• Journal of Technologic Dentistry
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• v.37 no.1
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• pp.9-15
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• 2015

Purpose: The purpose of this study was to compare the accuracy of the maxillary three-unit fixed dental prosthesis (FDPs) made using two CAD/CAM milling machines : DCM Group(Dentaim CAD/CAM milling machine), WCM Group(Wieland CAD/CAM milling machine). Methods: Each of 10 duplicate models was scanned by blue light scanner(Identica, Medit, Korea), and the three-unit FDPs (STL file) was designed using DelcamCAD. A total of 20 three-unit FDPs was fabricated, comprising 2 groups of 10 specimens each (shrinkage ratio is 1:1). The first three-unit FDPs STL file was used as a CAD reference model (CRM). Obtained STL files by scanning the inner surface of three-unit FDPs were convened into the point clouds-ASC II files. Discrepancies between the point clouds and CRM were measured by superimposition software. Statistical methods to analyze the data were used non-parametric method. The mean (SD) values were compared by a Mann-Whitney U-test. Type one error rate was set at 0.05. Results: WCM group had small discrepancies with $2.17{\mu}m$ of mean value compared to $4.44{\mu}m$ in DCM group. The accuracy values between the two groups showed a sratistically significant difference (Table 2, p<.05). Conclusion: The accuracy of the three-unit fixed dental prosthesis(FDPs) made of two CAD/CAM milling machines were statistically different. Accuracy with which the prosthesis made of WCM group was superior.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.285-294
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• 2017

Purpose: This study was carried out in order to examine organizational commitment in dental technicians and turnover intention level according to it, and to analyze its effects. Methods: A self-reported questionnaire survey was carried out by having convenience sampling as 200 dental technicians. 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 analysis. The following are the analytical results of the collected materials. Results: In consequence of analyzing organizational commitment level in research subjects, there was a significant difference in the items for age, task field, job position in charge, career in dental laboratory technology, and monthly income(p<.05). The average of the item for organizational commitment level stood at 3.29, thereby having been indicated to be high. As a result of analyzing turnover intention level in research subjects, there was a significant difference in the items for task field, job position in charge, career in dental laboratory technology, and monthly income(p<.05). The average of the item for turnover intention reached 3.04, thereby having appeared to be relatively high. As for a correlation between organizational commitment and turnover intention, all variables were shown to have inverse correlation at a significant level. In consequence of conducting regression analysis in order to analyze the influence of organizational commitment upon turnover intention, a factor of having the most impact on turnover intention appeared to be normative commitment. The test value of the model was statistically significant. The explanation power about this was indicated to be 26.9%. Conclusion : In the above findings, the dental technicians are considered to need to be immersed in work with a sense of mission in performing job in charge, to strive to possibly have an opportunity of achievement and self-growth, and to perform a research and development in a manpower management strategy such as turnover prevention.

• Journal of Technologic Dentistry
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• v.39 no.3
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• pp.179-185
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• 2017

Purpose: It is intended to raise awareness of importance of protective equipment and necessity of safety education by examining the actual condition of measures to deal with accident, occurrence of injury, whether safety education is received or not, the actual condition of wearing protective equipment, and working environment of dental lab and dental technician. Methods: A self-administered survey was conducted for a total of 150 dental technologists. A chi-squared test and independent-samples t-test was carried out by using SPSS WIN Program (version 12.0) in order to analyze the actual condition of safety education according to work experience and position and whether injury occurred according to whether to wear protective equipment. Significance level was 0.05. Results: With regard to whether injury occurred according to whether safety education was received, there was 'receiving the safety education-injured (71.8%)', 'not receiving the safety education-injured (79.7%)', 'receiving the safety education-not injured (28.2%)', and 'not receiving the safety education-not injured (20.3%)'. The statistical results of injury occurrence according to safety education were not significant. With regard to whether to be injured according work experience, there was 'less than 10 years-injured (68.4%)', 'less than 10 years- not injured (31.6%)', '10 years or above-injured (89.1%)', and '10 years or above-not injured (10.9%)'. The statistical results of injury occurrence according to work experience were significant (p<0.001). Conclusion: Dental lab and specialized agencies should continue to be interested in periodic safety training, recommending wearing protective equipment and personal protective equipment support and so on.

• Journal of Technologic Dentistry
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• v.45 no.1
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• pp.8-13
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• 2023

Purpose: This study aims to induce interest in the future society that could change with the advance of the 4th Industrial Revolution. It also intends to identify the direction of university education by investigating the perception of university students majoring in dental laboratory technology about the latest technology used in this era. Methods: The study recruited 240 college students majoring in dental laboratory technology at K and D universities in Gangwon-do and Daejeon, respectively. Online and face-to-face surveys were conducted from March 20, 2022 to April 10, 2022. Results: Although their interest in the use of emerging technologies during the 4th Industrial Revolution was above average 3.85, the dental laboratory technology students exhibited relatively high levels of anxiety 3.19 and reluctance 2.96. Second, their interest in emerging technologies demonstrated positive correlations with major satisfaction and understanding of concepts and readiness, whereas reluctance and anxiety pointed to negative correlations with understanding of the concepts of the 4th Industrial Revolution. Conclusion: Formulating guidelines is necessary to help students increase their understanding of the 4th Industrial Revolution and prepare them appropriately by setting an educational direction that can flexibly respond to the rapidly changing industrial environment.

• Journal of Technologic Dentistry
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• v.16 no.1
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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.

• Journal of Technologic Dentistry
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• v.25 no.1
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• pp.103-109
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• 2003

The purpose of this study is to ensure natural restoration of gingiva's form by making effective use of materials in a bid to improve the technique of festooning for denture base. 1. The improved technique is expected to prevent the degradation and deformation of cavity structure and restore it. 2. The improved technique is expected to prevent the change of facial appearance from esthetic viewpoint and restore it. 3. The improved technique is expected to impress again the deformed part on wax denture for additional festooning.

• Journal of Technologic Dentistry
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• v.43 no.2
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• pp.69-69
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• 2021

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.395-403
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• 2013

Purpose: This article examined the affecting factors of a malocclusion status of a patient for orthodontic treatment, orthodontics medical expenses and oral health behavior on orthodontic satisfaction. Methods: This paper conducted a survey from the 15th of July to 30th of September 2012 for the patients who were under orthodontic treatment at three dental clinics where are in Deagu, and distributed a total of 210 questionnaires and analyzed 194 questionnaires, excepting for some questionnaires that were answered unfaithfully. Results: This study classified the related factors into a feeling of satisfaction with treatment and mental satisfaction for finding orthodontic satisfaction. There were the effect of the right tooth-brushing method, a periodic scaling and orthodontics medical expenses on a feeling of satisfaction with treatment, and power of explanation was 16.7%. Conclusion: There were the effect of a malocclusion status, matters that requires attention during orthodontic treatment, a periodic scaling during orthodontic treatment and orthodontics medical expenses on mental satisfaction, and power of explanation was 16.9%. Based on the result above, this paper concluded that preventive treatment and early treatment should be emphasized through developing a program for regular oral examination suited to each medical type, including the method for improving the medical treatment condition and care service for increasing orthodontic satisfaction, which the dental medical-service providers could consider the patients and secure trust.

• The korean journal of orthodontics
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• v.44 no.2
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• pp.69-76
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• 2014

Objective: This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Methods: Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of interexaminer and inter-method variability. Results: The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. Conclusions: The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.

• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.347-358
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• 2019

Purpose: The purpose of this study was to analyze dental technicians' job stress and Job satisfaction level and to examine its correlation. Methods: A self-administered survey was conducted from September 2 to October 2, 2019, on 230 selected dental technicians. The collected data were statistical data on frequency and percentage were obtained, and t-test, one-way ANOVA, correlation analysis and regression analysis were carried out. Results: When the job stress was analyzed, there were significant differences according to their field of work, working hours(p<.05). Their average score in the items about a job stress was 3.57. As a result of analyzing the job satisfaction of the dental technicians, there were significant differences according to their working hours, plan for task continuity in dental technician(p<.05). The average score in job satisfaction items was 3.11. Conclusion: As a result of research, that as for the correlation between a job stress and job satisfaction, a higher the job stress led to lower the job satisfaction, as every variable had a significant reverse correlation with each other. In addition, physical environment, heavy workload, conflict during the work performance, personal matters were identified as the factor that exerted the influence on both of job satisfaction.