• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.613-625
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• 2006

Periodontal ligament(PDL) cells and human gingival fibroblasts(HGFs) play important roles in development, regeneration, normal function, and pathologic alteration. PDL cells and HGFs have the similarity related with general characteristics of fibroblast such as spindle shaped morphology, the presence of vimentin intermediate filament and the synthesis of interstitial collagens and fibronectin. There were many studies about the differences between PDL cells and HGFs, but they were not about whole gene level. In this study, we tried to explain the differences of gene expression profiles between PDL cells and HGFs, and the differences among three individuals by screening gene expression patterns of PDL cells and HGFs, using cDNA microarray. Although there were some variants among three experiments, a set of genes were consistentely and differentially expressed in one cell type. Among 3,063 genes, 49 genes were more highly expressed in PDL cells and 12 genes were more highly expressed in HGFs. The genes related with cell structure and motility were expressed more highly in PDL cells. These are cofilin 1, proteoglycan 1 secretory granule, collagen type I(${\alpha}$ 1), adducin gamma subunit, collagen type III(${\alpha}$ 1), fibronectin, lumican(keratan sulfate proteoglycan), and ${\alpha}$ -smooth muscle actin. Tissue inhibitor of metalloproteinase known as the enzyme controlling extracellular matrix with matrix metalloproteinase is more highly expressed in PDL cells, osteoprotegerin known as osteoclastogenesis inhibitory factor is more highly expressed in HGFs. We performed northern blot to verify cDNA microarray results on selected genes such as tissue inhibitor of metalloproteinase, fibronectin, osteoprogeterin. The result of northern blot analysis showed that each cell expressed the genes in similar pattern with cDNA microarray result. This result indicates that cDNA microarray is a reliable method in screening of gene expression profiles.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.641-654
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• 1996

In infectious disease, invasion of host tissue by bacteria or their products frequently induces a wide variety of inflammatory and immunopathologic reaction. Evidence indicates that cytokines are involved in the initiation and progression of chronic inflammatory diseases, such as periodontitis. Interleukin-6, which is a multifunctional cytokine, has important roles in acute and chronic inflammation and may also be implicated in bone resorption. Periodontal diseases are characterized by chronic inflammation of the periodontium with alveolar bone resoption. A principal driving force behind this response appears to lie in the immune system's response to bacteria. Many of the cell components which have been shown to function as virulence factors in gram-negative bacteria are associated with the bacterial surface. Of these, lipopolysaccharide has been characterized as one that mediates a number of biological activities which can lead to the destruction of host tissue. Non-steroidal antiinflammatory drug is used for reduce inflammation, and most of NSAIDs inhibit prostaglandine $E_2$ production, but it is shown that $PGE_2$ production is stimulated by IL-1 in recent study. So, the influence of other cytokines except $PGE_2$ on periodontium can not be avoided. Therefore, new antiinflammatory drug is needed. Rhizoma coptidis is used in oriental medicine for anti-inflammation and antiseptics. In this present study, we examined the IL-6 release in periodontal ligament cells treated with the lipopolysaccharide, and also the effect of rhizoma coptidis on cellular activity and IL-6 production of periodontal ligament cells. To evaluate the effect of rhizoma coptidis on cellular activity, the cells were seeded at a cell density of $1{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 1-6, 10-9 and 10-12 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 1 and 2 days, respectively. Then, MTT assay were carried out. To evaluate the effect of rhizoma coptidis on IL-6 production, the cells were seeded at a cell density of $1.5{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 10-9 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 3, 6, 12 and 24 hours. Then, amounts of IL-6 production is measured by IL-6 ELISA kit used. The results were as follows : 1. Rhizoma coptidisrbelow to ($10^{-6}g/ml$) significantly increaed cellular activity of periodontal ligament cells than control. 2. Rhizoma coptidist ($10^{-9}g/ml$) significantly increased cellular activity of LPS($5{\mu}g/ml$)-treated periodontal ligament cells than control. 3. LPS(5 and $10{\mu}g/ml$) significantly increased IL-6 production of periodontal ligament cells than control. 4. Rhizoma coptidis($10^{-9}g/ml$) decreased IL-6 production of LPS ($5{\mu}g/ml$)-treated periodontal.ligarnent cells than LPS only tested group. These findings suggest that stimulation of the IL-6 release of periodontal ligament cells by LPS may have a role in the progression of inflammation and alveolar bone resoption in periodontal disease, and that inhibition of the IL-6 release of cells and stimulation of cellular activity by rhizoma coptidis may help the periodontal regeneration.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.923-939
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• 1997

This study was performed to evaluate the effect of mixed culture of rat's calvaria cells and periodontal ligament cells on calcification. These cells have been known to do important role on the periodontal tissue regeneration, especially alveolar bone and cementum. Experimental groups were made which based on the different rate of rat's calvaria cells and periodontal ligament cells, and then these cells were cultured with Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum, $50{\mu}g/ml$ ascorbic acid, and 10mM/ ml $Na-{\beta}-glycerophosphate$. Each group was characterized by examining the cell proliferation rate, amount of total protein synthesis, alkaline phosphatase activity, and the number of calcified nodules in vitro. In cell proliferation rate , the cells of control groups were cultured Dulbecco's Modified Eagle's Medium contained with 10 % fetal bovine serum. The results were as follows : 1. The cell proliferation rate in control groups decreased stastically significantly along with the decrease of the rate of bone cells at 7 day and 20 day(P < 0.01). 2. The cell proliferation rate in experimental groups decreased stastically significantly along with decrease of the rate of bone cells at 3 day and 14 day(P < 0.01). 3. The amount of total protein synthesis was significantly decreased along with decrease of the rate of bone cells at 3 day and 6 day(p < 0.01). 4. Alkaline phosphatase activity showed reverse time dependent pattern and was significantly decreased along with decrease of the rate of bone cells during the experimental periods (P < 0.01). 5. Calcified nodules were observed in group 1 (Rat calvaria cells alone) for the first time, and the number of calcified nodule decreased stastically significantly along with the decrease of the rate of bone cells at 12 day(P < 0.01). From the above results, When bone cells and periodontal ligament cells were mixed cultured, the cell proliferation rate was mostly dependent on the actual rate of bone cells and same pattern was showed in amount of total protein synthesis, alkalinephosphatase activity, and the number of calcified nodules. And the calcified nodule forming capacity of bone cells was inhibited by periodontal ligament cells

• 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.

• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.167-176
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• 2009

Purpose: The purpose of this study is to histologically and histomorphometrically evaluate the effect of PLGA on bone regeneration compared with bone graft material. Methods: The experimental study was conducted in 10 rabbits with 2 different healing periods of 2 and 4 weeks. Following surgical exposure of the calvarium, 4 circular bone defects with a diameter of 4.6mm were formed. Rabbits were divided into control group, test groups I, and II. 10 defects assigned to the test group Ⅰ were grafted with Nu-oss and other 10 defects assigned to the test group II were grafted with PLGA. The rest of the defects were in the negative control group. At 2nd and 4th week after surgery, 10 rabbits were sacrificed through intracardiac perfusion and then specimens were obtained. Histological analysis was performed following staining with trichorme and transversal sectioning of the calvarial bone. Results: A group which used PLGA showed tissue reactions characterized by severe inflammation, rather than distinctive new bone formation. Conclusions: The present experimental investigations have failed to prove any beneficial effects of PLGA. PLGA used in this study exhibited foreign body reactions and a less favorable pattern of new bone formation in comparison to control group. Conclusion: PLGA did not function as scaffold. Further investigations of many types of micro PLGA that could improve its potential in GBR procedures are needed.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.91-109
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• 2001

The purpose of this study is to evaluate histologically the resorption and tissue response of various resorbale membranes used for guided tissue regneration procedures, using a subcutaneous model on the dorsal surface of the rat. In this study, 12 Sprague-Dawley male rats(mean BW 150gm) were used and the commercially available materials included dense collagen membrane, freeze-dried bovine dura mater loos collagen membrane, PLA/PLGA membrane. Animals were sacrificed at 3, 6 and 8 weeks after implantation of various resorbable membranes. Specimens were prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows: 1. Resorption : Loose collagen membrane group was resorbed most rapidly. Dense collagen membrane group and freeze-dried bovine dura mater group were rarely resorbed. 2. Inflammatory reactions : PLA/PLGA membrane group showed persistent and severe inflammatory reactions for 3 to 8 weeks. Moderate inflammatory reactions and the ectopic formation of calcified material were observed in dense collagen membrane group. Freeze-dried bovine dura mater group and loose collagen membrane group showed mild inflammatory reactions 3. In PLA/PLGA membrane group, multinucleated giant cells by foreign body reactions were observed. In conclusion, the resorption of freeze-dried bovine dura mater didn't happen for 3-6weeks, which showed the best bio-compatibility. Therefore, freeze-dried bovine dura mater was considered proper resorbable membrane for guided tissue regeneration.

• Journal of Periodontal and Implant Science
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• 제52권1호
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• pp.3-27
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• 2022

Purpose: This study was conducted to evaluate and compare the effects of different graft materials used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge, assessed using cone-beam computed tomography (CBCT) scans. Methods: A systematic electronic search of MEDLINE and the Cochrane Central Register of Controlled Trials and a manual search were conducted from November 2019 until January 2020. Randomized controlled trials were included if they assessed at least 1 variable related to vertical or horizontal hard tissue changes measured using CBCT scans. After a qualitative analysis of the included studies, subgroups were formed according to the graft material used, and a quantitative analysis was performed for 5 outcome variables: changes in vertical alveolar bone height at 2 points (midbuccal and midpalatal/midlingual) and changes in horizontal (buccolingual) alveolar bone width at 3 different levels from the initial crest height (1, 3, and 5 mm). Results: The search resulted in 1,582 studies, and after an independent 3-stage screening, 16 studies were selected for qualitative analysis and 9 for quantitative analysis. The metaanalysis showed a significantly (P<0.05) lower reduction of alveolar ridge dimensions for the xenogenic subgroup than in the allogenic subgroup, both vertically at the midbuccal aspect (weighted mean difference [WMD]=-0.20; standard error [SE]=0.26 vs. WMD=-0.90; SE=0.22) as well as horizontally at 1 mm (WMD=-1.32; SE=0.07 vs. WMD=-2.99; SE=0.96) and 3 mm (WMD=-0.78; SE=0.11 vs. WMD=-1.63; SE=0.40) from the initial crest height. No statistical analysis could be performed for the autogenic subgroup because it was not reported in sufficient numbers. Conclusions: Less vertical and horizontal bone reduction was observed when xenogenic graft materials were used than when allogenic graft materials were used; however, the loss of alveolar ridge dimensions could not be completely prevented by any graft material.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.305-324
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• 2000

This study compared the short-term(4 months) clinical results of regenerative therapy with bioabsorbable membranes($BioMesh^{(R)}$) and bone allograft for the treatment of periodontal(intrabony and furcation) defects in smokers and nonsmokers.(16 smokers) 32 subjects with 92 defects participated in the study(46 in smokers and 46 in non-smokers). This study also evaluated a bioresorbable barrier with and without decalcified freeze-dried bone allograft(DFDBA). The 92 periodontal defects were randomly treated with either the resorbable barrier alone or resorbable barrier in combination with DFDBA following thorough defect debridement and root preparation with tetracycline. Each patient received both types of treatment modalities. Clinical examinations(probing depth, gingival recession, clinical attachment level, plaque index and gingival index) were carried out immediately before and 4 months after surgery. Significant(p<0.001) gains in mean attachment level were observed for both smokers(2.93mm) and non-smokers(3.30mm) but there were not significant difference between two groups. Similarly, significant reductions in mean probing depthshowed for smokers(4.52mm) and non-smokers(4.26mm). However, when comparing gingival recession, smokers were found to exhibit significantly poorer treatment results(1.59mm vs 0.96mm, p<0.05). Using the split-mouth-design, no statistically significant difference between the two modalities could be detected with regard to pocket depth reduction, gingival recession, or attachment gain. These results illustrate that the attachment gain is better in the non-smoker and the best in the non-smoker with the combination therapy of resorbable barrier and DFDBA than with resorbable barrier alone but smoking had no significant effect on clinical treatment outcome, even though smokers show more significant gingival recession. In addition, both treatments, either resorbable barrier plus DFDBA or resorbable barrier alone, promoted significant resolution of periodontal defects but the addition of DFDBA with a bioabsorbable membrane appears to add no extra benefit to the only membrane treatment.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.235-247
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• 1998

Calcium sulfate has a long history of medical use as an implant material. The biocompatibiliry of the material has been clearly established. Bone ingrowth concomitant with resorption occurs rapidly with efficient conduction of bone from particle to particle. Calcium sulfate also has a potential for functioning as a good bamer membrane. The purpose of this study was to compare the biocompatibility of different types of calcium sulfate grafting materials including an expelimental calcium sulfate compound on periodontal ligament cells in vitro as a preliminary test towards the development of a more convenient and useful form of grafting material which could promote regeneration of periodontal tissue. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. cells were cultured in a.MEM culture medium containing 20% FBS, at $37^{\circ}C$ and 100% humidity, in a 5% CO2 incubator. Cells were cultured into 96 well culture plate $1{\times}104$ cells per well with $\alpha$-MEM and incubated for 24 hours. After discarding the medium, those cells were cultured in $\alpha$-MEM contained with 10% FBS alone (control group), in medcal-grade calcium sulfate(MGCS group), in plaster(plaster group), experimental calcium sulfate paste(CS paste group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTI assay, collagen synthesis. The results \vere as follows. 1. In the analysis of cell proliferation by cell counting, both medical-grdde calcium sulfate group and plaster group showed no stastically significant difference at day 1, 2, 3 accept for plaster group at day 1 compared to control group, but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.05). 2. In the analysis of cytotoxicity by MIT assay, both medical-grade calcium sJlfate group and plaster group showed no stastically significant difference compared to control group at day 1, 2, 3 but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.OS). 3. In the analysis of collagen synthesis by immunoblotting assay, high level was detected for medical-grade calcium sulfate group and plaster group at day 1, 2, 3 compared to CS paste group. On the basis of these results, medical-grade calcium sulfate and plaster was shown to possess biocompatibility whereas the CS paste had unfavourable outcome. This observation shows a need for modification of the materials contained in calcium sulfate paste.

• 대한소아치과학회지
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• 제32권3호
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• pp.395-402
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• 2005

손상 받은 치주 조직의 치유과정은 치주인대 섬유 모세포의 세포 활성도에 영향을 받는다. 또한 치유과정 중 치주인대 섬유 모세포간의 재부착이 이루어져야 한다. 본 연구의 목적은 표피성장인자가 치주인대 세포의 증식과 부착에 미치는 영향을 알아보는 것으로 이를 바탕으로 향후 완전 탈구된 치아의 보관용액이나 재식전 처리제로서의 표피성장인자의 효용성을 고찰해 보기 위함이다. 발치된 사람의 제 1소구치에서 치주인대 섬유모세포를 채취 및 배양한 후, 세포독성을 및 세포의 최고 활성도를 평가 하기 위해 MTT assay를 시행하였다. 표피성장인자가 첨가된 실험군과 대조군의 세포증식의 차이를 비교하였고, western blot을 통해서 세포 부착에 관여하는 섬유결합소의 발현을 실험군과 대조군을 통해 비교하여 다음의 결과를 얻었다. 표피성장인자는 치주인대 섬유모세포에 대하여 세포독성을 보이지 않으며, 최고의 활성도를 보이는 농도는 10ng/ml였다. 또한 치주인대 섬유모세포의 배지내 증식정도는 10ng/ml의 실험군에서 대조군에 비해 유의하게 높았다. 세포간 부착에 관여하는 섬유결합소의 발현율이 실험군에서 대조군에 비해 유의하게 증가하였다. 본 연구를 통해 표피성장인자는 치주인대 섬유모세포의 재생을 촉진하며 따라서 완전 탈구된 치아의 보관용액이나 재식전 처리제로 사용될 수 있음을 시사한다.