• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.65-76
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• 2022

Purpose: The present study measured changes in arteriolar and venular capillary flow and structure in the gingival tissues during the development of plaque-induced gingival inflammation by combining dynamic optical coherence tomography (OCT), laser perfusion, and capillaroscopic video imaging. Methods: Gingival inflammation was induced in 21 healthy volunteers over a 3-week period. Gingival blood flow and capillary morphology were measured by dynamic OCT, laser perfusion imaging, and capillaroscopy, including a baseline assessment of capillary glycocalyx thickness. Venular capillary flow was estimated by analysis of the perfusion images and mean blood velocity/acceleration in the capillaroscopic images. Readings were recorded at baseline and weekly over the 3 weeks of plaque accumulation and 2 weeks after brushing was resumed. Results: Perfusion imaging demonstrated a significant reduction of gingival blood flow after 1 and 2 weeks of plaque accumulation (P<0.05), but by 3 weeks of plaque accumulation there was a more mixed picture, with reduced flow in some participants and increased flow in others. Participants with reduced flux at 3 weeks also demonstrated venular-type flow as determined by perfusion images and evidence of the development of venular capillaries as assessed by the velocity/acceleration ratio in capillaroscopic images. After brushing resumed, these venular capillaries were broken down and replaced by arteriolar capillaries. Conclusions: After 3 weeks of plaque accumulation, there was wide variation in microvascular reactions between the participants. Reduced capillary flow was associated with the development of venular capillaries in some individuals. This is noteworthy, as an early increase in venous capillaries is a key vascular feature of cardiovascular disease, psoriasis, Sjögren syndrome, and rheumatoid arthritis-diseases with a significant association with the development of severe gingival inflammation, which leads to periodontitis. Future investigations of microvascular changes in gingival inflammation might benefit from accurate capillary flow velocity measurements to assess the development of venular capillaries.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.142-149
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• 2022

Objective: To evaluate clinical parameters and gingival crevicular fluid (GCF) cytokines in children with anterior open bite receiving passive orthodontic treatment with spurs. Methods: Twenty children with indications for interceptive orthodontic treatment, an anterior open bite, and good oral hygiene and periodontal health were included in this study. GCF samples were collected from the mandibular and maxillary central incisors before (baseline) and 24 hours and 7 days after spur bonding. Clinical and periodontal examinations and cytokine analyses were performed. Results: At 7 days after spur attachment, gingival bleeding in the mandibular group was increased relative to that in the maxillary group. Visible plaque was correlated with gingival bleeding at 7 days and the GCF volume at 24 hours after spur attachment. Compared with those at baseline, interleukin (IL)-8 levels in the maxillary group and IL-1β levels in both tooth groups increased at both 24 hours and 7 days and at 7 days, respectively. At 24 hours, IL-8, IL-1β, and IL-6 levels were higher in the maxillary group than in the mandibular group. Cytokine production was positively correlated with increased GCF volume, but not with gingival bleeding, visible plaque, or probing depth. Conclusions: Although orthodontic treatment with spurs in children resulted in increased gingival bleeding around the mandibular incisors, IL levels were higher around the maxillary incisors and not correlated with periodontal parameters. Increased cytokine levels in GCF may be associated with the initial tooth movement during open bite correction with a passive orthodontic appliance in children.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.169-175
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• 2023

Background: Although microbial infection is direct cause of periodontal disease, various environmental factors influence the disease severity. Aging is considered a risk factor for oral diseases, with the prevalence of periodontal diseases increasing with age. Moreover, senescence-associated secretory phenotype (SASP) expressed in age-related diseases is a key marker of chronic inflammation and aging phenotypes. Therefore, this study aimed to understand the relevance of senescent cells to periodontal health and disease, investigate the possibility of regulating the expression of aging- and osteolysis-related factors in gingival fibroblasts, and investigate the effect of senescence induction in gingival fibroblasts on osteoclast differentiation in mouse bone marrow-derived macrophages (BMMs). Methods: After stimulation with 400 nM hydrogen peroxidase, human gingival fibroblasts (HGFs) were examined for senescence-associated β-galactosidase. Western blot and enzyme-linked immunosorbent assays were performed to assess the expression of SASP. Osteoclast formation was assessed in BMMs using a conditioned medium (CM) from hydrogen peroxide-stimulated HGFs. Osteoclastic differentiation was investigated using tartrate-resistant acid phosphatase (TRAP) staining and activity. Data analysis was performed using SPSS version 25.0. Results: The expression of senescence-related molecules, including p53, p16, and p21, and the expression of osteolytic factors, including IL-6, IL-8, and IL-17, were found to be significantly higher in the hydrogen peroxide-stimulated HGF than in the control group. Regarding the indirect effects of senescent gingival cells, the number of osteoclasts and TRAP activity increased according to the differentiation of BMM cultured in CM. Conclusion: Our results on the of between osteolytic factors and cellular senescence in gingival fibroblast cells helped to reveal evidence of pathological aging mechanisms. Furthermore, our results suggest that the development of novel therapies that target specific SASP factors could be an effective treatment strategy for periodontal disease.

• Journal of Periodontal and Implant Science
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• v.53 no.6
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• pp.417-428
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• 2023

Purpose: To investigate the effect of xenogeneic collagen matrix (XCM) with polydeoxyribonucleotide (PDRN) for gingival phenotype modification compared to autogenous connective tissue graft. Methods: Five mongrel dogs were used in this study. Box-type gingival defects were surgically created bilaterally on the maxillary canines 8 weeks before gingival augmentation. A coronally positioned flap was performed with either a subepithelial connective tissue graft (SCTG) or XCM with PDRN (2.0 mg/mL). The animals were sacrificed after 12 weeks. Intraoral scanning was performed for soft tissue analysis, and histologic and histomorphometric analyses were performed. Results: One animal exhibited wound dehiscence, leaving 4 for analysis. Superimposition of STL files revealed no significant difference in the amount of gingival thickness increase (ranging from 0.69±0.25 mm to 0.80±0.31 mm in group SCTG and from 0.48±0.25 mm to 0.85±0.44 mm in group PDRN; P>0.05). Histomorphometric analysis showed no significant differences between the groups in supracrestal gingival tissue height, keratinized tissue height, tissue thickness, and rete peg density (P>0.05). Conclusions: XCM soaked with PDRN yielded comparable gingival augmentation to SCTG.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.277-288
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• 2003

It has been suggested that increased number and activity of phagocytes in periodontitis lesion results in a high degree of reactive oxygen species (ROS) such as superoxide anion, hydrogen peroxide, nitric oxide and peroxynitrite. There are few reports on the relationship between ROS and MMPs expressions in gingival fibroblast. We studied to elucidate whether and how ROS, especially nitric oxide affects the MMP expression. Human gingival fibroblasts and HTl080 cells (human fibrosarcoma sell line as reference) were grown in DMEM supplemented with 10 mM HEPES, 50 mg/L gentamicin, and 10% heat inactivated fetal bovine serum with addition of various reactive oxygen species (ROS). Culture media conditioned by cells were examined by gelatin zymography. HT1080 cells expressed proMMP-2 and proMMP-9, but human gingival fibroblasts (HGF) produced only proMMP-2. Hydrogen peroxide upregulated MMP-9 expression in HT1080 cells, whereas in human gingival fibroblast SNP treatment showed marked increase in MMP-2 level compared to other ROS. These results suggest that the effects of ROS on MMPs expressions are cell-type specific. RT-PCR for MMP-2 and TIMP-2 m-RNA were performed using total RNA from cultured cells under the influence various kinase inhibitors. In HT1080 cells, treatment with FPTI III (Ras processing inhibitor) and LY294002 (PI3-kinase inhibitor) resulted in inhibition of MMP-2 and MMP-9 expressions, suggesting that Ras/P13-kinase pathway is important for MMPs expression in HT1080 cells. In gingival fibroblasts, treatment with FPTI III and PDTC (NF-kB inhibitor) showed marked decrease in MMP-2 regardless of the of SNP , suggesting that Ras/NF-kB could be the key pathway for NO-induced MMP-2 expression in gingival fibroblasts. This study showed that ROS, especially nitric oxide, could be the critical mediator of periodontal disease progression through control of MMP-2 expression in gingival fibroblasts possibly via Ras/NF-kB pathway.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.889-905
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• 1996

It is known that growth factors function as potent biologic mediators regulating numerous activities of wound healing via cell proliferation, migration and extracellular matrix formation and they also promote periodontal regeneration. But, method of growth factor application is controversial yet. So purpose of this study is to evaluate the effect of demineralized root surface as one of method of growth factor application. The ginigival fibroblasts were primary cultured and fifth or sixth subpassages were used in these experiments. In first experiment, root surface blocks demineralized with 100mg/ml tetracycline for 5 minutes and pH 1 citric acid for 3 minutes(experimental groups) and nonteminerilized root surface blocks (control groups) were placed in 100ng/ml PDGF-BB for 5 minutes. Then the cells were seeded on each root surface blocks and cultured for 6, 24, 48, 72 hours. In second experiment, root surface blocks deminerilized with tetracycline and citric acid and nondemineralized root surface blocks were placed in 200ng/ml PDGF-BB for 5 minutes and another non-demineralized root surfcae blocks were placed in DMEM without PDGF-BB. At 1, 2, 4, 6, 8 days, the cells were seeded in 24-well plate and using of each eluent, cultured for 72 hours. The results of the four determinants were presented as mean and S.D.. The results were as follows : The attachment and proliferation of human gingival fibroblast on root surface were more increased when PDGF-BB was applicated on root surfrace demineralized with tetracycline or citric acid than non-demineralized root surface. And, in comparision tetracycline with citric acid, there were more attachment and proliferation of human gingival fibroblast on root surface demineralized with tetracycline than citric acid, and proliferation of human gingival fibroblast on demineralized root surface was increased time dependently 1 day to 3 days. In second experiment using eluent, proliferation of human gingival fibroblast was more increased to 6 days when human gingival fibroblast was cultured in eluent that PDGF-BB was applicated on demineralized root surface than two control groups, and degree of proliferation was decreased time dependently 1 day to 6 days. Proliferation of human gingival fibroblast cultured in eluent without PDGF-BB was constant 1 day to 6 days. After 6 days, degree of proliferation of human gingival fibroblast was similar in four groups. This means that release duration of PDGF-BB from demineralized root surface is 6 days. And in comparision tetracycline with citric acid, there was more proliferation of human gingival fibroblast in tetracycline-treated group than citric acid. In conclusion, demineralized root surface as primary site for PDGF-BB application, especially demineralized with tetracycline has important roles in attachment and proliferation of human gingival fibroblast, and may be useful clinical applications in periodontal regenerative procedures.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.841-858
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• 1996

Epidermal growth factor(EGF) is one of polypeptide growth factors. EGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purposes of this study is to evaluate the effects of EGF on the human periodontal ligament cells and human gingival fibroblast cells that promote regeneration of periodntal tissue. The mitogenic effects of epidermal growth factor on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of 5-Bromo-2'-deoxy-uridine into DNA of the cells in a dose dependent manner. The prepared cells were the primary cultured gingival fibroblast and periodontal ligament cells from humans, the fourth or sixth subpassages were used in the experiments. Cells were seeded in DMEM containing 10% FBS. 1, 10, 50, 100, $200{\eta}g/ml$ and epidermal growth factor were added to the quiescent cells for 24 hours, 48 hours and 72 hours. They were labeled with $10\{mu}l/200{\mu}l$ 5-Bromo-2'-deoxy-uridine for the last 6 hours of each culture. The results of the five determinants were presented as mean and S.D.. The results were as follows : The DNA synthetic activity of human gingival fibroblasts were increased dose dependently by epidermal growth factor at 24 hours, 48 hours and 72 hours. The mitogenic effects were similar at the 24 and 48 hours of epidermal growth factor, but the DNA synthetic activity of human gingival fibroblasts generally decreased at 72 hours. The DNA synthetic activity of human periodontal ligament cells were increased dose dependently by epidermal growth factor at 24 hours but the DNA synthetic activity decreased at $200{\eta}g/ml$ of each hour. Generally the maximum mitogenic effects were observed at the 48 hours application of epidermal growth factor. The DNA synthetic activity of human periodontal ligament cells generally decreased lower at 24, 72 hours than at 48 hours the application of epidermal growth factor. In the comparison of DNA synthetic activity between human gingival fibroblasts and human periodontal ligament cells, human periodontal ligament cells had slightly higher proliferation activity than human gingival fibroblasts for a longer time at the high dosage of the epidermal growth factor. In conclusion, epidermal growth factor have important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, and thus may be useful for clinical applications in periodontal regenerative procedures.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.296-302
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• 2011

Idiopathic gingival fibromatosisrarely occurs, but frequently recurred after surgical removal. It usually occurs in generalized symmetrical pattern but sometimes in localized unilateral pattern. The localized pattern usually affects the maxillary molar and tuberosity area. This disease usually causes tooth migration, malocclusion, and problems in eating, speech, and esthetics. A boy showed dense gingival fibromatosis localized at primary maxillary right lateral incisor area at the age of 5 years, and his maxillary right lateral incisor become severely displaced at the age of 9 years. He had no medical and hereditary factors relevant to the gingival fibromatosis. However, the dense fibrous tissue was dominant in his labial gingiva of maxillary right incisors. In order to realign the displaced incisors by orthodontic treatment, the dense fibrous tissue covered the defect space between the central incisor and the displaced lateral incisor was surgically removed. The removed specimen was examined by simple immunohistochemical(IHC) array method. IHC array showed increased expression of CTGF, HSP-70, MMP-1, PCNA, CMG2, and TNF-${\alpha}$ in keratinocytes, fibroblasts, endothelial cells, and macrophages of gingival fibromatosis tissue. Therefore, it was suggested that the gingival fibromatosis be caused by the concomitant overexpression of CTGF, HSP-70, MMP-1, PCNA, CMG2, and TNF-${\alpha}$, and resulted in the fibroepithelial proliferation and the inflammatory reaction of gingival tissue.

• Journal of Periodontal and Implant Science
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• v.27 no.2
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• pp.317-328
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• 1997

Since laser therapy has been applied to dentistry, many dental practitioners are very interested in laser therapy on various intraoral soft tissue lesions including gingival hyperplasia and aphthous ulcer. The purpose of the present study was to determine the therapeutic effect and the harmful effect of a pulsed-Nd:YAG laser irradiation on human gingival tissue. In twenty periodontal patients with gingival enlargement, the facial gingival surface of maxillary anterior teeth was randomly irradiated at various power of 1.0W(100mJ, 10Hz), 3.0W(100mJ, 30Hz) and 6.0W(l50mJ, 40Hz) for 60 seconds by contact delivery of a pulsed-Nd:YAG laser(EN.EL.EN060, Italy). Immediately after laser irradiation, the gingival tissues were surgically excised and prepared in size of 1mm3. Subsequently the specimens were processed for prefixation and postfixation, embedded with epon mixture, sectioned in $1{\mu}$ thickness, stained with uranyl acetate and lead citrate, and observed under transmission electron microscope(JEM 100 CXII). Following findings were observed; l. In the gingival specimens irradiated with l.OW power, widening of intercelluar space and minute vesicle formation along the widened intercellular space were noted at the epithelial cells adjacent to irradiated area. 2. In the gingival specimens irradiated with 3.0W power, the disruption of cellular membrane, aggregation of cytoplasm, and loss of intercellular space were observed at the epithelial cells adjacent to irradiated area. 3. In the gingival specimens irradiated with 6.0W power, the disruption of nuclear and cellular membrane was observed at the epithelial cells adjacent to irradiated area. The ultrastructural findings of this study suggest that surgical application of a pulsed-Nd:YAG laser on human gingival tissue may lead somewhat delayed wound healing due to damage of epithelial cells adjacent to irradiated area.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.4
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• pp.328-334
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• 2014

Gingival fibromatosis is a rare oral condition that is characterized by proliferative fibrous overgrowth of the attached gingiva, the marginal gingiva, and the interdental papilla, typically presenting in the growth period. A case of a 27-month-old girl with a generalized severe gingival overgrowth is described herein. The patient had no known systemic disease, but enlarged gingival tissue had gradually covered her teeth. The excess gingival tissue was removed by conventional gingivectomy, which involved extraction of the retentive primary teeth under general anesthesia when she was 5 years old. Post surgical follow-up at 18 months after the surgery demonstrated no recurrence. Resectional surgery of the enlarged gingival tissue is the treatment choice for gingival fibromatosis, although there is a high risk of recurrence. More frequent professional follow-ups and oral hygiene instruction might be required. A delay in the surgical treatment may have significant consequences for the patient, such as primary dentition retention and consequent delay in the eruption of the permanent teeth, difficulties in mastication and phonation, malpositioning of the teeth, and psychological problems. Early surgical treatment should be performed according to the severity of enlargement.