• 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.

• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.621-628
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• 2008

Purpose: Osteopontin is one of the major non-collagenous protein of hard tissue. Use of peptide domain of biologically active protein has some advantages. The objective of this experimental study is evaluation of periodontal regenerative potency of synthetic peptide gel which containing collagen binding domain of osteopontin in the degree III periodontal defect of beagle dogs. Material and Methods: Experimental degree III furcation defect was made in the mandibular third and fourth premolar of beagles. Regenerative material was applied during flap operation. 8 weeks after regenerative surgery, all animals were sacrificed and histomorphometric measurement was performed to calculate the linear percentage of the new cementum formation and the volume percentage of new bone formation. Result: The linear percent of new cementum formation was 41.6% at control group and 67.1% at test group and there was statistically significant difference. The volume percent of new bone formation was 52.1% at control group and 58.9% at test group. Conclusion: As the results of present experiment, synthetic peptide gel containing collagen binding domain of osteopontin significantly increase new bone and cementum formation in the degree III furcation defect of canine mandible.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.276-292
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• 1996

The purpose of this study was to evaluate whether removal of gingival epithelium with pulsed Nd :YAG laser could inhibit the downgrowth of junctional epithelium after alloplastic material grafting in periodontal bone defect. The periodontal bone defects were created surgically on the palatal aspect of the upper right and left molar teeth in 30 rats and filled with resorbable calcium carbonate($Biocoral\;450^{(R)}$: Inoteb, France). The control sites(right molar area) was sutured. The test side (left molar area) received controlled deepithelization of the oral and sulcular epithelium with pulsed Nd:YAG laser($Sunrise\;Maste^{(R)}$: Sunrise Technologies, U.S.A.) under the mode of 1.75W, 15Hz, 116mJ/pulse and was sutured. The control and test sites were evaluated clinically and histologically, at 1, 3, 7, 14, and 28 days postoperation. Clinically, the gingiva showed normal color and shape at the 5th day in the control site and at the 10th day in the test sites. Histologically, the junctional epithelium was formed at the 7th day in the control sites and at the 14th day in the test sites, and the long JE attachment were observed at the 28th day in both sites. The attachment of connective tissue to root surface was observed initially at the 7th day in the control sites and at the 14th day in the test sites, and completed at the 28th day in both sites. In summary, these results showed that the removal of oral epithelium using pulsed Nd:YAG Laser could not prevent epithelial downgrowth after alloplastic material implantation in rat periodontal bone defect.

• Imaging Science in Dentistry
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• 제42권4호
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• pp.243-247
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• 2012

Purpose: This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Materials and Methods: Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. Results: There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm ($IC_{95%}$:6.04-6.54) and 6.79 mm ($IC_{95%}$:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm($IC_{95%}$:6.40-6.89) and 6.79mm($IC_{95%}$:6.45-7.11), respectively. Conclusion: The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2005년도 제45회 종합학술대회 연제초록
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• pp.163-164
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• 2005

• Journal of Korean Dental Science
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• 제11권2호
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• pp.43-56
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• 2018

Purpose: The purpose of this study was to assess the adhesiveness and cytotoxicity of 3, 4-dihydroxyphenylalanine (DOPA), and to evaluate the role of collagen membrane with DOPA in the guided bone regeneration. Materials and Methods: Peel resistance and cell cytotoxicity test were performed. Four defect types in nine rabbit calvaria were randomly allocated: i) control, ii) membrane, iii) deproteinized porcine bone mineral (DPBM) covered by membrane with DOPA, and iv) DPBM covered by membrane with cyanoacrylate. Animals were sacrificed at 2 (n=4) and 8 weeks (n=5) for microcomputed tomography and histomorphometric analysis. DOPA showed low peel resistance but high cell viability. Result: Cyanoacrylate and DOPA groups showed significantly higher mineralized tissue volume (MTV) compared to control and membrane groups at 2 weeks (P<0.05). At 8 weeks, DOPA group showed the highest MTV. Significantly higher new bone area was found in DOPA group at 8 weeks (P<0.05). Bone formation increased from 2 to 8 weeks in DOPA group (P<0.05). Conclusion: DOPA showed high cell viability and in vivo study revealed predictable performance in bone regeneration.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.325-336
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• 2000

Bone morphogenetic protein-2/4 are members of Transforming Growth Factor-$\beta$(TGF-$\beta$) superfamily and they may induce formation of cartilage and bone in vivo. This study was performed to investigate the cellular target and period of action of BMP-2/4 and understanding of actions of BMP-2/4 at cellular level. The appearance of BMP-2/4 during healing of mandibular and periodontal defect in rat was evaluated immunohistochemically. 40 Sprague-Dawley strain white male rats, each weighing about 300gm were used. Bony defect was performed in the mandible and they were sacrificed at the day of 3rd, 10th, 20th, 30th after operation. The specimens were harvested and examined histologically and immunohistochemically by localization of anti-BMP-2/4. The results were as follows: 1. Woven bone was observed at 10th day and perfect healing of defect with compact bone and periodontal ligment space at 30th day. 2. Osteoprogenitor cells, osteoblastic cells and periosteum were positive reaction to immunohistochemical stain at 10th day. 3. Cells of bone marrow space and surface cells of osteocytes and cementoblasts were positive reaction to immunohistochemical stain at 20th day. 4. Newly formed osteocytes and cementocytes were positive reaction to immunohistochemical stain at 30th day. From the above findings, we could conclude that BMP-2/4 acted significant roles as factors of induction, proliferation and differentiation during bone healing process.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.497-509
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• 2007

Bone morphogenetic proteins(BMPs) are regarded as members of the transforming growth $factor-{\beta}$ superfamily with characteristic features in their amino acid sequences. A number of studies have demonstrated the biologic activities of BMPs, which include the induction of cartilage and bone formation. Recently there was a attempt to overcome a limitation of mass production, and economical efficieny of rh-BMPs. The method producing PTD by using bacteria have advantages of acquiry a mass of proteins. Hences, a new treatment which deliver protein employed by protein transduction domain(PTD) has been tried. The purpose of this study was to evaluate the bone regenerative effect of TATBMP-2 and TAT-HA2-BMP-2 employed by PTD from HlV-1 TAT protein for protein translocation in the rat calvarial model. An 8mm calvarial, critical size osteotomy defect was created in each of 32 male Spraque-Dawley rats(weight $250{\sim}300g$). The animals were divided into 4 groups of 32 animals each (4 animals/group/healing interval). The defect was treated with TATBMP-2/ACS(Absorbable collagen sponge) (TATBMP-2 0.1mg/ml), TAT-HA2-BMP-2/ACS(TAT-HA2-BMP-2 0.1mg/ml), ACS alone or left untreated for surgical control(negative control). The rats were sacrificed at 2 or 8 weeks postsurgery, and the results were evaluated histologically. The results were as follows: New bone formation were not significantly greater in the TATBMP-2/ACS group relative to negative, and positive control groups. New bone was evident at the defect sites in TAT-HA2-BMP-2/ACS group relative to negative, positive control and TATBMP-2 groups. There were a little bone regeneration in TATBMP-2 groups. While, enhanced local bone formation were observed in TAT-HA2-BMP-2 group. But, The results was not the same in all rat defects. Therefore, further investigations are required to develop a method. which disperse homogenously, and adhere to target cells.

• Journal of Periodontal and Implant Science
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• 제27권3호
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• pp.633-645
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• 1997

The recent trend of research and development on guided tissue regeneration focuses on the biodegradable membranes, which eliminate the need for subsequent surgical removal. They have demonstrated significant and equivalent clinical improvements to the ePTFE membranes. This study evaluate guided tissue regeneration wound healing in surgically induced intrabony periodontal defects following surgical treatment with a synthetic biodegradable membranes, made from a copolymer of glycolide and lactide, in 8 beagle dogs. After full thickeness flap reflection, exposed buccal bone of maxillary and mandibular canine and premolar was removed surgically mesiodistally and occlusoapically at $6mm{\times}6mm$ in size for preparation of periodontal defects. In experimental sites a customized barrier was formed and fitted to cover the defect. Flap was replaced slightly coronal to CEJ and sutured. Plaque control program was initiated and maintained until completion of the study. In 4, 8, 16 and 24 weeks after surgery, the animals were sacrificed and then undecalcified specimens were prepared for histologic evaluation. Histologic examination indicated significant periodontal regeneration characterized by new connective tissue attachment, cementum formation and bone formation. These membranes showed good biocompatibility throughout experiodontal period. The barriers had been completely resorbed with no apparent adverse effect on periodontal wound healing at 24 weeks. These results implicated that present synthetic biodegradable membrane facilitated guided tissue regeneration in periodontal defect.