• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.4
• /
• pp.282-289
• /
• 2020

Purpose: The aim of this in vitro study was to evaluate the accuracy of three different intraoral scanners (IOSs) on digital impressions of different types of endocrown cavity preparations. Materials and methods: Two human mandibular molar teeth were prepared with different endocrown abutment designs: one with a buccal wall (Class 2) and the other without a buccal wall (Class 3). Both cavity designs were scanned using a reference desktop scanner (E3) and three different intraoral scanners: Trios3 (TRI group), Cerec Omnicam (CER group), and i500 (I5 group). The obtained Standard Tessellation Language (.stl) datasets were exported to metrology software. The precision was evaluated based on deviations among repeated scan models recorded by each IOS. The trueness was evaluated based on deviations between the reference data and repeated scans. For detecting interaction, data were statistically analyzed using a univariate analysis of variance (ANOVA) and for analyzing the comparison of the test groups data were analyzed by one-way ANOVA and post-hoc Tukey test at the significance level of .05. Results: The deviation values for both cavity designs in the I5 group were significantly lower than those in the other IOS groups in terms of trueness. For both cavity designs, the TRI group exhibited better precision than the other IOS groups. Conclusion: Different technologies of IOS device's and different endocrown prepration designs affected the accuracy of the digital scans.

• Korean journal of communication and information
• /
• v.26
• /
• pp.83-104
• /
• 2004

Most studies of Korean Newspaper in historical view have focused on the news writing form and editorial practice. Those studies have much rely on the memories of ex-journalist or the impression of scholars. So this study aims to give the concrete figures of news writing forms and editing practices in 1920-30's by investigating Kim Dong-Seong's activities as a journalist. He was a first journalist who studies journalism. He studied journalism during his stay in the Ohio State University as an english department student. After he came back to Seoul, he worked at the Dong-A Il Bo as an one of the first publish members. His activities as a journalist have much important meanings because of his varied works and careers. He also wrote a practical affair book for reporters which was the first book in Korea. As a result of research about Kim Dong-Seong's activities in 1920-30's, the feature of edit practice in 1920's had much emphasis not only on the headline but on the relation between type and print, and at the same time the combination of news or the change of typography was one of methods which make the editing more variety. News materials were collected varied news sources and legworks by reporter. These results show us that such a news reporting practice in 1920-30's is similar co the contemporary.

• The Journal of Korean Academy of Prosthodontics
• /
• v.53 no.2
• /
• pp.111-119
• /
• 2015

Purpose: The objective of this study was to evaluate the accuracy of a stereolithographic surgical guide that was made with information from intraoral digital impressions and cone beam CT (CBCT). Materials and methods: Six sets of resin maxilla and mandible models with missing teeth were used in this study. Intraoral digital impressions were made. The virtual models provided by these intraoral digital impressions and by the CBCT scan images of the resin models were used to create a surgical guide. Implant surgery was performed on the resin models using the surgical guide. After implant placement, the models were subjected to another CBCT scan to compare the planned and actual implant positions. Deviations in position, depth and axis between the planned and actual positions were measured for each implant. Results: The mean deviation of the insertion point and angulation were 0.28 mm and $0.26^{\circ}$, apex point were 0.11 mm and 0.14 mm respectively. The implants were situated at a mean of 0.44 mm coronal to the planned vertical position. Conclusion: This study demonstrates that stereolithographic surgical guides created without the use of impressions and stone models show promising accuracy in implant placement.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.7 no.3
• /
• pp.181-188
• /
• 2005

This study attempted to investigate the plastic characteristics of cyber punk fashion with a focus on fashion in the cyber punk movies in order to inquire into how the influence of the cyber punk taking the lead in the spiritual culture and way of life of the humankind in the 21th century would be expressed in fashion. For this purpose, it sought to analyze the beauty of new fashion creating the cyber environment and identify its contemporary meaning. An attempt was made to investigate the image of cyber punk fashion with a focus on fashion expressed in the cyber punk movies. As a result, the following findings were obtained: First, the image of cyber punk fashion expressed in the cyber punk movies was simplicity, which was to express the modest silhouette and details exclusive of decoration. In addition to clean and smooth gloss, it contained the modest image of resistance', not 'revolt' by borrowing the partial motive and image from existing punk fashion. The change of cyber punk fashion into the characteristic of concise, smooth external appearance brought about the restraint of its image and symbolism as well as its plastic characteristic. Second, it was characterized by the Eroticism nature of emphasizing the body line while expressing the future and modest image or exposing the body. Cyber punk fashion expressed the avant-garde image by using materials that gave a mysterious and future feelings, as well as unsymmetrical silhouette, the slit of body-conscious line, coarse cutting, the method of do-constructing and reconstructing the silhouette, the method of applying diverse underwears such as corset, brassiere and the like. Third, cyber punk fashion was marked by the nature of mined sex. It had the masculine image by using the black color containing the image of masculinity and resistance in female clothing and expressing the suit, coat and military looks giving an masculine impression. And it expressed the image of mixed sexes with the masculine image in male clothing by borrowing feminine images such as body-conscious line, widely cut neckline, floral decoration, leggings and the like. Fourth, cyber punk fashion was marked by naturalness. It was expressed as clothing made from silhouette, knit, cotton and the like in the atmosphere expressing love, comfortableness and truth. This contained the image of naturalness, a return to the primitive, that human being wanted to return to their original figure in the future element. The cyber punk movie may contain a dismal, gloomy future image on the whole, which can be overcome, and shows the possibility that it may grow into the alternative culture, not the revolting culture. The movie of 'The Fifth Element' demonstrates the meaning and role that shows the bright future image. It is thought that designers should make efforts for cyber punk fashion to perform its role in changing the gloomy future image into the bright image of society

• Archives of design research
• /
• v.14 no.3
• /
• pp.177-186
• /
• 2001

Modern times is called the age of image. It means that our society's importance is transferring from the commodity-centered industrial society to intangible culture-oriented society Therefore, it is becoming very important that what kind of image, concept and psychological factor act upon the space, things, incident and time (event) which is constituted around our environment. As regards this standpoint, from the early period, that advanced countries have been taking advantage of the national symbol image very positive way and function for domestic things and place and event and so on which make a standout for the nation's positive image and taken an effort for promoting a pride of their fellow countrymen through this. This study approaches the basic images of national symbol which includes the country's name, national anthem, national flag through the design principle which could express some certain above level of pattern and composition. I suggested various applicative motif based on basic expressions of each individual image and the applied sample goods of this idea, and through the introduction of the process of image development, and I tried to offer a moment of more prosperity and development at a later time. This is for encouraging fellow citizens to use national symbol in the free and positive way which make them to increase a national pride, and give a familiar image in the citizens'daily life. I intended to offer basic materials for promoting ourselves whenever we need it. And also by the offering information on our nation for foreigners which make them to have a favorable impression of our nation. I tried to promote a positive national image.

• Journal of Periodontal and Implant Science
• /
• v.27 no.1
• /
• pp.61-78
• /
• 1997

PDGF-BB has been recognized as a highly potential growth factor for guided tissue regeneration in periodontal defect. This study carried out histologic and histometric evaluation of $200ng/cm^2$ PDGF-BB loaded bioresorbable membrane made from polyglycolic and polylactic acid. It was tested for its biocompatibility, ability to prevent epithelial downgrowth and amount of periodontal regeneration. Without membrane and PDGF-BB unloaded bioresorbable membrane were used as control. Healthy six beagle dogs were used. Each dog was anesthetized and buccal flaps were reflected in the mandibular and maxillary premolar areas. Buccal alveolar bone between the mesiobuccal and distobuccal line angles was surgically removed on the lower 2nd and 4th premolar in mandible, 2nd premolar in maxilla, to a level 4mm apical to the cementoenamel junction with creating a Class II buccal furcation defect for available space. Care was taken not to remove the root cementum layer and rubber impression materials were placed over each surgically created defect. Flaps were repositioned and sutured. Reconstructive surgery was performed 1 month after defect preparation. PDGF-BB loaded membranes and controls were randomly placed on maxillary 2nd premolars and mandibular 2nd and 4th premolars. Plaque control regimen was instituted with daily brushing with a 0.1% chlorhexidine digluconate during experimental periods. The animals were sacrificed 2 and 5 weeks after surgery and undecalcified specimens were prepared for histologic evaluation. The degree of coronal regrowth of new bone, new cementum and the amonut of new bone areas formed on the defected area of the PDGF-BB loaded membrnae turned superior to without membrane and drug unloaded membrane. Experimental membrane could prevent the epithelial downgrowth irrespective of drug loaded or not and showed good biocompatiblity, These results implicated that PDGF-BB loaded bioresorbable membrane could be highly useful tool for guided tissue regeneration of periodontal defects.

• Journal of dental hygiene science
• /
• v.15 no.2
• /
• pp.226-231
• /
• 2015

The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.3
• /
• pp.185-192
• /
• 2020

Purpose: The purpose of this study is to investigate dental students' self-perception of clinical care ability after a denture treatment experience. Materials and methods: Of the 58 fourth-year students at the dental school in 2019, 50 students completed the questionnaire concerning their denture treatment session, including treatment planning and pre-prosthetic treatment (4 questions), clinical and laboratory procedures (20 questions), and students' opinions on clinical denture education (4 questions). Each question was answered on a five-point scale, of which points four and five, "agree" and "strongly agree" respectively, were classified as positive responses while points one and two, "disagree" and "strongly disagree" respectively, were classified as negative. Results: All the items on clinical and laboratory procedures received a positive response rate of over 60%, and the overall self-perception of the students appeared to be positive. However, the questions on the ability to perform denture treatment independently after graduation received only 48% of positive answer. Those on patient management, explanations of denture precautions, customized tray production, boxing, and work model production were answered with the highest positive response rate whereas those on treatment planning, final impression acquisition, and surveying, were the lowest in each session. Conclusion: The dental students with experience in denture treatment generally have a positive opinion of their clinical care ability, but further education may be necessary to improve their ability to treat their patients independently.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.3
• /
• pp.228-238
• /
• 2020

In order to deliver fixed partial denture to a patient successfully, dentist must take into many considerations beforehand. Patient's occlusal pattern should be fully understood before delivering any type of prosthesis, whether it's canine guidance or group function occlusion. In order to do so, movement of mandible should be recorded precisely. Introduced by Meyers in 1933, functionally generated path technique (FGP) has been successfully used to record mandibular movement with various materials, such as wax, and utilize it in fabricating precise prosthesis. In the following cases, patients showed secondary caries or endodontic-periodontic lesion on maxillary molars. Root canal treatment and subgingival curettage were done for each patient. Since the long term prognosis of each tooth was questionable, lateral force should be minimized. In order to do so, FGP technique was used to record mandibular movements precisely. Instead of using conventional plaster impression, intra-oral scanning of wax tracing was done to fabricate prosthesis efficiently. After delivery of fixed partial denture, favorable outcome was obtained.

• Journal of the Korean Society of Earth Science Education
• /
• v.11 no.3
• /
• pp.182-192
• /
• 2018

The purpose of this study was to examine the effects of school forest activities program on elementary students' science process skill and attitude toward science to make suggestions to help develop and extend the program. The subjects of the study were 49 students of two classes. One class of 24 students, experimental class, took developed 10 periods of school forest activities program. While the other class of 25 students, comparative class, took ordinary teacher driven periods using photo materials and study papers. Before and after the program, pre and post test were done. The results of this study can be summarized as follows: First, the school forest activities program didn't have a meaningful effect on students' science process skill. Second, the school forest activities program had a meaningful effect on the improvement of students' attitude toward science. From the interview with experimental class, we could know that students had a favorable impression and high satisfaction level about the activities program.