• Title/Summary/Keyword: impression materials

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Clinical and Radiographic Evaluation of Recurrent Odontogenic Keratocysts (재발성 치성각화낭의 임상 및 방사선학적 평가)

  • Jo, Hyung-Woo;Choi, So-Young;Kim, Hyun-Soo;Kwon, Tae-Geon;Jang, Hyun-Jung;Lee, Sang-Han;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.5
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    • pp.431-436
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    • 2010
  • Purpose: It is estimated that the odontogenic keratocyst (OKC) makes up 10% to 12% of all developmen-tal odontogenic cysts. The lesion has been of particular interest because of its specific histopathologic fea-ture, high recurrence rate, and aggressive behavior. Materials and Methods: We investigated 266 OKCs of Korean patients for the sex of patient, the age of the patient, the location of OKC, the recurrence rate related to radiographic impression. Results: The male-to-female ratio was 1.47:1, showing a slight male predilection. Odontogenic keratocysts had a peak of occurrence in the third decade of life. The mandibular angle and ascending ramus area (49.6%) is the most frequent site of OKCs in the jaws. Fourteen cases of unilocular (12%) and 5 cases of multilocular (20%) OKCs recurred. Thirteen cases of smooth (12.9%) and 6 cases of lobulated (14.6%) OKCs recurred. Seventeen cases of OKCs without perforation of cortical bone (12.5%) and 2 cases of OKCs with perforation of cortical bone (33.3%) recurred. Fifteen people of patients with single lesion (12.2%) and 4 people of patients with multiple lesions (66.7%) recurred. Conclusion: In this resul, we consider multiple odontogenic keratocysts can recur more easily. So we have to treat them more carefully and need long-time follow-ups.

Effect of two-phase fabrication method for the optimum fit of light-polymerized record bases

  • Huh, Jung-Bo;Kang, Min-Goo;Shin, Sang-Wan;Ryu, Jae-Jun
    • The Journal of Advanced Prosthodontics
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    • v.2 no.3
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    • pp.102-105
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    • 2010
  • PURPOSE. The aims of this study were to suggest a method of fabrication of the record base using a light-polymerized resin by applying the two-phase fabrication method for the improvement of the fit of the record base and to compare the degree of fit according to the separation site. MATERIALS AND METHODS. In the edentulous cast of maxilla, four test groups were considered. In the first, second, third, and fourth test groups (n = 12 in each group) the separation was done at 0, 5, 10, and 15 mm, respectively below the alveolar crest along the palatal plane. For the control group, the record base was made without separating the two sections. The light-body silicone material was injected into the fitting surface of the record base. It was then placed onto the cast and finger pressure was applied to stabilize it in a seated position followed by immediate placement onto the universal test device. Finally, the mass of the impression material was measured after it was removed. ANOVA was performed using the SAS program. For the post-hoc test, the Wilcoxon Rank-Sum test and the Tukey-Kramer HSD test were performed ($\alpha$ = 0.05). RESULTS. The control group and Group 3, 4 showed significant differences. The Group 3 and 4 showed significantly smaller inside gaps than the control group which was not made with the two-phase fabrication method. CONCLUSION. The two-stage polymerized technique can improve the fit of the denture base particularly when the separation was made at 10 to 15 mm from the alveolar crest.

Repeatability and reproducibility of individual abutment impression, assessed with a blue light scanner

  • Jeon, Jin-Hun;Kim, Dong-Yeon;Lee, Jae-Jun;Kim, Ji-Hwan;Kim, Woong-Chul
    • The Journal of Advanced Prosthodontics
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    • v.8 no.3
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    • pp.214-218
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    • 2016
  • PURPOSE. We assessed the repeatability and reproducibility of abutment teeth dental impressions, digitized with a blue light scanner, by comparing the discrepancies in repeatability and reproducibility values for different types of abutment teeth. MATERIALS AND METHODS. To evaluate repeatability, impressions of the canine, first premolar, and first molar, prepared for ceramic crowns, were repeatedly scanned to acquire 5 sets of 3-dimensional data via stereolithography (STL) files. Point clouds were compared and the error sizes were measured (n=10, per type). To evaluate reproducibility, the impressions were rotated by $10-20^{\circ}$ on the table and scanned. These data were compared to the first STL data and the error sizes were measured (n=5, per type). One-way analysis of variance was used to assess the repeatability and reproducibility of the 3 types of teeth, and Tukey honest significant differences (HSD) multiple comparison test was used for post hoc comparisons (${\alpha}=.05$). RESULTS. The differences with regard to repeatability were 4.5, 2.7, and $3.1{\mu}m$ for the canine, premolar, and molar, indicating the poorest repeatability for the canine (P<.001). For reproducibility, the differences were 6.6, 5.8, and $11.0{\mu}m$ indicating the poorest reproducibility for the molar (P=.007). CONCLUSION. Our results indicated that impressions of individual abutment teeth, digitized with a blue light scanner, had good repeatability and reproducibility.

Study on Wearing Fusion Hanbok at Child's First Birthday Party

  • Jang, Se-Yoon;Lee, Yu-Ri
    • International Journal of Costume and Fashion
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    • v.11 no.2
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    • pp.13-24
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    • 2011
  • This study explores the opportunities for new market of traditional Korean costumes, Hanbok, following not only the consumer's needs and wants, but marketing trends of fashion industry. This paper is the exploratory consumer research of fusion Hanbok, it aims at examining how consumers wear fusion Hanbok. Study participants were limited to mothers who wore Korean-fusion Hanbok to their baby's first birthday party once or more. A total of 221 respondents completed online questionnaires. The results of this study are as follows. First, regarding the reasons of wearing fusion Hanbok is a beautiful and traditional dress although traditional Hanbok is uncomfortable and inconvenient. Second, the most satisfactory aspect of fusion Hanbok was found to be its design. Satisfaction with the color, size and length was also high. Third, most female consumers in their 20s and 30s have stronger preferences for and intentions of purchasing fusion Hanbok. Some people criticize that as fusion Hanbok is westernized in its designs and materials, it has lost the classical beauty and impression of traditional Hanbok. However, if no one routinely wears Hanbok, Hanbok will never be popularized or globalized. This study suggest that traditional Hanbok should be improved by developing effective merchandising strategies based on consumer needs for traditional Hanbok such as various product assortment and promotion strategies using traditional Korean beauty. So, traditional Hanbok could be retained and succeeded in the future by improving consumers' dissatisfactions of traditional Hanbok and creating the new market of traditional Hanbok in which fusion Hanbok are produced focused on consumers' needs and market environments.

A Comparative Study on the Edition Statement in Bibliographic Description (서지기술에 있어 판사항에 관한 비교연구)

  • Kim Jeong-Hyen
    • Journal of the Korean Society for Library and Information Science
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    • v.38 no.4
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    • pp.149-166
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    • 2004
  • This study make comparative analysis of the cataloging rules on the edition area included in the KCR4, NCR(2001), AACR2R, ISBD(M), and ISBD(ER). There is a delicate difference between the cataloging rules. The main features on the edition are as the follows. (1) In the bibliography description the concept of the edition is a general application. That is to say, the edition construct the new edition and the impression. The former comes the purview of a change content, the size, and a printing type. The latter publish newly- (2) The requisite for description of the edition area consists of a edition statement, statements of responsibility relating to the edition, additional edition statement, and statements of responsibility following an additional edition statement. Voluntary rules transcribe the parallel edition statement. (3) In the case of the electronic materials special versions on content and Auction indicates as the edition, but the environment of software does not indicate as it. (4) Parallel statement of responsibility relating to the edition, parallel additional edition statements, and parallel statements of responsibility following an additional edition statement are voluntary rules or not transcribed in the edition area.

Reaction Pattern Influenced by Relative Values in the Evaluation of Preference for Image (이미지에 대한 선호도 평가에 있어 상대가치 작용 반응 패턴)

  • Heo, Seong-Cheol
    • Science of Emotion and Sensibility
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    • v.17 no.4
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    • pp.41-50
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    • 2014
  • This study examined the characteristics of brain's reaction pattern concerning the preference for product images and compared them with the result of subjects' intuitive evaluation of their preference for the same materials. Two tests were conducted; the first one that calculated comfort properties based on brainwave measurements in order to examine the impression given by the images of products presented separately, one-by-one, and the second one that had subjects evaluate the preference directly by comparing the images of all products simultaneously. The first test was titled 'Independent Cognitive Response' and the second test, 'Relative Cognitive Response', and their characteristics were as follows. In the 'Independent Cognitive Response', the state of emotion was expressed in absolute values based on the comparison with the information accumulated through the subject's own experience and the feeling expressed as 'pleasant' or 'unpleasant' persisted as absolute values. In the 'Relative Cognitive Response', the state of emotion relative to the information of other images compared in the stage of perceiving the images was expressed, and in this case, the state of emotion described as 'calm' or 'excited' acted as relative values.

Identifying Medical Waste Management Status by Different Types of Dental Institutions (치과의료기관별 의료폐기물 관리 현황 파악)

  • Seong, Mi-Ae;Park, Ji-Hye;Sakong, Joon
    • Journal of Environmental Health Sciences
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    • v.44 no.5
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    • pp.452-459
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    • 2018
  • Objectives: We aimed to examine whether dental waste was being managed adequately at different types of dental institutions in City D in South Korea. Methods: The staff responsible for disinfection at 101 dental offices and clinics (six dentistry departments of general hospitals, 12 dental hospitals, and 83 dental clinics) was interviewed. Results: Solid suction pump waste was handled appropriately at four of the general hospital dentistry departments (66.7%), six dental hospitals (50.0%), and 15 dental clinics (18.1%). Solid spittoon waste was handled appropriately at four general hospital dentistry departments (66.7%), seven dental hospitals (58.3%), and 14 dental clinics (16.9%). Developer and fixer were handled appropriately by a subcontractor at two general hospital dentistry departments (100.0%), five dental hospitals (100.0%), and 24 dental clinics (75.0%). Impression materials were handled appropriately at four general hospital dentistry departments (66.7%), six dental hospitals (50.0%), and 11 dental clinics (13.3%). The plastic covers of intra-oral radiography films were handled appropriately at five general hospital dentistry departments (100.0%), eight dental hospitals (72.7%), and 22 dental clinics (30.1%). Conclusion: South Korea must implement detailed and specialized guidelines for the disposal of solid and general medical waste from dental institutions. Moreover, waste disposal training should be provided annually, and not only once every three years.

Color Culture of Japanese Medieval Age: Focusing on Kamakura & Muromachi Periods (일본 중세의 색채 문화: 가마쿠라·무로마치 시대를 중심으로)

  • Lee, Kyunghee;Kim, Gumhwa
    • Journal of Fashion Business
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    • v.19 no.1
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    • pp.95-105
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    • 2015
  • This study investigated the color culture in the Japanese Medieval Age. The Japanese Medieval Age included the Kamakura period (1180-1333) and Muromachi period (1336-1573), and the leading group transitioned from the Kuge families to the Buke families. The taboos about colors from ancient times became nominal, and forbidden colors, such as purple, celadon, and red, became the colors of the samurai, leading to beautiful soldier gears that were unparalleled in history. In the Kamakura period, colors that conveyed a strong impression were created and preferred with the combination of a samurai's reasonable spirit and zen thoughts. The period was also called "the era of hari", and cross dyeing based on basic colors such as suou (red), ai (blue), and kuchinasi (yellow) was popular. In both the Kamakura and Muromachi periods, conspicuous and strong colors were sought for costumes, and embroidery was used with gold leaf, silver leaf, gold threads, silver threads, and background color. The colors of costume preferred by Buke men in the period included green, blue, and brown. In the characteristics of the kosode, the sugan and hitadare were used for men's formal dress, while kosode was used for the grooming of the working class. In these periods, additionally, the working class began to be socially engaged in actively wearing the one-layer kosode, which became popular, and the characteristics of the Japanese Medieval Age, during which functionality and practicality was valued, were also reflected in the dressing.

Computational design of mould sprue for injection moulding thermoplastics

  • Lakkannan, Muralidhar;Mohan Kumar, G.C.;Kadoli, Ravikiran
    • Journal of Computational Design and Engineering
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    • v.3 no.1
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    • pp.37-52
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    • 2016
  • To injection mould polymers, designing mould is a key task involving several critical decisions with direct implications to yield quality, productivity and frugality. One prominent decision among them is specifying sprue-bush conduit expansion as it significantly influences overall injection moulding; abstruseness anguish in its design criteria deceives direct determination. Intuitively designers decide it wisely and then exasperate by optimising or manipulating processing parameters. To overwhelm that anomaly this research aims at proposing an ideal design criteria holistically for all polymeric materials also tend as a functional assessment metric towards perfection i.e., criteria to specify sprue conduit size before mould development. Accordingly, a priori analytical criterion was deduced quantitatively as expansion ratio from ubiquitous empirical relationships specifically a.k.a an exclusive expansion angle imperatively configured for injectant properties. Its computational intelligence advantage was leveraged to augment functionality of perfectly injecting into an impression gap, while synchronising both injector capacity and desired moulding features. For comprehensiveness, it was continuously sensitised over infinite scale as an explicit factor dependent on in-situ spatio-temporal injectant state perplexity with discrete slope and altitude for each polymeric character. In which congregant ranges of apparent viscosity and shear thinning index were conceived to characteristically assort most thermoplastics. Thereon results accorded aggressive conduit expansion widening for viscous incrust, while a very aggressive narrowing for shear thinning encrust; among them apparent viscosity had relative dominance. This important rationale would certainly form a priori design basis as well diagnose filling issues causing several defects. Like this the proposed generic design criteria, being simple would immensely benefit mould designers besides serve as an inexpensive preventive cliché to moulders. Its adaption ease to practice manifests a hope of injection moulding extremely alluring polymers. Therefore, we concluded that appreciating injectant's polymeric character to design exclusive sprue bush offers a definite a priori advantage.

Prospective randomized clinical trial of hydrophilic tapered implant placement at maxillary posterior area: 6 weeks and 12 weeks loading

  • Kim, Seong-Beom;Yun, Pil-Young;Kim, Sang-Yun;Yi, Yang-Jin;Kim, Ji-Yun;Kim, Young-Kyun
    • The Journal of Advanced Prosthodontics
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    • v.8 no.5
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    • pp.396-403
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    • 2016
  • PURPOSE. Early loading of implant can be determined by excellent primary stability and characteristic of implant surface. The implant system with recently improved surface can have load application 4-6 weeks after installing in maxilla and mandible. This study evaluated the effect of healing period to the stability of hydrophilic tapered-type implant at maxillary posterior area. MATERIALS AND METHODS. This study included 30 patients treated by hydrophilic tapered-type implants (total 41 implants at maxilla) and classified by two groups depending on healing period. Group 1 (11 patients, 15 implants) was a control group and the healing period was 12 weeks, and Group 2 (19 patients, 26 implants) was test group and the healing period was 6 weeks. Immediately after implant placement, at the first impression taking, implant stability was measured using Osstell Mentor. The patients also took periapical radiographs after restoration delivery, 12 months after restoration and final followup period. The marginal bone loss around the implants was measured using the periapical radiographs. RESULTS. All implants were survived and success rate was 97.56%. The marginal bone loss was less than 1mm after 1 year postoperatively except the one implant. The stabilities of the implants were not correlated with age, healing period until loading, insertion torque (IT), the diameter of fixture and the location of implant. Only the quality of bone in group 2 (6 week) was correlated with the stability of implant. CONCLUSION. Healing period of 6 weeks can make the similar clinical prognosis of implants to that of healing period of 12 weeks if bone quality is carefully considered in case of early loading.