• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.294-300
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• 2021

Necrotizing periodontal disease caused by plaque bacteria is showed clinical findings including pseudo-membrane, interproximal necrosis of the affected area, pain on palpation and gingiva bleeding. Microbiological examination is showed that patients have fusospirochetal bacteria. Two patients who were provisionally diagnosed as necrotizing periodontal disease received nonsurgical periodontal treatments in conjunction with dressing using 3% hydrogen peroxide and local antibiotic delivery. Before and 3 - 5 days after initial treatment, the levels of periodontal bacteria in gingival crevicular fluid obtained using quantitative PCR were compared. After treatment, patients recovered normal gingiva. The number of periodontal diseases related bacterial species decreased from seven or eight to one. As a result, periodontium of patients with necrotizing periodontal disease was recovered to normal periodontium by nonsurgical periodontal treatments.

• The korean journal of orthodontics
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• v.52 no.4
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• pp.278-286
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• 2022

Objective: To evaluate differences in the adhesion levels of the most common oral pathogens, Streptococcus mutans and Porphyromonas gingivalis, in human saliva-derived microcosm biofilms with respect to time and raw materials of orthodontic brackets. Methods: The samples were classified into three groups of bracket materials: 1) monocrystalline alumina ceramic (CR), 2) stainless steel metal (SS), and 3) polycarbonate plastic (PL), and a hydroxyapatite (HA) group was used to mimic the enamel surface. Saliva was collected from a healthy donor, and saliva-derived biofilms were grown on each sample. A real-time polymerase chain reaction was performed to quantitatively evaluate differences in the attachment levels of total bacteria, S. mutans and P. gingivalis at days 1 and 4. Results: Adhesion of S. mutans and P. gingivalis to CR and HA was higher than the other bracket materials (SS = PL < CR = HA). Total bacteria demonstrated higher adhesion to HA than to bracket materials, but no significant differences in adhesion were observed among the bracket materials (CR = SS = PL < HA). From days 1 to 4, the adhesion of P. gingivalis decreased, while that of S. mutans and total bacteria increased, regardless of material type. Conclusions: The higher adhesion of oral pathogens, such as S. mutans and P. gingivalis to CR suggests that the use of CR brackets possibly facilitates gingival inflammation and enamel decalcification during orthodontic treatment.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.522-530
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• 2022

In this study we aimed to develop novel ZnO-NP/chitosan/β-glycerophosphate (ZnO-NP/CS/β-GP) antibacterial hydrogels for biomedical applications. According to the mass fraction ratio of ZnO-NPs to chitosan, mixtures of 1, 3, and 5% ZnO-NPs/CS/β-GP were prepared. Using the test-tube inversion method, scanning electron microscopy and Fourier-transform infrared spectroscopy, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) cocultured with hydrogel in each group was above 90% after 24, 48, and 72 h. These results suggest that ZnO-NPs improve the temperature sensitivity and bacteriostatic performance of chitosan/β-glycerophosphate (CS/β-GP), which could be injected into the periodontal pocket in solution form and quickly transformed into hydrogel adhesion on the gingiva, allowing for a straightforward and convenient procedure. In conclusion, ZnO-NP/CS/β-GP thermosensitive hydrogels could be expected to be utilized as adjuvant drugs for clinical prevention and treatment of peri-implant inflammation.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.116-126
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• 2022

Purpose: This study evaluated the efficacy of treating periodontitis using subgingival nano-hydroxyapatite powder with an air abrasion device (NHAPA) combined with scaling and root planing (SRP). Methods: A total of 28 patients with stage III periodontitis (grade B) were included in this study, although 1 was lost during follow-up and 3 used antibiotics. The patients were divided into a test group and a control group. All patients first received whole-mouth SRP using hand instruments, and a split-mouth approach was used for the second treatment. In the test group, the teeth were treated with NHAPA for 15 seconds at 70% power per pocket. Subgingival plaque samples were obtained from the 2 deepest pockets at the test and control sites before treatment (baseline) and 3 months after treatment. The full-mouth plaque index (PI), gingival index (GI), papillary bleeding index (PBI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 1- and 3-month post-treatment. Real-time polymerase chain reaction was used to determine the colonisation of Treponema denticola (Td), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans in the subgingival plaque. Results: From baseline to the first month, the test group showed significantly larger changes in BOP and CAL (43.705%±27.495% and 1.160±0.747 mm, respectively) than the control group (36.311%±27.599% and 0.947±0.635 mm, respectively). Periodontal parameters had improved in both groups at 3 months. The reductions of PI, GI, BOP, PD, and CAL in the test group at 3 months were greater and statistically significant. The total bacterial count and Td and Pg species had decreased significantly by the third month in both groups (P<0.05). Conclusions: Applying NHAPA in addition to SRP improves clinical periodontal parameters more than SRP alone. Subgingival NHAPA may encourage clot adhesion to tooth surfaces by increasing surface wettability.

• Journal of Periodontal and Implant Science
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• v.51 no.4
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• pp.254-263
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• 2021

Purpose: Periodontitis is associated with a dysbiosis of periodontopathic bacteria, which stimulate the interleukin (IL)-23/IL-17 axis that plays an essential role in the immunopathogenesis of this disease, leading to alveolar bone destruction through receptor activator of nuclear factor κB ligand (RANKL). IL-23 receptor mRNA (IL-23R) has been identified in periodontitis, and IL-17 receptor A mRNA (IL-17RA) and its protein have not yet been evaluated in patients with periodontitis. In this study was measure IL-23R and IL-17RA in gingival tissue (GT) from patients with generalized chronic periodontitis (GCP) and generalized aggressive periodontitis (GAP) and to explore correlations with clinical parameters. Methods: We included 16 healthy subjects (HS), 18 patients with GCP, and 14 with GAP. GT samples were collected during periodontal surgery. Both IL-23R and IL-17RA were detected by enzyme-linked immunosorbent assay. Results: The results were analyzed with Mann-Whitney U test and Spearman' rank correlation coefficients using SPSS version 25.0. We found lower IL-23R levels in patients with GCP and GAP than in HS. Contrarily, we observed higher IL-17RA levels in GCP and GAP patients than in HS. Moreover, we found negative correlations between IL-23R in GT and probing depth and clinical attachment loss (CAL). Likewise, a positive correlation of IL-17RA in GT with CAL was found. Conclusions: The results of these findings suggest that the reverse behavior between IL-23R and IL-17RA in periodontitis patients may also be involved with the activation of RANKL, which promotes alveolar bone loss.

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.28-38
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• 2022

Purpose: Macrophages play crucial roles as early responders to bacterial pathogens and promote/ or impede chronic inflammation in various tissues. Periodontal macrophage-induced pyroptosis results in physiological and pathological inflammatory responses. The transcription factor Dec2 is involved in regulating immune function and inflammatory processes. To characterize the potential unknown role of Dec2 in the innate immune system, we sought to elucidate the mechanism that may alleviate macrophage pyroptosis in periodontal inflammation. Methods: Porphyromonas gingivalis lipopolysaccharide (LPS) was used to induce pyroptosis in RAW 264.7 macrophages. Subsequently, we established an LPS-stimulated Dec2 overexpression cellular model in macrophages. Human chronic periodontitis tissues were employed to evaluate potential changes in inflammatory marker expression and pyroptosis. Finally, the effects of Dec2 deficiency on inflammation and pyroptosis were characterized in a P. gingivalis-treated experimental periodontitis Dec2-knockout mouse model. Results: Macrophages treated with LPS revealed significantly increased messenger RNA expression levels of Dec2 and interleukin (IL)-1β. Dec2 overexpression reduced IL-1β expression in macrophages treated with LPS. Overexpression of Dec2 also repressed the cleavage of gasdermin D (GSDMD), and the expression of caspase-11 was concurrently reduced in macrophages treated with LPS. Human chronic periodontitis tissues showed significantly higher gingival inflammation and pyroptosis-related protein expression than non-periodontitis tissues. In vivo, P. gingivalis-challenged mice exhibited a significant augmentation of F4/80, tumor necrosis factor-α, and IL-1β. Dec2 deficiency markedly induced GSDMD expression in the periodontal ligament of P. gingivalis-challenged mice. Conclusions: Our findings indicate that Dec2 deficiency exacerbated P. gingivalis LPS-induced periodontal inflammation and GSDMD-mediated pyroptosis. Collectively, our results present novel insights into the molecular functions of macrophage pyroptosis and document an unforeseen role of Dec2 in pyroptosis.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.2
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• pp.102-111
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• 2021

Implant placement in the anterior region is performed in several stages, and harmonization of both hard and soft tissues is essential. In addition, adequate esthetic and functional evaluations are necessary in the process of transitioning from the provisional to the final prosthesis to attain patient satisfaction. Although gingiva can be molded in the anterior region, depression in the occlusal view can yield good results through the augmentation procedure. However, the harvesting of connective tissue from the palate is not suitable for various reasons, such as postoperative discomfort and intraoperative bleeding. Compared to the palatal area, the harvesting of connective tissue from the maxillary tuberosity can easily result in relatively thick tissue and quick healing of the donor site, thus proving to be a good modality for graft procedures. The purpose of this report is to examine the relevant evidence from previous studies and evaluate the process of soft tissue augmentation through a case presentation.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.282-297
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• 2022

Purpose: To explore differences in the subgingival microbiome according to the presence of periodontitis and/or type 2 diabetes mellitus (T2D), a metagenomic sequencing analysis of the subgingival microbiome was performed. Methods: Twelve participants were divided into 4 groups based on their health conditions (periodontitis, T2D, T2D complicated with periodontitis, and generally healthy). Subgingival plaque was collected for metagenomic sequencing, and gingival crevicular fluids were collected to analyze the concentrations of short-chain fatty acids. Results: The shifts in the subgingival flora from the healthy to periodontitis states were less prominent in T2D subjects than in subjects without T2D. The pentose and glucuronate interconversion, fructose and mannose metabolism, and galactose metabolism pathways were enriched in the periodontitis state, while the phosphotransferase system, lipopolysaccharide (LPS) and peptidoglycan biosynthesis, bacterial secretion system, sulfur metabolism, and glycolysis pathways were enriched in the T2D state. Multiple genes whose expression was upregulated from the red and orange complex bacterial genomes were associated with bacterial biofilm formation and pathogenicity. The concentrations of propionic acid and butyric acid were significantly higher in subjects with periodontitis, with or without T2D, than in healthy subjects. Conclusions: T2D patients are more susceptible to the presence of periodontal pathogens and have a higher risk of developing periodontitis. The pentose and glucuronate interconversion, fructose and mannose metabolism, galactose metabolism, and glycolysis pathways may represent the potential microbial functional association between periodontitis and T2D, and butyric acid may play an important role in the interaction between these 2 diseases. The enrichment of the LPS and peptidoglycan biosynthesis, bacterial secretion system, and sulfur metabolism pathways may cause T2D patients to be more susceptible to periodontitis.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.2
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• pp.91-101
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• 2021

The interdental papilla area is a difficult area for connective tissue graft (CTG) due to its narrow space. So Regeneration of interdental papilla is very challenging work. It is very difficult when the teeth have contact with adjacent teeth, but if there was only 3mm of space between the teeth, CTG was not very difficult. Therefore, through the orthodontic force, a 3mm space between the teeth was intentionally created. The CTG was performed using a microblade, and only one vertical incision was performed off the gingival margin, and the graft was performed by inserting the grafts through here. After a period of maintenance, I was able to gather the teeth again with orthodontic force and regenerate the interdental papilla. I named this technique ELSA Technique (Enlargement of space - Labial graft - Squeezing - for Augmentation of papilla). If interdental papilla is lost due to periodontal disease, ELSA techniques can regenerate interdental papilla very efficiently.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.298-311
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• 2022

Purpose: The aim of this study was to evaluate the clinical outcomes of periodontal granulation tissue preservation (PGTP) in access flap periodontal surgery. Methods: Twenty patients (stage III-IV periodontitis) with 42 deep periodontal pockets that did not resolve after non-surgical treatment were consecutively recruited. Access flap periodontal surgery was modified using PGTP. The clinical periodontal parameters were evaluated at 9 months. The differences in the amount of granulation tissue width (GTw) preserved were evaluated and the influence of smoking was analyzed. Results: GTw >1 mm was observed in 97.6% of interproximal defects, and the granulation tissue extended above the bone peak in 71.4% of defects. At 9 months, probing pocket depth reduction (4.33±1.43 mm) and clinical attachment gain (CAG; 4.10±1.75 mm) were statistically significant (P<0.001). The residual probing depth was 3.2±0.89 mm. When GTw extended above the interproximal bone peak (i.e., the interproximal supra-alveolar granulation tissue thickness [iSUPRA-GT] was greater than 0 mm), a significant CAG was recorded in the supra-alveolar component (1.67±1.32 mm, P<0.001). Interproximal gingival recession (iGR) was significant (P<0.05) only in smokers, with a reduction in the interdental papillary tissue height of 0.93±0.76 mm. In non-smokers, there was no increase in the iGR when the iSUPRA-GT was >0 mm. The clinical results in smokers were significantly worse. Conclusions: PGTP was used to modify access flap periodontal surgery by preserving affected tissues with the potential for recovery. The results show that preserving periodontal granulation tissue is an effective and conservative procedure in the surgical treatment of periodontal disease.