• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1221-1223
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• 2010

본 논문에서는 한국인 아동의 우식치아로부터 S. mutans를 분리하고, acid stress하에서 분리한 S. mutans의 유전자의 발현의 변화를 분석하고자 하였다. 치아우식증의 주요한 요소로 작용하는 치태형성에 기여하는 glucan 및 fructan 합성에 관여하는 세포내 효소인 glucosyltransferase, glucosyltransferase, glucosyltransferase 및 fructosyltransferase의 발현량의 변화를 확인한 결과, lactic acid를 처리하지 않은 control의 경우보다 16배에서 3배까지 감소한 것을 확인할 수 있었다. Amino acid ABC transporter, adenylate kinase, fructokinase, 40k cell wall protein precursor에서는 모두 유전자의 발현량이 현저히 증가한 것을 볼 수 있었다. 이들 유전자는 acid stress에 관여하는 특이적 유전자로 추정된다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.604-613
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• 2009

Recently, researches to develop phased array ultrasonic examination techniques are proceeded to diagnose dental caries and the status of surgical operation of dental implant. Sound field analysis of phased array ultrasonic transducers were carried out in order to characterizing the ultrasonic phased array beams. The sound field of ultrasonic radiation was calculated for the sample called "gypsum-improved stone" with the similar characteristics of dental materials. Industrial phased array ultrasonic devices were utilized for the insptriion of the artificial flaws machined in the gypsum-improved stone. Dental implants were made at the pig jaw bone and defect images were confirmed for the dental implants.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.539-546
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• 2000

The purpose of this study is to investigate antibacterial activities of Sophora flavescens Ait. extracts for the prevention of dental caries caused by Streptococcus mutans. The fraction 5-4-3 of the ethyl acetate soluble extract of Sophora flavescens Ait. Showed strong growth inhibition activity against Streptococcus mutans (MIC, 3.13 ${\mu}$g/ml). The glucosyltransferase activity inhibited the formation of glucan by the fraction 5-4-3 and showed 77% of the antiproliferative effect at 100 ${\mu}$g/ml. This showed a significant activity (p<0.05). These results suggest that the fraction 5-4-3 of the ethyl acetate soluble extract of Sophora flavescens Ait. may be a valuable material as the prevention of dental caries.

• Journal of Korean society of Dental Hygiene
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• v.18 no.5
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• pp.843-852
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• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• Journal of Korean society of Dental Hygiene
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• v.20 no.4
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• pp.435-445
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• 2020

Objectives: This study investigated the relationship between obesity and dental caries of Korean adolescents. Methods: Data from the Korea National Health and Nutrition Examination Survey (KNHNES VI) (2013 to 2015) were used and targeted adolescents aged 13 to 18 years. For statistical analysis, the SPSS 18.0 program was used, and the significance level was set at 0.05. Results: For the general and health-related characteristics, female students (p=0.001) showed higher decayed, missing, and filled teeth (DMFT) index than male students. Furthermore, DMFT showed higher tendency, as age was higher (p<0.001). Smoking (p=0.011) and drinking experience (p=0.027) revealed higher DMFT. The dental caries experience was significantly different among students who were female (p=0.033), older (p=0.001), and overweight or underweight (p=0.022). In the BMI for the general and health-related characteristics, male students had higher obesity rate than female students (p=0.003), and obese subjects had higher dental checkup in the last year (p=0.013). In multiple linear regression analysis of obesity and DMFT, the unadjusted model showed that the obesity group's DMFT was about 0.8 higher than that of the normal group (p=0.024). However, statistical significance was not shown in the adjusted models. In the logistic regression analysis of obesity and dental caries experience, the unadjusted model 1 (1.93 times), the adjusted model 2 (1.79 times), and model 3 (1.76 times) showed significantly higher dental caries experience. Conclusions: Both obesity and dental caries are related to diet habits and lifestyles and have a negative impact on adult health. Therefore, it is necessary to create a healthy social environment around the adolescent, and proper intervention through education is required to form healthy habits.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.2
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• pp.120-126
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• 2013

Preserving the pulp is important in the treatment of carious pulp exposure in young permanent teeth. Pulpotomy is a vital pulp therapy in which a portion of the coronal pulp tissue is surgically removed, and the remaining radicular tissue is covered with suitable material that protects the pulp from further injury and permits and promotes healing. It is important to develop biocompatible treatment directed at maintaining pulp vitality and increasing tooth longevity. Platelet-rich fibrin (PRF) has been referred to as a second-generation platelet concentrate. Two clinical cases in which PRF was applied as a medicament after pulpotomy of an immature permanent tooth are presented. After isolation, caries removal and pulpotomy with PRF was performed. A layer of mineral trioxide aggregate (MTA) was placed over the PRF, and the final restoration was performed. Postoperatively, the patient had no pain or discomfort, and follow-up radiographs revealed normal periodontal ligament space and trabecular bone pattern.

• Journal of Korean society of Dental Hygiene
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• v.22 no.4
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• pp.241-247
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• 2022

Objectives: This study aimed to determine the Missing Teeth (MT; mean number of missing permanent teeth) index experienced by year for adults between the ages of 19 and 64. Methods: This study was conducted by analyzing the raw data of participants in the 4th to 8th periods of the National Health and Nutrition Examination Survey (NHANES). For the statistical program, IBM SPSS / WIN 26 was used and an independent sample t-test was performed. Results: The average number of MT by year showed a decreasing trend. In 2007, 2008, 2010 and 2011, the average number of MT by sex was higher among females, and this was statistically significant (p<0.05). However, in 2019, males had a higher average number of MT than females, which was statistically significant (p<0.05). Conclusions: Males had a higher average number of MT than females in Korea, so it is considered that oral health programs or oral hygiene management according to sex are necessary.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.113-117
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• 2022

In this study, the antibacterial and phagocytosis regulation effects of Hordeum vulgare extract and pine needle extract on S. mutans, the causative bacteria of dental caries, were investigated. Ethanol extracts of domestic Hordeum vulgare powder and pine needle powder were used, and the antibacterial and phagocytic ability against S. mutans was confirmed according to the concentration of the extracts. As a result, S. mutans colony formation did not show a significant difference in the Hordeum vulgare extract but was significantly decreased in the pine needle extract. As a result of confirming the phagocytic ability of THP-1 cells for S. mutans, there was no significant difference in the Hordeum vulgare extract, but the phagocytic ability of immune cells was improved in the pine needle extract. Therefore, it suggests that pine needle extract can be used as a material for preventing dental caries.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.51-59
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• 1998

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 30 adolescent patients who were classified into an experimental group and a control group, 15 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The change of S. mutans in saliva was observed by $Cariescreen^R$ SM kit at pre and post 2, 4, 6, 8 weeks. The results were as follows 1. There were significant reduction in the number of S. mutans in saliva between pre and post 2 weeks(p<0.01), 4 weeks(p<0.05), 6 weeks(p<0.001), and 8 weeks(p<0.001) in experimental group. And significant reduction also were observed in the number of S. mutans in saliva between post 2 weeks, 6 weeks(p<0.05), and 8 weeks(p<0.05), but no significant reduction were showed in control group. 2. There were significant correlation in the number of S. mutans between each measurement time(pre and post 2, 4, 6, 8 weeks) in control group. 3. There were no correlation between pre and post 2 weeks, but significant correlation were observed between 2, 4, 6, 8 weeks in experimental group.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.427-437
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• 2020

The purpose of this study was to investigate the effects of public preventive dental healthcare services named the "Dental Preventive Health Services for Children" (DPHSC) on oral health-related quality of life (OHRQoL) in Korean children. Of the total 20,802 beneficiaries in 2018, 110 10-year-old elementary school students were randomly selected and were requested to complete a survey using the Korean version of Child Oral Health Impact Profile (COHIP) questionnaire before and after participating in DPHSC. Overall, 107 participants completed the pre- and post-survey. COHIP scores and clinical results such as numbers of decayed and missing teeth, malocclusion, and oral hygiene status from dental examination were statistically analyzed and the reliability and the validity of the responses were verified. There was a significant clinical increase in mean overall COHIP scores following DPHSC (p < 0.001, effect size 1.05). Children with decayed and missing teeth demonstrated poor OHRQoL. In conclusion, DPHSC can improve the OHRQoL of 10-year-old children.