• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.159-169
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• 2017

PURPOSE. The purposes of this study were to evaluate the marginal and internal gaps, and the potential clinical applications of three different methods of dental prostheses fabrication, and to compare the prostheses prepared using the silicone replica technique (SRT) and those prepared using the three-dimensional superimposition analysis (3DSA). MATERIALS AND METHODS. Five Pekkton, lithium disilicate, and zirconia crowns were each manufactured and tested using both the SRT and the two-dimensional section of the 3DSA. The data were analyzed with the nonparametric version of a two-way analysis of variance using rank-transformed values and the Tukey's post-hoc test (${\alpha}=.05$). RESULTS. Significant differences were observed between the fabrication methods in the marginal gap (P < .010), deep chamfer (P < .001), axial wall (P < .001), and occlusal area (P < .001). A significant difference in the occlusal area was found between the two measurement methods (P < .030), whereas no significant differences were found in the marginal gap (P > .350), deep chamfer (P > .719), and axial wall (P > .150). As the 3DSA method is three-dimensional, it allows for the measurement of arbitrary points. CONCLUSION. All of the three fabrication methods are valid for measuring clinical objectives because they produced prostheses within the clinically acceptable range. Furthermore, a three-dimensional superimposition analysis verification method such as the silicone replica technique is also applicable in clinical settings.

• Journal of Environmental Health Sciences
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• v.44 no.4
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• pp.360-369
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• 2018

Objectives: Outdoor tobacco smoke can penetrate into the indoor environment through cracks in the building envelope. This study aimed to characterize the particle size distribution of infiltrated secondhand smoke (SHS) through the gap in a single glazed and a secondary glazed window according to pressure differences in a chamber. Methods: Two polyvinyl chloride sliding windows were evaluated for infiltration, one with a glazed window and the other with a secondary glazed window. Each window was mounted and sealed in a polycarbonate chamber. The air in the chamber was discharged to the outside to establish pressure differences in the chamber (${\Delta}P$). Outdoor smoking sources were simulated at a one-meter distance from the window side of the chamber. The particle size distribution of the infiltrated SHS was measured in the chamber using a portable aerosol spectrometer. The particle size distribution of SHS inside the chamber was normalized by the outdoor peak for fine particles. Results: The particle size distribution of SHS inside the chamber was similar regardless of window type and ${\Delta}P$. It peaked at $0.2-0.3{\mu}m$. Increases in particulate matter (PM) concentrations from SHS infiltration were higher with the glazed window than with the secondary glazed window. PM concentrations of less than $1{\mu}m$ increased as ${\Delta}P$ was increased inside the chamber. Conclusions: The majority of infiltrated SHS particles through window gap was $0.2-0.3{\mu}m$ in size. Outdoor SHS particles infiltrated more with a glazed window than with a secondary glazed window. Particle sizes of less than $1{\mu}m$ were associated with ${\Delta}P$. These findings can be a reference for further research on the measurement of infiltrated SHS in buildings.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.235-242
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• 2017

Purpose: The aim of this study was to evaluate the marginal and internal gap of zirconia copings fabricated by CAD/CAM system and to research the effect of cement space on the fit of zirconia prosthesis. Methods: Zirconia copings were designed using 3shape software and then milled from presintered zirconia blocks by Kavo dental milling machine. The cement space was set at $0{\mu}m$ around the margins for all groups, and additional cement space appling 1 mm above the finish lines of tooth. The samples were classified into 4 groups according to the cement space setting(Cs-0, Cs-40, Cs-80, Cs-120). Replica technique used to investigate marginal and internal gap. The silicone film thickness was recorded using a optical microscope with image software analysis system at 75${\times}$magnification. The assessment performed on the six points in bucco-lingual and mesio-distal sections(4 groups, 10 copings per group, 12 measuring points per coping). The data were statistically analyzed with one-way ANOVA followed by pair-wise Tukey's post hoc tests(${\alpha}$<0.05). Results: Better marginal and internal fit values were exhibited by $80{\mu}m$ cement space. The results showed that different cement space values had statistically significant effect on the marginal and internal gap of zirconia copings(p<0.001). The gap of margin and axial wall area was smaller than that the gap of occlusal area in all groups(p<0.001). Conclusion : Effect of different cement spaces on the marginal and internal gap of zirconia copings.

• Journal of Technologic Dentistry
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• v.38 no.4
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• pp.299-304
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• 2016

Purpose: This research is conducted for better clinical test of Zirconia as we find out the fracture strength difference of Zirconia on cement gaps of full Crown that made use of Zirconia which is somewhat being used in recent dental technology. Methods: We produced each nine of Zirconia Crown of Zirconia fracture cement gaps A group(0.03 mm), B group(0.05 mm), C group(0.08 mm) on cement gaps by use of CAD/CAM, and compared the results. We could end up getting conclusions as following. Results: There was fracture strength difference per cement gaps but no impact(P<0.05). There was difference between $1.962{\pm}0.259$ from group A and $2.005{\pm}0.367$ from group B, but no impact(P<0.05). There was difference between $1.962{\pm}0.259$ from group A and $2.478{\pm}0.331$ from group C, but it's hard to be considered as an impact(P<0.05). Conclusion: Because of the hight pressure 0.08 mm is fractured and Margin has a lot of empty space due to gap for 0.08 mm. To identify the difference between 0.08 mm and 0.05 mm, 0.08 mm is selected as a gap. Therefore when it comes to using 0.05 mm authentically 0.05 mm is quite practical to use as a gap.

• Korean Journal of Human Ecology
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• v.22 no.1
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• pp.57-74
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• 2013

The purpose of this study was to identify how age-identity is associated with the attitude toward the elderly and self-esteem of the aged. The subjects were 366 adults aged 60 and over. The statistics used for the data analysis were reliability test, frequency, percentage, mean, standard deviation, one way ANOVA, correlation and multiple regression. The results of this study were as follows; First, The majority of elderly acknowledged psychological ages as their actual ages. Secondly, The degrees of elderlys' age-identity was 2.12, and the levels of the attitude toward the elderly was 60.62. Also, The degrees of elderlys' self-esteem was 24.16. The surveyed data showed higher means than medians. Third, The age-identity of elderly was significant with respect to spouse, religion, career, living state, sex, age, gap of actual age, health state, economic state, education, monthly living expenses. And the attitude toward the elderly was stastically significant with respect age-identity, career, spouse, religion, living state, health state, education, monthly living expenses, economic state, gap of actual age, and age. Moreover, The elderlys' self-esteem level was significant with respect to spouse, age-identity, living state, religion, career, economic state, monthly living expenses, the attitude toward the elderly, health state, education, and age. Finally, The variables affecting the age-identity of elderly were health state, economic state, religion, age that explained about 34% of the total variance. And The attitude toward the elderly were age-identity, health state, gap of actual age that explained about 19% of the total variance. Also, The variables that affect elderlys' self-esteem were economic state, age-identity, the attitude toward the elderly, sex, monthly living expenses that explained about 33% of the total variance.

• Journal of Technologic Dentistry
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• v.41 no.3
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• pp.187-193
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• 2019

Purpose: The purpose of this study was to compare two-dimensional fitness of the monolithic zirconia prosthesis by using different type of scanner. Methods: No. 26 abutment tooth of FDI system was selected for the study. Using the extraoral scanner and intraoral scanner, the abutment tooth was scanned 10 times and the scanned files were saved as STL files. CAD/CAM system was used to produce the monolithic zirconia prosthesis. marginal and internal gap of the monolithic zirconia prosthesis were measured by digital microscope(x160) and applied silicone replica technique was applied. t-test, a statistical software, was used to perform data analysis. Results: Marginal gap $mean{\pm}SD$ of the monolithic zirconia prosthesis was $33{\pm}7.5{\mu}m$ with extra oral scanner and $34.7{\pm}11.1{\mu}m$ with intraoral scanner. axial gap mean was $40.5{\pm}3.5{\mu}m$ with extra oral scanner and $44.6{\pm}11.6{\mu}m$ with intraoral scanner. occlusal gap mean was $110.1{\pm}25.4{\mu}m$ with extra oral scanner and $64{\pm}9.7{\mu}m$ with intraoral scanner. Conclusion: In this study, fabricating zirconia prosthesis with different type of scanner was clinically applicable.

• Korea Journal of Hospital Management
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• v.26 no.3
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• pp.43-55
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• 2021

Purposes: The purpose of this study is to confirm the effect of mother's nationality on screening rates for infants and children health screening. We intend to find out if there is a difference in health level between infants of multicultural families and infants of domestic families, and contribute to policies to enhance future national health levels by providing information on them. Methodology: Data for those who received the first infant and children health screening between 2012 and 2018 were obtained from the National Health Insurance Service(NHIS) DB. Frequency analysis, chi-square test and logistic regression analysis were performed with the SAS 9.4 program, and the case where all the 1st to 3rd checkups were completed was defined as type I, and the case of all the 1st to 7th checkups completed, type II. Findings: Complete screening rates for type I and type II were 45.8% and 20.0%, respectively. Especially, complete screening rate of infants whose mothers nationality is foreign is only 3-4th of that of domestic mothers, and it also differed according to nationality. Practical Implications: The difference in the screening rate according to the mother's nationality is likely to lead to a health gap between multicultural families and domestic families. It is necessary to promote and encourage proper monitoring and health management through continuous health screening for infants and children.

• Health Policy and Management
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• v.31 no.1
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• pp.100-113
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• 2021

Background: This study aims to figure out the gaps in health status by estimating amenable mortality rate by region, reflecting the characteristics of Korea, and estimating the years of life lost (YLL) per capita by disease. Methods: People who died from amenable diseases between 2008 and 2018 were extracted from the cause of death statistics provided by Statistics Korea. The age-standardized amenable mortality rates were estimated to compare the health status of 229 regions. YLL per capita was calculated to compute the burden of diseases caused by treatable deaths by region. The YLL per capita by region was calculated to identify the burden of disease caused by amenable deaths. Results: First, while the annual amenable mortality rate in Korea is on a steady decline, but there is still a considerable gap between urban and rural areas when comparing the mortality rates of 229 areas. Second, YLL per capita due to the amenable deaths is approximately 14 person-years during the analysis period (2008-2018). Conclusion: Although the health status of Koreans has continuously improved, there is still a gap in health status region by region in terms of amenable mortality rates. Amenable death accounts for a loss of life equivalent to 14 person-years per year. Since the amenable mortality rate is an indicator that can measure the performance of the health care system, efforts at each local area are required to lower it.

• Journal of Acupuncture Research
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• v.20 no.5
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• pp.1-27
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• 2003

• The Journal of Advanced Prosthodontics
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• v.7 no.3
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• pp.257-263
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• 2015

PURPOSE. In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. MATERIALS AND METHODS. Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. RESULTS. According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, $24.47{\pm}5.82{\mu}m$ before and $35.11{\pm}6.52{\mu}m$ after cementation; in the laser-sintered Co-Cr structure, it was, on average, $60.45{\pm}8.87{\mu}m$ before and $69.33{\pm}9.03{\mu}m$ after cementation. A highly significant difference (P<.001) was found in marginal gap measurements of galvano copings and a significant difference (P<.05) was found in marginal gap measurements of the laser-sintered Co-Cr copings. According to the SEM examination, surface properties of laser sintered Co-Cr copings showed rougher structure than galvano copings. The galvano copings showed a very smooth surface. CONCLUSION. Marginal gaps values of both groups before and after cementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.