• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2478-2484
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• 2009

The purpose of this study is to conduct an oral examination of total 220 students (1st grade) at S Boys' High School in Seoul metropolitan City. The results of oral examination can be outlined as follows: According to survey on experience of oral symptoms 85.5% students had no experience of tooth fracture, 76.8% students had no experience of hemodia, and 90.9% students had no experience of toothache. And it was found that 86.4% students had no experience of periodontal disease, 98.2% students had no experience of intraoral pain, and 88.2% had no experience of subjective halitosis symptom. According to survey on oral health behaviors, 73.6 % students had no experience of visiting any dental clinic over last one year. In particular, it was found that 57.3% students brushed their teeth after breakfast every day, 19.1% students didn't enjoy having any confectionery or sweet stuff, or taking soft drink like coke on a daily basis, and 19.5% students used fluoride toothpaste for toothbrushing as of this survey. According to oral health examination, 55.9% students had no dental caries, and 44.1% students had dental caries. And it was found that most students (79.2%) had dental calculus resulting from periodontal disease.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.136-144
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• 2018

Objectives: The aim of this study is to analyze the differences in factors related to the incidence of dental caries between children in fluoridated and non-fluoridated areas and compared the DMFT and DMFS scores to confirm the effect of water fluoridation program (WFP) in Geoje and Changwon. Methods: The oral health examination and questionnaire survey were conducted in fluoridated and non-fluoridated areas. The number of surveyed children aged 8, 10, and 12 years in the fluoridated and non-fluoridated area of two cities was 1,524 and 1,383, respectively. Self-recorded questionnaires included self-perception of their own dental health, daily toothbrushing frequency, intake frequency of cariogenic sweet snacks and beverages, experience of gingival bleeding, experience of unmet dental treatment, and use of oral hygiene device except for toothbrush and toothpaste. The prevalence of caries and fissure-sealant status were surveyed. The logistic regression analysis was used to analyze the difference in children's self-rated oral health status between the fluoridated and non-fluoridated area. The mean number of sealed teeth and surfaces, marginal means of the DMFT and DMFS scores adjusted for the difference in the samples' sex distribution, and region were compared between the fluoridated and non-fluoridated areas. Results: In the fluoridated area, the experience rate of unmet dental treatments was higher among children aged 10 years, intake frequency of cariogenic sweet snacks and beverages were higher among the whole sample, and experience rate of professional fluoride application were lower than in the non-fluoridated area. The DMFT score for permanent dentition adjusted for differences in sex, region, and mean number of fissure-sealed teeth in the fluoridated area was significantly lower among whole samples and 8-, 10-, and 12-year-olds alone than in the non-fluoridated area. Conclusions: WFP can alleviate oral health inequality because it is effective in reducing the incidence of caries among children is disadvantaged demographic, socioeconomic, and cultural contexts.

• Journal of Life Science
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• v.31 no.12
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• pp.1072-1078
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• 2021

The oral pathogen Streptococcus mutans is considered a major causative agent of dental caries in humans. The use of dental hygiene products, including toothpaste and mouthwash, is used for caries control. However, food intake can lead to the recurrence of oral microorganisms. This study aimed to explore why this bacterium dies so quickly during prolonged incubation and to assess whether this growth characteristic is closely associated with the secretion of metabolic products. Notably, the number of live S. mutans cells rapidly declined after 24 hr during the entire period tested, whereas the number of Escherichia coli cells, an indicator strain, remained steady over the same period. To test whether the S. mutans supernatants contained possible signals that accelerated the death of neighbor cells, we obtained the individual supernatants at the above time points. Following pH neutralization, the cells in which the supernatant was supplemented with glucose grew well. However, pH adjustment alone could not fully recover cell growth in conditions in which the supernatant was supplemented, with or without glucose. These phenotypes of S. mutans may be associated with signaling, not only resulting from nutrient depletion. The findings on the survival phenotype of S. mutans provide new insights into cell-cell communication in the biology of this bacterium.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.371-378
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• 2002

In this study, 40 hypersensitive teeth of 19 patients were investigated. The procedures performed were as follows: Before desensitization, EPT at occlusal third of buccal surface was done for the evaluation of pulp vitality and the EPT value was recorded for the reference value. And mechanical and thermal test was executed for the test of hypersensitivity. If the tooth responded to the above tests, we did EPT at the exposed surface, using toothpaste as a electrolite medium and recorded the EPT value at patient's response. After the tests had been done, desensitization procedures with Gluma(R) Desensitizer were performed according to the manufacturer's instructions. After desensitization, the same tests except EPT at occlusal third were repeated. All the 40 teeth responded positive before desensitization and negative after desensitization procedures. The EPT value at occlusal third ranged from 31 to 65 (48.9${\pm}$7.2). Before desensitization 34 teeth responded at EPT value of 2 and the remaining 6 teeth was in the range of 17 to 25. After desensitization all 40 teeth responded from 12 to 27 (19.6${\pm}$3.5). The 6 teeth responded at greater number than 2 before desensitization was in the range of 18 to 23. Within the limitations of this study we can conclude that: When a tooth with dentinal hypersensitivity responds to mechanical and thermal stimulation, the tooth shows very low resistance to electricity at the exposed surface while when a tooth is desensitized and doesn't show respond to mechanical and thermal stimuli, the tooth shows increased level of resistance to electric stimulation at the exposed surface. EPT can be used for the diagnosis of dentinal hypersensitivity. Furthermore EPT will be useful to evaluate the outcome of desensitization procedures. However, EPT is not a valid tool for measuring dentinal hypersensitivity.

• Journal of dental hygiene science
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• v.3 no.1
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• pp.23-31
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• 2003

In this research, dental health awareness of 3rd graders of high schools in Icheon-city was investigated in order to use the result of this research as the basic data for school dental health program, education direction, and educational purpose. The research was done from Sep. 23. to Oct. 5 and the followings are the results of survey. (1) 85.0% of the students brush their teeth once or twice a day and more female students brush their teeth 3 times a day than male students. (2) 77% of the students had experienced dental caries and 38.0% of the students have periodontal disease, which has lower percentage than cavity. (3) Most of the students can not go to the dentists because they do not have time and 84.0% of the students have been treated in dental clinics so this tells that most of the students had experienced dental treatment. (4) 46.8% of the students had interests in dental health and male students showed more interests than female students and the difference was statistically significant(p<0.05). (5) Most of the students hear the importance and information of dental health from mass media such as TV and radio or from people around. The research shows that most of the students do not get periodic dental checkups. (6) 80.8% of the students had never taught dental health education for improvement of dental health and 76.2% of the students think that the dental health education is needed. There was no difference according to the gender. (7) Most of the students think that the dental health education is needed to prevent cavity and gingiva disease and it shows that more students tend to attend the dental health education. (8) 69.3% of the students think that brushing your teeth is important to maintain good dental health and there was no difference according to the gender. Most of the students weren't aware that periodic dental checkups, right brushing, and using fluoric toothpaste is effective for cavity protection. (9) After looking into the knowledge of the students on dental health, it shows that the knowledge is low and there is no difference according to the gender.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.418-426
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• 2008

The objectives of this study were to examine the properties of fluoride-releasing resin composite restorative materials. Four commercially available compomer materials (Compoglass F: CF, $Dyract^{(R)}$ AP: DA, $Dyract^{(R)}$ flow: DF, F2000: FT) and one fluoride-releasing composite resin ($Tetric^{(R)}$ Ceram: TC) were selected as experimental materials. Rectangular-shaped tensile test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. Disk-shaped specimens were fabricated in the split teflon mold with diameter of 15mm and thickness of 1mm. After curing for an hour, specimens were immersed in deionized water at $37^{\circ}C{\pm}1^{\circ}C$ for 30 days. All specimens were thermocycled for 10,000 cycles with 15 seconds of dwelling time in each $5^{\circ}C$ and $55^{\circ}C$ water baths. Toothbrush abrasion test was conducted under a load of 1.5 N and the abraded surfaces were examined with surface roughness tester (SV-3000, Mitutoyo Co, Japan) and SEM (JSM-5800, JEOL, Japan). Fluoride recharging was done by toothbrushing for 3 min. using a fluoride toothpaste (Perio Alpine Herb, LG Household & Health Care, Korea). The results obtained were summarized as follows; 1. The highest tensile strength value of 32.3 MPa was observed in TC group and the lowest value of 16.8 MPa was observed in CF group. The tensile strength of TC group was significantly higher than those of CF and DF groups (P<0.05). 2. The lowest Ra value of 0.287 was observed in TC group and the highest value of 1.516 was observed in FT group. The Ra value of FT group was significantly higher than other groups (P<0.05). 3. The abraded surfaces revealed the increase of surface roughness due to the protrusion and missing of filler particles. 4. The release of fluoride of compomers after tooth brushing by Perio Alpine Herb was initially large and then followed by small and continuously. But it remains small and constant in fluoride-releasing composite resin of TC. 5. The highest value of fluoride release after toothbrushing by Perio Alpine Herb was $2.064{\mu}g/cm^2$ in CF group and the lowest value was $0.1119{\mu}g/cm^2$ in TC group. The amount of fluoride release of CF group was significantly higher than other groups (P<0.05).

• Journal of Distribution Research
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• v.12 no.3
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• pp.23-48
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• 2007

Category management has been implemented to enhance competitiveness in the food distribution industry since 2000 in Korea. This study helps to understand why suppliers achieve better or worse performance than competitors in a category. The major objective of this article is to explore which category tactics are effective to have influence on category performance when suppliers as a category captain implement category management with variety enhancer categories like shampoo, toothpaste, and detergent. The Nielsen data were analyzed using regression and Chow test. The empirical results that were varied upon the store type and market position found out which specific actions on product assortments, pricing, shelving, and product replenishment can increase category sales. Specifically, in the case of market leader in large supermarket, the significant indicators of category sales with respect to category tactics are the out-of-stock rate, the variance across brand shares, the forward inventory, and the days supply of a product. However, in the case of follower in large supermarket, the significant indicators of category sales are the variance across brand shares, the forward inventory, and the days supply of a product. On the other hand, in the case of small supermarket, the significant factors on category sales for both market leader and follower are the retail distribution rate, the variance across brand shares, the forward inventory, and the days supply of a product category. In sum, regardless of the store type and market position, dominant brands in a category, the forward inventory, and short days supply of a product improved performance in all categories. Critical difference is that the out-of-stock rate acted as a key ingredient for the market leader between large and small supermarket and the retail distribution rate for the follower between large and small supermarket. This article presents some theoretical and managerial implications of the empirical results and finalizes the paper by addressing limitations and future research directions.

• Journal of dental hygiene science
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• v.2 no.2
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• pp.95-103
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• 2002

This study was carried out to investigate recognition level and practical application status of oral hygiene devices through making a survey of Seoul inhabitants. And survey was implemented in order to propose oral hygiene device for household health care activities. The following results were obtained by analyzing personal interviews of 347 commuting patients at two university hospitals and seven dental clinics. 1) The average length of toothbrush head was estimated as 22.3 mm and average changing cycle was 2.3 months. The user ratio of flat-headed brush was estimated as 51.9% and 46.7% were using fluoridated toothpaste. 2) Generally the ratio of toothpick users was higher than other device users. But the user ratio of dental floss was higher than toothpick in case of patients under orthodontic treatment. 3) The patients under orthodontic treatment were not familiar with handling orthodontic toothbrush. Though 45.8% among orthodontic patients recognized this type of toothbrush, only 25.4% of them knew how exactly to use it. 4) It was shown very low user ratio of oral hygiene devices that the patients who had periodontal problem, hypersensitive trouble, halitosis, implant or denture 5) The patients who had halitosis showed the highest user ratio of toothpick. The patients who had separation of teeth showed the highest user ratio of dental floss. The patients who're under orthodontic treatment showed the highest user ratio of interproximal brush and motorized brush. 6) In response to the most interesting dental disease, it's surveyed as follows; 60.3% of dental caries, 24.0% of periodontal disease, 14.8% of false occlusion and 0.9% of oral cancer. 7) Regarding the motivation of using those oral hygiene devices, 45% responded that it was because of recommendation by dental clinics. Among the negative answers, 38.6% responded that it was because of no selection guidance. 31.3% answered that they didn't use hygiene device because it's inconvenient. 12.0% answered that it's difficult to buy and expensive. 7.8% responded that they didn't feel significant improvement. 4.8% answered that dental hospitals and clinics didn't even introduce those hygiene devices. Therefore efficient campaign for those hygiene devices over all Korea nation should be developed and education program must be prepared for each case of patients in every dental hospitals and clinics.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.289-292
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• 2008

Trisodium phosphate 12 hydrate and citric acid monohydrate mixture showed the strong anti-sticking effect on Streptococcus mutans, Streptococcus mitis, and Streptococcus salivarius, which are adhered to glass beads. Each Streptococcus species was shaking-cultured in brain heart infusion broth containing three glass beads. After 18 hr, glass beads were slightly washed into normal saline by three-pin-pointed pincette. Each three glass-beads set was put into reagent -containing tubes, which have 40 mg of bits of weighing paper for gaining brushing effect as similar as brushing one's teeth. The tubes were shaken by vortex mixer for 10 min except non-oral microbe, Streptococcus agalactiae (5 min). The samples were colony-counted by serial agar dilution method. Experiment was repeated three times for each Streptococcus species. The relative ratios of bacterial de-adherence by reagents were calculated in comparison with normal saline control. The de-adherence degree of citric acid-trisodium phosphate-saline mixture (CTS, pH 6.0) against Streptococcus mutans came to an average of 12.5 times compared with normal saline control. Trisodium-saline (TS, pH 8.4) showed the average of 7.5 times, and citric acid-saline (CS, pH 4.6) showed 6.0 times compared to the control group. The bacterial de-adherence degree against Streptococcus salivarius was each 7.2,2.6 and 2.8 times in above reagent sequence in comparison with saline control. CTS and TS showed 2.4 and 3.4 times of anti-sticking effect on Streptococcus mitis respectively, but CS had no anti-sticking effect on this bacterium. CTS, TS and CS showed 0.7, 0.6, and 0.6 times on non-oral microbe, Streptococcus agalactiae, separately compared with saline control. These results show that oral Streptococcus mutans, Streptococcus salivarius, and Streptococcus mitis, which are causative of dental caries or subacute endocarditis, may be easily removed from oral cavity by CTS mixture. It is conceivable that our experimental results will enable the development of a new conceptive toothpaste to prevent dental caries or subacute endocarditis after drawing teeth.

• Journal of the Korean Society of School Health
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• v.13 no.2
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• pp.295-317
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• 2000

This study was conducted to prevent oral disease of primary school, middle school, and high school students, providing basic data for the development of oral health education programs. Data were collected from 898 primary school, middle school, and high school students from March 2, 1999 to May 31, 1999. The results of this study are summarized as follows; 1) The subjects of this study were primary school students(32.6%), middle school students(33.0%), and high school students(34.4%). Boy students were slightly more prevalent than girl students. That is, primary school boys were 56.3%, middle school boys were 53.2%, and high school boys were 52.6%. 2) According to the self-judgement of oral health, primary school students were better than middle/high school students and boy students were better than girl students, 63.5% of primary school students and 57.8% of middle/high school students brushed their teeth once or twice a day. 3) 76.3% of middle/high school students and 63.5% of primary school students experienced dental caries. Girl students were higher than boy students in experiencing dental caries, 35.9% of primary school students and 27.6% of middle/high school students experienced periodontal disease. 4) 22.9% of primary school students and 7.9% of middle/high school students received oral examinations periodically. Girl students showed a higher rate than boy students in primary school, while boy students showed a higher rate than girl students in middle/high school. 5) Explaining to the reasons for reluctant visits to dental hospitals and clinics, 'no time to go' was highest(22.9% of primary school students; 27.4% of middle/high school students) and the rate of 'feeling scared' was second highest. Middle/high school students were more reluctant to visit dental hospitals and clinics than primary school students. In case of problematic symptoms in the mouth, the rate of 'feeling painful or cold in teeth when eating cold or hot foods' was highest, 71.3% of primary school students was concerned about oral health, while 68.6% of middle/high school students was concerned about it. 6) In gathering to the sources of information on oral health, the rate of medical institutions was highest(30.0%) in primary school students, while the rate of family members or persons around them was highest in middle/high school students. 7) 54.9% of primary school students received oral health education, while 13.1% of middle/high school students received it. Only 4.7% of middle school and high school girls received it. In relation to dental health education, the rate of 'possibility of prevention of oral caries or disease of the gum' was highest. 79.5% of primary school students and 80.3% of middle school students answered that they would attend oral health education. 8) 60.4% of primary school students and 60.2% of middle/high school students think the purpose of oral health is to prevent dental caries and disease of the gums. In preventing dental caries, 78.8% of primary school students and 71.8% of middle school students thought that periodical oral examination was effective, 88.4% of primary school students and 88.8% of middle/high school thought that brushing one's teeth was effective and 64.1% of primary school students and 50.7% of middle school students thought that the use of toothpaste containing fluoride was effective. In preventing periodontal disease, 91.1% of primary school students and 90.2% of middle/high school students thought that brushing one's teeth was effective, while 72.4% of primary school students and 70.3% of middle/high school students thought that teeth cleaning was effective. 9) 16.0% of middle school students and 12.7% of high school students thought that their oral health condition was healthy. According to individual experiences in dental treatment, the rate of experience of middle school students was higher than that of high school students, 12.7% of middle school students received oral examinations periodically, while only 3.3% of high school students did so. 10) In cases of 'having no problematic symptoms in the mouth' and 'concerns about oral health', the rate of middle school students was higher than that of high school students. In gathering obtaining information on oral health, the rate of obtaining it through broadcast media including TV, Radio, etc. was highest in middle school students, while the rate of obtaining it through family members or persons around them was highest in high school students. 11) 81.7% of middle school students have not received oral health education. In case of girl students, 97.3% have not received it in high school students. 85.6% of middle school students and 151.2% of high school students think that oral health education is necessary. 12) According to the knowledge level of oral health, the point of high school students($26.33{\pm}2.33$) was similar to the point of high school students($26.23{\pm}2.30$). It appeared that the point of primary school students was highest($26.35{\pm}2.50$) The more concerned about oral health the students were the higher the knowledge level of oral health was. In conclusion, the middle/high school students' knowledge level of oral health was lower than primary school students. The rate of middle/high School students' experience in oral health education was too low. Therefore, it is necessary to intensify oral health education for middle/high school students. Especially, the necessity of oral health education to girl students is strongly recommended. Developing an oral health education program for primary school, middle school, and high school students, related public authority and organizations, teachers; and dentists must actively make efforts together in order to maintain healthy teeth through having students prevent dental caries and periodontal disease.