• The Journal of Advanced Prosthodontics
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• v.3 no.2
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• pp.85-89
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• 2011

PURPOSE. The purpose of this study was to evaluate the amount of resorption and thickness of labial bone in anterior maxillary implant using cone beam computed tomography with Hitachi CB Mercuray (Hitachi, Medico, Tokyo, Japan). MATERIALS AND METHODS. Twenty-one patients with 26 implants were followed-up and checked with CBCT. 21 OSSEOTITE $NT^{(R)}$. (3i/implant Innovations, Florida, USA) and 5 $OSSEOTITE^{(R)}$. implants (3i/implant Innovations, Florida, USA) were placed at anterior region and they were positioned vertically at the same level of bony scallop of adjacent teeth. Whenever there was no lesion or labial bone was intact, immediate placement was tried as possible as it could be. Generated bone regeneration was done in the patients with the deficiency of hard tissue using $Bio-Oss^{(R)}$. (Geistlich, Wolhusen, Switzerland) and $Bio-Gide^{(R)}$. (Geistlich, Wolhusen, Switzerland). Second surgery was done in 6 months after implant placement and provisionalization was done for 3 months. Definite abutment was made of titanium abutment with porcelain, gold and zirconia, and was attached after provisionalization. Two-dimensional slices were created to produce sagittal, coronal, axial and 3D by using OnDemand3D (Cybermed, Seoul, Korea). RESULTS. The mean value of bone resorption (distance from top of implant to labial bone) was $1.32 \;{\pm}\; 0.86\; mm$ and the mean thickness of labial bone was $1.91 \;{\pm}\; 0.45 \;mm$. CONCLUSION. It is suggested that the thickness more than 1.91 mm could reduce the amount and incidence of resorption of labial bone in maxillary anterior implant.

• Molecules and Cells
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• v.37 no.7
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• pp.562-567
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• 2014

Human Hertwig's epithelial root sheath/epithelial rests of Malassez (HERS/ERM) cells are epithelial remnants of teeth residing in the periodontium. Although the functional roles of HERS/ERM cells have yet to be elucidated, they are a unique epithelial cell population in adult teeth and are reported to have stem cell characteristics. Therefore, HERS/ERM cells might play a role as an epithelial component for the repair or regeneration of dental hard tissues; however, they are very rare population in periodontium and the primary isolation of them is considered to be difficult. To overcome these problems, we immortalized primary HERS/ERM cells isolated from human periodontium using SV40 large T antigen (SV40 LT) and performed a characterization of the immortalized cell line. Primary HERS/ERM cells could not be maintained for more than 6 passages; however, immortalized HERS/ERM cells were maintained for more than 20 passages. There were no differences in the morphological and immunophenotypic characteristics of HERS/ERM cells and immortalized HERS/ERM cells. The expression of epithelial stem cell and embryonic stem cell markers was maintained in immortalized HERS/ERM cells. Moreover, immortalized HERS/ERM cells could acquire mesenchymal phenotypes through the epithelial-mesenchymal transition via TGF-${\beta}1$. In conclusion, we established an immortalized human HERS/ERM cell line with SV40 LT and expect this cell line to contribute to the understanding of the functional roles of HERS/ERM cells and the tissue engineering of teeth.

• Restorative Dentistry and Endodontics
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• v.39 no.3
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• pp.187-194
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• 2014

Objectives: The effects of bone morphogenetic protein-2 (BMP-2) and enamel matrix derivative (EMD) respectively with mineral trioxide aggregate (MTA) on hard tissue regeneration have been investigated in previous studies. This study aimed to compare the osteogenic effects of MTA/BMP-2 and MTA/EMD treatment in MC3T3-E1 cells. Materials and Methods: MC3T3-E1 cells were treated with MTA (ProRoot, Dentsply), BMP-2 (R&D Systems), EMD (Emdogain, Straumann) separately and MTA/BMP-2 or MTA/EMD combination. Mineralization was evaluated by staining the calcium deposits with alkaline phosphatase (ALP, Sigma-Aldrich) and Alizarin red (Sigma-Aldrich). The effects on the osteoblast differentiation were evaluated by the expressions of osteogenic markers, including ALP, bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN) and osteonectin (OSN), as determined by reverse-transcription polymerase chain reaction analysis (RT-PCR, AccuPower PCR, Bioneer). Results: Mineralization increased in the BMP-2 and MTA/BMP-2 groups and increased to a lesser extent in the MTA/EMD group but appeared to decrease in the MTA-only group based on Alizarin red staining. ALP expression largely decreased in the EMD and MTA/EMD groups based on ALP staining. In the MTA/BMP-2 group, mRNA expression of OPN on day 3 and BSP and OCN on day 7 significantly increased. In the MTA/EMD group, OSN and OCN gene expression significantly increased on day 7, whereas ALP expression decreased on days 3 and 7 (p < 0.05). Conclusions: These results suggest the MTA/BMP-2 combination promoted more rapid differentiation in MC3T3-E1 cells than did MTA/EMD during the early mineralization period.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.4-4
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• 2012

Proteins enable biology to be viable through molecular interactions (such as in antigen-antibody, ligand-receptor, and drug-target) with

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.149-156
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• 2009

Purpose: Deproteinized bovine bone substitutes are commonly used in dental regenerative surgery for treatment of alveolar defects. In this study, three different bovine bone minerals - OCS-B (NIBEC, Seoul, Korea), Bio-Oss (Geistlich - Pharma, Switzerland), Osteograft/N - 300 (OGN, Dentsply Friadent Ceramed. TN, USA) - were investigated to analyze the basic characteristics of commercially available bone substitutes. Methods: Their physicochemical properties were evaluated by scanning electron microscopy, energy dispersive X-ray spectrometer (EDS), surface area analysis, and Kjeldahl protein analysis. Cell proliferation and alkaline phosphatase (ALP) activity of human osteosarcoma cells on different bovine bone minerals were evaluated. Results: Three kinds of bone substitutes displayed different surface properties. Ca/P ratio of OCS - B shown to be lower than other two bovine bone minerals in EDS analysis. Bio-Oss had wider surface area and lower amount of residual protein than OCS - B and OGN. In addition Bio - Oss was proved to have lower cell proliferation and ALP activity due to lots of residual micro particles, compared with OCS - B and OGN. Conclusions: Based on the results of this study, three bovine bone minerals that produced by similar methods appear to have different property and characteristics. It is suggested that detailed studies and quality management is needed in operations for dental use and its biological effects on new bone formation.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.114-115
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will bel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field frill be presented. And some problems arising for the somatic embryogenesis system will be also discussed.

• BMB Reports
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• v.44 no.6
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• pp.410-414
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• 2011

Chana series are new chalcone derivatives. To evaluate the possibility of Chana series as therapeutic agents of type 2 diabetes, the inhibitory effects of Chana series on the activities of ${\alpha}$-glucosidase and DPP-4 were investigated using in vitro enzyme assays, and their effects on adipocyte differentiation were investigated in C3H10T1/2 cells. Chana 1 and Chana 7 among the Chana series showed significant inhibition of ${\alpha}$-glucosidase activity. In DPP-4 enzyme assay, Chana 1 exhibited the highest inhibitory activity while Chana 7 did not. In MTT assay, Chana 1 did not show significant cytotoxicity up to a concentration of $250{\mu}M$, whereas cytotoxicity was observed with Chana 7 at a concentration of $300{\mu}M$. In addition, Chana 1 induced adipocyte differentiation. Therefore, Chana 1 showed inhibitory effects on ${\alpha}$-glucosidase and DPP-4 as well as a stimulatory effect on adipocyte differentiation, suggesting that Chana 1 may be a potential beneficial agent for the treatment of type 2 diabetes.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10b
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• pp.16-17
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will hel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/ or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field will be presented. And some problems arising for the somatic embryogenesis system will be also discussed.lso discussed.

• BMB Reports
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• v.52 no.6
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• pp.409-414
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• 2019

Natural compounds isolated from medicinal herbs and plants have immense significance in maintaining bone health. Hydrolysable tannins have been shown to possess a variety of medicinal properties including antiviral, anticancer, and anti-osteoclastogenic activities. As a part of a study on the discovery of alternative agent against skeletal diseases, we isolated a hydrolysable tannin, 2-O-digalloyl-1,3,4,6-tetra-O-galloyl-${\beta}$-D-glucose (DTOGG), from Galla Rhois and examined the effect on osteoclast formation and function. We found that DTOGG significantly inhibited receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation by downregulating the expression of the key regulator in osteoclastogenesis as well as osteoclast-related genes. Analysis of RANKL/RANK signaling revealed that DTOGG impaired activation of $I{\kappa}B{\alpha}$ and p65 in the nuclear factor kappa-lightchain-enhancer of activated B cells (NF-${\kappa}B$) signaling pathway. Furthermore, DTOGG reduced bone resorbing activity of osteoclasts, compared to the vehicle-treated control. These results suggest that DTOGG could be a useful natural compound to manage osteoclast-mediated skeletal diseases.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.190-196
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• 2020

Several factors, including genetic and environmental insults, impede protein folding and secretion in the endoplasmic reticulum (ER). Accumulation of unfolded or mis-folded protein in the ER manifests as ER stress. To cope with this morbid condition of the ER, recent data has suggested that the intracellular event of an unfolded protein response plays a critical role in managing the secretory load and maintaining proteostasis in the ER. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone and hydrophilic bile acid that is known to inhibit apoptosis by attenuating ER stress. Numerous studies have revealed that TUDCA affects hepatic diseases, obesity, and inflammatory illnesses. Recently, molecular regulation of ER stress in tooth development, especially during the secretory stage, has been studied. Therefore, in this study, we examined the developmental role of ER stress regulation in tooth morphogenesis using in vitro organ cultivation methods with a chemical chaperone treatment, TUDCA. Altered cellular events including proliferation, apoptosis, and dentinogenesis were examined using immunostaining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, altered localization patterns of the formation of hard tissue matrices related to molecules, including amelogenin and nestin, were examined to assess their morphological changes. Based on our findings, modulating the role of the chemical chaperone TUDCA in tooth morphogenesis, especially through the modulation of cellular proliferation and apoptosis, could be applied as a supporting data for tooth regeneration for future studies.