Earticle

Purpose: The purpose of this study is to evaluate the fitness of lower jaw compete denture with glass fiber. Methods: Lower jaw edentulous model was selected as the master model. Ten study models were produced using Type Ⅳ stone(n=10). Lower jaw trial dentures were produced by the wax denture base and artificial teeth. Conventional complete denture (CD) group was fabricated by excluding glass fiber reinforcement (n=5). Glass fiber complete denture (GD) group was fabricated with glass fiber reinforcement (n=5). The lower jaw trial complete denture was invested using a plaster. PMMA resin was injected and curing was performed. The CD and GD groups measured the fit using silicone replica technology. The measured data was verified by t-test. Results: The anterior area of the CD group showed the smallest value. There was a statistically significant difference in the anterior area of the CD group and the GD group (p<0.05), but there was no statistically significant difference in the posterior area (p>0.05). Conclusion : Complete denture with glass fiber showed low fitness and further study is needed to apply it clinically.

Purpose: The purpose of this study was to evaluate the clinical acceptability of the marginal and internal gap of Co-Cr metal copings fabricated with stereolithography (SLA). Methods: Titanium master dies were milled after scanning of the prepared tooth (n=30). For group I, Co-Cr metal copings were made from conventional lost-wax technique(LWT, n=10). For group II, the master dies were scanned and designed with CAD system. Then, metal copings were milled with Co-Cr(SUB, n=10). For group III(ADD, n=10), the scanning and design procedures were same as group II and burn-out resins were fabricated with SLA device. The marginal and internal discrepancies were measured under an optical microscope(100x) on ten reference points and were statistically analyzed with one-way ANOVA(α=.05). Results: The mean total discrepancies were 53.76±12.42μm in the LWT group and 69.82±15.48μm in the ADD group. The SUB group showed the largest total mean value 110.33±13.77μm. There was statistically significant difference between the SUB and the other groups(P<0.05). Conclusion : Co-Cr metal copings fabricated with SLA technology showed clinically acceptable value on marginal and internal gap and there was no statistically significant difference between conventional lost-wax technique and SLA.

Purpose: The aim of this study was to evaluate accuracy of three type complete mandibular denture of before and after polymerization. Methods: Mandibular edentulous model was selected as the master model. 15 study models were made by Type Ⅳ stone. Wax complete mandibular dentures were produced by the denture base and artificial teeth. Before and after curing, STL files were obtained using a blue scanner. By superimposing the digitized complete mandibular denture data(after curing) with the CAD-reference(before curing) three-dimensionally, visual fi t-discrepancies were drawn by calculating the root mean square (RMS) and visualized on a color-difference map. Each calculated RMS-value was statistically analyzed by 1-way analysis of variance(ANOVA) (α = .05). Results: Mean(SD) RMS-values was OM group 88.98(6.10)㎛, BM group 82.35(13.46)㎛, BDM group 77.83(9.46)㎛. The results of the 1-way ANOVA showed no statistically signifi cant differences in the RMS values of the Three groups for the material (P > .241). Conclusion : Deformation of artificial teeth position was observed in all groups after resin polymerization. But the values, all group were within the clinically acceptable range. The values of BDM group showed the least deformation than the other two groups.

Purpose: The purpose of this study was to evaluate the effect of denture cleansers on the flexural bond strength of heat curing denture base resin and reliners. Methods: The denture base resin was bonded to the reliners(vertex self curing, kooliner, rebase Ⅱ) to make the specimen. The specimens were immersed in denture cleansers(Polident, Cleadent) and evaluated after 1week, 3week, 5weeks. After denture reliners were injected, flexural bond strength was measured. Results: The bond strength of denture base resin and vertex self curing resin as reliner was significantly decreased at 5 weeks in cleadent and polident(p<0.05). The bond strength of kooliner and rebase Ⅱ was significantly decreased at 5 weeks in denture cleaners(p<0.05). Kooliner was significantly decreased at 3 and 5 weeks in polident and rebase Ⅱwas significantly decreased at 3 and 5 weeks in all denture cleansers(p<0.05). Conclusion : The flexural strength between the denture base resin and the reliners decreased significantly as the treatment time increased.

Purpose: The development of the dental technology industry has digitized the dental process. Definition of Digitalization of Dental Implantation Digitalization is the process of model making and prosthodontic processing using 3D CAD and CAM. Currently, it is becoming popular due to the spread of various devices. However, precision evaluation at this stage is an important factor in precision-based dental procedures. Therefore, in this study, we want to analyze the precision of the processed body made with digital dental machine. Methods: The accuracy of digital dental pore devices was evaluated. Specimens were fabricated with 5 types of 3D printers. The external shape was measured with the prepared specimen. The surface roughness was measured. Results: As a result, precision was excellent in order of EP2 specimen, EP1 specimen, and EA2 specimen. The precision of EP3 specimen and EA1 specimen is not excellent. And the precision of the specimen processed with polymer 3D printer is excellent. The accuracy of LCPS type polymer 3D printers is considered to be excellent. Conclusion : 1. Observation of the shape The 3D printer for LCPS system and the 3D printer for SLM 40μm system were found to be precisely processed. 2. Surface roughness results The LCPS system polymer 3D printer has been shown to have a precise surface.

Purpose: The purpose of this study was to investigate the denture attachment status and the denture need of elderly Koreans and to provide basic data for improving the quality of life by developing methods and education programs for the oral health of the elderly. Methods: This study selected 4,340 persons who completed questionnaires and oral examinations among elderly people aged 65 or older only from the National Health and Nutrition Examination Survey data of the 6th period (2013-2015). Results: There was a significant relationship between age, residence, and education level in complete dentures. There was a significant relationship between gender, age, residence, and education level in the partial denture wearing state. In the complete denture need, there was a significant relationship with age. The need for partial denture was found to be significant in gender, age, and residence. Conclusion : Based on the results of this study, it can be used as basic data for oral health education and dental prosthesis related to denture which can improve oral health of the elderly in the future.

Purpose: This study aimed to investigate the relationship between dental technology students’ life stress and smartphone addiction in order to detect smartphone over-users early, prevent them from getting addicted, and obtain basic data for creating a positive environment for academic achievement by using smartphone in a right way. Methods: The subjects of this study were university students at D University and G University in Daejeon Metropolitan City and Gangwon-do. A questionnaire survey was conducted to the subjects who understood the purpose of this study and participated in it from March 1 to June 10, 2018, and 243 were finally analyzed except 24 questionnaires without sufficient answers. Results: As a result of multiple regression analysis with variables, which were significant in univariate analysis, as independent variables, there were gender and smartphone dependency as general characteristics affecting the degree of smartphone addiction, and family relations and future problems among stress sub-factors were selected as significant variables. Conclusion : In the case of college students, they choose the smartphone as the easiest way to relieve stress because they lack the time and space to actually release stress. Therefore, club activities or on-campus and extra-curricular activities are recommended, and it needs to seek a way to get rid of stress by solving the cause of stress through counseling.

Purpose: The purpose of this study is to clarify the mediating effect of the basic occupational ability in relation to the career barrier and job-seeking efficacy of dental technology students. It aims to provide the basic data for NCS-based education and career guidance. Methods: The subject of the questionnaire survey was dental technology students. The collected data were analyzed using the SPSS 21.0 program. For reliable verification, a significance level of α = .05 was used and reliability analysis, frequency analysis, descriptive statistics analysis, correlation analysis and regression analysis were performed. Results: The results of the analysis showed that the basic occupational ability had a mediating effect in relation to career barriers and job-seeking efficacy. It was found that the basic occupational ability had a mediating effect in the relationship between job-seeking efficiently and other variables such as difficulty in an interpersonal relationship, lack of self-clarification, conflict with others in important positions, lack of job information, and lack of interest. Conclusion : The results of this study confirmed the importance of the basic occupational ability in improving job-seeking goals, job motivation, job search strength, job skills, and other related areas. If it appears difficult to overcome career barriers such as interpersonal difficulty, lack of self-clarification, conflict with other important people, lack of job information, and lack of interest, then the improvement of the basic occupational ability can be expected to enhance the job-seeking efficiency.

목적: 본 연구는 실무 현장과 교육 현장의 조사를 통한 종합적인 의견을 수렴하여 합리적인 치과기공사 양성 및 배출을 위한 개선안을 도출하고자 한다. 방법: 3회에 걸쳐 설문조사가 진행되었으며, 1차는 개방형 문항으로 조사되었고, 2차, 3차는 폐쇄형 문항으로 조사되었다. 델파이 조사를 위한 조사 인원 선정을 100명(정책집단: 20명, 교육집단: 20명, 임상가 집단: 60명)으로 지정하였다. 1차 개방형 조사결과를 토대로 2차 설문문항을 작성하였으며, 2차 설문조사 결과를 토대로 3차 설문문항을 작성 후 조사하였다. 수집된 자료의 분석은 통계패키지 프로그램 SPSS Ver. 21.0를 활용하여 델파이 기법(Delphi Method)을 활용한 연구 결과에서 전문가 집단의 의견을 수렴하기 위해 빈도분석과 기술통계분석을 실시하였다. 결과: 현 교육체계의 문제점은 임상현장과의 차이와 실무능력저하, 국가시험위주의 교육이 문제점으로 대두되었으며, 현행 평가제도의 문제점은 임상현장을 충분히 반영하지 못한 점, 실무능력이 미 반영된 실기평가로 지적되었다. 결론: 결론적으로 치과기공사의 교육과정과 평가제도는 현실적인 내용을 고려하면서 임상 실무와의 연계성을 높이는 방향으로 개선되어야 할 것으로 사료된다.