• 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.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.263-263
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• 2017

• 월간산업보건
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• s.234
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• pp.63-64
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• 2007

• 월간산업보건
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• s.104
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• pp.2-14
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• 1996

• Journal of Nutrition and Health
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• v.7 no.2
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• pp.1-16
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• 1974

• Journal of Preventive Medicine and Public Health
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• v.22 no.1 s.25
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• pp.116-124
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• 1989

To assay the cytogenetic toxicity of $NiCl_2,\;K_2Cr_2O_7CdCl_2,\;and\;HgCl_2$, the frequencies of sister chromatid exchanges(SCEs) and chromosomal aberrations were observed in the metaphase chromosomes of the human lymphocytes which were cultured with above materials. The frequencies of SCEs are dose-dependently increased by all materials in this experiment. Chromosomal aberrations, especially gap and break, are increased by the nickel and chromic compounds, while not significantly increased by the cadmium and mercurial compounds. This results indicate the dose dependent relationship between the frequencies of SCEs and the concentrations of the heavy metals, but the increasing rates of the SCEs induced by the heavy metals are less sensitive than other mutagens or carcinogens which were confirmed.

• Health Policy and Management
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• v.23 no.4
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• pp.326-342
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• 2013

Background: Engaging and Involving stakeholders who have different interests in changing health care policies are difficult task. As the literature on the governance in Korean health care field is rare, this study aims to provide empirical evidence of 'governing health policy'-the ways health care policy is made, implemented, and evaluated from a political perspective. Methods: The authors of this study conducted interviews with elites in policy and clinical areas, which was considered to be the most effective approach to gather in-depth information about the background of changing payment policy as well as the barriers or contributors for making the policy sustainable. A total of 14 experts (3 government officials, 2 representatives from medical profession, 3 professors form academic field, and 6 healthcare providers from New DRG pilot program hospitals) participated in 2 hour long interviews. Results: There was a perception gap of the feasibility and substantiality of new payment system among elites. The score was higher in government officers than those in scholars or clinical experts. Next, the interviewees indicated that Korean New DRG might not sustain without significant efforts to improving democratic aspects of the governance. It is also notable that all interviewees except healthcare providers provided negative expectation of the contribution of new payment system to increase administration efficiency. For clinical efficiency, every stakeholders perceived there was no increased efficiency after introduction of New DRG payment. Like general perception, there was a wide gap between the perception of stakeholders in quality change after implementing the new payment system. Finally, interview participants negatively assumed about the likelihood of New DRG to remain a case of successful reforms. Conclusion: This study implied the importance of social consensus and the governance of health policy.

• Journal of Korean society of Dental Hygiene
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• v.1 no.2
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• pp.227-242
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• 2001

The purpose of this study was 10 examine whether or not the dental- health education experiences of elementary school teachers have any influence on their oral-health awareness and attitude. The subjects in this study were 414 selected teachers from Seoul and North Cholla province. The instrument used by Lee Heung-su was modified into self- reporting questionnaire, and the schools where the subjects were working were visited to conduct a survey for 28 days from September 15 to October 13, 2000. For data analysis, SPSS was employed, and chi-squre, t-test and ANOVA were implemented. The findings of this study could be listed as below: 1. 184(44.4%) out of the techers investigated had ever been educated in dental health, and 230 teachers(55.6%) hadn't. 47% replied they hadn't received oral-health education for the lack of education opportunities. 2. In regard to dental-health awareness and attitude. the presence or absence of dental-health education experiences didn't make any difference to their daily toothbrushing frequency(p>0.05). The use of fluorine was significantly different between the groups(p<0.01), as 42.9% of the teachers with dental-health education experiences and 63.9% of the others with no such a experience didn't use that, 45.7% of the former group and 29.1 % of the latter accurately knew how to brush teeth, and the difference between the two was significant (p<0.01). 3. Concerning student-related dental-health awareness and attitude, the dental-health education experiences make 45.7% of the educated group and 31.7% of the uneducated group agreed to the strong need for oral examination, and the gap between the two was significant(p<0.01). 90.8% of the former group gave counsel to students on dental health, and 77.2% of the latter didn't. The gap between the two was significant as well (p<0.01). 77.2% of the educated group and 41.3% of the uneducated group offered frequent dental-health education, and the difference between the two was significant (p<0.01). 4. Their awareness of the fluorine-based toothbrushing project differed significantly by region(p<0.05), as the teachers from North Cholla province recognized it better than those from Seoul. The female teachers provided more education regarding that project, and those who were older or had more teaching experiences were more aggressive in instructing that project(p<0.01). And the married teachers took more forward attitude than the unmarried (p<0.01). By school location, the teachers from Seoul showed more active attitude than those from North Cholla province(p<0.01), and the gap between the two was significant. As to cooperation, those who were older or had more teaching experience were more cooperative, and the married teachers joined forces better than the unmarried. The gap was significant (p<0.01). 5. Concerning the awareness and attitude of the fluorine-based toothbrushing project, the educated teachers took more aggressive attitude, and the difference between the two was significant(p<0.01). The above-mentioned findings suggested that the dental-health awareness and attitude of the elementary school teachers were under a lot of influence of their oral-health education experiences, and there is a need to develop and carry out education programs for teacher.

• Journal of Technologic Dentistry
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• v.37 no.2
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• pp.69-76
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• 2015

Purpose: In this study, the marginal fitness of ceramic Co-Cr metal crown made by precision casting, milling, and selective laser melting method were compared. Methods: The ceramic Co-Cr metal crown manufactured by precision casting used the lost wax(LC specimen) method. The abutment were scanned and then made by milling(CM specimen), selective laser melting(CS specimen) method. The specimen were cut bucco-lingual and mesio-distal, and absolute marginal discrepancy and marginal gap were measured using a digital microscope. The surface roughness of the crown was also observed. Results: On the bucco-lingual axial, absolute marginal discrepancy was the LC specimen $31.72({\pm}4.58){\mu}m$, the CM specimen $78.29({\pm}3.28){\mu}m$ and the CS specimen $143.13({\pm}3.83){\mu}m$, respectively. On the bucco-lingual axial, marginal gap was the LC specimen $22.70({\pm}1.46){\mu}m$, the CM specimen $22.70({\pm}1.49){\mu}m$ and CS specimen $99.60({\pm}1.57){\mu}m$, respectively. Conclusion: For ceramic Co-Cr metal crowns, LC specimen was superior for absolute marginal discrepancy and marginal gap. The surface of metal crowns by selective laser melting were the roughest.