• 대한치과기공학회지
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• 제43권1호
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• pp.13-18
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• 2021

Purpose: This study aimed to compare the flexural properties and perform the Weibull analysis of photo-curing three-dimensional (3D) printing resin. Methods: Photo-curing temporary resin (3D polymer) was used as a printing resin. Specimens (65 × 10 × 3.3 ㎣) were prepared following the ISO 20975-1 guidelines and according to the different printing orientations using a digital light processing 3D printer (D2 120; Dentium). The flexural strength (FS), flexural modulus, and work of fracture (WOF) were measured using a universal testing machine (Instron 3344; Instron) at a crosshead speed of 5 mm/min. Results: In this study, the 0° orientation exhibited higher FS and WOF than the 45° orientation. Significant differences were found among the printing orientations (p<0.05). Specimens printed at the 0° orientation were the most accurate. In the Weibull analysis, 0° showed the greatest Weibull modulus (m), which represents a higher reliability. Conclusion: 3D printing should be selected and used by considering flexural properties, size accuracy, and reliability.

• 대한치과기공학회지
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• 제43권4호
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• pp.181-185
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• 2021

Purpose: This study aims to make suggestions for the implementation of the job-based dental technician practical exam. Methods: The duties of dental technicians and the recent trends in the dental technician field were defined and identified, respectively, to achieve the purpose of the current study. The practical test system of domestic and foreign national tests was comparatively analyzed to seek improvements. Additionally, the direction of the practical test to be taken in the future was investigated through a public hearing of domestic experts. Results: As a result of this study, the job site of dental technicians was recently found to be undergoing many changes, and it can be observed that related laws and the work site have already changed. Comparison of overseas test systems showed that Korea was limited to a rather small evaluation range; in general, the scope of the evaluation of the practical tests in foreign countries was widely conducted. In the results of the public hearing, opinions exist that the evaluation range of the practical test was expanded and that new subjects were needed, but the opinion on the existence of practical difficulties was mainly mentioned. Conclusion: The evaluation range of the current practical examination subjects should be expanded and the evaluation of digital dental engineering subjects should be added to proceed with the job-based practical examination. However, it seems that efforts should be made gradually through various efforts in the future due to practical difficulties.

• 대한치과기공학회지
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• 제27권1호
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• pp.115-129
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• 2005

The purpose of this study was to identify injury characteristics happened in the college dental laboratory technique classes and to provide the empirical accident findings for safety education development for the college dental technology classes. The research data were collected from a self-administered survey distributed to the conveniently selected college students. The study participants were 476 freshmen, sophomore and junior students whose major was the dental laboratory technology of the 4 colleges in 2 metropolitan cities and 2 medium-size cities. All collected survey responses were encoded and analyzed in SPSS 12.0. The findings were as follows. The accidents happened to the college students during the dental laboratory technology classes: 1. The accident rate was the highest in the sophomore and the freshmen, junior in order. 2. The body parts frequently injured were hands, face, eyes, arms, and legs in order. 3. The frequent injury types were cut, burnt, stuck, wound, and suffocated in order. 4. The treatment methods for their accidents were the simple first-aids, no treatment, and the emergency room visits in order. 5. The laboratory training conditions inducing the accidents were significantly frequent under wire-related, and wax-related, iron-related, alcohol-related jobs in order, but not frequent in investing material-related, porcelain-related, resin-related, and agar-related jobs. Polishing was the most accident-prone job explaining 63% of the laboratory accidents and then, model producing, wax patterning, casting, burning, and investing jobs in order. In summary, the college dental laboratory accidents had the certain patterns by the training level and by the material or machine involved in each class. Thus, the planned and organized safety education programs should be produced and investigated for college students before their major laboratory classes.

• 대한치과기공학회지
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• 제42권2호
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• pp.173-185
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• 2020

Purpose: The purpose of this study was to investigate dental technicians' awareness of infections and to enhance their interest and commitment towards infection prevention. Methods: A self-reported questionnaire survey was conducted among dental technicians. Total of 195 responses were used for analysis. A cross-tabulation analysis was used to compare dental technicians' awareness of infections according to their levels of education on infection prevention (α=0.05). Results: Dental technicians were educated on infection prevention (40.5%). Most participants received infection prevention education from school (29.8%). Dental laboratories had an infection control guideline (34.9%). Dental technicians were not aware of infection risks at their workplaces or believed that they were not at risk of infections at their workplaces (59.3%). Conclusion: Dental technicians must be consistently educated on infection prevention and control through systematic education at school and wider promotion through media. Research is needed to economically and efficiently improve equipment used by dental technicians and to protect them from infectious diseases. A budget for infection prevention must also be determined. Institutional measures such as providing support for dental technicians at the policy level and developing a basic infection prevention manual are necessary. Solving these issues not only protects dental technicians from infections but also allows them to provide high-quality medical services.

• 대한치과기공학회지
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• 제41권1호
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• pp.1-7
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• 2019

Purpose: The objectives of this study was to evaluate clinical adaptation of dental prostheses printed by 3 dimensional(3D) printing technology. Methods: Ten study models were prepared. Ten specimens of experimental group were printed by 3D printing(3DP group). As a control group, 10 specimens were fabricated by casting method on the same models. Marginal gaps of all specimens were measured to evaluate clinical adaptation. Marginal adaptations were measured using silicone replica technique and measured at 8 sites per specimen. Wilcoxon's signed-ranks test was used for statistical analysis(${\alpha}=0.05$). Results: Means of marginal adaptations were $95.1{\mu}m$ for 3DP group and $75.9{\mu}m$ for CAST group(p < 0.000). Conclusion : However, the mean of the 3DP group was within the clinical tolerance suggested by the previous researchers. Based on this, dental prosthesis fabricated by 3D printing technology is considered to be clinically acceptable.

• 대한치과기공학회지
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• 제24권1호
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• pp.43-49
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• 2002

To develop the natural antibacterial agents which don't have any toxicity against man, collected several species of medicinal plants were tested for their antibacterial activity from dental caries bacteria Streptococcus sanguis. The result of using paper disc method and the result of viable cell counting method, Phellodendri Cortex was selected as antibacterial agent. The high antibacterial activity was acquired at high extraction temperature and long extraction temperature. The antibacterial of Phellodendri Cortex was not effected by the concentration of ethanol.

• 대한치과기공학회지
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• 제33권3호
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• pp.227-236
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• 2011

Purpose: The purpose of this study was to reduce the remake rate of dental prosthesis. We examined remake cause and major factor of dental prosthesis to determine methods for raising dental prosthesis satisfaction. Methods: Subjects included dental technicians in the metropolitan areas of the cities of Daegu and Gyeong-buk. Surveys were filled out by consenting dental technicians. Statistical analysis was done using SPSS version 19.0 for Windows. We determined frequencies and percentage, calculating means, and standard deviations, and determining statistical significance using t-tests, analysis of variance. Results: Impression or material transform is high among remake cause and margin is high among remake major factor. Crown class showed differences in General characteristics associated with age, number of employees, and number of connection dental. Porcelain class showed differences in General characteristics associated with age, number of employees, and number of connection dental. Denture class showed differences in General characteristics associated with age, monthly salaray, and career. Implant class showed differences in General characteristics associated with age, education, and career. Conclusion: In order to reduce remake rate of dental prosthesis, communication of dentist, dental technician, and the patient are require and correct information of patient and dental prosthesis are need.

• 대한치과기공학회지
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• 제18권1호
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• pp.39-65
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• 1996

The purpose of this to inquire of the people who run a dental mechanical laboratory having troubles to manage and to find out the reform measures on the point at issue. With having done random sampling for the chiefs of dental mechanical labs across the nation, and then marking the analysis of the data for the survey, I came to a conclusion to be as follow. 1. The operating problems in dental mechanical laboratory in Korea is that it is too near at hand that the requested days for the manufacture of dental prosthesis appliances form dental clinics(45%)(P<0.01) 2. The problem of dental mechanic manpower was due to a small salary and inferior working environment(35% each)(P<0.01) 3. Some of them discount dental mechanical charges in manufacturing dental prosthesis appliances(36.7%)(P<0.01) 4. Many of them employed unlicensed dental technicians(61.7%)(P<0.01) As a counterplan for the aforementioned, I think that the whole dental mechanics should cooperate in breaking off the customary custom to allow a discount on the dental mechanical charges and readjust the dental mechanical charge to a realistic level so as to contribute to the development of the dental mechanical community and the vetterment of the public oral hygience.

• 치위생과학회지
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• 제19권3호
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• pp.147-153
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• 2019

Background: With increased interest in oral health, several efforts have been made to improve oral health conditions. To achieve this, needs for oral health must be precisely determined and accurately measured. Therefore, factors influencing both objective unmet dental needs, which were determined by experts, and perceived unmet dental needs, which were determined by patients, were examined in this study. Methods: Responses of 17,735 respondents aged greater than 19 years from the Korean National Health and Nutrition Survey collected using the fifth (2010~2012) rotation sample survey were analyzed. Based on the information collected from the survey and dental examination, we determined the associations between the independent (sex and socioeconomic level) and dependent variables using a chi-squared test. Moreover, ordinal logistic regression analyses on multiple categorical values were performed using perceived and objective dental needs as the dependent variables. Results: Generally, factors influencing both perceived and objective dental needs were similar. These included sex, household income, educational level, private insurance, and subjective oral health status. However, the high-income groups had lesser perceived and objective dental needs compared to the low-income groups. Furthermore, factors such as sex, educational level, and marital status had different influence on both needs. Conclusion: Generally, factors that affect perceived and objective dental needs were similar. To minimize unmet dental needs, factors influencing both perceived and objective dental needs should be examined for a broad dental insurance coverage, and efforts to prevent oral diseases are also required.

• 한국산업융합학회 논문집
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• 제25권5호
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• pp.869-880
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• 2022

This study was conducted on 54 freshmen of the department of dental technology in D University to examine the effect of dental morphological practice mobile application utilization on the students' perception of class and satisfaction with learning. Major results of the study showed that satisfaction and utility towards functions of mobile application strengthened positive perception of dental morphology class, leading to improvement of satisfaction with learning, which suggested that functional convenience and utility in the use of applications were the effective factors for increasing the satisfaction with learning. Those results need to be given important consideration in designing the class using the mobile applications.