• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.303-315
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• 1995

An adequate and homogeneous cure of light-activated restroative material is very important for improvement of marginal adaptation and prevention of marginal leakage, secondary caries and pulpal irritation as well as expressing natural physical property of that material. The purpose of this study was to evaluate the change of surface hardness and cure uniformity of light-activated glass ionomer cements. Restorative(Fuji II LC, Vitremer) and lining(Baseline VLC, Vitrebond) light-activated glass ionomer cements were investigated for this study. The surface hardness of the top and bottom surfaces and cure uniformity of each 1mm, 1.5mm, 2mm, 2.5mm & 3mm in the thickness of specimen were measured immediately, at 1 hour, 24 hours and 1 week after light activation. The surface hardness change and cure uniformity of all the specimens were measured by Knoop hardness tester. The results were as follows. 1. The surface hardness of top and bottom surfaces in all groups increased with time(p<0.01). 2. Both top and bottom surfaces hardness of Vitrebond group measured immediately after light-activation were significantly lower than those of the other groups(p<0.01). 3. The surface hardness of top and bottom surfaces of restorative light -activated glass ionomer cements was higher than those of lining materials at 1 week(p<0.10). 4. Surface hardness of Vitremer group decreased as the specimen thickness increased, except top and bottom surfaces hardness of the specimen at 1 week(p<0.01). There was no significant difference in the surface hardness of Fuji II LC with changes in the thickness except bottom surface hardness of specimen at 24 hours and 1 week (p>0.05). 5. Surface hardness of Vitrebond group significantly decreased as the specimen thickness increased(p<0.01). There was no significant difference in the surface hardness of Baseline VLC group with changes in the thickness except bottom surface hardness of specimen measured immediately after light -activation(p>0.05). 6. The hardness ratio of top against bottom surface in all groups decreased with time(p<0.05). 7. There was no significant difference in the hardness ratio of top against bottom surface with changes of the thickness except Vitrebond group, 24 hours and 1 week of Vitremer group and 1 week of Baseline VLC group (p>0.05). These results suggest that surface hardness of restorative ligh-activated glass ionomer cements were highter than those of lining light-activated materials. In all groups, the surface hardness and cure uniformity continuously increased with time.

• Journal of Korean society of Dental Hygiene
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• v.8 no.3
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• pp.1-11
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• 2008

Oral health projects that cater to the disabled should be more prevailing in order to ensure the maintenance and successful promotion of the oral health of disabled people. 70 public dental clinics that conducted oral health projects geared toward the disabled were examined to get a precise grip on their oral health projects. The findings of the study were as follows: 1. 31 out of 70 public dental clinics investigated(44.3%) were equipped with two or more dental hygienists who were professional human resources in charge of the oral health projects for the disabled. As for the age and disability type of the beneficiaries of the oral health projects, adolescents(74.3%) and people with mental retardation(87.1%) benefited most from the oral health projects. Concerning the most common implementation frequency of the projects, the projects were carried out once to three times a week(62.9%). 2. The most dominant oral disease treatment provided to disabled people was amalgam treatment and resin treatment(68.6%), which were the early dental caries treatment. The most common preventive treatment that was offered to improve their oral health was oral prophylaxis(82.9%). As for reform measures for the oral health projects, education of personnels in charge of the projects and their specialization(58.6%) were most emphasized. 3. Regarding factors related to the preventive oral health projects for the disabled, the implementation of oral prophylaxis and toothbrushing education was linked to the age of the beneficiaries. More oral prophylaxis was offered to teens, and more toothbrushing education was provided to preschoolers and adolescents. The age of the beneficiaries and the number of dental hygienists responsible for the projects had something to do with the application of fluorides. 4. Concerning the relationship of the preventive oral health projects for the disabled to the number of dental hygienists, one of the personnels in charge of the projects, the application of fluorides( 54.4%) and pit & fissure sealing(56.8%) were more prevalent when there were two or more dental hygienists. There was a statistically significant disparity in that regard(p<0.05). The above-mentioned findings illustrated that in order to boost the oral health of the disabled, dental hygienists who are responsible for the oral health projects for the disabled should put ceaseless efforts into fostering their professional knowledge and ability and offering quality service to disabled patients. Every public dental clinic should be equipped with plenty of professional personnels to enlarge the scope of treatment and ensure the efficiency of treatment and the preventive projects.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.155-160
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• 2011

Purpose: Fibrillar collagens like type I collagen, are the major constituent of the extracellular matrix and structural protein of bone. Also, it can be a scaffold for osteoblast migration. The purpose of this study is to estimate the effects of absorbable atelo-collagen sponge (Teruplug$^{(R)}$, Terumo biomaterials Co., Tokyo, Japan) insertion in tooth extraction sites on periodontal healing of the second molar, healing of the fractured mandibular bone and new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Methods: In our study of six cases of mandibular angle fractures, all of them underwent the extraction of the third molar tooth & absorbable atelo-collagen sponge insertion in tooth extraction site. Three of them had a intraoral infection & oral opening to fracture site, two of the six had dental caries, and only one had reduction problem due to third molar position. Six consecutive patients with noncomminuted fractures of the mandibular angle were treated by open reduction and internal fixation using one noncompression miniplates and screws placed through a transoral incision. Results: All of the patients have showed good postoperative functions and have not experienced complications requiring second surgical intervention. There was well healing of the mandibular bone and the most new bone formation of third molar socket after the extraction of the impacted third molar with mandibular angle fracture. Conclusion: The results of this study suggest that absorbable atelo-collagen sponge is relatively favorable bone void filler with prevention of tissue collapse, food packing, and enhance periodontal healing. Thus, the use of atelo-collagen sponge and one noncompression miniplate seems to be relatively easy, safe, and effective for the treatment of fractures of the mandibular angle and third molar extraction.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.553-567
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• 2007

Migrant Worker are rapidly increasing in Korea since 1990. They are nowadays main sources of laborer groups engaging in medium-sized factories. The purpose of this study is to provide the basic information to establish proper oral health policy. Dental caries and periodontal disese are the most common disease that occur in the mouth. Periodontal disease is the most common disease in humans and the biggest reason for the loss of the teeth in the adult population. The CPITIN has been developed jontly by the international Dental Federation and the World Health Organization. CPITN is now an established index of level, of periodontal condition in populations for which specific intervention might be considered. This study was conducted to obtain the information regarding to CPITN of migrant workers located in Daegu, Questionaire survey was carried out for 289 workers from July 9 to August 8, 2006. Total survey was 289, 224 males and 65 females. The result was as follows: First, The number of nationality was 14. The first majority was China as 31.8% Among 14 nationalities were Cambodia 18.0%, Vietnam 12.8%, Sri Lanka 12.1%, Indonesia 7.3%, Nepal 4.2%, the other 13.8%, those who are aged from 20 to 29 were 43.9%, and salary from 1,000,000 won to 1,490,000 won 51.2%.(as for their residence, those who resided) over 3 years were 42.6% and not insured reached 68.5%. Second, more than 93.4% of the subjects need periodontal treatment, only 4.9% of non-smoker was health periodontal states, four times frequency of tooth brushing per a day was 16.7%. Third, 28.7% of migrant workers had experienced visit of dental clinic, and 22.9% had received treatment of decayed tooth. Fourth, It is difficult for them 65.1% of them to visit dental clinic in korea, the First was a communication problem and the second was time. Fifth, Most of them didn't have a oral health education but 85.1% of them said that they wish they attend oral health education. We conclude that the situation of migrant workers was very bad considering their working conditions, circumstances, and health condition. According to this study, more than 93.4% of the people need periodontal treatment. Besides they didn't have accurate knowledge about prevention of periodontal disease. Therefor our considering these facts, the policy of dental health by government should be established for migrant workers.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.240-246
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• 2012

It's basically meant to make a contribution to the promotion of the oral health of shipbuilding workers and to the improvement of oral health education planning, industrial oral health policy setting and the related system, as it seems that the working environments of shipbuilding workers are very harsh due to the unique characteristics of their working process. The subjects in this study were the workers who were selected by convenience sampling from shipbuilding companies and their subcontractors in South Jeolla Province that numbered 10. The workers were surveyed to determine the relationship between their oral health education experience and oral health awareness, and the findings of the study were as follows: Out of the 310 workers investigated, 89.4 percent had no experience to receive oral health education, those who had no experience to receive oral health education fell behind in terms of oral health knowledge, awareness, concern and perception of oral health importance, and there was close correlation among their oral health knowledge, awareness, concern and perception of oral health importance. Those without oral health education experience cited lack of opportunities as the reason, the workers preferred to receive education about the prevention and treatment of dental caries, and their favorite educational method was lectures given by dentists, the workers who had oral health education experience had a more intention to receive oral health education than the others who hadn't.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.1
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• pp.18-23
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• 2000

The changes of the microorganism composition after therapeutic radiation for oral cancer patients are not well known and the long-term follow-up data are not reported. To obtain basic data for understanding of pathogenesis and prevention and treatment of dental caries and mucositis occuring after radiation therapy, 7 of the oral cancer patients presented at the Seoul National University Oral & Maxillofacial Department between 1997 and 1998 whose treatment plan included radiation therapy were recruited to investigate the changes in bacterial composition(total aerobic count, Candida, Staphylococci, Lactobacilli, S. mutans, and S. salivarius (mitis, sanguis)) of the saliva before, during, and after radiation therapy. The basic data obtained from this study on identification and composition change of the bacteria in saliva of patients treated with radiation therapy can be used (1) as a reference for deciding on the ideal anti-microbial spectrum of the oral rinsing agent to be used in patients treated with radiation therapy for malignant tumor of the head and neck region. (2) to enhance the understanding of increase of opportunistic infection after immunochemical changes of the saliva and its relation to specific bacterial infection. (3) as a reference in prescribing prophylactic antibiotics in immunodepressed patients after radiation therapy.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.335-351
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• 1998

Salivary proteins which are produced in the saliary acinar cells have been known to be involved in the Calcium and phosphate metabolism. The acquired pellicle resulting from such metabolism is considered as a secondary defence membrane against tooth caries. In this respect, some proteins included in saliva probably play an important role in the prevention of demineralization in enamel. On the other hand, fluoride has long been known to prevent the demineralization of enamel by the inhibition of the growth of Streptococcus mutans(S. mutans) and by the chemical reaction with calcium and phosphate, Therefore, I have examined the roles of amylase and albumin in the demineralization of enamel and compared these preteins with fluoride in terms of anticariogenic effect. 1. The demineralization caused by S. mutans occurred slowly and progressively for the first 60 min, then the rate of demineralization was accelerated afterwards. 2. pH decreased continuously during the entire period of each experiment. 3. The demineralization was significantly inhibited by the preteatment of amylase and fluoride but albumin had little effect on it. 4. An addition of 0.1 mM lactic acid (final concentration 0.1 ${\mu}M$) caused a rapid increase in calcium concentration reaching a maximum within 10 min. 5. pH decreased rapidly by the addition of 0.1 mM lactic acid and reached a minimum within a few seconds followed by an increase in pH. pH reaced a plateu with 10 min. 6. Fluoride, amylase and albumin played little role in the 0.1 mM lactic acid-induced demineralization. 7. A slow infusion of 0.1 M lactic acid at a rate of 5 ${\mu}l/min$ caused a slower increase in calcium concentration compared with the bolus addition of lactic acid. 8. Fluoride had an inhibitory effect on the calcium release caused by slow infusion of lactic acid while amylase and albumin had no effect on it. These results suggest that fluoride inhibits demineralization by protecting the HA from the acid attack whereas amylase has a direct effect on S. mutans to prevent demineralization.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.485-490
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• 2009

The purpose of this study was to obtain basic data for improvement about oral health education, contents and method for college and university students. A question was used 10 questionnaire by 332 college and university students in the Tae gu-city and Gu mi-city. In conclusion, 1. They answered that dental caries cause is 'No-brushing'(88.3%). The man respondents answered that the cause of periodontal disease is 'weak disease'(39.2%). 2. The reason about visit to dental clinic is 'for treatment'(72.0%) and they answered that the tooth is 'very important in their life'(82.5%). 3. They answered that the frequency of tooth-brushing is 'two times in a day'(44.8%) and using auxiliary oral hygiene material is 'dental floss' by male(15.2%) and female(16.6%). 4. In the case of high oral health knowledge level showed high response rate about level of oral health attitude and oral health recognition.

• Journal of dental hygiene science
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• v.12 no.3
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• pp.209-215
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• 2012

Somok, the heart wood of Caesalpinia sappan is used in traditional Chinese medicine. This study was performed to investigate the effect of growth and culture conditions of brazilin from C. sappan against S. mutans ATCC 25175. The bacteria were cultured in brain heart infusion (BHI) broth, and then incubated under 5% $CO_2$ at $37^{\circ}C$ for 18-24 hours. The effect of brazilin against S. mutans was confirmed under the changes of the culture conditions, such as growth curve and the change of pH, protein, and total carbohydrate. The growth of S. mutans in control medium was the highest at 24 hr, while brazilin-added medium (0.3 mg/ml) showed maximum growth at 32 hr. The pH values of the control medium was 5.25 at 16 hr, but the media supplemented with brazilin (0.3 mg/ml) was 7.0 at 16 hr. The amounts of total carbohydrate of the control medium was 11 mg/ml at 8 hr, but the brazilin-added media (0.3 mg/ml) was 18 mg/ml at 8 hr. In the protein change of the culture medium, the control culture broth and the brazilin supplemented-cultures was 2.4 mg/ml and 2.54 mg/ml at 24 hr, respectively. Polysaccharide contents of the control medium and test media were 3 mg/ml and 2 mg/ml at 8 hr, respectively. Thus, the application of C. sappan can be considered a useful and practical material for the prevention of dental caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.281-289
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• 2006

Topical fluoride application for children is a widely performed procedure in the field of Pediatric Dentistry for its dental caries prevention effects However, it is recently recognized as having some unwanted effects on several esthetic restorative materials, the author immersed glass ionomer cement, compomer and composite resin specimens in APF gel and measured the surface roughness and also, examined the specimens under the scanning eletron microscope. The followings are the results: 1. In the specimens of glass ionomer cement and compomer, APF gel 4 minute immersion group and pH cycling group show statistically significant increased surface roughness than artificial saliva immersion group (p<0.01). 2. There was no statistically significant surface roughness for composite resin in all group (p>0.05). 3. When the specimens were examined under scanning electron microscope, the surface change were in the order of glass ionomer cement, compomer, composite resin and also in the order of pH cycling group, APF gel 4 minutes immersion group, artificial saliva immersion group.