• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2006년도 춘계학술대회
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• pp.208-208
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• 2006

• Journal of Periodontal and Implant Science
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• 제33권1호
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• pp.61-77
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• 2003

The major goals of periodontal therapy are the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. Bone graft & guided tissue are being used for the regeneration of destroyed periodontium these days. Non-resorbable membranes were used for Guided tissue regeneration in early days, however more researches are focused on resorbable membranes these days. The aim of this study is to evaluate the osteogenesis of paradioxanone membrane on the calvarial critical size defect in Sprague Dawley rats. An 8 mm diameter surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into three groups: Untreated control group, Biomesh(R) group and paradioxanone group. The animals were sacrificed at 4, 8 and 12 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric analyses. The results are as follows: 1. In histological view on Biomesh(R), no visible signs of resorption was observed at 4 weeks but progressive resorption was observed at 8 weeks through 12 weeks. Paradioxanone membrane expanded at 4 weeks, and rapid resorption was observed at 8 weeks. In both the membranes, inflammatory cells were observed around them. Inflammatory cells decreased with time but were still present at 12 weeks. More inflammatory cells were observed in paradioxanone membranes than in Biomesh(R) membrane. 2. The area of newly formed bone in the defects were 0.001${\pm}$0.001, 0.006${\pm}$0.005, 0.002${\pm}$0.003 at the 4 weeks, 0.021${\pm}$0.020, 0.133${\pm}$0.073, 0.118${\pm}$0.070 at the 8 weeks and 0.163${\pm}$0.067, 0.500${\pm}$0.197, 0.487${\pm}$0.214 at the 12 weeks in the control group, Biomesh(R) group and experimental group respectively. Compared to the control group, Biomesh(R) group displayed significant differences at 4,8, and 12 weeks and the paradioxanone group at 8 and 12 weeks.(P<0.05)

• Archives of Reconstructive Microsurgery
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• 제13권2호
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• pp.93-100
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• 2004

This study was designed to investigate the optimal period of pedicles implantation in the prefabricated periosteofascial flap with a vascular tissue transfer. The flap prefabrication was prepared with a transposition of left occipital pedicles on the calvarial fascia of male Sprague-Dawley rats. Thirty flaps were divided into five groups of six flaps, including control group (group I) of the conventional periosteofascial flap based on the lateral border of the rat calvarium. The prefabricated flap was elevated as an $1{\times}1cm$ sized island flap based on the implanted pedicle at 1, 2, 3, and 4 weeks after the pedicles transfer in groups II, III, IV, and V, respectively. After the completion of creating a critical-sized calvarial defect and implanting with hydroxyapatite granules, the flap was sutured back for covering the defect and kept isolated from surrounding tissues. Six weeks after flap repositioning, the osseous changes of the defect were examined with simple radiographic findings, radiodensitometric analysis, and histological studies. By simple radiographic findings, specimens of the control, groups IV and V showed homogeneous radioopacity within the defect. But in groups II and III, focal radiolucency was observed in the defect. In the radiodensitometric analysis, the control group and the group V showed significant increased radiodensites statistically. Histologically, the implanted hydroxyapatite was absorbed partly in the defect in groups II, III, and IV. In the defects of the control group and the group V, the implanted hydroxyapatite was kept in its volume and the deposition of the bone cells was observed sparsely. In conclusion, the prefabricated periosteofascial flap can be created with a vascular tissue transfer and the pedicles should be implanted at least for 4 weeks to bring out positive osseous changes in the calvarial defect.

• Journal of Periodontal and Implant Science
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• 제40권4호
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• pp.180-187
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• 2010

Purpose: This study evaluated the spontaneous healing capacity of surgically produced cranial defects in rabbits with different healing periods in order to determine the critical size defect (CSD) of the rabbit cranium. Methods: Thirty-two New Zealand white rabbits were used in this study. Defects of three sizes (6, 8, and 11 mm) were created in each of 16 randomly selected rabbits, and 15-mm defects were created individually in another 16 rabbits. The defects were analyzed using radiography, histologic analysis, and histometric analysis after the animal was sacrificed at 2, 4, 8, or 12 weeks postoperatively. Four samples were analyzed for each size of defect and each healing period. Results: The radiographic findings indicated that defect filling gradually increased over time and that smaller defects were covered with a greater amount of radiopaque substance. Bony islands were observed at 8 weeks at the center of the defect in both histologic sections and radiographs. Histometrical values show that it was impossible to determine the precise CSD of the rabbit cranium. However, the innate healing capacity that originates from the defect margin was found to be constant regardless of the defect size. Conclusions: The results obtained for the spontaneous healing capacity of rabbit cranial defects over time and the underlying factors may provide useful guidelines for the development of a rabbit cranial model for in vivo investigations of new bone materials.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권1호
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• pp.1-11
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• 2012

Purpose: The purpose of this study was to evaluate the bone regeneration capacity of silk fibroin (SF) when combined with beta tricalcium phosphate (${\beta}$-tricalcium phosphate [TCP]) and rh-bone morphogenetic protein (BMP) in vivo by micro-computed tomography (CT), soft x-ray, and histological analysis. Methods: A total of 56 critical size defects formed by a trephine bur made on 28 adult female Spague-Dawley rats were used for this study and the defect size was 5.0 mm in diameter. The defects were transplanted with (1) no graft material (raw defect), (2) autogenous bone, (3) SF ($10{\mu}g$), (4) SF-BMP ($10{\mu}g$, $0.8{\mu}g$ each), and (5) SF+${\beta}$-TCP ($10{\mu}g$). At 4 and 8 weeks after operation, the experimental animals were sacrificed. Samples were evaluated with soft x-ray, histological examinations and 3-dimensional micro-CT analysis. Results: In the 3-dimensional micro-CT evaluation, bone volume and bone surface data were higher in the SF-BMP ($12.8{\pm}1.5$, $138.6{\pm}45.0$ each) (P<0.05) and SF-TCP ($12.3{\pm}1.5$, $144.9{\pm}30.9$ each) group than in the SF group ($6.1{\pm}3.3$, $77.2{\pm}37.3$ each) (P<0.05), except for the autogenous group ($15.0{\pm}3.0$, $190.7{\pm}41.4$ each) at 4 weeks. At 8 weeks, SF-BMP ($16.8{\pm}3.5$, $173.9{\pm}34.2$ each) still revealed higher (P<0.05) bone volum and surface, but SF-TCP ($11.3{\pm}1.5$, $1132.9{\pm}52.1$ each) (P=0.5, P=0.2) revealed the same or lower amount compared with the SF group ($13.8{\pm}2.7$, $127.5{\pm}44.8$ each). The % of bone area determined by radiodensity was higher in the SF-TCP ($31.4{\pm}9.1%$) and SF-BMP ($36.2{\pm}16.2%$) groups than in the SF ($19.0{\pm}10.4$) group at the period of 4 weeks. Also, in the histological evaluation, the SF-BMP group revealed lower inflammation reaction, lower foreign body reaction and higher bone healing than the SF group at postoperative 4 weeks and 8 weeks. The SF-TCP group revealed lower inflammation at 4 weeks, but accordingly, as the TCP membrane was absorbed, inflammatory and foreign body reaction are increased at 8 weeks. Conclusion: The current study provides evidence that the silk fibrin can be used as an effective grafted material for tissue engineering bone generation through a combination of growth factor or surface treatment.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.125-136
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• 2007

Periodontal regenerative therapy and tissue engineering on defects destructed by severe periodontitis need maintaining of space, which provides the environment for cell migration, proliferation and differentiation. Application of bone grafts may offer this environment in periodontal defects. This study evaluated bone graft materials, $MBCP^{(R)}$ and $Algipore^{(R)}$ , in surgically created i-wall periodontal intrabony defects of minipigs by histological analysis. Critical sized($4mm{\times}4mm$), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four minipigs. The control group was treated with debridement alone, and experimental group was treated with debridement and $MBCP^{(R)}$ and $Algipore^{(R)}$ application. The healing processes were histologically observed after 8 weeks and the results were as follows. 1. In the control group, limited new bone formation was observed. 2. In MBCP group, more new bone formation was observed compared to other groups. 3. Histologically, dispersed mixture of new bone, biomaterial particles and connective tissue were shown and osteoblasts, osteoclasts and new vessels were present in this area. 4. Defects with Algipore showed limited new bone formation and biomaterial particles capsulated by connective tissue. 5. Histologically, lots of osteoclasts were observed around the biomaterial but relatively small numbers of osteblasts were shown. Within the limitation to this study protocol, $MBCP^{(R)}$ application in 1-wall intrabony defect enhanced new bone formation rather than $Algipore^{(R)}$ application.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• International Journal of Oral Biology
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• 제42권4호
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• pp.203-211
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• 2017

The aim of this study was to evaluate the role of demineralized and particulate autogenous tooth, and interleukin-6 in bone regeneration. A demineralized and particulate autogenous tooth was prepared and human osteoblast-like cells (MG63) and human osteosarcoma cells were inoculated into the culture. The rate of cell adhesion, proliferation and mineralization were examined, and the appearance of cellular attachment was observed. An 8 mm critical size defect was created in the cranium of rabbits. Nine rabbits were divided into three groups including: An experimental group A (3 rabbits), in which a demineralised and particulate autogenous tooth was grafted; an experimental group B (3 rabbits), in which a demineralized, particulate autogenous tooth was grafted in addition to interleukin-6 (20 ng/mL); and a control group. The rabbits were sacrificed at 1, 2, 4 and 6 weeks for histopathological examination with H-E and Masson's Trichrome, and immunohistochemistry with osteocalcin. The cell-based assay showed a higher rate of cell adhesion, mineralization and cellular attachment in the experimental group A compared with the control group. The animal study revealed an increased number of osteoclasts, newly formed and mature bones in the experimental group A compared with the control group. Eventually, a higher number of osteoclasts were observed in the experimental group B. However, the emergence of newly formed and mature bone was lower than in the experimental group A. The current results suggest that treatment with demineralized and particulate autogenous tooth and interleukin-6 is not effective in stimulating bone regeneration during the bone grafting procedure.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.851-870
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• 2000

The major goals of periodontal therapy is the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chitin. Chitin is second only to cellulose as the most abundant natural biopolymer. It is a structural component of the exoskeleton of invertebrates(e.g., shrimp, crabs, lobsters), of the cell wall of fungi, and of the cuticle of insects. Chitosan is a derivative of chitin made by deacetylation of side chains. Many experiments using chitosan in various animal models have proven its beneficial effects. The aim of this study is to evaluate the osteogenesis of chitosan on the calvarial critical size defect in Sprague Dawley rats. An 8 mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into two groups: Untreated control group versus experimental group with 50mg of soluble chitosan gel. The animals were sacrificed at 2, 4 and 8 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric and radiodensitometric analyses. The results are as follows: 1. The length of newly formed bone in the defects was $102.91{\pm}25.46{\mu}m$, $219.46{\pm}97.81{\mu}m$ at the 2 weeks, $130.95{\pm}39.24{\mu}m$, $212.39{\pm}89.22{\mu}m$ at the 4 weeks, $181.53{\pm}76.35{\mu}m$ and $257.12{\pm}51.22{\mu}m$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. But, there was no statistically significant difference between the two groups. 2. The area of newly formed bone in the defects was $2962.06{\pm}1284.48{\mu}m^2$, $5194.88{\pm}1247.88{\mu}m^2$ at the 2 weeks, $5103.25{\pm}1375.88{\mu}m^2$, $7751.43{\pm}2228.20{\mu}m^2$ at the 4 weeks and $8046.20{\pm}818.99{\mu}m^2$, $15578.57{\pm}5606.55{\mu}m^2$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. 3. The density of newly formed bone in the defects was $14.26{\pm}6.33%$, $27.91{\pm}6.65%$ at the 2 weeks, $20.06{\pm}9.07%$, $27.86{\pm}8.20%$ at the 4 weeks and $22.99{\pm}3.76%$, $32.17{\pm}6.38%$ at the 8 weeks in the control group and experimental group respectively. At all periods, the means of experimental group was greater than those of control group. The experimental group showed statistically significant difference to the control group at the 2 and 8 weeks. These results suggest that the use of chitosan on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.77-86
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• 2009

Purpose: Recombinant human bone morphogenetic protein-2(rhBMP-2) has been evaluated as potential candidates for periodontal and bone regenerative therapy. In spite of good prospects in BMP applications, there is economically unavailable for clinical use in dental area. The purpose of this study was to evaluate the osteogenic effect of rhBMP-2 produced by E.coli expression system. Materials and methods: Eight-mm critical-size calvarial defects were created in 48 male Sprague-Dawley rats. The animals were divided into 6 groups of 8 animals each. Each group received one of the following: Negative control(sham-surgery control), positive control(absorbable collagen sponge(ACS) alone) and experimental(ACS loaded with rhBMP-2). Defects were evaluated by histologic and histometric parameters following 2- and 8-week healing intervals. Results: The experimental group showed significant defect closure at 2 and 8weeks than the sham surgery and positive control groups. Moreover, the experimental group showed significantly greater new bone and augmented area than the other groups at both 2 and 8weeks. Conclusion: rhBMP-2 produced by E.coli expression system may be effective for bone regeneration.