• Journal of Periodontal and Implant Science
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• 제33권2호
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• pp.193-213
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• 2003

The purpose of this study is to evaluate the phenomenon of attachment and spreading of the cultured rat　calvarial cell inoculated on their surface of different kinds of biodegradable membrane which had been used on tissue regeneration on periodontal defects by using scanning electron microscope. In this experiment 30 Sprague-Dawley male rats (mean BW 150gm) were used to harvest abundant number of cell in the short period. The rats were sacrificed by decapitatioan 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. Biodegradable barrier membrane were collected with collagen type, and were divided into 3 different kind of surface such as scattered, polarized and fine-net type as their surface texture. Microcover plate which usually used for cell culture was used as control for smooth surface. All the membrane were seeded with cultured calvarial cell on their surface. The number of cell inoculated on the membrane were $1{\times}10^6$ Cells/ml. After the culture as designed time, all the membrane were washed with 0.1 M Phosphate Buffered saline and fuxed with 2.5% Glutaraldehyde. And all specimen were treated with $OsO_4$, and Tannic acid before drying the cell for coating the cell with gold. Scanning Electron Microscope was used to observation. The following results were obtained. I. During the whole period of experiment, the phenomenon of cell attachment and spreading were revealed similar pattern to compare with smooth surface culture plate and ordinary culture dish. 2. The shape of cell attachment and spreading on the surface of barrier membrane were observed no remarked difference pattern between smooth surface culture plate and ordinary culture dish. 3. The cytoplasmic process of cultured calvaria cell extent to the deep portion of barrier membrane like as their own proper shape. 4. There were no remarkable relationships between the degree of cultured cell spreading and surface structure of barrier membrane. 5. Slight starified layer of cultured calvaria cell were observed on the scattered type of resorbable membrane, Conclusively, this study thus suggest that cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of carrier for many cell which could be used as new tissue regeneration, and those tissue engeering technique may become an new method in the approach to the repair of bone defects.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.279-289
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• 1995

The most important object of periodontal treatment is the perfect regeneration of destructed periodontal tissue. The healing of periodontal lesion is affected by several cells & factors, which result in formation of long juntional epithelium, root resorption, bony ankylosis or connective tissue attachment. And ideal healing is enhanced by epithilial exclusion or periodontal ligament cell activation. In this investigation, I studied the effect of Zizyphus Fructus extract which enhances biologic activity& collagen synthesis, on the chemotaxis & cell nature. The cells were obtained from interdental area & middle third area of the freshly extracted teeth for the orthodontic purpose. And they were fully incubated in${\alpha}-MEM$ solution containing $100{\mu]g/ml$ penicillin & $100{\mu]g/ml$ streptomycin followed by 6 generation incubation. The test cells were collected by trypsin-EDTA & centrifuge in the fully incubated cells, counted by Hernacyotmeter, incbated $5{\times}10^5/ml$ cells for 24 hours, re-incubated 24 hours in media containing natural extract and photographed. The cells were incubated for 4 hours in 48 well microchemotaxis chamber bisecting upper & lower chamber by 8ug/m pore polycarbonate membrane coating 5mg/ml gelatin solution. The migrated cells in microscope were counted, which meaned cell chemotaxis activity. The study had shown that the morphology of cell was spindle-shaped as the control group, and the subextract test groups were not significantly different. In gingival fibroblasts, the chemotaxis effect of PDGF was statistically significant compared to control group. The Zizyphus Fructus extract was more or less enhanced chemotaxis effect and in $1{\mu}g/ml$ concentration the chemotaxis effect was slightly elevated compared with $10{\mu}g/ml$ concentration. But, among the subextracts, it was not significantly defferent. In PDL cells, the chemotaxis effect of PDGF in statistically significant, and the zizyphus Fructus extract had shown the enhanced effect. The effect was slightly higher in $1{\mu}g/ml$ concentration than 10g/ml concentration,and no significance among the subextracts.

• Journal of Periodontal and Implant Science
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• 제23권2호
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• pp.261-281
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• 1993

The author transplanted periodontally-diseased teeth which had been treated with citric acid into a clinically healthy extraction sockets and periodontally-affected extraction sockets, and compared with the healing processes within these tissues. Recipient sites were prepared by surgically removing a part of alveolar bone of premolars of adults dogs, placing elastic orthodontic ligatures for 8weeks, thereby inducing periodontal disease. The diseased roots were extracted and transplanted into healthy extraction sockets, and these were designated as control group 1. Diseased roots transplanted into diseased sockets were designated as control group 2. Diseased roots which had been root planed, treated with citric acid and transplanted into healthy sockets were designated as experimental group 1, while identically treated roots which had been transplanted into diseased sockets were designated as experimental group 2. Observations were made at weeks 2, 8 and 12, with following results. 1. At week 2, experimental group 2 showed some inflammatory cell infiltration in the connective tissue above the extraction sockets, while control groups showed less inflammatory or foreign body reactions throughout the experiment. 2. In both control groups, root surface resorption was observed throughout the experiment, while experimental groups showed a little resorption. 3. Control group 1 & 2 showed ankylosis by newly-formed bone ground the resorbed root surfaces, while experimental group 1 & 2 displayed collagen fibers which are not functionally-arranged, with random, loose arrangement or parallel orientation to root surfaces, and newly-formed bone outside of them. 4. In both control groups & experimental groups which had been transplanted into a clinically healthy extraction sockets & periodontally affected extraction sockets groups, histological differences were not significant. 5. Root resorption or ankylosis in control group 1 & 2 had increased quantitatively as experiment progressed. 6. New bone formation developed from the base and lateral wall of extraction sockets. In both control groups & experimental groups, root surfaces lying next to the upper portion of extraction sockets showed little alveolar bone formation and surrounded by connective tissue fiber at weeks 2 & 8, while at weeks 12, they did show alveolar bone formation. 7. At week 12, experimental group 2 showed numerous cells which appeared to be periodontal ligament cells, with functionally arranged connective tissue fibers between the roots and alveolar bone.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.883-908
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• 1997

Bone remodeling is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. The process is tightly regualted at the local level by an incompletely known netwotk of peptide and non-peptide fators. Nitric oxide(NO), synthesized by nitric oxide synthetase(NOS) from L-arginine, is becoming recognized as an important bioregualtory molecule in a variety of tissue, but little is known about its possible role in periodontal tissue. The purpose of this study is to investigate the expression of nitric oxide synthetase(NOS) in inflamed gingiva and the effects of cytokine on the expression of NOS protein. The expression of NOS in gingival tissue was evaluated by immunohistochemical staining for $NOS_1$, $NOS_2$, $NOS_3$. The effect of cytokine on the expression of NOS in human periodontal ligament cells and osteoblast-like HOS cells by western blot analysis. Further, we studied that NO functions in periodontal ligament cells as a regulatory molecule. PDL cells incubated with NOS inhibitor and donor. The protein expression, type I collagen & non-collagenous protein, nitrate production and cell proliferation were evaluated The results were as follows. 1. $NOS_1$, $NOS_2$, $NOS_3$ was rarely distributed in healthy gingiva, but stronger stained in gingival epithelium, endothelial cells, and mononuclear cells of inflammed gingiva. 2. The cytokine stimulated $NOS_1$, and $NOS_3$ protein were not inducing or inhibitory effect to compared with control in PDL and HOS cells. 3.Incubation of cells with combination of $TNF-{\alpha}$, $IFN-{\gamma}$, LPS result in a time dependant increase in $NOS_2$ expression, reaching a maximal level after 24 hours of stimulation. 4. The osteonectin protein inhibitory effect of NMA, inhibitor of NOS, was reversed by Larginine in dose dependant manner. 5. NMA decreased cell poliferation and nitrate production, but the inhibitory efffect of NMA was also prevented by the NO donor, sodium nitropruiside. These results suggest that exogenously synthesized NO was playing a stimulating effect on cell proliferation or on non-collagenous protein expression. Therefore NO have an important role in mediation of localized bone destruction associated inflammatory bone disease such as periodontitis.

• Journal of Periodontal and Implant Science
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• 제47권6호
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• pp.352-362
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• 2017

Purpose: Furcation involvement in the molars is difficult to treat, and has been recognized as a risk factor for tooth loss. Although periodontal regenerative therapies, including guided tissue regeneration and various types of bone grafts, have been applied to furcation defects, the effects of these treatments are limited, especially in large class III furcation defects. The purpose of this pilot study was to investigate the effect of reciprocal autologous root transplantation on periodontal wound healing and regeneration in class III furcation defects in dogs. Methods: Furcation defects (7 mm wide and 6 mm high) were surgically created after root separation of the unilateral third and fourth premolars in 4 dogs. Eight furcation defects were randomized to receive either reciprocal autologous root transplantation (test) or no further treatment (control). In the test group, the mesial and distal roots were transplanted into the distal and mesial extraction sockets, respectively. The animals were sacrificed 10 weeks after surgery for histologic evaluation. Results: The healing pattern in the control group was characterized by extensive collapse of the flap and limited periodontal regeneration. New bone formation in the test group ($3.56{\pm}0.57mm$) was significantly greater than in the control group ($0.62{\pm}0.21mm$). Dense collagen fibers inserting into the residual cementum on the transplanted root surfaces were observed in the test group. Slight ankylosis was observed in 2 of the 4 specimens in the test group on the mesiodistal sides where the root-planed surfaces faced the existing bone. Root resorption (RR) was detected in both the control and test groups. Conclusions: Within the limits of this study, it can be concluded that reciprocal autologous root transplantation was effective for bone regeneration in class III furcation defects in dogs. However, further studies are required to standardize the approach in order to prevent unwanted RR prior to clinical application.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.99-109
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• 2005

It has been focused on the importance of the host inflammatory response in periodontal pathogenesis and progression, treatment has been introduced to control the host response and the method, which diminishes production and activity of MMP by doxycycline, has been used in periodontal field. MMP is a proteolytic enzyme which plays a major role in tissue destruction and MMP-1 is secreted in the periodontally healthy tissue, while MMP-8, 9, 13, etc in the inflammatory state. Among these, MMP-13 has been discovered lately and reported to degrade primarily type II collagen. Periodontal ligament (PDL) cell plays a role in destruction of periodontal tissue. This study was to evaluate the effect of doxycycline and mefenamic acid, non-steroidal antiinflammatory drug on MMP-13 mRNA expression in the rat PDL cell. Doxycycline concentration of $1{\sim}100\;{\mu}g/ml$ was added rat PDL cell and cell activity was measured by MIT assay at day 1 and 3. MMP-13 gene expression was evaluated by RT-PCR after PDL cells were pre-treated for 1hour with doxycycline (50 ${\mu}g/ml$) alone or with mefenamic acid ($10^{-6}M$), then added $IL-1{\beta}$(1.0 ng/ml) and incubated for 16-18 hours. The results are as follows: 1. Cell activity decreased Significantly at 24 and 72 hours in 100 ${\mu}g/ml$ (p<0.05). 2. Level of MMP-13 mRNA was in 20.2% increase by $IL-1{\beta}$ and in pre-treating doxycycline group, expression of $IL-1{\beta}$ induced MMP-13 mRNA was inhibited by 31% than $IL-1{\beta}$ treated only. 3. Mefenamic acid did not inhibit on the expression of $IL-1{\beta}$ induced MMP-13 mRNA, while mefenamic acid in combination with doxycycline inhibited the expression by 41% compared to only $IL-1{\beta}$ stimulation. These results suggest that doxycycline synergistically inhibit the expression of $IL-1{\beta}$ induced MMP-13 mRNA in combination with mefenamic acid.

• Journal of Periodontal and Implant Science
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• 제31권4호
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• pp.669-687
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• 2001

On the basis of the evidence that electrical stimulation could promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on rat extraction socket, and to evaluate the potential of clinical application of electrical stimulation. Forty rats were used and divided into control groups(l0)and the experimental groups(30) in this study. The maxillary 1st molar were extracted in both groups. In experimental group, electrical stimulation was given at the current intensity of lmA(Test-1), l0mA(Test-2), 25mA(Test-3) each day. At 1,3,5,7 days after the tooth extraction, rats in both groups were serially sacrificed. And the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows; 1. At 1 day after the extraction, the periodontal ligament was found in the extraction socket wall. The formation of blood clot with dense infiltration of inflammatory cells in control group and there were less inflammatory cells in test group. 2. At 3 day after the extraction, the cells and collagen of the periodontal ligament were so actively proliferated and synthesized that invaded into the connective tissue of the extraction sockets in the control group. There were the formation of new bone in the basal & lateral portion of socket wall in test -2 and -3. 3. At 5 days after the extraction, there were no formation of new bone in control group. But the more electrical stimulation was applied, the more formation of new bone in test group. 4. At 7 days after the extraction, the extraction sockets were almost filled with trabecular bone in each group. Bone maturarity was remarkable in test-3. 5. The electrical stimulation at l0mA and 25mA was more effective in the bone formation at 5 and 7 days after the extraction. From the above results, electrical stimulation could promote the extraction socket wound healing, and be utilized in the clinical application of the residual ridge expansion.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.1-17
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• 1997

Tetracycline is known to be effective in eliminating periodontopathogens and have collagenolytic activity. This study was performed to observe the desorption kinetics and structural changes of tetracycline-treated barrier membranes for guided tissue regeneration. Four kinds of barrier membranes were tested : $Tefgen^{(R)}$(American Custom Medical, USA) and $Gore-Tex^{(R)}$(W.L. Gore & Associates Inc., USA) as nonresorbable membranes ; Resolut(polyglycolide & polylactide copolymer, W.L. Gore & Associates Inc., USA) and $Biomend^{(R)}$(collagen, Collatec Co., USA) as resorbable membranes. The membranes were cut into discs(diameter : 4mm) and were immersed in 5% tridodecylmethylammonium chloride(TIMAC) ethanol and air-dried. The membrane discs were absorbed with $100{\mu}g/ml tetracycline solution(pH8) for one minute and dried. For desorption kinetics, TC treated discs were immersed in phosphate buffered saline solution (PBS, pH 7.4). PBS was exchanged daily and TC concentration was measured by absorbance at 276nm on UV spectrophotometer. To measure remaining antibacterial activity, discs of 1 day to 4 weeks after desorption were placed on Mueller Hinton agar containing Bacillus cereus and incubated aerobically in $37^{\circ}C$ for twelve hours and the inhibition diameters were measured. To observe the structural change of membranes after TIMAC treatment or immersion in PBS, the membrane discs were examined under SEM. The results were as follows : 1. Total amounts of TC absorbed into membrane discs($0.7536mm^2$) were $2000{\mu}g$, $1800{\mu}g$, $2625{\mu}g$ and $2499{\mu}g$ for $Tefgen^{(R)}$, $Gore-Tex^{(R)}$, $Biomend^{(R)}$ and $Resolut^{(R)}$. 2. The concentration of TC released from barrier membrane discs was maintained over $4{\mu}g/ml$ until the fifth day in nonresorbable membranes and $Resolut^{(R)}$, but until the fourth day in $Biomend^{(R)}$, Until the ninth day in nonresorbable membranes and until the seventh day in resorbable membranes, the TC concentration was maintained over $1{mu}g/ml$. 3. The four membrane discs in the first day showed similar size of inhibition zone. One to four weeks later, the inhibition zone was much smaller in resorbable membrane discs than nonresorbable membrane discs. 4. Any structural change due to treatment of TIMAC was not observed on the nonresorbable membranes. $Resolut^{(R)}$ did not show any structural change except fibrillar loosening during immersion period, but Biomend showed destruction of membrane structure from the first week of immersion. This study indicates that tetracycline treated barrier membranes lead to the sustained release of tetracycline for over 7 days. This slow release pattern of tetracycline may contribute to the favorable clinical outcome of guided tissue regeneration.

• Macromolecular Research
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• 제10권3호
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• pp.158-167
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• 2002

In order to endow with new bioactive functionality from small intestine submucosa (SIS) powder as natural source to poly (L-lactide) (PLA) and poly (lactide-co-glycolide) (PLGA) synthetic biodegradable polymer, porous SIS/PLA and SIS/PLGA as natural/synthetic composite scaffolds were prepared by means of the solvent casting/salt leaching methods for the possibility of the application of tissue engineered bone and cartilage. A uniform distribution of good interconnected pores from the surface to core region was observed the pore size of 40~500 ${\mu}{\textrm}{m}$ independent with SIS amount using the solvent casting/salt leaching method. Porosities, specific pore areas as well as pore size distribution also were almost same. After the fabrication of SIS/PLA hybrid scaffolds, the wetting properties was greatly enhanced resulting in more uniform cell seeding and distribution. Five groups as PGA non-woven mesh without glutaraldehyde (GA) treatment, PLA scaffold without or with GA treatment, and SIS/PLA (Code No.3 ; 1 : 12 of salt content, (0.4 : 1 of SIS content, and 144 ${\mu}{\textrm}{m}$ of median pore size) without or with GA treatment were implanted into the back of nude mouse to observe the effect of SIS on the induction of cells proliferation by hematoxylin and eosin, and von Kossa staining for 8 weeks. It was observed that the effect of SIS/PLA scaffolds with GA treatment on bone induction are stronger than PLA scaffolds, that is to say, in the order of PLA/SIS scaffolds with GA treatment > PLA/SIS scaffolds without GA treatment > PGA nonwoven > PLA scaffolds only with GA treatment = PLA scaffolds only without GA treatment for the osteoinduction activity. The possible explanations are (1) many kinds of secreted, circulating, and extracellular matrix-bound growth factors from SIS to significantly affect critical processes of tissue development and differentiation, (2) the exposure of SIS to GA resulted in significantly calcification, and (3) peri-implant fibrosis due to covalent bonding between collagen molecule by crosslinking reaction. In conclusion, it seems that SIS plays an important role for bone induction in SIS/PLA scaffolds for the application of tissue engineering area.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권4호
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• pp.329-334
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• 2005

Polymethyl-methacrylate(PMMA; Artecoll$^{(R)}$) microspheres suspended 1 : 3 in a 3.5% collagen solution has been used as an injectable implant for long lasting correction of wrinkles and minor skin defects. The patients with mandibular prognathism have increased necessity for nasal augmentation. Usually these patients usually get an additional rhinoplasty after orthognathic surgery. The purpose of this study is to evaluate the result of PMMA injection for nasal ridge augmentation simultaneously with the orthognathic surgery. PMMAs were injected to the nasal dorsum of 13 patients with mandibular prognathism to augment the nasal ridge at the end of the orthognathic surgery. The cephalometric X-ray and clinical facial photograph were taken at 2, 4 and 6 months after operation. Using S-N line, we calculated the change of soft tisuue on the nasal ridge and also investigated the degree of patients satisfaction at 6 months after operation. Most of the patients were satisfied with their nasal ridge height status from moderate to good degree. The average amount of nasal ridge augmentation was $1.4{\pm}0.5$ mm immediately after operation, $1.2{\pm}0.4$ mm at 2 months after operation. The postoperative nasal ridge height seemed to be remained stable after 2 months. Intraoperative PMMA injection is considered to be simple and effective technique which can be used for the minor augmentation of nasal ridge in the orthognathic patients.