• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.539-546
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• 2014

PURPOSE. Silk fibroin (SF) is a new degradable barrier membrane for guided bone regeneration (GBR) that can reduce the risk of pathogen transmission and the high costs associated with the use of collagen membranes. This study compared the efficacy of SF membranes on GBR with collagen membranes (Bio-$Gide^{(R)}$) using a rat calvarial defect model. MATERIALS AND METHODS. Thirty-six male Sprague Dawley rats with two 5 mm-sized circular defects in the calvarial bone were prepared (n=72). The study groups were divided into a control group (no membrane) and two experimental groups (SF membrane and Bio-$Gide^{(R)}$). Each group of 24 samples was subdivided at 2, 4, and 8 weeks after implantation. New bone formation was evaluated using microcomputerized tomography and histological examination. RESULTS. Bone regeneration was observed in the SF and Bio-$Gide^{(R)}$-treated groups to a greater extent than in the control group (mean volume of new bone was $5.49{\pm}1.48mm^3$ at 8 weeks). There were different patterns of bone regeneration between the SF membrane and the Bio-$Gide^{(R)}$ samples. However, the absolute volume of new bone in the SF membrane-treated group was not significantly different from that in the collagen membrane-treated group at 8 weeks ($8.75{\pm}0.80$ vs. $8.47{\pm}0.75mm^3$, respectively, P=.592). CONCLUSION. SF membranes successfully enhanced comparable volumes of bone regeneration in calvarial bone defects compared with collagen membranes. Considering the lower cost and lesser risk of infectious transmission from animal tissue, SF membranes are a viable alternative to collagen membranes for GBR.

• Journal of Periodontal and Implant Science
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• 제41권3호
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• pp.123-130
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• 2011

Purpose: The purpose of this study was to determine the biological effects of cyanoacrylate-combined calcium phosphate (CCP), in particular its potential to act as a physical barrier - functioning like a membrane - in rabbit calvarial defects. Methods: In each animal, four circular calvarial defects with a diameter of 8 mm were prepared and then filled with either nothing (control group) or one of three different experimental materials. In the experimental conditions, they were filled with CCP alone (CCP group), filled with biphasic calcium phosphate (BCP) and then covered with an absorbable collagen sponge (ACS; BCP/ACS group), or filled with BCP and then covered by CCP (BCP/CCP group). Results: After 4 and 8 weeks of healing, new bone formation appeared to be lower in the CCP group than in the control group, but the difference was not statistically significant. In both the CCP and BCP/CCP groups, inflammatory cells could be seen after 4 and 8 weeks of healing. Conclusions: Within the limits of this study, CCP exhibited limited osteoconductivity in rabbit calvarial defects and was histologically associated with the presence of inflammatory cells. However, CCP demonstrated its ability to stabilize graft particles and its potential as an effective defect filler in bone augmentation, if the biocompatibility and osteoconductivity of CCP were improved.

• 한국임상수의학회지
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• 제27권4호
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• pp.325-329
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• 2010

본 연구에서는 hydroxyapatite/poly $\varepsilon$-caprolactone composite (HA/PCL) 지지체와 matrigel을 랫드의 두개골 결손부 모델에 함께 이식 시의 골형성 정도를 평가하였다. 두개골결손부는 Sprague Dawley rat (n = 18)에서 수술적으로 형성하였으며 실험군은 Matrigel과 함께 HA/PCL 지지체를 이식한 군(M-HA/PCL group, n = 6)과 HA/PCL 지지체단독이식군(HA/PCL group, n = 6)으로 나누었고 대조군(CD group, n = 6)에는 아무 것도 이식하지 않았다. 수술 4주 후, 골형성은 방사선촬영, micro CT 및 조직검사를 통해 평가되었다. 방사선상에서 CD군의 골형성은 관찰되지 않았으나 HA/PCL과 M-HA/PCL군에서는 관찰되었고 골과 유사한 방사선비투과성이 M-HA/PCL군에서 더 많이 관찰되었다. Micro CT 평가에서 골부피는 HA/PCL군보다 M-HA/PCL군에서 더 높았으나 두 군 사이의 유의적 차이는 관찰할 수 없었다. 그러나 골밀도에서는 HA/PCL군보다 M-HA/PCL군이 더 유의적으로 높음을 확인할 수 있었다(p < 0.05). 조직학적 검사에서는 CD군에서 새로운 골은 원래 존재하던 골로부터만 형성되었으며 두개골결손부 내의 골형성은 보이지 않았다. HA/PCL군에서 새로운 골형성은 원래 존재하던 골로부터만 유래되었으나 M-HA/PCL군은 가장 많은 골형성을 보여주었으며 새로운 골이 원래 존재하던 골과 HA/PCL지지체 주변에서도 관찰되었다. 이러한 결과로 미루어볼 때 HA/PCL 지지체와 matrigel을 함께 사용하는 것이 골의 임계결손부에서 골형성을 증대시키는 효과적인 방법이 될 수 있을 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.483-509
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• 1999

Biodegradable barrier membrane has been demonstrated to have guided bone regeneration capacity on the animal study. The purpose of this study is to evaluate the effects of cultured calvarial cell inoculated on the biodegradable barrier membrane for the regeneration of the artificial bone defect. In this experiment 35 Sprague-Dawley male rats(mean BW 150gm) were used. 30 rats were divided into 3 groups. In group I, defects were covered periosteum without membrane. In group II, defects were repaired using biodegradable barrier membrane. In group III, the defects were repaired using biodegradable barrier membrane seeded with cultured calvarial cell. Every surgical procedure were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). After anesthesia, 5 rats were sacrificed by decapitation to obtain the calvaria for bone cell culture. Calvarial cells were cultured with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. The number of cell inoculated on the membrane were $1{\times}10^6$ Cells/ml. The membrane were inserted on the artificial bone defect after 3 days of culture. A single 3-mm diameter full-thickness artificial calvarial defect was made in each animal by using with bone trephine drill. After the every surgical intervention of animal, all of the animals were sacrificed at 1, 2, 3 weeks after surgery by using of perfusion technique. For obtaining histological section, tissues were fixed in 2.5% Glutaraldehyde (0.1M cacodylate buffer, pH 7.2) and Karnovsky's fixative solution, and decalcified with 0.1M disodium ethylene diaminetetraacetate for 3 weeks. Tissue embeding was performed in paraffin and cut parallel to the surface of calvaria. Section in 7${\mu}m$ thickness of tissue was done and stained with Hematoxylin-Eosin. All the specimens were observed under the light microscopy. The following results were obtained. 1 . During the whole period of experiment, fibrous connective tissue was revealed at 1week after surgery which meant rapid soft tissue recovery. The healing rate of defected area into new bone formation of the test group was observed more rapid tendency than other two groups. 2 . The sequence of healing rate of bone defected area was as follows ； test group, positive control, negative control group. 3 . During the experiment, an osteoclastic cell around preexisted bone was not found. New bone formation was originated from the periphery of the remaing bone wall, and gradually extended into central portion of the bone defect. 4 . The biodegradable barrier membrane was observed favorable biocompatibility during this experimental period without any other noticeable foreign body reaction. And mineralization in the newly formed osteoid tissue revealed relatively more rapid than other group since early stage of the healing process. Conclusively, the cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of regeneration of artificial bone defects of alveolar bone. This study thus demonstrates a tissue-engineering the approach to the repair of bone defects, which may have clinical applications in clinical fields of the dentistry including periodontics.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.835-852
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• 2000

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue and repair of function. For more than a decade there have been many efforts to develop materials and methods of treatment to promote periodontal wound healing. Recently many efforts are concentrated on the regeneration potential of material used in oriental medicine. In some in vitro and in vivo experiments, there have been many evidences that these materials have an effect on bone regeneration. The purpose of this study was to evaluate histologically and radiologically in Sprague-Dawley rats the effects of safflower seed extracts on the regeneration of the calvarial defects surgically produced. So in this study, the critical size defects were surgically produced in the calvarial bone of 30 Sprague-Dawley rats using the 8mm trephine bur. The safflower seed extract was applied into the defect of each rat in experimental group, whereas nothing was applied into the defect of each rat in control group. Rats were sacrificed at 2, 4, 8 weeks following operation and histomorphometric and radiodensitometric analysis were performed. 1. The newly formed bone length was $102.91{\pm}22.05$, $178.29{\pm}24.40$ at 2 week in the each control, experimental group, $130.95{\pm}39.24$, $242.62{\pm}50.33$ at 4 week and $181.53{\pm}76.35$, $240.36{\pm}22.00$ at 8 week($unit,{\mu}m$). In the 2, 4 week, there were statistically significant difference between control and experimental group(P<0.05). 2. The newly formed bone area was $2962.06{\pm}1284.48$, $10648.35{\pm}1284.48$ at 2 week, $5103.25{\pm}1375.88$, $9706.78{\pm}1481.81$ at 4 week, $8046.02{\pm}818.99$, $12057.06{\pm}740.47$ at 8 week($unit,{\mu}m^2$). In every week, there were statistically significant difference between control and experimental group(P<0.05). 3. The radiopacity was $14.26{\pm}.33$, $25.47{\pm}4.33$ at 2 week, $20.06{\pm}9.07$, $26.61{\pm}2.78$ at 4 week, $22.99{\pm}3.76$, $27.29{\pm}1.54$ at 8 week(unit, %). In the 2 week, there was statistically significant difference between control and experimental group(P<0.05). In conclusion, the results of the present study suggest that safflower seed extract initially has an effect on the newly formed bone area, length and radiopacity when it is applied to the calvarial defect of Sprague - Dawley rat. Then. the material has an effect on newly formed bone area and length.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.264-264
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• 2006

The nanoparticle-hydrogel complex as a new bone defect replacement matrix, which is composed of the nanoparticles for the sustained release of BMP and the hydrogel for filling the bone defect site and playing a role as a matrix where new bone can grow, is presented. In vivo evaluation of bone formation was characterized by soft X-ray, MT staining, and calcium assay, based on the rat calvarial critical size defect model. The effective bone regeneration was achieved by the BMP-2 loaded nanoparticles in fibrin gel, compare to bare fibrin gel, the nanoparticle-fibrin gel complex without BMP-2, or the BMP-2 in fibrin gel, in terms of the new bone area and the gray level in X-ray, the bone marrow are, and the calcium content in the initial defect site. These findings suggest that the BMP-2 loaded nanoparticle-fibrin gel complex can a promising candidate for a new bone defect replacement matrix.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.36-48
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• 2008

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, $Ca_{10}[PO_4]_6[OH]_2,\;Bongros^{(R)}$, Bio@ Co., KOREA) and tricalcium phosphate (${\beta}-TCP,\;Ca_3[PO_4]_2$, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst $100^{(R)}$). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

• Journal of Periodontal and Implant Science
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• 제49권1호
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• pp.2-13
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• 2019

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

• 한국방사선학회논문지
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• 제5권1호
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• pp.11-18
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• 2011

다능성 세포를 포함하는 골막은 골모세포와 연골세포로 분화될 수 있다. 그리고 배양된 골막유래세포는 골형성 능력을 가지고 있다. 이 연구의 목적은 골막유래 세포들과 골이식재 간의 상호작용을 평가하는 것이다. Sprague-Dawley 랫드의 두개골 골막에서 세포를 분리한 다음, 배양된 골막유래세포를 beta-tricalcium phosphate (${\beta}$-TCP)와 함께 임계결손부 크기의 두개결손부에 이식하였다. 모든 랫드는 골이식 수술 후 8주째에 희생되었으며, 골이식부의 골형성 능력은 일반방사선, micro CT 및 조직검사를 통해 평가되었다. ${\beta}$-TCP와 함께 이식된 골막유래세포는 골결손부에서 더욱 증가된 석회화작용을 나타내었으며, 골결손부 안쪽 및 가장자리에 골밀도 증가와 신생골이 형성되었다. 특히 골막유래세포는 ${\beta}$-TCP만 단독으로 이식하였을때보다 함께 이식 시 효과적으로 신생골을 형성하였다. 이러한 결과는 배양된 골막유래세포가 골결손부에서 골형성을 증진시킬 수 있는 가능성을 보였다.

• Journal of Periodontal and Implant Science
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• 제32권4호
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• pp.769-779
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• 2002

This present study was carried out to find the effects of calcium aluminate cement($CaO\;{\cdot}\;Al_2O_3$, CAC), which has been developed with bio-compatibility and mechanical properties, in biological environments. Two different particle sizes of CAC - 3.5${\mu}m$ vs. 212${\sim}$250${\mu}m$ which is recommended in periodontal bone grafting procedures-were filled in 8mm calvarial defect in Sprague-Dawley rat. The specimens were examined histologically, especially the bone-cement interface and the response of surrounding tissues. The results are as follows; 1. In the control group, inflammatory cells were observed at 2 weeks. At 8 weeks, periosteum and dura mater were continuously joined together in the defect areas. But in the center of defect area were filled up with the loose connective tissues. 2. In the experimental group l($212{\mu}m{\sim}250{\mu}m$ particle), immature bone was formed and outermost layer was surrounded by osteoid layer at 2 weeks. Osteoblasts were arranged between immature bone and osteoid layer. And, osteoid layer was remained until 8 weeks after surgery. 3. In the experimental group 2, periosteum and dura mater lost its continuity at 2 weeks. Scattering of CAC particles and infiltration of inflammatory cells were observed, which this findings deepened at 8 weeks. The result of this study shows that when calvarial defects in white rats are filled with calcium aluminate cement of 212${\sim}$250${\mu}m$, the materials are to be bio-compatible in growth and healing on surrounding tissues. When further researches are fulfilled, such as direct bone adhesion and bone regeneration ability, it's possible that CAC could be applied to various periodontology fields in the future.