• 대한치과보철학회지
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• 제35권3호
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• pp.445-457
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• 1997

Poor marginal fidelity resulting in a large marginal gap increases plaque accumulation, gingival inflammation and dental caries. The purpose of this study was to evaluate the marginal fit of three different cervical finishing methods of prepared teeth. A stereomicroscope was used to measure the space between the margin of restoration and the finishing line of prepared tooth. The results were statistically analyzed using the ANOVA and Multiple Range Test(Tukey's HSD). The results were as follows : 1. There were no significant differences concerning the types of tooth and positon (P>0.05), whereas the differences were statistically significant in case of cervical finishing methods (P<0.05). 2. There were statistically significant differences between before and after cementation (P<0.05). 3. In comparison according to variable margins after cementation, the gap discrepancies were increased in $130^{\circ}$ shoulder margin, chamfer margin and $90^{\circ}$ shoulder margin in ascending order, and there were significant differences between $90^{\circ}$ shoulder margin and chamfer, $130^{\circ}$ shoulder margin 4. In comparison according to variable margins, the gap discrepancies were increased in chamfer margin, $130^{\circ}$ shoulder margin and $90^{\circ}$ shoulder margin in ascending order, and there were significant differences between $90^{\circ}$ shoulder margin and chamfer, $130^{\circ}$ shoulder margin. 5. This study demonstrated a better marginal fit with all-ceramic crowns fabricated on chamfer and $130^{\circ}$ shoulder margin compared with $90^{\circ}$ shoulder margin.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.843-855
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• 1995

Occupational Dentistry was introduced in Korea about 70 years ago. During the colonial period occupied by Japan till 1945, there were few documents about industrial dentistry, furthermore most cases of occupational diseases and accidents might have been concealed intentionally by the colonial government. After being an independent country, several dentists made efforts to set up 'Preventive Dentistry for Workers' performing specific oral health surveys, even though which were stopped by Korean War. In 1960s' and 1970s', some investigations of oral status were carried out intermittently for specific small groups;white-collar workers, mentally retarded person, buddhist monks and crews of ocean liners. At the same time there was important study in Korean history of occupational dentistry, which was 'a comparison of the oral hygiene conditions in the female workers of a spinning factory at intervals of 30 years.' In 1980s', young researchers began to give attention to erosion of the teeth due to sulphuric acid in the acid-related industry and dental caries due to sugar and flour in the sweets industry. After being democratic labor union movement activated in 1987, hidden and suppressed occupational diseases under the military dictatorship were exposed and flushed in the newspapers. It was shocking for all people that 15-year old boy had been dead due to mercury intoxication after 3-month employment in 1988. In 1990s', the activity for studying oral status of workers in their workplaces was launched and 'Occupational Accidents and Diseases in Oral and Maxillofacial Field' was published. And also The Korean Association of Occupationl Dentistry was established. Oral health examination of workers at the time of employment and of workers exposed to 5 special chemicals at the time of routine special health examination was adopted in 1992, and epocally oral health examination was also included in periodic routine examination of workers' health in 1995. So, occupational dentistry in Korea should cope with the changing needs of working environment and the altering scheme of health examination.

• Restorative Dentistry and Endodontics
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• 제37권2호
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• pp.90-95
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• 2012

Objectives: The purpose of this study was to determine the effect of resin infiltration technique on color and surface hardness of white spot lesion (WSL) with various degrees of demineralization. Materials and Methods: Ten human upper premolars were cut and divided into quarters with a $3{\times}4mm$ window on the enamel surface. Each specimens were separated into four groups (n = 10) and immersed in demineralization solution to create WSL: control, no treatment (baseline); 12 h, 12 hr demineralization; 24 h, 24 hr demineralization; 48 h, 48 hr demineralization. Resin infiltration was performed to the specimens using Icon (DMG). $CIEL^*a^*b^*$ color parameters of the enamel-dentin complex were determined using a spectroradiometer at baseline, after caries formation and after resin infiltration. Surface hardness was measured by Vickers Micro Hardness Tester (Shimadzu, HMV-2). The differences in color and hardness among the groups were analyzed with ANOVA followed by Tukey test. Results: Resin infiltration induced color changes and increased the hardness of demineralized enamel. After resin infiltration, there was no difference in color change (${\Delta}E^*$) or microhardness among the groups (p < 0.05). Conclusion: There was no difference in the effect of resin infiltration on color and hardness among groups with different extents of demineralization.

• 대한치과보철학회지
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• 제57권4호
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• pp.490-494
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• 2019

국소의치 장착자에서 2차 우식 등의 문제가 발생하여 지대치 치료 후 크라운 재수복이 필요한 경우가 있다. 기존 국소의치가 잘 기능하고 있고 환자가 여러 가지 원인으로 국소의치를 새로 제작할 수 없을 경우에는 기존 국소의치에 맞도록 지대치 보철물을 제작해야 한다. 그러나 이 과정은 기술적으로 난이도가 높고, 기공과정이 복잡하다. 국소의치를 지지하는 지대치에 합병증이 발생하기 전의 원본 모형이 있고 참고점이 될 수 있는 다른 치아들을 포함하고 있다면, CAD/CAM을 이용하여 retrofitting 보철물을 매우 간단하고 효율적으로 제작할 수 있다. 본 증례는 지대치의 포스트, 코어 및 보철물이 복합적으로 탈락하여 내원한 환자에서, computer-aided design and computer-aided manufacturing (CAD/CAM)을 이용해 기존 국소의치에 맞는 보철물을 제작하였고 높은 적합도와 조정 과정의 최소화 등 만족스러운 결과를 얻어 이를 보고하는 바이다.

• Nutrition Research and Practice
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• 제13권2호
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• pp.134-140
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• 2019

BACKGROUND/OBJECTIVES: Excessive sugar consumption may increase the risk for development of several diseases. Although average dietary sugar intake of Koreans is within the recommended level, an increasing trend has been found in all age groups. This study aimed to evaluate the population attributable fractions (PAF) to dietary sugar for disease and death in Korea, and to estimate the socioeconomic effects of a reduction in dietary sugar. MATERIALS/METHODS: The prevalence of sugar-sweetened beverages (SSB) overconsumption (${\geq}20g$ of sugar from beverages) was analyzed using the Korean National Health and Nutrition Examination Survey 2015. Disease-specific relative risks of excessive SSB consumption were obtained through reviewing previous studies. Using the prevalence of SSB overconsumption and each relative risk, PAFs for morbidity and mortality were calculated. Socioeconomic costs of diseases and death attributable to SSB overconsumption were estimated by using representative data on national medical expenditures, health insurance statistics, employment information, and previous reports. RESULTS: Disease-specific PAF to SSB consumption ranged from 3.11% for stroke to 9.05% for obesity and dental caries, respectively. Costs from disease caused by SSB overconsumption was estimated at 594 billion won in 2015. About 39 billion won was estimated to be from SSB consumption-related deaths, and a total of 633 billion won was predicted to have been saved through preventing SSB overconsumption. CONCLUSIONS: Sugars overconsumption causes considerable public burdens, although the cost estimates do not include any informal expenditure. Information on these socioeconomic effects helps both health professionals and policy makers to create and to implement programs for reducing sugar consumption.

• 미생물학회지
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• 제55권3호
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• pp.280-282
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• 2019

본 논문에서는 농흉 환자의 흉막액에서분리된 Bifidobacterium dentium ATCC 15424균주의 유전체 염기서열을 분석하여 보고한다. 이 균주의 유전체는 구강에서 분리된 다른 B. dentium 균주에 존재하지 않는 type III 및 IV secretion system proteins, N-acetylmuramoyl-L-alanine amidase 그리고 PRTRC system protein E를 암호화하는 유전자 등 247개의 ATCC 15424균주 특이적인 유전자들을 포함한다. 이 유전체의 서열 정보는 B. dentium의 자연적 변이와 세균 종 내의 유전체 다양성을 이해하는 데 유용할 것이다.

• 대한통합의학회지
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• 제10권2호
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• pp.49-59
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• 2022

Purpose : The purpose of this study is to directly understand the health condition of residents of mental health sanatoriums nationwide, which has been difficult to ascertain in surveys conducted to date. The study presents specific measures for improving the health of these residents. Methods : A "physical examination questionnaire for residents of mental health sanatoriums" was developed to check the basic physical condition of residents, and 20 out of 59 mental health sanatoriums nationwide were randomly selected. Medical personnel visited the sanatoriums, interviewing and examining the residents in person. A total of 396 health surveys were completed. Results : Many of the residents were underweight but had abdominal obesity. It was confirmed that chronic diseases among the residents were not diagnosed early or were not properly managed. Among the subjective symptoms complained of by the residents, musculoskeletal symptoms were the most common. Oral examinations revealed a serious level of oral health problems among the residents, including dental caries and missing teeth. Basic physical examinations found health problems that required additional examination or medical treatment. Blood pressure abnormalities made up the highest percentage of the health problems. Conclusion : Regular health surveys are needed to determine the health condition of residents of mental health sanatoriums. Access to and quality of primary medical services within the sanatoriums need to be dramatically improved. A delivery system for severe diseases and emergency medical care in the sanatoriums should also be specifically presented. The residents should be notified upon admission and during their stay that they have the right to the enjoyment of the highest attainable standard of mental and physical health. The issue of health rights should be addressed within a larger framework of reorganizing management plans for people in the community - not only residents - with chronic mental illness.

• 대한소아치과학회지
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• 제51권1호
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• pp.80-87
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• 2024

Silver diamine fluoride, which can arrest dental caries, is alkaline and may cause mild soft tissue irritation. Water-based silver fluoride has a neutral pH, which is closer to the physiological range, and is biocompatible for use in the oral environment. This study aimed to evaluate the effect of water-based silver fluoride on remineralizing early enamel lesions by comparing it with other fluoride agents through microhardness and quantitative light-induced fluorescence measurements. An in vitro study with intact bovine incisors was performed. Artificial enamel lesions were induced and subjected to microhardness and quantitative light-induced fluorescence testing. Specimens were randomly divided into 4 groups for treatment. The specimens in group I were treated with water-based silver fluoride and potassium iodide, group II with silver diamine fluoride and potassium iodide, group III with sodium fluoride varnish, and group IV with distilled water. After 8 days of pH cycling, the specimens were subjected to microhardness and quantitative light-induced fluorescence testing. Water-based silver fluoride and silver diamine fluoride showed the greatest increases in microhardness and quantitative light-induced fluorescence, with no significant differences between the two. Sodium fluoride varnish also exhibited a significant increase in microhardness and quantitative light-induced fluorescence, but the differences were smaller than those for water-based silver fluoride and silver diamine fluoride. Water-based silver fluoride is considered useful in a clinical setting for remineralizing enamel lesions, with the advantages of no risk of tissue burn and improved taste and smell.

• 대한소아치과학회지
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• 제51권2호
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• pp.132-139
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• 2024

This study aimed to compare the fluoride-releasing ability and degree of microbial attachment of a newly developed glass-hybrid restorative material (GH) with those of a high-viscosity glass ionomer (HvGIC), resin-modified glass ionomer (RMGI), and composite resin (CR). In addition, the correlation between fluoride-releasing ability and microbial attachment between materials was evaluated. Specimens were prepared in a disc shape and divided into 4 groups according to the materials (GH, HvGIC, RMGI, and CR). The fluoride release experiments were performed in each group (n = 15). The amount of fluoride released was measured on days 1, 3, 7, 14, 28, and 42 after storage. For the microbial attachment experiment, 12 specimens were produced per group using Mutans Streptococci (S.mutans ), a cariogenic microorganism. S. mutans was cultured on the specimens for 24 hours, and the number of bacteria was measured. GH had the highest cumulative fluoride release and showed a significant difference when compared with RMGI (p = 0.001) and CR (p < 0.0001). Microbial attachment was the lowest in GH; however, no significant difference was observed between the materials (p = 0.169). There was no significant correlation between fluoride release from materials and microbial attachment (p > 0.05). From this perspective, remineralization of low-mineralized areas could be expected due to the high fluoride release of GH, and the effect of delaying the progression of dental caries could be predicted from the low cariogenic microbial attachment. Therefore, GH might be a useful restorative material for treating immature permanent teeth with hypomineralized enamel. However, further studies are needed about the degree of remineralization of hypomineralized areas after restoration and the capacity to recharge fluoride.

• 생명과학회지
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• 제18권2호
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• pp.167-174
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• 2008

치아우식균으로 알려져 있는 Streptococcus mutans에 대한 초피(Zanthoxylum piperitum)의 항균활성을 조사하기 위해, 뿌리, 줄기, 잎, 과피, 그리고 종자 부분을 methanol, ethyl acetate, hexane, methylene chloride등의 유기용매로 추출한 후 그 추출물의 항균활성을 $1{\sim}3$ mg/disc 농도범위에서 측정하였다. 그 결과, 종자의 경우만 활성이 나타났으며 특히 methylene chloride 추출물에서 비교적 높은 항균활성이 확인되었다. 초피종자의 항균활성이 종자의 정유성분을 추출할 경우에도 회수되는지를 조사하기 위해 초피종자 및 초피과피로부터 정유성분을 추출하고 이들의 S. mutans에 대한 항균활성을 측정하였다. 이때 두 정유성분 모두는 종자의 methylene chloride 추출물 보다 더 강한 항균효과를 보였다. 이 정유성분들의 S. mutans에 대한 최소저해농도(MIC)를 액체배양으로 측정한 결과, 초피종자 정유성분의 MIC는 0.3 mg/ml 로, 또한 초피과피 정유성분의 MIC는 4 mg/ml로 나타났다. S. mutans에 대한 항균활성이 가장 높게 나타난 종자의 정유성분을 박층크로마토그래피 방법으로 7가지 분획으로 나누어 그 항균효과를 서로 비교 조사한 결과, 다섯번째 분획(CS-SD-E)의 항균활성이 다른 분획들의 항균활성에 비해 상대적으로 높았으나, 분획 전의 정유성분에 비해서는 모두 항균활성이 낮았다. 초피종자의 항균활성성분을 조사하기 위해, 초피종자의 methylene chloride 추출물과 초피종자 정유성분을 GC-MS로 비교 분석하였다. 초피종자의 methylene chloride 추출물에서는 S. mutans에 대한 항균활성이 이미 보고된 물질로서 carvacrol (0.24%), ${\beta}$-caryphyllene (1.72%), ${\alpha}$-humulene (0.88%)등이 검출되었고, 초피종자 정유성분에서는 sabinene (1.57%), linalool (1.55%), citronellal (13.67%), terpinene-4-ol (0.45%), citronellol (3.69%), geraniol (0.9%), linalyl acetate (1.35%), ${\beta}$-caryophyllene (1.35%), ${\alpha}$-humulene (0.7818%) 및 ${\delta}$-cadinene (0.67%) 등이 S. mutans에 대한 항균활성이 보고된바 있는 물질로서 확인되었다. 이상의 연구결과는 초피종자가 S. mutans에 대해 항균활성을 가지며, 수증기 증류를 통해 확보하는 종자의 정유성분 회수가 이러한 항균물질을 추출하는 효과적인 방법임을 시사한다. 아울러 본 연구결과는 초피종자 유래의 정유성분이 S. mutans에 의해 발생하는 치아우식의 예방에 활용될 수 있음을 시사한다.