• Restorative Dentistry and Endodontics
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• 제42권3호
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• pp.216-223
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• 2017

Objectives: The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. Materials and Methods: Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU), and Dia-PT (DPT). To test torsional resistance, 5 mm of the straightened file's tip was fixed between polycarbonate blocks (n = 15/group) and continuous clockwise rotation until fracture was conducted using a customized device. To evaluate cyclic fatigue resistance, files were rotated in an artificial curved canal until fracture in a dynamic mode (n = 15/group). The torsional data were analyzed using 1-way analysis of variance and the Tukey post-hoc comparison test, while the cyclic fatigue data were analyzed using the Mann-Whitney U test at a significance level of 95%. Results: PTU showed significantly greater toughness, followed by DPT and G6 (p < 0.05). G6 showed the lowest resistance in ultimate torsional strength, while it showed a higher fracture angle than the other files (p < 0.05). In the cyclic fatigue test, DPT showed a significantly higher number of cycles to failure than PTU or G6 (p < 0.05). Conclusions: Within the limitations of this study, it can be concluded that the torsional resistance of NiTi files was affected by the cross-sectional area, while the cyclic fatigue resistance of NiTi files was influenced by the surface treatment.

• Restorative Dentistry and Endodontics
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• 제49권1호
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• pp.6.1-6.16
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• 2024

Objectives: This study aimed to investigate the elemental analysis and microhardness of a bioactive material (Activa) and marginal tooth structure after storage in different media. Materials and Methods: Fifteen teeth received cervical restorations with occlusal enamel and gingival dentin margins using the tested material bonded with a universal adhesive, 5 of them on the 4 axial surfaces and the other 10 on only the 2 proximal surfaces. The first 5 teeth were sectioned into 4 restorations each, then stored in 4 different media; deionized water, Dulbecco's phosphate buffered saline (DPBS), Tris buffer, and saliva. The storage period for deionized water was 24 hours while it was 3 months for the other media. Each part was analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis for different substrates/distances and the wt% of calcium, phosphorus, silica, and fluoride were calculated. The other 10 teeth were sectioned across the restoration, stored in either Tris buffer or saliva for 24 hours or 3 months, and were evaluated for microhardness of different substrates/areas. Data were analyzed using analysis of variance and Tukey's post hoc test. Results: Enamel and dentin interfaces in the DPBS group exhibited a significant increase in calcium and phosphorus wt%. Both silica and fluoride significantly increased in tooth structure up to a distance of 75 ㎛ in the 3-month-media groups than the immediate group. Storage media did not affect the microhardness values. Conclusions: SEM-EDS analysis suggests an ion movement between Activa and tooth structure through a universal adhesive while stored in DPBS.

• 환경영향평가
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• 제23권2호
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• pp.157-167
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• 2014

The purpose of this study is to seek the application of IUCN categories of overlapping protected areas which is legally designated in South Korea. Different government departments in South Korea have managed and designated as protected areas. However, the protected areas due to different management agencies can be confused with restricting behaviors and supporting residents. The IUCN presents the reasonal standardization classifying the protected areas which could be applied all over the world. Six categories issued by the IUCN could be applied to deal with the problems of the overlapping protected areas. We suggested the application of the IUCN categories compared with legal frame in South Korea. Most areas are overlapped in designation, but the areas are important for ecology and landscape. Moreover, each protected areas in South Korea have zone districts. Comprehensively considered all these things, we made rationale matrix correlated with the IUCN categories and the zone districts of the protected areas in South Korea. For the result of this study, this matrix could be helped to the application of the IUCN categories in domestic protected areas. Although the protected areas has been recognized as regulatory regions, it is expected to expand and sustain the areas based on the matrix.

• International Journal of Costume and Fashion
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• 제8권1호
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• pp.65-74
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• 2008

Religion is deeply connected with human culture and life, and affects all areas of religious people's lives. The aim of this study was to find out how fashion-conservativeness of religious people and non-religious people differ in Korea. Ten religious people and ten atheists all in their twenties were interviewed to find out the differences between religious people and non-religious people related to their viewpoints on clothes. The twenties age group was selected because people in their twenties are sensitive to fashions and styles, and a fair proportion of males and females were selected. The subjects were asked demographic questions, questions about their religion and faith, whether or not they thought they were conservative or affected by religion, and finally, what they thought of photographs of certain styles. 12 photographs from the 2006-7 F/W collections of London, Paris, New York and Milan were presented to the subjects. The photographs were from the Vogue U.K. website and divided into 6 major styles based on verbal evidence used to describe the collections in catwalk reports: "Sexy," "attitude/confidence," "luxury," "sophisticated/chic," "feminine," and "rock." In conclusion, religious people were found to be more conservative than non-religious people in their twenties because they prefer more conservative and covered up styles, have more negative views of bold and skin-showing trends, and regard some styles to be too sexy when non-religious people do not.

• Restorative Dentistry and Endodontics
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• 제17권1호
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• pp.214-221
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• 1992

The five different types of bacteria, Bacteroides, Actinomyces, Capnocytophaga, Streptococcus, Fusobacterium which had frequently been recovered in infected canals, were investigated. The purpose of this study was to investigate the bacteriologic status in the traumatized nonvital teeth, and to investigate the effects of bacteria on the size of the le8ion and on the discoloration of teeth. The canal contents of sxiteen traumatized nonvital teeth were sampled and cultured aerobically and anaerobically for growth in five selective agar plates for five bacterial species. The sizes of the radiolucent areas in periapical films were measured and according to the sizes, the samples were divided into two groups. The discoloration of the teeth was checked and according to the existence of the discoloration, the samples were divided into two groups, also. The difference of bacterial colonial numbers in each group was investigated and the following results were obtained. 1. In traumatized nonvital teeth, all of the samples gave bacterial growth except one case. 2. Streptococcus was isolated in four cases but Bacteroides, Actinomyces, Fusobacterium and Capnocytophaga were not isolated. 3. The number of bacterial colonies was not found to be related the size of the lesion periapical films. 4. The number of bacterial colonies was not found to be related the discoloration of teeth.

• Journal of Yeungnam Medical Science
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• 제36권2호
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• pp.92-98
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• 2019

Forefoot disorders are often seen in clinical practice. Forefoot deformity and pain can deteriorate gait function and decrease quality of life. This review presents common forefoot disorders and conservative treatment using an insole or orthosis. Metatarsalgia is a painful foot condition affecting the metatarsal (MT) region of the foot. A MT pad, MT bar, or forefoot cushion can be used to alleviate MT pain. Hallux valgus is a deformity characterized by medial deviation of the first MT and lateral deviation of the hallux. A toe spreader, valgus splint, and bunion shield are commonly applied to patients with hallux valgus. Hallux limitus and hallux rigidus refer to painful limitations of dorsiflexion of the first metatarsophalangeal joint. A kinetic wedge foot orthosis or rocker sole can help relieve symptoms from hallux limitus or rigidus. Hammer, claw, and mallet toes are sagittal plane deformities of the lesser toes. Toe sleeve or padding can be applied over high-pressure areas in the proximal or distal interphalangeal joints or under the MT heads. An MT off-loading insole can also be used to alleviate symptoms following lesser toe deformities. Morton's neuroma is a benign neuroma of an intermetatarsal plantar nerve that leads to a painful condition affecting the MT area. The MT bar, the plantar pad, or a more cushioned insole would be useful. In addition, patients with any of the above various forefoot disorders should avoid tight-fitting or high-heeled shoes. Applying an insole or orthosis and wearing proper shoes can be beneficial for managing forefoot disorders.

• Restorative Dentistry and Endodontics
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• 제33권1호
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• pp.39-44
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• 2008

심미적으로 중요한 전치부에서 단일치아 임플란트를 이용한 보철수복은 임상의에게 새로운 도전과제중의 하나가 되었다. 그러나 전치부에서 single-unit implant는 식립할 부위의 치조골 상태가 양호해야 하는데 치은연하 파절로 인해 치아 주위에 골 손실이 있는 경우 immediate implant는 심미적으로 문제를 야기 할 수 있다. 따라서 본 증례는 "orthodontic extrusive remodeling"을 통해 파절치와 주위 조직을 교정적으로 정출시켜 임플란트 식립을 위한 연조직과 경조직을 증대시킨 후 임플란트 식립을 통해 상악측절치에서 성공적 인 심미수복을 이룬 증례에 관한 것이다.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.10.1-10.10
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• 2023

The purpose of this paper was to review the problems relating to Korea's occupational health services and suggest ways to improve them. Korea can be classified as a welfare state type of conservative corporatism partially interwoven with liberalism. While experiencing compressed economic growth, the economic sectors of developed (excess areas) and developing (deficient areas) countries are interwoven. Therefore, it is necessary to perfect conservative corporatism along with a complementary reinforcement of liberal contents and to apply a multilayered approach focusing on complementing the deficient areas. It is essential to form a national representative indicator related to occupational health, and a strategy for selection and concentration is needed. The proposed central indicator is the occupational health coverage rate (OHCR), which is the number of workers who have applied for mandatory occupational health services under the Occupational Safety and Health Act in the numerator with the total working population in the denominator. This paper proposes ways to raise the OHCR, which is currently at the level of 25%-40%, to 70%-80%, which is the level of Japan, Germany, and France. To achieve this target, it is necessary to focus on small businesses and vulnerable workers. This is an area of market failure and requires the active input of community-oriented public resources. For access to larger workplaces, the marketability of services should be strengthened and personal intervention using digital health resources should be actively attempted. Taking a national perspective, work environment improvement committees with tripartite (labor, management, and government) participation for improvement of the working environment need to be established at the center and in the regions. Through this, prevention funds linked to industrial accident compensation and prevention could be used efficiently. A national chemical substance management system must be established to monitor the health of workers and the general public.

• Restorative Dentistry and Endodontics
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• 제25권4호
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• pp.491-493
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• 2000

A case of a botryoid odontogenic cyst of the globulomaxillary area between the right upper lateral incisor and the canine presenting as an apical periodontal cyst was reported. The cyst showed an unilocular radiolucency with a well delineated hyperostotic border. Histologic examination revealed multiple cysts lined by one or two-cell layers, some areas demonstrated a bud-like thickening of the epithelium. Clear cells were also conspicuous, but devoid of inflammatory reaction in the cystic wall. Some considerations regarding differential diagnosis, histogenetic and biologic behaviour of the lesion were discussed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.135-139
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• 2003

저자 등은 본과에 내원하여 함치성 낭종으로 진단된 5명의 소아 환자에서 보존적인 조대술을 이용하여 매복된 영구치를 발거하지 않고 이차 치유를 유도하였다. 술 후 병소는 신생골로 치유되었으며 매복 영구치도 정상적인 위치로 맹출하였다. 이와 같이 소아에서 함치성 낭종의 경우 주기적인 예후 관찰이 가능하다면 보다 보존적인 조대술 등을 이용시에는 영구치의 정상적인 유도와 낭종의 치유를 유도할 수 있으리라 사료된다. 또한 인접치아의 경사 등에 의한 정상적인 치아의 맹출이 어려운 경우에는 교정치료와 병행시에 정상적인 영구 치열을 확보할 수 있을 것으로 사료되어 문헌고찰과 함께 보고하는 바이다.