1.Spectrophotometric analysis of the influence to shade of zirconia core on the color of ceramic.
Kihyun BAEK ; Yi Hyung WOO ; Kung Rock KWON ; Hyeong Seob KIM
The Journal of Korean Academy of Prosthodontics 2008;46(4):409-419
STATEMENT OF PROBLEM: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. PURPOSE: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE L*a*b* system. MATERIAL AND METHODS: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE L*a*b* coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation deltaE* = [(deltaL*)2+(deltaa*)2+(deltab*)2]1/2. RESULTS: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. CONCLUSIONS: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.
Ceramics
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Dental Porcelain
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Dentistry
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Esthetics
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Hand
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Humans
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Tooth
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Zirconium
2.Generation and Qualification of Functionally Active Leukemia-derived DCs from Malignant Blasts in Acute Leukemia.
Soyoung BAEK ; Chul Won JUNG ; Myung Joo KIM ; Kihyun KIM ; Jin Seok AHN ; Hyunah LEE
Korean Journal of Hematology 2007;42(3):264-275
BACKGROUND: Dendritic cells (DCs) are increasingly being utilized for anti-cancer immunotherapy. Acute myeloid leukemia (AML) blasts are able to generate leukemia-derived DC. Advances in culture techniques and AML-DC characterization justify possible clinical applications. We investigated the ability of AML, acute lymphoblastic leukemia (ALL) and biphenotypic acute leukemia (BAL) blasts to differentiate into DCs in vitro and the qualified function of the leukemia-derived DCs. METHODS: Leukemia cells from 11 patients with AML, 3 patients with ALL and 2 patients with BAL were cultured with GM-CSF, IL-4 and with or without SCF. Cultured leukemia cells were evaluated by phenotype, mixed lymphocyte reaction (MLR), cytokine production and cytotoxic T cell (CTL) inducing activity. RESULTS: DCs were generated with GM-CSF and IL-4 from the leukemic blasts in 72% of the AML patient cells. MHC class I/II, CD11c and ICAM-1 were highly expressed in the AML-derived DCs. MLR and enzyme linked immunospot (ELISPOT) assays demonstrated that AML-DCs were able to induce T cell proliferation and activation into IFN-gamma secreting effector cells. The ALL blasts from two out of three patients differentiated into DCs with MHC class I/II+, CD11c+ only in the presence of GM-CSF, SCF and IL-4 for 14 days. CONCLUSION: These results suggest that functionallyactive DCs can be differentiated from AML blasts using GM-GSF and IL-4 and ALL, BAL blasts were differentiated into DCs only under stem cell-DC culture conditions.
Cell Proliferation
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Culture Techniques
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Dendritic Cells
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Granulocyte-Macrophage Colony-Stimulating Factor
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Humans
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Immunotherapy
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Intercellular Adhesion Molecule-1
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Interleukin-4
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Leukemia*
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Leukemia, Biphenotypic, Acute
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Leukemia, Myeloid, Acute
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Lymphocyte Culture Test, Mixed
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Phenotype
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Precursor Cell Lymphoblastic Leukemia-Lymphoma
3.Impact of Wildfire Smoke Exposure on Health in Korea
Kihyun LEE ; Sung-Soo OH ; Kyoung Sook JEONG ; Yeon-Soon AHN ; Sei Jin CHANG ; Se Hwa HONG ; Dae Ryong KANG ; Sung-Kyung KIM ; Sang-Baek KOH
Yonsei Medical Journal 2022;63(8):774-782
Purpose:
The characteristic topography and climate often affect the occurrence of large-scale wildfires in the Eastern Gangwon-do region of Korea. However, there are no studies on the health effects of these wildfires in Korea. This study aimed to analyze the differences in medical use between a wildfire-affected area and an adjacent non-affected area before and after a wildfire in 2019 in Gangwon-do, Korea.
Materials and Methods:
We used medical usage data from the Korean National Health Insurance Corporation. Rates of medical use were determined for citizens of a wildfire-affected area in the Eastern Yeongdong region and a non-affected area in the Western Yeongseo region. Logistic regression analysis was performed considering an increase in medical use per individual as a dependent variable; age, sex, income, smoking, drinking, and exercise were included as confounding variables.
Results:
The odds ratio for medical use in Yeongdong region increased significantly after 3 days, 3 months, and 1 year after a fire occurred, compared with Yeongseo region.
Conclusion
The results of this study confirmed that the use of medical care increased for residents of a wildfire-affected area, compared with those of an adjacent non-affected area. This is the first study on the relationship between wildfires and inpatient medical use in Korea.