• 한국산학기술학회논문지
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• 제12권11호
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• pp.5079-5086
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• 2011

이 연구의 목적은 치기공과 학생들의 구강위생관리 실태 및 지식을 파악하여 지역사회의 구강건강을 향상시킬 수 있는 동기를 부여하고, 구강보건 교육에 도움이 되고자 함이다. 조사대상자는 충청도 소재 대학의 치기공과에 재학 중인 학생 160명을 대상으로 2010년 11월 10부터 12월 9일까지 설문조사를 실시하였고, 다음과 같은 결론을 얻었다. 일반적 특성에 따른 구강관리 지식차이는 성별로 남자가 여자보다 높았고, 연령별로는 연령이 높아질수록 높았고, 학년별 항목에서는 학년이 높을수록 높았고, 통계적으로 유의한 차이가 있었다(p<0.05). 구강위생관리 실태에 따른 구강관리지식차이는 일일 잇솔질 횟수가 5회 이상에서 가장 높았고, 잇솔질 방법은 옆으로 치아만 한다에서 높았다. 치간 칫솔 이용유무 항목에서는 사용한다가 높았고, 통계적으로 유의한 차이가 있었다(p<0.05). 따라서 전반적인 구강위생관리 실태는 구강보건교육의 경험이 있는 치기공과 학생들이 양호한 것으로 나타났으며, 이를 통해 수업시간에 계속적으로 구강보건교육을 받고 익히는 사람들에게서 구강건강관리가 달라지는 것을 알 수 있었다. 이에 지역사회에서도 구강보건교육의 기회를 확대시켜 국민의 구강건강을 향상시키도록 해야하겠다.

• 대한치과기공학회지
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• 제39권2호
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• pp.75-82
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• 2017

Purpose: This study provided the basic data for selection the zirconia block and CAM by means of marginal fitness observations, flexural strength test and hardness test. Methods: Three dental zirconia blocks(ABCera, NaturaZ, ST98) and two dental milling machines(CAD/CAM MS, DWX-50) were used in this study. Metal abutment(diameter 10 mm, height 5 mm, inclined angle $3^{\circ}$ taper, 1 mm chamfer margin) was fabricated by Ti customized abutment, and then zirconia copings were fabricated for each ten specimens. Silicone replica technique was used to observe the marginal fitness of cross-sections with a stereomicroscope at ${\times}50$ magnification. The dental zirconia blocks was cut into 10 pieces each having a size of $25mm{\times}5mm{\times}1mm$, and fabricated according to the manufacturer's instructions, and flexural strength was measured using a universal testing machine. For hardness test, a micro Vickers hardness tester was used as it was in the flexural strength test. Statistical analysis was performed by one way ANOVA and post-test was performed by Scheffe test. Results: For marginal fitness of bucco-lingual axial, ZU group($59.7{\pm}10.3{\mu}m$) was the lowest, followed by RA, ZA, ZD, RD, RU. For marginal fitness of mesio-distal axial, ZU group($59.3{\pm}10.2{\mu}m$) was the lowest, followed by RA, ZA, RD, ZD, RU. One-way ANOVA showed statistically significant difference between groups(p<0.05). For flexural strength, ABCera block($718.0{\pm}57.2MPa$) was the highest, followed by NaturaZ, ST98. For hardness, ABCera block($1550.3{\pm}19.8Hv$) was the highest, followed by ST98, NaturaZ. There was no significant difference in flexural strength and hardness between blocks(p>0.05). Conclusion: Based on the results of this study, the type of dental zirconia block did influence the marginal fitness, and all dental zirconia blocks are expected to be suitable for clinical application. The highest flexural strength and hardness were ABCera block, and no statistically significant difference was observed.

• The Journal of Advanced Prosthodontics
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• 제9권3호
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• pp.176-181
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• 2017

PURPOSE. The purpose of this study was to evaluate the marginal and internal gaps of Ni-Cr and Co-Cr copings, fabricated using the dental ${\mu}-SLA$ system. MATERIALS AND METHODS. Ten study dies were made using a two-step silicone impression with a dental stone (type IV) from the master die of a tooth. Ni-Cr (NC group) and Co-Cr (CC group) alloy copings were designed using a dental scanner, CAD software, resin coping, and casting process. In addition, 10 Ni-Cr alloy copings were manufactured using the lost-wax technique (LW group). The marginal and internal gaps in the 3 groups were measured using a digital microscope ($160{\times}$) with the silicone replica technique, and the obtained data were analyzed using the non-parametric Kruskal-Wallis H test. Post-hoc comparisons were performed using Bonferroni-corrected Mann-Whitney U tests (${\alpha}=.05$). RESULTS. The mean (${\pm}$ standard deviation) values of the marginal, chamfer, axial wall, and occlusal gaps in the 3 groups were as follows: $81.5{\pm}73.8$, $98.1{\pm}76.1$, $87.1{\pm}44.8$, and $146.8{\pm}78.7{\mu}m$ in the LW group; $76.8{\pm}48.0$, $141.7{\pm}57.1$, $80.7{\pm}47.5$, and $194.69{\pm}63.8{\mu}m$ in the NC group; and $124.2{\pm}52.0$, $199.5{\pm}71.0$, $67.1{\pm}37.6$, and $244.5{\pm}58.9{\mu}m$ in the CC group. CONCLUSION. The marginal gap in the LW and NC groups were clinically acceptable. Further improvement is needed for CC group to be used clinical practice.

• 대한치과기공학회지
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• 제24권1호
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• pp.83-93
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• 2002

This study was performed to evaluate the importance of parents, knowledge, cognition and behaviour about dental health care on the development of dental caries in preschoolers. Subjects were comprised of 170 preschoolers collected from three preschoolers placed in Pusan and Kimhae area and study period were 6 months from January, 2000. Examination on the preschoolers' dental health and questionnarie survey on parents' knowledge, cognition and behaviour about dental health care were conducted. Collected data were analyzed by chi-square test and t-test using SAS program. Dental caries was so prevalent as the rate of 73.5%. And, the rate was different by the area(p=0.001), and increased with preschooler's age(P=0.004). The parents gain the knowledge about dental health care mainly from dentist or dental hygienist(32.9%), newspaper, magazine booklets(26.5%), TV and VTR tape(20.0%), etc, but rarely from school health education(4.7%). Caries prevalence was significantly lower in case of regular brushing than that of insufficient brushing(p=0.002) and in case of consistently informing brushing time to their children(p=0.014). This results showed that the dental health care for preschoolers is insufficient and the most important factor for caries prevention is regular brushing. And it seemed that the parent's concern and knowledge play an important role for the prevention of preschooler's dental caries. Dental health education would be focused on the parents, especially for the practice of preventive behavior by preschoolers themselves.

• 대한치과기공학회지
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• 제28권2호
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• pp.375-397
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• 2006

The main purposes of this thesis are to examine the job satisfaction of dental technicians, to explore the factors which have impacts on the job satisfaction of the dental technicians, and finally to address some suggestions for dental technicians in order to improve their job satisfaction. This study is based on the survey data which were conducted among dental technicians engaged in the dental technical places in Daegu area from March 1, 2003, to March 31, 2003. Three hundreds and twenty questionnaires were distributed and 304 of them were collected. Among them 293 questionnaires were eventually used for the statistical analysis. Descriptive and regression analysis were introduced, and in which 12 independent variables and one dependent variable were included. The results of this study are as follows: Approximately 50 percent of the dental technicians in Daegu expressed that they were satisfied with their job, while about 20 percent of them were not satisfied with their job. According to the multiple regression analysis, work environment($\beta$,=0.216), human relationship($\beta$,=0.405), and self-esteem($\beta$,=0.156) have statistically significant positive effects on job satisfaction. On the other hand, conflicts caused in the process of carrying out their jobs have statistically a significant negative effect($\beta$,=-0.166) on job satisfaction. Among 12 independent variables, human relationship has the strongest effect($\beta$,=0.405) on job-satisfaction and 12 independent variables explains approximately 35 percent of variance in the job-satisfaction of dental technicians in Daegu. In conclusion, with regard to the improvement for the job-satisfaction of dental technicians, the association of dental technicians' active concern and long-term plans are necessary. Finally, some suggestions for the increase of the level of job satisfaction of dental technicians are introduced and discussed.

• 대한치과기공학회지
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• 제41권4호
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• pp.279-285
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• 2019

Purpose: The dental CAD / CAM system has been popular with the development of the digital dental industry. Zirconia is a typical material in dental CAD / CAM systems. Zirconia crowns are classified into single layer and double layer. This study is about the double layer crown of zirconia. The surface roughness, bond strength and fracture patterns of the zirconia surface were observed. Methods: Zirconia blocks were cut using a low speed cutter. Sintered to form a plate shape (6mm × 6mm × 3mm). The prepared specimens were surface treated in four ways. Surface roughness and bond strength were measured. And the fracture pattern was observed. Results: Result of surface treatment of zirconia. The surface roughness test results were as ET 2.87 ㎛, ST 2.67 ㎛, LT 2.44 ㎛, AT 2.41 ㎛, CN 2.08 ㎛ order. Bond Strength results were as LT 25.09 MPa, AT 23.27 MPa, ST 21.27 MPa, ET 21.09 MPa, CN 16.12 MPa order. Fracture patterns showed cohesive failure of 25-50% of the bond area. Conclusion: Surface roughness, bond strength and fracture pattern of the zirconia surface were observed. Etching the surface treatment of zirconia materials has been shown to affect the surface roughness. Zirconia special binder treatment has been shown to affect the bond strength improvement.

• 한국치위생학회지
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• 제19권6호
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• pp.1089-1097
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• 2019

Objectives: The purpose of this study is to assess the accuracy of provisional restorative resins fabricated using dental three-dimensional (3D) printers. Methods: Provisional restorative resins were fabricated using the first molar of the right mandibular. Three groups comprising a total of 24 samples of such resins were fabricated. The prepared abutment was scanned initially and then designed using a computer-aided design (CAD) software. The conventional subtractive manufacturing system was employed to fabricate the first group of resins, while the second and third groups were fabricated using a digital light processing (DLP) 3D printer and a stereolithography (SLA) 3D printer, respectively. The internal surfaces of the resins were scanned and 3D measurements of the resins were taken to confirm their accuracy. Results: The root-mean-square deviation (RMS±SD) of the accuracy of the resins fabricated using the conventional subtractive manufacturing system, DLP 3D printer, and SLA 3D printer were 68.83±2.22 ㎛, 74.63±6.23 ㎛, and 61.74±4.09 ㎛, respectively. A one-way analysis of variance (ANOVA) test showed significant differences between the three groups (p < 0.05). Conclusions: Provisional restorative resins fabricated using DLP and SLA 3D printers demonstrated clinically-acceptable results.

• 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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• 제44권4호
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• pp.144-153
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• 2022

Purpose: This study examines the influence and the relevance of personal background factors, social activity factors, and satisfaction factors for university education of college students in terms of changes in core competencies required by companies, so as to provide basic data for developing a curriculum necessary for improving core competencies. Methods: A self-administered questionnaire survey was administered to 172 college students from the Department of Dental Laboratory Technology at K University in Gangwon Province, who understood the purpose of this study and agreed to participate, from September 10, 2022 to September 30, 2022. Results: 1. The core competency scores of university students in the dental technology department for teamwork was 3.91±0.65, creativity was 3.66±0.70, challenging spirit was 3.64±0.74, professionalism was 3.54±0.74, global was 3.29±0.69. 2. To enhance the core competencies of college students in the dental technology department, it is necessary to improve the satisfaction with the curriculum through the expansion of educational infrastructure, and help in the career decision and preparation process. Conclusion: It is necessary to seek research that identifies the core competencies of dental technicians and university students based on the image of human resources desired by companies in a more diverse way and programs necessary to promote them.