• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.153-162
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• 2008

Purpose: Recombining bone morphogenetic protein (BMP) is usually acquiredfrom high level animals. Though this method is effective, its high cost limits its use. The purpose of this study was to evaluate the effect of bone morphogenetic protein-2 with protein transduction domain (BMP-2/PTD;TATBMP-2) on bone regeneration. Rat calvarial defect model and osteoblastic differentiation model using MC3T3 cell were used for the purpose of the study. Materials and Methods: MC3T3 cells were cultured until they reached a confluence stage. The cells were treated with 0, 0.1, 1, 10, 100, 500 ng/ml of BMP-2/PTD for 21 days and at the end of the treatment, osteoblastic differentiation was evaluated usingvon Kossa staining. An 8mm, calvarial, critical-size osteotomy defect was created in each of 48 male Spraque-Dawley rats (weight $250{\sim}300\;g$). Three groups of 16 animals each received either BMP-2/PTD (0.05mg/ml) in a collagen carrier, collagen only, or negative surgical control. And each group was divided into 2 and 8 weeks healing intervals. The groups were evaluated by histologic analysis(8 animals/group/healing intervals) Result: In osteoblastic differentiation evaluation test, a stimulatory effect of BMP-2/PTD was observed in 10ng/ml of BMP-2/PTD with no observation of dose-dependent manner. The BMP-2/PTD group showed enhanced local bone formation in the rat calvarial defect at 2 weeks. New bone was observed at the defect margin and central area of the defect. However, new bone formation was observed only in 50% of animals used for 2weeks. In addition, there was no new bone formation observed at 8 weeks. Conclusion: The results of the present study indicated that BMP-2/PTD(TATBMP-2) have an positive effect on the bone formation in vitro and in vivo. However, further study should be conducted for the reproducibility of the outcomes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.470-478
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• 2007

The purpose of this study was to investigate the clinical, biomechanical, and histologic changes in new distraction osteogenesis(DO) technique combined with a compression stimulation in accordance to different compression-distraction force ratio. 23 adult male rabbits underwent open-osteotomy at the mandibular body area and a external distraction device was applied. In the control group of 8 rabbits, only a 8 mm of distraction was performed by conventional DO technique. In an experimental group of 15 rabbits, a distraction followed by a compression force was performed according to the ratio of compression-distraction suggested by authors. The rate of experimental group I was set up as a 2 mm compression versus 10 mm distraction and the rate of experimental group II was set up as a 3 mm compression versus 11 mm distraction. All the rabbits were sacrificed for a gross finding, biomechanical, histomorphometric and histologic findings at the time of 55 days from the operation day. The results were as follows: 1. On the gross findings, because all rabbits had a sufficient healing time, every distracted new bone had good bone quality and we could not find any difference among all three groups. 2. In the histologic findings, rapid bone maturation(wide lamellar bone formation in the cancellous and cortical bone areas) was observed in two experimental groups compared to the control group. 3. On the bone density tests, the experimental group II showed higher bone density than the other experimental group and control group(control group-$0,2906g/cm^2$, experimental group I-$0.2961g/cm^2$, experimental group II-$0.3328g/cm^2$). 4. On the biomechanical tests, the experimental group II had significantly higher bone microhardness than the other experimental group and control group(control group-252.7 MPa, experimental group I-263.5 MPa, experimental group II-426.0 MPa). 5. On the microhardness tests, when we compared the hardness ratio of distracted bone versus normal bone, we could find experimental group II had significantly higher hardness ratio than the other experimental group and control group(control group-0.47, experimental group I-0.575, experimental group II-0.80). From this study, we could deduce that the modified distraction osteogenesis method with a compression stimulation might improve the quality of bone regeneration and shorten the consolidation period in comparison with conventional distraction osteogenesis techniques.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.181-192
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• 2007

Periodontal surgery as part of the treatment of periodontal disease is mainly performed 1) to gain access to diseased areas for adequate cleaning; 2) to achieve pocket reduction or elimination; and 3) to restore the periodontal tissues lost through the disease; i.e., a new attachment formation of periodontal regeneration. To accomplish the latter, often referred to as the ultimate goal of periodontal therapy, a number of surgical procedures have been advocated throughout the years. Clinical studies have demonstrated that considerable gain of clinical attachment and bone can be achieved following guided tissue regeneration (GTR) therapy of intrabony defects. The aim of this study was to analyse the radiographic bone changes 2-year after GTR using a bone graft material and nonresorbable membrane. Patients attending the department of periodontics of Kyungpook National University Hospital were studied. Patients had clinical and radiographic evidence of intrabony defect(s), 33 sites of 30 patients aged 32 to 56 (mean age 45.6) were treated by GTR with a bone graft material and nonresorbable membrane. Baseline and 2-year follow-up radiographs were collected and evaluated for this study. Radiographic assessment includes a bone fill, bone crest change, defect resolution, and % of defect resolution. Pre- and post-treatment differences between variables (maxilla and mandible, defect depth, defect angle, bone graft materials) using the paired t-test were examined. We observed $2.86{\pm}1,87mm$ of bone fill, $065{\pm}0.79mm$ of crestal resorption, $3.49{\pm}2.11mm$ of defect resolution, and $44.42{\pm}19.51%$ of percentage of defect resolution. Mandible, deeper initial defect depth, narrower initial defect angle showed greater bone fill, defect resolution, and % of defect resolution. But no difference was observed between xenograft and allograft. Outcome of GTR as a therapy of intrabony defect was better than other therapy, but herein, good oral hygiene maintenance as a anti-infective treatment and periodic recall check of patients are essential.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.32-38
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• 2018

Purpose: The purpose of present study was to retrospectively analyze the survival rate of narrow diameter implant less than 3.6 mm by initial stability and radiographic measurements. Materials and Methods: In total, 24 patients who received 38 narrow diameter implants (${\leq}3.6mm$ in diameter, ${\geq}7mm$ in length) were enrolled in this retrospective study. The cumulative survival rate was calculated and various factors were investigated according to the implant platform diameter, body diameter, length, position, concomitant use of guided bone regeneration in implant placement and final prosthesis type. Initial stability was investigated with implant stability quotient (ISQ) value. The mesial and distal marginal bone level (MBL) change was calculated with radiography. Results: The overall survival rate was 92.11%. Mean ISQ value and MBL change of survival implants was 66.26 and $0.14{\pm}0.31mm$, respectively. None of the implants with platform diameters larger than the body diameter failed. Conclusion: In conclusion, the findings of present study suggest that narrow diameter implant could be predictable treatment in narrow alveolar ridge.

• Polymer(Korea)
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• v.29 no.5
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• pp.501-507
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• 2005

Small intestinal submucosa (SIS) had been widely used as a biomaterial without immune rejection responses. SIS sponges prepared by crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). SIS powders dissolved in $3\%(v/v)$ acetic acid aqueous solution for 48hrs and freeze-dried. EDC solution ($H_2O$ : ethanol = 5 : 95) as a crosslink agent was used in concentration of 100mM. In vitro, rat-BMSCs seeded in SIS sponges and induced the osteogenesis for 28 days. We have characterized the osteogenic potential of rat-BMSCs in SIS sponges by alkaline phosphatase activity(ALP), n assay, SEM and RT-PCR for osteogenic phenotype. In SEM, all morphology of SIS sponges was regular and showed interconnected pore structure. By RT-PCR analysis, we observed type I collagen expression. These results demonstrate osteogenic differentiation of rat-BMSCs. In conclusion, we confirmed that the morphology of surface, cross-section, and side of SIS sponges were highly porous with good interconnections between each pores, which can support the surface of cell growth, proliferation, and differentiation. This result indicates that SIS sponge is useful for osteogenesis of BMSCs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.1-8
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• 2019

Steel elevator pit was developed for the purpose of minimizing the excavation, simplifying the construction of the frame and economical efficiency by improving the problems that occurred in the existing reinforced concrete. It is common to apply conventional RC method through excavation to underground structures such as underground floor collector well and elevator pit. In recent years, the use of steel collector well and steel elevator pits to reduce construction costs by minimizing the materials of steel and concrete has been continuously increasing. The steel elevator pit is an underground structure and then the performance of the welding part and the structure system is important. Specimen with only steel plate and concrete without studs could support the load more than 3 times than the specimen with deck only. Therefore, even if there is no stud, the deck (steel plate) rib is formed and the effect of restraining the steel plate and the concrete during the bending action can be expected. However, since sudden fracture in the elevator pit may occur, stud bolt arrangement is necessary for the composite effect of steel plate and concrete. It is expected that the bending strength can be expected to increase by about 15% or more depending with and without stud bolts.

• Resources Recycling
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• v.17 no.2
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• pp.55-62
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• 2008

Amount of waste is always generated in industrialization process and it is gradually increasing. Domestic and industrial waste in 2003 increased by 9.5 percent than that of the last year(2002), whereas the amount of construction waste increased largely by 21 percent. Recently construction waste of total waste accounts for nearly 50 percent, waste concrete and Ascon from the construction waste takes up to 73 percent. Furthermore, amount of natural materials are gradually decreasing, that is, they are not sufficient any more. Owing to these reasons, the importance of recycling construction waste has been emphasized. The use of recycling aggregate makes the disposal of construction waste easier as well as protects environment from gathering raw aggregate. Also, it has the alternative effect economizing the insufficient new natural aggregate. This study employs the cost-benefit model to analyze the economic effect of construction waste recycling of Ascon which takes relatively high part of the total waste. The cost-comparison between raw aggregate and recycling aggregate were analyzed. With the model, the economic effect of Ascon recycling in 2003 and 2004 in capital area of Korea were analysed. Cost comparison between raw aggregate and recycling aggregate were also carried out. The result showed that the economic effect of Ascon recycling increased to 0.0808 for 2004 as compared 0.0694 for 2003. We could not conclude using above data, but this result shows that the economic benefit of Ascon recycling of construction waste has increased.

• Journal of the Korean Arthroscopy Society
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• v.15 no.2
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• pp.83-91
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• 2011

Purpose: Microfracture has been used as a first-line treatment to repair articular cartilage defects. In this study, a new technique using an extracelluar matrix biomembrane to cover the cartilage lesions after microfracture was evaluated in terms of cartilage repairability and clinical outcome compared with conventional microfracture technique in a prospective randomized trial. Materials and Methods: A total of 53 patients (59 cases) without osteoarthritis who had focal full thickness articular cartilage lesions were randomly assigned in two group. Seventeen patients (17 cases) underwent conventional microfracture procedure (control group) and thirty-six patients (42 cases) received microfracture and placing biomembrane cover (ArtiFilm$^{TM}$) concomitantly (experimental group). Clinical assessment was done through 6 months postoperatively using the subjective International Knee Documentation Committee IKDC questionnaire, and visual analog scale (VAS) for pain and satisfaction. Magnetic resonance imaging (MRI) was performed at 6 months after the operation in all patients. Results: In clinical outcomes, the significant difference was observed between both groups in IKDC, but not in VAS for pain and for satisfaction (final outcomes of IKDC, p=0.001; VAS for pain, p=0.074; VAS for satisfaction, p=0.194). The MRI showed good to complete defect fill (67 to 100%) in 33 patients (78.6%) of experimental group and 4 patients (23.5%) of control group, respectively. In control group, 9 of 17 patients (52.9%) showed poor defect fill (less than 33%), whereas 5 (11.9%) in experimental group (p=0.001). Assessment of peripheral integration revealed no gap formation in 35 patients (83.3%) in experimental group and 6 patients (35.3%) in control group (p=0.001). No serious complications or adverse effects related to the biomembrane were found. Conclusion: Good short-term follow-up clinical results were obtained in the group whose cartilage defects in the knee joint were covered with biomembrane after the microfracture, with the MRI findings confirming the excellent regeneration of the defective cartilage area. This suggests that the surgery to cover the defective area with biomembrane (ArtiFilm$^{TM}$) after the microfracture procedure is a safe, more effective treatment to induce cartilage regeneration.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.16.2-16
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• 1982

The palatine tonsils which are located in entrance of digestive and upper respiratory tracts are the most important organ in anatomical and functional structures of the pharyngeal lymphatic tissues. As for function of the tonsil, there have been many suspected theories that were included hematopoietic, hormonal, digestive function and production of vitamin, entry of bacteria with other antigenous materials and defence mechanism of which has taken charge by Virchow in 1860 in past. But among these theories, in recently, defence mechanism of the tonsil was strongly accepted immunologically. For the purpose of elucidating immune response of the tonsil, the author observed serum immunoglobulin levels, peripheral total lymphocyte counts and populations of T, B and Null lymphocytes before and after tonsillectomy in 30 cases of patients with chronic tonsillitis and 29 cases of healthy controls. The results obtained were as follows; 1) Serum Ig M level was significantly higher in patient group than in control group but was not significantly different preoperative from postoperative patient group. 2) Population of T-lymphocyte more significantly decreased in patient group than in control group but it was not significantly different preoperative from postoperative patient group. 3) Population of B-lymphocyte more significiantly increased in patient group than in control group but it was not significantly different preoperative from postoperative patient group. On the basis of these results, it may be suggested that tonsil play partially a role in the immune response of human.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.303-320
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• 1994

Current acceptable methods For promotin gperiodontal regeneration are base on removal of diseased soft tissue, root treatment, guided tissue regeneration, inteoduction of new graft materials and biological mediators. Platelet-derived growth factor(PDGF) is one of polypeptide growth factor. PDGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purposes of this study is to evaluate the effects of PDGF-AA, BB on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the first premolar tooth extracted for the orthodontic treatment and were cultured in DMEM/10% FBS at the $37^{\circ}C$, 5% $CO_2$ incubator. Author measured the DNA synthesis, total protein, collagen and noncollagenous protein synthesis and alkaline phosphatase activity according to the concentration of PDGF-AA and BB(0, 0.1, 1, 10, 100ng/ml). The results were as follows : The DNA synthetic activity was increased dose dependently by PDGF-AA and BB. The maximum mitogenic effect was at the 100ng/ml of PDGF-AA and 10ng/ml of PDGF-BB. The total protein, collagen and noncollagen systhesis was increased dose dependently by PDGF-AA and BB. The % of collagen was slightly decresed according to the concentration of PDGF-AA and BB. The effect of PDGF-AA and BB were not specific for collagen synthesis since it also increased noncollagenous protein synthesis. The effect of PDGF-AA and BB on alkaline phosphatase activity did not show any significant, meanwhile the alkaline phosphatase activity of 14 days group showed significnat increase. In conclusion, PDGF-AA and BB may have important roles in stimulation of DNA synthesis in human periodontal ligament cells, which means an increase in collagen-synthesizing cells, and may be useful for clinical application in periodontal regenerative procedures.