• Journal of Korean society of Dental Hygiene
• /
• v.9 no.2
• /
• pp.89-98
• /
• 2009

This study did question, and got following conclusion to ready necessary basic data to develop school oral health educational programs because grasp 388 man high school students in Jeolla-bukdo Namwon per June, 2008 realization about oral health and oral health education actual conditions. 1. Students of 56.7% recognized own oral health as is not healthy in realization about subjective oral health, and students of 72.2% were interested in oral health, and was recognizing oral fitness by important health problems. 2. Oral health realization by class was significant difference in toothbrushing reason, cause of dental caries, cause of periodontal disease. Students who respond that know adjusted water fluoridation did only for 10.3%, and it was 43.0% of students who responded that students of 57.0% do toothbrushing because of draft cleanliness, and responds that cause of dental caries is food dregs. 3. Responded that 87.1% is right toothbrushing by oral disease preservative, and next time was on-time oral medical examination 79.4%, smoking resection 58.5%, sugar intake limitation 55.4% round. 4. Students, who oral health education by interest degree of oral health is interested in oral health, is oral health educational experience and the need rate, participation intention was high when educate.

• Journal of Korean society of Dental Hygiene
• /
• v.16 no.1
• /
• pp.147-153
• /
• 2016

Objectives: The purpose of the study is to investigate the relationship between fluorine concentration within finger nails and the level of dentifrice in dental hygiene students and non-health majoring students. Methods: A self-reported questionnaire was completed by seventy female college students living in Daegu and Gyeongbuk that are not supplied with fluoridation from May to June, 2014. Informed consent was approved by institutional review board (IRB). The questionnaire consisted of general characteristics of the subjects (11 items) and oral health behavior including number of toothbrushing, duration of toothbrushing, number of mouth rinsing, and amount of dentifrice. A dentist and a dental hygienist examined directly the subjects by the guideline of World Health Organization (WHO). The oral examination included decayed tooth, healthy tooth, and filled tooth. The nail samples were obtained from seventy female students. Results: Comparing the dental hygiene students and non-health majoring students, 62.5% of dental hygiene students used approximately 1300mg of dentifrice and 55.2% of non-health majoring students used 1800mg or more of dentifrice. The non-health majoring students used more dentifrice (p<0.01). The fluorine concentration within nails was $1.9905{\mu}l/g$ in dental hygiene students and $3.2149{\mu}l/g$ in non-health majoring students. The fluorine concentration within nails in the dental hygiene students was significantly lower(p<0.01). Conclusions: The accumulation of fluoride in human body is not fully caused by dentifrice. However, The accumulation may occur due to toothbrushing so that it is necessary to educate the students about the right use of the dentifrice.

• Nuclear Engineering and Technology
• /
• v.49 no.8
• /
• pp.1711-1716
• /
• 2017

Uranium tetrafluoride ($UF_4$) is the most used nuclear material for producing metallic uranium by reduction with Ca or Mg. Metallic uranium is a raw material for the manufacture of uranium silicide, $U_3Si_2$, which is the most suitable uranium compound for use as nuclear fuel for research reactors. By contrast, ammonium uranyl carbonate is a traditional uranium compound used for manufacturing uranium dioxide $UO_2$ fuel for nuclear power reactors or $U_3O_8-Al$ dispersion fuel for nuclear research reactors. This work describes a procedure for recovering uranium and ammonium fluoride ($NH_4F$) from a liquid residue generated during the production routine of ammonium uranyl carbonate, ending with $UF_4$ as a final product. The residue, consisting of a solution containing high concentrations of ammonium ($NH_4^+$), fluoride ($F^-$), and carbonate ($CO_3^{2-}$), has significant concentrations of uranium as $UO_2^{2+}$. From this residue, the proposed procedure consists of precipitating ammonium peroxide fluorouranate (APOFU) and $NH_4F$, while recovering the major part of uranium. Further, the remaining solution is concentrated by heating, and ammonium bifluoride ($NH_4HF_2$) is precipitated. As a final step, $NH_4HF_2$ is added to $UO_2$, inducing fluoridation and decomposition, resulting in $UF_4$ with adequate properties for metallic uranium manufacture.

• Journal of Korean Dental Hygiene Science
• /
• v.3 no.1
• /
• pp.25-36
• /
• 2020

Introduction: The legal duties of Korean dental hygienists are different from the actual tasks. These factors cause dental hygienists to experience work stress. Therefore, it is necessary to investigate what tasks the dental hygienist expects to perform. Methods: This study examined the perception of dental hygienists' work on 158 prospective graduates of the 3rd-year and 4th-year course of dental hygiene. The questionnaire about the dental hygienist's duties was prepared based on the job description of dental hygienists by the Korea Health Personnel Licensing Examination Institute. Results: More than 84% said that all of the work in the second job description was possible as dental hygienists. subjects responded that the following items were not dental hygienists' duties: treatment plan based on medical history and dental history, treatment plan based on an intraoral and extraoral examination, treatment plan based on the results of teeth and periodontal examination, analysis of oral health data in community, planning of oral health promotion in community, planing of water fluoridation, reading of radiography, root planing, physical treatment on head and neck, using an ultrasonic device on head and neck, dealing with laser devices, making a temporary crown, suture and stitch-out, and intramuscular injection. Conclusions: Most graduates of dental hygiene departments have recognized that the tasks described in the second job description are dental hygienists' work; therefore, it is necessary to improve the gap between expected work and legal work.

• Journal of dental hygiene science
• /
• v.20 no.4
• /
• pp.187-199
• /
• 2020

Background: Korean dental hygienists perform various tasks under the supervision of dentists in addition to the tasks listed in the law. Many meaningful studies have been conducted to determine the actual tasks of dental hygienists, but these studies did not show common results due to the differences in research methods or designs. Hence, this study aimed to review the reported data on the tasks of dental hygienists in Korea and to clarify them based on a systematic literature review. Methods: For the literature search, the COre, Standard, and Ideal model presented by the National Library of Medicine was referenced. Seven databases were searched for literatures published in Korea, including PubMed, and Google Scholar. Of the 352 studies found using key words, titles, and abstracts, 46 were finally extracted based on the first and second exclusion criteria. After confirming the tasks of Korean dental hygienists in 46 literatures, 136 tasks were listed and calculated as appearance rate in the literature. Results: The most common tasks in 46 studies were fluoride application (67.2%), radiography (65.4%), scaling (65.4%), sealant (60.7%), patient management and counseling (56.7%), tooth-brushing education (52.2%), impression taking with alginate (50.1%), and making temporary crowns (47.9%). The most mentioned tasks of dental hygienists in public health centers were fluoride application (100%), sealant (100%), oral health education (71.4%), public oral health program evaluation (71.4%), school fluoride mouth-rinsing program (71.4%), water fluoridation (57.1%), tooth-brushing education (57.1%), school oral health programs (57.1%), and public elderly oral health programs (57.1%). Conclusion: This study showed that Korean dental hygienists had 136 tasks by reviewing 46 related studies and that the main job of Korean dental hygienists was oral disease prevention including scaling, sealant, and fluoride application.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.3
• /
• pp.130-135
• /
• 2023

Plasma-resistant ceramic (PRC) is a material used to prevent internal damage in plasma processing equipment for semiconductors and displays. The challenge is to suppress particles falling off from damaged surfaces and increase retention time in order to improve productivity and introduce the latest miniaturization process. Here, we confirmed the effect of suppressing plasma deterioration and reducing the etch rate through surface treatment of existing PRC with an initial illumination level of 200 nm. In particular, quartz glass showed a decrease in etch rate of up to 10%. Furthermore, it is believed that micro-scale secondary particles formed on the microstructure of each material grow as crystals during the fluoridation process. This is a factor that can act as a killer defect when dropped, and is an essential consideration when analyzing plasma resistance. The plasma etching suppression effect of the initial illumination is thought to be due to partial over etching at the dihedral angle of the material due to the sputtering of re-emission of Ar+-based cations. This means that plasma damage due to densification can also be interpreted in existing PRC studies. The research results are significant in that they present surface treatment conditions that can be directly applied to existing PRC for mass production and a new perspective to analyze plasma resistance in addition to simple etching rates.

• Journal of dental hygiene science
• /
• v.5 no.4
• /
• pp.165-170
• /
• 2005

The purpose of this study was to evaluate the usefulness of dental hygiene education curriculum such as oral prophylaxis, preventive dentistry, public oral health, oral health statistics, oral health education in the public oral health service performance. Questionnaire survey was posed to 96 dental hygienists working in health centers and health sub-centers. The relativity among frequency of task, usefulness, importance, and reinforcement of the education curriculum in the health centers, and the effect of current dental hygiene education curriculum on public oral health service were studied. The results were follows; 1. Sealant was performed the most frequently in the health centers and health sub-centers, and it was also the most useful content in the education curriculum. And the tooth brushing method was considered the most important in the curriculum. Therefore, oral health education was considered as factor which required the most reinforcement. However, the issues of school water fluoridation and water fluoridation in the public oral health were barely brought up as a matter of subject. 2. In the relationship between the frequency of task and the usefulness of curriculum, it showed that the more frequency of task was more useful. In the relationship between importance and reinforcements of curriculum, it showed that the more importance of the education curriculum requires more reinforcement. And more frequently performed task should be more strengthened. 3. According to the education course hours, current education curriculum course hours were 532.4 hours, which is 42.9 hours more spent than the original curriculum guideline. Lecture hours were 205.4 hours, which is 50.6 hours less, and the practice hours were 327 hours, which is 93.5 hours more than the original curriculum guideline. 4. Because of the insufficient course hours of curriculum compared to the frequency of the task, the oral health education, oral prophylaxis, and preventive dentistry should be reinforced more than now. But the oral health statistics and public oral health curriculum were not only emphasized, but also any reinforced compared to other tasks.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.204-219
• /
• 1997

The use of fluoride is one of the most effective methods for caries prevention. Fluoridation of public water supply has been recognized, for many years, as an effective way to reduce dental caries. The fluoride supplement has been recommended when the natural fluoride was unavailable or below the optimal range. However the mechanism of caries prevention by fluoride has not yet been clarified and it is well known that an overdose of fluoride results inacute and chronic toxicity, especially dental fluorosis. Fluoride mouthrinsing solution is widely used in dentistry due to its effectiveness in carrying anticariogenic action. Understanding the effects of fluoride mouthrinsing solution on human gingival fibroblasts will provide the safety rationale for its use during the caries preventive therapy. The purpose of this study was to evaluate the cytotoxic effect of fluoride mouthrinsing solution on the human gingival fibroblast in vitro. The human gingival fibroblasts were cultured from healthy gingiva on the extracted deciduous teeth of children. Cells were inoculated into a 24-well plate with $1{\times}10^4cells/well$ of medium at $37^{\circ}C$, 100% humidity, 5% $CO_2$ incubator for 24 hours. And the cells were counted by using the hemocytometer at each designed study. Human gingival fibroblasts were cultured in growth medium after one minute application range of 0.02%-0.2% NaF solution and 0.1% $SnF_2$ solution. The cells used in this study were between fifth to eighth passage number. The cell morphology was examined by inverted microscope and cell proliferation was measured by incorporating $[^3H]$-thymidine into DNA. DNA synthesis by human gingival fibroblasts was assessed by $[^3H]$-thymidine uptake assays while the cell activity was measured by MTT assay. Each concentrated fluoride mouthrinsing solution was estimated for its biocompatability with fibroblasts by the tissue culture technique. The results of this study were as follows : 1. It was observed that at 0.05%, 0.2% NaF mouthrinsing solution the cytoplasmic processes became globular. When 0.1% $SnF_2$ mouthrinsing solution was applied, the cytoplasmic process and cell morphology were disappeared. 2. DNA synthetic activity was reduced regardless of the concentration of the fluoride mouthrinsing solution. However, the result is statistically insignificant except 0.1% $SnF_2$ mouthrinsing solution(p<0.05). 3. Our results indicate that 0.02%, 0.05% concentrations of NaF mouthrinsing solution caused minimal cytotoxicity. But 0.2% NaF and 0.1% $SnF_2$ concentration were a significant difference between the cell activity in the experimental group and control group (p<0.05). 4. After appling 0.05% & 0.02% NaF fluoride mouthrinsing solution, cell activity was restored to the control groups level according to incubating time. The results suggest that direct exposure to fluoride solution inhibits gingival fibroblast activity. Therefore, for the most effective use of fluoride use, lowering the concentration of fluoride mouthrinsing is advisable because it maintains biocompatability and free ion in the oral fluid.

• Journal of Korean society of Dental Hygiene
• /
• v.1 no.2
• /
• pp.201-211
• /
• 2001

Dental caries causes the majority of tooth loss among Koreans. Korea is experiencing an increase in dental caries. And it shows a high prevalence of caries in preschool children, which contrasted with the much-improved situation in developed countries. So, it is important to control caries from preschool periods in Korea. Recently, inspections of the teeth of preschool children for evidence of dental disease became a legislative duty in Korea following Oral Health Act(2000). But, standardized oral health programs in preschool children is not yet proposed. Therefore, it is necessary to develop an community based oral health program in preschool children. The purpose of this study was to obtain basic data for the development of community based oral health program in preschool children of Sungnam city. Oral health status in primary dentition were surveyed in 862 2-6 year-old preschool children of Sungnam city by WHO criteria. From the data, df rate, percentage of preschool child ren with active caries, dft index, dt rate, percentage of preschool children with pit and fissure sealant of each age were calculated, and discussed. The obtained results were as follows : 1. The experience of dental caries in primary dentition showed a tendency to increase quickly between 2 and 3 year old children. So, the oral health program in preschool children should be developed to prevent dental caries and control their oral health under three years of age. 2. In 5 year-old children, the percentage with active caries was 60.8% and dft index was 5.06. The dt rate showed a tendency to decrease as proportion to age, but even though 6 year-old children, the dt rate was 47.7%. Therefore, the annual screening dental examination and oral health education programs at the institution for preschool children should be developed to detect and treat dental caries in primary dentition at early stage. 3. The percentage of preschool children with pit and fissure sealant at six years of age was 10.2%. So, pit and fissure sealant and professional fluoride application programs in Public Health Center should be developed to prevent dental caries. 4. Also, it is necessary to establish oral health goals in preschool children and develop water fluoridation program 10 improve and preserve oral health of preschool children in Seongnam city, effectively.

• Journal of Korean society of Dental Hygiene
• /
• v.10 no.2
• /
• pp.283-295
• /
• 2010

Objectives : It surveyed the recognition level of oral health in class teachers who have influence of students' oral health knowledges and behaviors in our country, developed a program available for supplementing reinforcement in school oral health education, and planned the knowledge contents necessary for school oral health education hereafter. Methods : To arrange the basic data necessary for school oral health program, it carried out questionnaire survey by personal self-administration targeting 460 teachers for 19 elementary schools where are located in Jinhae city from May 7, 2007 to June 13. The following conclusions were obtained. Results : 1. The path of acquiring oral health knowledge was shown the high frequency with 23.9% and 23.3%, respectively, through publicity brochure and dental clinic. As for the opinion about the aim of maintaining dental hygiene, the prevention of dental caries was the highest with 53.7%. 2. The opinion about which the regular visit to the dentist is very effective for preventing dental caries accounted for 56.7%. The opinions about which the limit to sugar intake and the use of dental floss are effective for preventing dental caries accounted for 52.2% and 46.3%, respectively. 3. The opinion about which the fluoridation beverage intake and the sealant are effective for preventing dental caries accounted for 33.9% and 33.0%, respectively. 4. The opinion about which the regular toothbrushing without toothpaste has a little effect and has no effect on preventing dental caries accounted for 42.6% and 38.5%, respectively. Conclusions : The elementary-school age period, which is the most core field out of the whole oral health, is the important period that is formed the basis of lifelong oral health care. It surveyed the recognition level of oral health in class teachers who are in charge of direct health care while making continuous life with students, and developed program available for supplementing reinforcement in school oral health education. Through this, there will be necessity for cultivating ability available for properly managing oral health for the whole life by allowing elementary-school students, who will be led to future adults' oral health, to be formed the attitudes toward the rationally oral health care.