collision energy for stress induced phase transformation. Conclusions: A study on the improvement of bonding strength between zirconia and dental ceramic glass steadily carried out for the future to practical use.

• 대한치과기공학회지
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• 제38권4호
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• pp.381-399
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• 2016

Purpose: The purpose of this study was to examine the awareness of dental technicians on demand for this occupation, their occupational satisfaction and factors affecting the supply and demand of dental technicians. Methods: A self-reported questionnaire survey was carried out by having convenience sampling as 200 dental technicians who work in Seoul Metropolis, Gyeonggi-do Province, Chungnam-do Province from September 26, 2016 to October 15. An analysis of the collected data was computationally processed by using SPSS Win 19.0 program. An analytical technique was made by using statistical techniques such as frequency & percentage, T-test, One-way ANOVA or ANCOVA analysis. The following are the analytical results of the collected materials. Results: When the occupational satisfaction of the selected subjects was analyzed, there were significant differences according to academic credential, marital status, duties in charge, position and monthly income. Their preference for this occupation as a lifelong job significantly varied with age, academic credential, duties in charge, position and monthly income. Their turnover plans significantly differed with age, position, career and monthly income(p<.05). As a result of analyzing what factors affected manpower supply and demand, they placed a lot of importance on the areas of required time and satisfaction, and they attached a less importance to the areas of interpersonal relationships and workload. Their total average score in these areas was 3.06. Conclusion: As a result of research, the manpower supply and demand factors that exerted significant influences on occupational satisfaction were pride. required time and the appropriateness of the number of workers, and the manpower supply and demand factors that had significant impacts on job preference as a lifelong occupation were satisfaction, pride and the appropriateness of the number of workers. The manpower supply and demand factors that affected turnover plans in a significant way were pride, satisfaction and the appropriateness of the number of workers.

• 대한치과기공학회지
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• 제16권1호
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• pp.57-77
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• 1994

The purpose of this study is to investigate the extent to which dental laboratories use proper materials, procedures, devices, and equipments to fabricate crown & bridge, PFM(Porcelain Fused to Metal) crown & bridge, partial denture, complete denture, and other prosteses. 100 laboratories in Seoul were selected for this investigation. Questionnaires were constructed focusing on five topocs:crown & bridge, PFM crown & bridge, partial denture, complete denture, and other prostheses. The results from this survey were as follows : 1. Most dental laboratories used old, inexpensive, and familiar materials rather than newly developed ones. 2. Most of the dental technicians did not stick to the standard procedures of handling materials, but to their own experiences. 3. Newly developed equipments to fabricate dental prostheses were possessed by nearly 30% dental laboratories. 4. About 80% of dental laboratories were using the procedures they had learned in the school : die trimming for accurate crown margin and softening heat treatment after RPD gold casting. But less than 30% of laboratories were shown to follow the boxing procedure to produce master cast and laboratory remounting in the process of complete denture. The findings show that dental laboratory procedures to fabricate dental prostheses are incomplete and inaccurate in some instances. So, further studies are neededs to clarify the causes of some inaccurate procedures, the better and more equipments should be supplied to produce the more accurate dental posthesis, and more efforts at enancing the appropriate use of dental materials and procedures should be made.

• 대한치과기공학회지
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• 제11권1호
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• pp.5-22
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• 1989

We investigated 974 male and female students who are in 4th, 5th and 6th year of 8 elementary schools are located win Puan-kun, the farm area of Chollabuk-do, and the results are as follows. 1. Visiting dental clinic in order to be treated for dental caries hold the highest rate as 26.1% of male students and 30.3% of female students. 2. On fear when children visit dental clinic, first, 25.6% of male students and 35.1% of female students mark the highest rate as some what fear. Second, 23.1% of male students represent to be usual and 29.4% of female students represent to be very fear. There fore it speaks for dissimilarity in character between male and female students. 3. On reason of developing dental caries, 62.5% of male students and 55.8% of female students replied that it was developed because they frequently ate the sweet things. 4. Children who pull out decidous teeth alone mark the highest rate as 44.7% of male students and 38.6% of female students. 5. On important thing for ordinary dental health, 56.2% of male students and 58.5% of female students as the highest rate replied that they often brushed their teeth.

• 대한치과기공학회지
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• 제32권3호
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• pp.211-220
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• 2010

Purpose: The purpose of this study was to analyze dental laboratory's working environment and turnover intention level and to examine its correlation. Methods: 180 dental technicians in Seoul, Incheon, and Chungnam area were selected. Survey was carried out from April 6, 2009 to May 20, 2009 by using self-administered questionnaire. As for the tools for this study, the structured questionnaire was used with its proven reliability and feasibility, and the contents of questionnaire consisted of 43 questions on the basis of related references. The questionnaire consisted of total 32 questions which included general attribute of subjects(14 questions), working Environment(20 questions) and turnover intention(9 questions). The data analysis was processed by computerized system with SPSS 12.0. Statistical analysis techniques included frequency, percentage, T-test, F-test analysis and regression analysis. Results: As a result of analyzing the research subjects' working environment level, there was significant difference in the item of health(P<0.05). The average in the working environment was indicated to be high with 1.53. As a result of analyzing the research subjects' turnover intention level, there was difference in the item of working hours a day(Hour), job satisfaction level, plan for task continuity, most difficulty given task(P<0.05). The average of turnover intention was indicated to be high with 2.85. Conclusion: Correlation between working environment and turnover intention, most of variables were indicated to have reverse correlation, thereby having been shown that the worse working environment leads to the more turnover intention.

• 대한치과기공학회지
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• 제39권1호
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• pp.1-7
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• 2017

Purpose: The purpose of this in vitro study compared to evaluation of repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry. Methods: To evaluate repeatability of scanning abutment tooth stone model, were repeatedly scanned to obtain 11 data via 3D stereolithography (STL) files. 10 data (STL files) were compared with the first 3D data (STL file), and the error sizes were measured by using 3D superimposing software(n=10). Also, the repeatability of scanning abutment tooth impression was evaluated with the same procedure. Independent t test was performed to evaluate the repeatability of scanning abutment tooth stone model versus impression through root mean square(RMS) and standard deviation(SD)(${\alpha}=0.05$). Results: $RMS{\pm}SD$ with regard to repeatability were $14.7{\pm}2.5{\mu}m$, $17.1{\pm}4.0{\mu}m$, respectively, with scanning abutment tooth stone model and impression(p=0.129). Conclusion: This study results showed a little different repeatability of scanning abutment tooth stone model and impression applied CAD/CAM ISO standard in dentistry, will suggest futures good studies and clinical advantages.