• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.438-457
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• 1995

The origin of fibroblasts, their proliferative activity and roles in the early stages of periodontal regeneration were investigated in order to better understand the periodontal healing process in furcation defects of the beagle dog after guided tissue regeneration. Newly divided cells were identified and quantitated by immunolocalization of bromodeoxyuridine (BrdU) injected 1 hour prior to sacrificing the animals. The results were as follows :1. During periodontal healing in horizontal furcation defect, three different stages, namely the granulation tissue, connective tissue, and bone formation stages, were identified on the basis of major types of cells and tissue. 2. In the early stages of periodontal regeneration, both the remaining periodontal ligament and alveolar bone compartment were the major sources. 3. The majority of BrdU-labeled fibroblasts were located at the following areas ; 1) the coronal zone of the defect in case of the connective tissue fanned on the root surface. 2) the area within an 400 ${\mu}m$ distance from the remaining bone level in case of the periodontal ligament. 3) the area within an 100 ${\mu}m$ distance from the bone surface in case of areas of active bone formation.4. The highly proliferative fibroblasts adjacent to bone surface played a major role in the formation of osteoblast precursor cells, whereas both paravascular and endosteal cells played a minor role in new bone formation, In conclusion, it was suggested that the fibroblasts in the remaining periodontal ligament and bone will play a major role in periodontal regeneration, whereas both paravascular and endosteal cells will play a minor role in new bone formation.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.87-97
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• 1994

The ultimate goal of periodontal therapy is to fully reconstruct the periodontal attachment apparatus. Commonly used techniques for treatment of infrabony defects include a combination of root planing, curettage and root treatment. To prevent the apical migration of epithelial cells, the technique of guided tissue regeneration is used. The aim of this study is to compare the effects of root treatment with Citric acid & Tetracycline and Guided tissue regeneration in dogs. Experimental periodontitis was induced by the ligation of orthodontic elastic threads in the upper right and left premolars 3, 4 of five adult dogs for 6 weeks. 4 types of procedures were performed as follows; 1) Control graup : Mucoperiosteal flap 2) Experinental I : GTR used Gore-tex(R) membrane 3) Experinental II : Root treatment with citric acid (PHl) 4) Experinental III : Root treatment with tetracycline HCl (50mg/ml) There after, dogs were serially sacrificed at the 1, 2, 4, 5, 8 weeks, and the specimens were prepared, and stained with hematoxylin-eosin for the light microscopic evaluation. The results of this study were as follows; 1. Junctional epithelium reached to the notch through the furcation area in control group at 8 weeks. 2. In the aspects of the inflammatory cell infiltration, control group showed severe aggregation than experimental group I, II, III through the experimental period 3. New cementum was observed over the notch from 5 weeks in experimental group II 4. In the aspects of the amount of new bone formation, experimental group was better than control group, but there was not significant differences among the experimental group, I, II, III

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.191-200
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• 2009

Dental Pulp Stem Cells are superior to other types of adult stem cell. Because of teeth are easy to access and are extracted throughout life. A supernumerary tooth is an important clinical problem found in various populations of the world. The incidence of supernumerary teeth varies depending on the literature source. Pediatric dentists are routinely extracted them. However, no studies have been reported regarding Dental Pulp stem cells in a supernumerary tooth, and we failed to note that a valuable source of human stem cell. Herein, we tried to show that a supernumerary tooth contains cells that display the characteristic features of stem cells.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.12-16
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• 2002

Concentration of quercetin and soluble tannin in Houttuynia cordata were determined at different growth stages as well as plant parts and application amounts of compost. Both contents of quercetin and tannin at growth stages were decreased before flowering time but slightly increased after flowering. The both contents of components in Houttuynia cordata collected on April 20 were shown to be markedly increased compared to those collected in May or June. The contents of quercetin and tannin at different organs were the highest in the flower. In the experiment of application amounts of compost, as application amounts is increased, fresh weight of aerial part was increased but the contents of quercetin and tannin were decreased. The contents of quercetin and tannin were the highest with 0.67% and 2.3%, respectively, in the compost non-treatment.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.161-172
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• 2002

The present study evaluated the effects of guided tissue regeneration using xenograft material(deproteinated bovine bone powder), with and without biodegradable membrane in beagle dogs. Contralateral fenestration defects (6 ${\times}$ 4mm) were created 4 mm apical to the buccal alveolar crest of maxillary premolar teeth in 5 beagle dogs. Deproteinated bovine bone powders were implanted into fenestration defect and one randomly covered biodegradable membrane (experimental group). Biodegradable membrane was used to provide GTR. Tissue blocks including defects with soft tissues which were harvested following four & eight weeks healing interval, prepared for histo-phathologic analysis. The results of this study were as follows. 1. In control group, at 4 weeks after surgery, new bony trabecular contacted with interstitial tissue and osteocytes like cell were arranged in new bony trabecule. Bony lamellation was not observed. 2. In control gruop, at 8 weeks after surgery, scar-like interstitial tissue was filled defect and bony trabecule form lamellation. New bony trabecular was contacted with interstitial tissue but defect was not filled yet. 3. In experimental group, at 4 weeks after surgery, new bony trabecular partially recovered around damaged bone. But new bony trabecular was observed as irregularity and lower density. 4. In experimental group, at 8 weeks after surgery, lamella bone trabecular developed around bone cavity and damaged tissue was replaced with dense interstitial tissue. In conclusion, new bone formation regenerated more in experimental than control groups and there was seen observe more regular bony trabecular in experimental than control groups at 4 weeks after surgery. In control group, at 8 weeks after surgery, the defects was filled with scar-like interstitial tissue but, in experimental group, the defects was connected with new bone. Therefore xenograft material had osteoconduction but could not fill the defects. We thought that the effective regeneration of periodontal tissue, could be achieved using GTR with biodegradable membrane.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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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.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.171-177
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• 2022

Peri-implantitis is an inflammatory lesion of the periodontium surrounding an endosseous implant, with progressive loss of the supporting peri-implant bone. The main purposes of treatment for peri-implantitis due to biological factors include addressing the inflammation and restoring a healthy but reduced periodontium around the implant, similar to the treatment of periodontitis in natural teeth. The proposed treatment protocol includes surgical treatment, mainly resective surgery, after non-surgical treatment such as oral hygiene instructions, mechanical cleansing of the fixture, and general or topical antiseptic or antibiotic application according to the extent of inflammation. In this article, we present a 6-year follow-up case showing unusual marginal bone regeneration after resective surgery and decontamination of an implant surface for the treatment of peri-implantitis and discuss the possible reasons.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.165-174
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• 1998

The turnover of collagen is controlled by the balance between collagen synthesis and degradation. The production of collagenase (matrix metalloproteinase-1) and its inhibitor, tissue inhibitor of matrix metallopmteinase-1 (TIMP-1) are one of the substances which regulate this balance. The periodontal ligament fibroblast plays an important role in collagen metabolism during orthodontic treatment and is believed to be an origin of the osteoblast in the alveolar bone. The collagenase secreted by the periodontal ligament fibroblast and the osteoblast initiates the bone resorption by removing the osteoid layer in the alveloar bone. The interleukin-$1{\beta}$ is secreted by the macrophage during orthodontic treatment. The present study was undertaken to assess the effect of mechanical stress and interleukin-$1{\beta}$ on the expression of collagenase and TIMP-1 in the periodontal ligament fibroblasts using reverse transcription polymerase chain reaction and immunohistochemical staining. The periodontal ligament fibroblasts were stitched by placing the $Petriperm dish^{\circledR}$ dish on the top of spheroidal convex watch glass ($5\%$ surface increase) and tented with interleukin-$1{\beta}$ (1.0 ng/ml), or treated with both of them. Treatment with mechanical stress and/or interleukin-$1{\beta}$ resulted in increased collagenase mRNA expression. The mechanical stress treated group (1.61, 1.62, 1.37 fold increase), the interleukin-$1{\beta}$, tented group (1.68, 1.60, 3.78 fold increase), the mechanical stress and interleukin-$1{\beta}$ treated group (1.89, 1.72, 5.48 fold increase) induced increases in collagenase mRNA compared with the control group after 2, 4, 8 hours respectively. But TIMP-1 mRNA expressions at experimental groups were decreased after 2, 4 hours and increased after 8 hours. The mechanical stress treated group (0.16, 0.49 fold decrease and 3.77 fold increase), the interleukin-$1{\beta}$ treated group (0.15,0.44 fold decrease and 4.46 fold increase), the mechanical stress and interleukin-$1{\beta}$ tented group (0.15, 0.69 fold decrease and 4.81 fold increase) induced changes in TIMP-1 mRNA compared with the control group after 2, 4, 8 hours, respectively. Immunohistochemical stain showed that increased collagenase and TIMP-1 staining of the mechanical stress tented group, the interleukin-$1{\beta}$ treated group, and the mechanical stress and interleukin-$1{\beta}$ treated group compared with that of the control group after 8 hours. These findings suggest that mechanical stress and interleukin-$1{\beta}$ regulate expression of collagenase and TIMP-1.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.85-96
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• 1993

To investigate the alteration of transferrin receptor (TfR) in the proliferating or transformed liver cells, $^{125}I-transferrin$ binding experiment was carried out in the isolated parenchymal cells (PC) or nonparenchymal cells (NPC) from normal regenerated rat liver after partial hepatectomy and from the liver of 3-methyl-4-dimethyl-aminoazobenzene (3-Me-DAB) treated rat. With the administration of 3-Me-DAB for 8 weeks, the liver tissue showed marked morphologic changes of oval cell proliferation, regenerations of hepatocytes, and atypical proliferations of bile ducts, but these changes were little affected by partial hepatectomy. Transferrin binding values in PC or NPC homogenate from the regenerated liver of normal rat, were increased by 3rd day and diminished to control level at 7th day after partial hepatectomy. With the treatement of 3-Me-DAB for 8 weeks, transferrin binding sites in homogenates were higher than those of normal rat liver and increased by 7th day after partial hepatectomy. Transferrin binding sites (Bmax) in the cell membrane of NPC were higher than those of PC of normal rat liver, but there was no significant difference in Kd values between both groups (5.05, 6.3 nM). In the normal resenerated rat liver, transferrin binding sites in the PC or NPC plasma membrane, were increased by 3rd day and diminished to control level at 7th day after partial hepatectomy. With 3-Me-DAB tratment, transferrin binding sites in both liver NPC and PC plasma membrane were increased about 3 folds, compared to those in each plasma membrane of normal rat liver. And after partial hepatectomy of 3-Me-DAB trated rat, transferrin binding sites were increased by the 3rd day in the NPC plasma membrane but increased by the 7th day in the PC plasma membrane. In the transferrin binding sites of the PC or NPC plasma membrane of 3-Me-DAB treated liver, two kinds of Kd values $(3.1{\sim}4.7\;nM,\;25.4{\sim}54.1\;nM)$ were detected. The present results suggest that 1) TfRs are distributed in the liver PC as well as NPC; 2) Increased TfRs in PC or NPC plasma membrane of normal regenerated liver after partial hepatectomy and 3-Me-DAB treated rat liver, may be due to increased intracellular synthesis; 3) Increased TfRs in normal regenerated liver after partial hepatectomy might be related to the expression of a single type of high affinity site $(Kd,\;3.1{\sim}7.5\;nM)$, but in 3-Me-DAB treated rat liver might be related to the expression of high and low affinity types of receptors $(Kd,\;25.4{\sim}54.1\;nm)$.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.737-744
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• 2008

Purpose: In advanced case of periodontitis, surgical treatment without bone contouring may result in residual pockets inaccessible to proper cleaning during post-treatment maintenance. This problem can be avoided or reduced by applying guided tissue regeneration. Materials and Methods: All of 3 patients had deep periodontal pocket depth and bleeding on probing, and radiograph revealed osseous defect, so we planned guided tissue regeneration using resorbable membrane with or without xenograft. Result: 6 months later, periodontal pocket depth and bleeding on probing was improved and gingiva was stable. Conclusion: Guided tissue regeneration using resorbable membrane with or without xenograft in osseous defect is predictable.