• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.2
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• pp.90-96
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• 2022

Purpose: The purpose of this study was to investigate antimicrobial activity of extracts from shiitake mushroom against periodontopathogens and its cytotoxicity for human gingival fibroblast. Materials and Methods: Shiitake mushroom was soaked in water and acetone, and the supernatant was dried to collect its extract. The susceptibility of periodontopathogens for the extracts was investigated. Human gingival fibroblast was treated with the extracts, and the cell viability was measured CCK-8 solution. Results: The water extract from shiitake mushroom significantly reduced the growth of periodontopathogens at 2.5 mg/ml (P < 0.05). The acetone extract significantly inhibited the growth of Porphyromonas gingivalis and Tannerella forsythia at 0.32 mg/ml and Treponema denticola growth at 0.64 mg/ml (P < 0.05). The cytotoxicity of the extract was shown at a concentration of 2.5 mg/ml. The extracts with a concentration of 1.25 mg/ml appeared to be reduce cell viability after 4 h. Conclusion: The extracts of shiitake mushroom have antimicrobial activity against periodontitis-causing bacteria and relieving inflammation. Therefore, the extracts may be a candidate for preventing and treating periodontal disease.

• Journal of the Korea Society of Computer and Information
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• v.27 no.12
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• pp.259-266
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• 2022

In this paper, we propose a study is to prepare basic data for integrated health promotion education by preventing dry mouth and dry eyes through lifestyle management. From October 7 to 17, 2022, a total of 516 respondents who voluntarily agreed and responded through a self-written structured questionnaire were statistically analyzed for university students in their 20s across the country. As for the factor of feeling dry mouth among the living habits of the study subjects, the more smoking per day, the higher(8.41±2.041) and very high(7.75±2.927) felt dry mouth(p=.015), and the time spent using smart phones. The shorter this was, the lower(1.16±0.784) and very low(1.83±1.672) felt dry mouth(p=.022). The main factors contributing to dry mouth and dry eyes were dry eyes (odds ratio 3.651, p=.000), and high smoking(odds ratio 0.916, p=.038), and the more you use your smart phone (odds ratio 0.256, p=.004), the more you feel dry mouth. When feeling dry eyes, they felt dry mouth more(odds ratio 4.002, p=.000), and the more they exercised, the more dry eyes they felt(odds ratio 1.600, p=.009). As a result, since dry mouth and dry eyes appear as common inconveniences, it was found that lifestyle management is necessary to maintain and promote a healthy life. Therefore, it is proposed to build an integrated health platform that can improve the quality of life and implement personalized health management programs.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.155-167
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• 2023

The aim of this study was to investigate the effects of slow maxillary expansion (SME) on the dentoalveolar, skeletal, upper airway, and maxillary sinus using cone-beam computed tomography (CBCT). Twenty-three orthodontic patients (mean age 8.93 ± 1.61 years) who were treated with maxillary expansion using banded hyrax in the Department of Pediatric Dentistry at Jeonbuk National University Dental Hospital were included. According to the expansion speed applied, they were divided into two groups: SME (12 subjects, mean age 8.92 ± 1.45 years) and rapid maxillary expansion (RME, 11 subjects, mean age 8.94 ± 1.84 years). CBCT were obtained before (T0) and after (T1) the treatment and were analyzed with InVivo5 software (Anatomage, San Jose, CA, USA). Descriptive statistics showed no significant differences between the two groups in age, sex, or skeletal maturity. There were significant increases in maxillary width at the dentoalveolar and skeletal levels for both groups. Upper airway volume revealed a significant increase of 38.59% in the SME group and 28.72% in the RME group. However, there was no significant difference between SME group and RME group in all measurements. This study suggested the efficacy of SME in growing patients. SME was effective in increasing not only dentoalveolar and skeletal measurements but also airway volume. Therefore, pediatric dentists should select an appropriate expansion method considering the physiological aspects of periodontal tissues and discomfort in growing children.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.24-34
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• 2023

The aim of this study was to retrospectively analyze the effects of pulp treatment on exfoliation of primary teeth and its related factors. In this study, 167 teeth of 97 patients aged 6 months to 12 years who were treated with pulp treatment at Dankook Dental Hospital were selected, and information related to pulp treatment and tooth loss was collected. The included subjects were 72 primary anterior teeth (43.1%) and 95 primary posterior teeth (56.9%), of which 56 were males (57.7%) and 41 females (42.3%). The mean follow-up period was 106.1 ± 38.7 months, and the mean age at pulp treatment was 34.8 ± 15.4 months for primary anterior teeth and 69.1 ± 25.1 months for primary posterior teeth. Unilaterally pulpectomized teeth were significantly exfoliated earlier than the same tooth on the opposite side (p < 0.05). Also, in the case of teeth with periapical lesions, despite pulp treatment, the probability of extraction due to infection has been increased on primary anterior teeth (p < 0.05), but not on posterior teeth (p > 0.05). Pulpectomized teeth were lost earlier, an average of 7.8 months for primary anterior teeth and 8.5 months for primary posterior teeth. Early loss of the primary tooth can lead to space loss and premature eruption of the successor, so this can be considered when planning or performing treatment of the primary tooth.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.186-192
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• 2022

This study investigated 110 contractual industries to identify the effects of curriculum development and educational environment improvement through Ulsan College LINC+ Program on job education and training. As a result of the study, core competency and job competency were 5.73 points each in field practice and educational environment, and job performance was significant with OJT 5.58 points and 5.74 points for educational environment(p<0.05). The relationship between suitability of the curriculum, educational environment, and recruitment performance was significant with 5.73 points for OJT, 5.74 points for field training during the education and training period, and 5.79 points for educational environment, and job reeducation/training expense was significant with 5.73 points for OJT and 5.79 points for educational environment(p<0.05). Also, students who completed the LINC+business curriculum shortened their job period by 1 to 6 months in 86.3% of the respondents, and responded that the education expense for new employees was reduced. Therefore, it was identified that the LINC+ Program of Ulsan College has the effect of shortening the job adaptation period and reducing education expenses for new employees by operating the curriculum reflecting the needs of the industry and improving the same educational environment as the industrial field.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.213-221
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• 2022

Purpose: The efficacy of the amount of sealer in the root canal and two retreatment NiTi file systems in removing filling materials. Materials and Methods: Extracted premolars with a single root canal were selected for this study. After access opening and root canal preparation up to size #40/.06, the specimens were randomly divided into four groups. Gutta percha (GP) tapers of .06 or .04 were used for each group and filled using a single-cone filling technique with CeraSeal, a calcium silicate-based sealer. Each group was retreated either using the ProTaper Universal Retreatment System (PTUR) or the Hyflex Remover (HR). The time taken to remove the filling material, the amounts of apically extruded debris, and canal cleanliness were measured and compared. Results: The amount of sealer did not affect the efficiency when removing the filling materials. However, the filling material was removed faster in the HR group than in the PTUR group. Two types of NiTi files showed similar retreatment effects in the amounts of apically extruded debris and in the degree of canal cleanliness. Conclusion: The amount of sealer in canal filling had no significant effect on retreatability. Retreatment with HR removed filling materials is faster than PTUR. There was no difference in other removal efficiencies according to the type of retreatment NiTi file.

• Korean Journal of Culture and Social Issue
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• v.19 no.3
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• pp.343-365
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• 2013

This study examined the effects of various individual differences on children's memory of a stressful experience. The participants for the current study were children (N=85) aged 4-9 years those who experienced a naturally occurring stressful experience from a dental procedure. There was overall negative relation between the level of stress and children's memory performance. However, more interestingly, the results of this study provided some further evidence that several cognitive (i.e., receptive language ability and working memory capacity) and emotional (i.e., children's general anxiety condition, children's self-report of pain and anxiety about the event) individual difference factors were associated with variations in children's remembering across ages. The results suggest that the relation between stress and children's memory might be impacted in part by children's various individual characteristics. Furthermore, the findings are discussed in the applied context that based on the results clinical and legal professionals can tailor interviews to best meet children's needs and capabilities, and create developmentally and individually sensitive guidelines for interviewing children in the legal system.

• Implantology
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• v.18 no.2
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• pp.120-138
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• 2014

Purpose: The purpose of this study was to review the outcomes of a series of studies on tissue regeneration conducted in multiple institutions including the Department of Periodontology, College of Dentistry, Yonsei University. Materials and Methods: Studies were performed divided into the following three subjects; 1) Development of three-dimensional nano-hydroxyapatite (n-HA) scaffold for facilitating drug release and cell adhesion. 2) Synergistic effects of bone marrow-derived mesenchymal stem cells (BMMSC) application simultaneously with platelet-rich plasma (PRP) on HA scaffolds. 3) The efficacy of silk scaffolds coated with n-HA. Also, all results were analyzed by subjects. Results: Hollow hydroxyapatite spherical granules were found to be a useful tool for the drug release and avidin-biotin binding system for cell attachment. Also, BMMSC simultaneously with PRP applied in an animal bone defect model was seen to be more synergistic than in the control group. But, the efficacy of periodontal ligament cells and dental pulp cells with silk scaffolds could not be confirmed in the initial phase of bone healing. Conclusion: The ideal combination of three elements of tissue engineering-scaffolds, cells and signaling molecules could be substantiated due to further investigations with the potentials and limitations of the suggested list of studies.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.73-82
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• 2023

Purpose : Cymbopogon citratus, also known as lemongrass, has widely spread around the world and its essential oil is usually applied in food, perfume, and other industrial purposes. In addition, C. citratus has also been used for the treatment of inflammation, digestive disorders, and diabetes in traditional medicine. In this study, the antioxidative activity of C. citratus ethanol extract (CCEE) was analyzed in RAW 264.7 cells through the induction of one of phase II enzymes, heme oxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor (Nrf)2, mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/Akt. Methods : The antioxidative activity of CCEE against oxidative stress and its underlying molecular mechanisms were analyzed by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results : The results exhibited that CCEE potently attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS levels in a dose-dependent manner without any cytotoxicity. CCEE treatment significantly induced the expression of HO-1 which is known for its antioxidative capacity. In addition, CCEE treatment significantly upregulated the expression of Nrf2, a corresponding transcription factor for the regulation of antioxidative enzymes, which was in accordance with the HO-1 overexpression. MAPK and PI3K/Akt were also evaluated for their important roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, the potent HO-1 expression was mediated by not extracellular regulated kinase (ERK), c-Jun NH2 terminal kinase (JNK), p38, but phosphoinositide 3-kinase (PI3K) phosphorylation. To confirm the antioxidative activity of CCEE-induced HO-1 expression, oxidative damage was initiated by t-BHP and attenuated by CCEE treatment, which was identified by HO-1 selective inhibitor and inducer. Conclusion : Consequently, CCEE potently induced the HO-1-mediated antioxidative potential through the modulation of Nrf2 and PI3K/Akt signaling pathways in RAW 264.7 cells. These results suggest that CCEE could be a promising strategy for the mitigation against cellular oxidative damage.

• Journal of Life Science
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• v.33 no.10
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• pp.776-782
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• 2023

Silymarin, which is derived from dried Silybum marianum (milk thistle) seeds and fruits, possesses various beneficial properties, such as hepatoprotective, antioxidative, anti-inflammatory, and anticancer activity. This research aimed to explore the antioxidative activity of silymarin against oxidative stress and understand its molecular mechanism in RAW 264.7 cells. The study employed cell viability and reactive oxygen species (ROS) formation assays and western blot analysis. The results demonstrated that silymarin effectively reduced intracellular ROS levels induced by lipopolysaccharide (LPS) in a dose-dependent manner without causing any cytotoxic effects. Moreover, silymarin treatment significantly upregulated the expression of heme oxygenase (HO)-1, a phase II enzyme known for its potent antioxidative activity. Additionally, silymarin treatment significantly induced the expression of nuclear factor-erythroid 2 p45-related factor (Nrf) 2, a transcription factor responsible for regulating antioxidative enzymes, which was consistent with the upregulated HO-1 expression. To investigate the involvement of key signaling pathways in maintaining cellular redox homeostasis against oxidative stress, the phosphorylation status of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) was estimated by western blot analysis. The results showed that silymarin potently induced HO-1 expression, which was mediated by the phosphorylation of p38 MAPK. To further validate the antioxidative potential of silymarin-induced HO-1 expression, tert-butyl hydroperoxide (t-BHP)-induced oxidative damage was employed and attenuated by silymarin treatment, as identified by a selective inhibitor for each signaling molecule. In conclusion, silymarin robustly enhanced antioxidative activity by inducing HO-1 via the Nrf2/p38 MAPK signaling pathway in RAW 264.7 cells.