• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.8.1-8.8
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• 2017

Background: For an effective bone graft for reconstruction of the maxillofacial region, an adequate vascular network will be required to supply blood, osteoprogenitor cells, and growth factors. We previously reported that the secretomes of bone marrow-derived mesenchymal stem cells (MSC-CM) contain numerous growth factors such as insulin-like growth factor (IGF)-1, transforming growth factor $(TGF)-{\beta}1$, and vascular endothelial growth factor (VEGF), which can affect the cellular characteristics and behavior of regenerating bone cells. We hypothesized that angiogenesis is an important step for bone regeneration, and VEGF is one of the crucial factors in MSC-CM that would enhance its osteogenic potential. In the present study, we focused on VEGF in MSC-CM and evaluated the angiogenic and osteogenic potentials of MSC-CM for bone regeneration. Methods: Cytokines in MSC-CM were measured by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were cultured with MSC-CM or MSC-CM with anti-VEGF antibody (MSC-CM + anti-VEGF) for neutralization, and tube formation was evaluated. For the evaluation of bone and blood vessel formation with micro-computed tomography (micro-CT) and for the histological and immunohistochemical analyses, a rat calvarial bone defect model was used. Results: The concentrations of IGF-1, VEGF, and $TGF-{\beta}1$ in MSC-CM were $1515.6{\pm}211.8pg/mL$, $465.8{\pm}108.8pg/mL$, and $339.8{\pm}14.4pg/mL$, respectively. Tube formation of HUVECs, bone formation, and blood vessel formation were increased in the MSC-CM group but decreased in the MSC-CM + anti-VEGF group. Histological findings suggested that new bone formation in the entire defect was observed in the MSC-CM group although it was decreased in the MSC-CM + anti-VEGF group. Immunohistochemistry indicated that angiogenesis and migration of endogenous stem cells were much more abundant in the MSC-CM group than in the MSC-CM + anti-VEGF group. Conclusions: VEGF is considered a crucial factor in MSC-CM, and MSC-CM is proposed to be an adequate therapeutic agent for bone regeneration with angiogenesis.

• The Journal of the Korean dental association
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• v.51 no.12
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• pp.643-649
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• 2013

The aim of this study was to achieve the healing of peri-implantitis defects and the hard tissue regeneration using the augmentation of a xenograft on defect site. Two patients were treated with the surgical approach. With a full muco-periosteal flap elevation, the implant surfaces were exposed and taken the debridement of granulation tissue around the abutment. Each surface of the abutments was prepared with the air-abrasive device (PerioFlow$^{(R)}$) for decontamination. Bovine-derived bone mineral (Bio-Oss collagen$^{(R)}$) was then used to fill the defects, and no membrane was placed on the grafting site. Radiographs and clinical photo was taken to compare from baseline status. Within the limits of the present case, this case shows the significance of the surgical treatment of peri-implantitis. And this also verifies the stability of bovine-derived bone mineral and effectiveness of Air-abrasive device (PerioFlow$^{(R)}$).

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.229.1-229.1
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• 2003

Recently, the barrier membranes have been applied for regenerating bone surrounding peri-implant defects in guided bone regeneration(GBR). GBR membrane should provide mechanical support sufficient to withstand in vivo forces and maintain wound space for bone regeneration. The ability to exclude unwanted tissues of cells(connective tissue and epithelium) is needed. In addition large surface area is conductive to tissue ingrowth. The search for ideal materials that biocompatible, bioresorbable and can support the growth and phenotypic expression of osteoblasts is a major challenge in the biomedical application for the repair of bone defects. (omitted)

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.297-313
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• 1999

The ultimate goal of periodontal treatment is the regeneration of periodontal tissues which have been lost due to periodontal disease. Recently, many natural medicines have been studied for their potential of anti-bacterial, anti-inflammatory and regenerative effects in periodontal tissues. Safflower seeds have been traditionally used as a drug for treatment of fracture and blood stasis in oriental medicine. The objective of the present study is to examine the biologic effects of safflower seeds extract on bone formation and regeneration of rat calvarial defects. The calvarial defects were made with 8mm trephine bur and extract of safflower seeds were placed directly at these defects. 24 rats were divided into control and experimental groups, and each group was sacrificed at 1 week, 4 weeks and 8 weeks. To study a histopathology related to bone regeneration, Goldner's Masson Trichrome stain and histomorphologic measuring was done at each weeks. In the early phase of bone healing, less inflammatory infiltration and capillary proliferation was found in experimental group compared to control. Dense bony tissues and matured bone structures in defect areas were found in experimental groups. And area of new bone formation was significantly increased at 8 weeks in experimental group. These results indicate that direct local application of safflower seeds extract reduces the early inflammatory response and promotes the regeneration of new bone in calvarial defects of rats.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.209-217
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• 2013

The objective of this study was to evaluate the bone regeneration capability of silk membrane plus 3% 4-hexylresorcinol (3% 4-HR plus SM) in a rabbit calvarial defect model. Twenty New Zealand white rabbits were used in this study. Bilateral round shaped defects were created in the parietal bone (diameter: 8.0 mm). And the defects were covered with (1) 3% 4-HR plus SM, (2) collagen membrane (CM), (3) no graft material. After surgery, the animals were sacrificed at 4 weeks and 8 weeks. Bone regeneration was analyzed in each section by micro-computerized tomography (${\mu}$-CT). And Hematoxylin and eosin stains were used for histological analysis. As measured by ${\mu}$-CT analysis 4 weeks after surgery, the average of new bone formation in animals treated with 3% 4-HR plus SM was greater than that of animals treated with CM. and the difference was statistically significant. And well organized lamella bones were observed in the histological view of the 3% 4-HR plus SM group. Therefore, more bone regeneration was seen in animals treated with 3% 4-HR plus SM than in those treated with CM or uncovered control.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.949-961
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• 1997

To date, various clinical procedures have been used to restore periodontal apparatus destroyed by periodontal disease. And then, many experimental approaches have been proceeded to develop treatment methods to promote periodontal regeneration. Mechanical, chemical treatments to enhance the attachment of periodontal tissue cells as changing the physical properties of root surfaces, bone graft procedure, and treatments for guided tissue regeneration have been used for periodontal regeneration. However, recent studies have revealed that biologic factors such as growth factors promote biologic mechanism associated with periodontal regeneration. This study was done to enucleate how ELF stimulus affect the periodontal regeneration. We can have following conclusions from this experimental results. The influence of low frequency(ELF) electric stimulus (30Hz at $lO{\mu}A$) known to promote bone formation in vivo, was evaluated for its ability to affect bone cell function in vitro. After 12 hour exposure of ELF stimulus at most appropriate densities ($5{\times}10^4\;cells/cm^2$) to increase osteoblastic cells normally, rat calvarial cells were incubated for 60 hours were used in this study. We have found ELF stimulus suppress calvarial cell proliferation and the ability of protein synthesis, enhance the alkaline phosphatase activity significantly.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.9-15
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• 2010

Aim of the study: As an injectable scaffold, MPEG-PCL diblock copolymer was applied in bone tissue engineering. In vivo bone formation was evaluated by soft X-ray, histology based on the rat calvarial critical size defect model. Materials and Methods: New bone formation was evaluated with MPEG-PCL diblock copolymer in rat calvarial critical size bone defect. No graft was served as control. 4, 8 weeks after implantation, gross evidence of bone regeneration was evaluated by histology and soft X-ray analysis. Results: The improved and effective bone regeneration was achieved with the BMP-2 and osteoblasts loaded MPEG-PCL diblock copolymer. Conclusion: It was confirmed that MPEG-PCL temperature sensitive hydrogels was useful as an injectable scaffold in bone regeneration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.1
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• pp.15-24
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• 1997

The principle of guided tissue regeneration (GTR), as applied to bone healing, is based on the prevention of connective tissue from entering the bony defect during the healing phase. This allows the slower bone producing cells to migrate into and reproduce bone within the defect. GTR has demonstrated a level of success in regenerating bone defect. Several types of membrane barrier have been utilized to apply this principle in bone regeneration. The purpose of this study was to evaluate whether improved bone regeneration can be achieved with different membrane barriers ($Gore-Tex^{TM}$membrane, $COLLACOTE^{(R)}$). In the 10 NewZealand white rabbits, full-thickness bone defects on three sites of each rabbit calvaria were made. Experimental group 1 was covered with $COLLACOTE^{(R)}$, and group 2 was covered with $Gore-Tex^{TM}$membrane. Macroscopic, microscopic examinations were made serially on 1, 2, 3, 6, 12 weeks after operation. The results were as follows : 1. Macroscopically, both of experimental group 1, 2 were filled with bone-like mass but the defects of experimental group 1 disclosed markedly thinner than the original bone. 2. Microscopically, the defect of experimental group 1, 2 was filled with bony trabeculae without infection and adverse reaction. But multinucleated giant cell infiltration around $COLLACOTE^{(R)}$ was seen till 6th week. 3. Resorption of $COLLACOTE^{(R)}$ started from 3rd week and it was completely resorped on the 12th week.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.277-287
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• 2000

For the regeneration of osseous defect on the furcation area, autogeneous bone graft has been primarily used. But it has the limitation of donor site, additive surgical operation etc. Recently anorganic xenogenic bone graft materials of removing all organic components are commonly used for the regeneration of periodontal defects. This study was the comparison of the effect on the regeneration with two types xenografts($Bio-oss^{(R)}$ and Ca-P thin coated Bovine bone powder) on the furcation involvement in Beagle dogs. After surgically induced chronic periodontitis in bifurcation area of premolar, $Bio-oss^{(R)}$ and Ca-P BBP were grafted on the osseous defects. Tissue blocks including defects with soft tissues were harvested following a four-& eight-week healing interval and prepared for histologic analysis. The results of this study were as follows: 1. $Bio-oss^{(R)}$ group: there were significant differences among the $Bio-oss^{?}$ group at 4weeks and 8weeks, but the control group had various appearances : new bone formation, resorption of graft materials by multinuclear giant cells, connective tissue cells intervention in the bone graft sites etc. 2. Ca-P BBP group: lots of new bone formation were observed but the arrangement of periodontal ligament was not completed at 4weeks. New bone were replaced mature bone and the periodontal ligaments showed the functional arrangement at 8weeks. 3. By reason of undergrowing the epithelium within the osseous defects, new bone formation was not happened in the upper area of bifurcation in $Bio-oss^{(R)}$ group. 4. In Ca-P BBP group, epithelial undergrowth was not seen and generally showed much more new bone formation. 5. Ca-P BBP group showed the osteocyte-like cells at the inner portion of the graft materials 6. Both groups were similar to resorptive appearances of graft materials, but Ca-P BBP group had the better effects of osteoconduction.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.339-350
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• 2017

Purpose: The purpose of this study was to determine the critical diabetes duration in a streptozotocin (STZ)-induced diabetic rat calvarial defect model for experimentation regarding bone regeneration by evaluating the association between diabetes duration and bone healing capacity through histological and radiographic analyses. Methods: Experimental diabetes was induced in 50 of 60 rats by an STZ injection. The rats were divided into 5 groups, including a control group (group 1), according to diabetes durations of 0, 2, 4, 6, and 8 weeks, respectively. Eighteen rats survived: 4 in group 1, 4 in group 2, 4 in group 3, 5 in group 4, and 1 in group 5. Calvarial defects were created at 0, 2, 4, 6, and 8 weeks after STZ injection in groups 1-5. Cone-beam computed tomography scanning was performed at baseline and at 5 and 7 weeks after surgery. The rats were sacrificed 7 weeks after surgery, followed by histological evaluation. Results: The voxel gray values (VGVs) of group 1 and group 2 increased, whereas the VGVs of group 3 and group 4 decreased starting 5 weeks after surgery, although this trend did not reach statistical significance between groups. On the reconstructed 3-dimensional images and based on an analysis of histological features, groups 1 and 2 showed apparent bone regeneration, while groups 3-5 showed very limited bone regeneration. Conclusions: The critical diabetes duration in an STZ-induced diabetic rat calvarial defect model for experimentation regarding bone regeneration was between 2 and 4 weeks. It is suggested that researchers who use STZ-induced diabetic rats wait for more than 2 weeks following diabetes induction before placing implants or conducting bone regeneration studies to allow definite disturbances in bone healing to emerge.