• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.403-414
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• 2018

The purpose of this study was to investigate the knowledge and satisfaction of tooth bleaching. From June 1st, 2017, 328 patients who visited a dental clinic in Ulsan Metropolitan City for two weeks were asked to do a self - filling questionnaire. As a result of the study, the tooth bleaching satisfaction according to tooth bleaching knowledge was not statistically significant (p<0.05), and the highest(8-10) degree of satisfaction was 3.86 when the knowledge of tooth bleaching was high, and the lowest(0-3) was 3.00. The tooth bleaching satisfaction according to general characteristics was significantly different in age and gender. The score of women were 3.74 and higher than men's 3.11 The tooth bleaching experience and tooth bleaching satisfaction were statistically significant (p <0.05) and professional tooth bleaching (4.41) was higher than OCT bleaching (2.64). Also, when the tooth bleaching was done by the invitation of the hospital, it was higher than the case of experiencing tooth bleaching through media advertising. Therefore, the satisfaction of tooth bleaching is required not only for general characteristics but also for tooth tooth bleaching, and it is influenced by tooth bleaching method and tooth bleaching motivation. These factors may be useful to establish a treatment plan to improve the satisfaction of tooth bleaching.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.194-203
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• 2013

Objectives: To investigate the effect of enamel matrix derivative (EMD) on periodontal healing of replanted teeth in animal models. Materials and Methods: The authors searched MEDLINE, PubMed, EMBASE, Cochrane Library, Web of Knowledge and Scopus for articles published up to Oct 2012. Animal studies in which EMD was applied in transplanted or replanted teeth with adequate controls and histological data were considered. Normal periodontal healing or root resorption determined by histology after EMD was applied in replanted teeth with adequate controls was used as outcome measures. The following search strategy was used: ('Emdogain' OR 'enamel matrix proteins' OR 'enamel matrix derivative') AND ('avulsion' OR 'transplantion' OR 'autotransplantation' OR 'replantation'). Results: Six animal studies were included in the final review. There was great heterogeneity in study design among included studies. Two studies with similar study designs were identified and analyzed by a meta-analysis. The pooled estimates showed a significantly higher normal healing and surface resorption and significantly less inflammatory and replacement resorption in EMD-treated groups compared with non-EMD-treated groups. Conclusions: With the limitations of this systematic review, the use of EMD led to greater normal periodontal healing and surface root resorption and less inflammatory and replacement root resorption in the presence of periodontal ligaments. However, no definite conclusion could be drawn with regard to the effect of EMD on periodontal healing and root resorption when no periodontal ligaments exist.

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.65-76
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• 2022

Purpose: The present study measured changes in arteriolar and venular capillary flow and structure in the gingival tissues during the development of plaque-induced gingival inflammation by combining dynamic optical coherence tomography (OCT), laser perfusion, and capillaroscopic video imaging. Methods: Gingival inflammation was induced in 21 healthy volunteers over a 3-week period. Gingival blood flow and capillary morphology were measured by dynamic OCT, laser perfusion imaging, and capillaroscopy, including a baseline assessment of capillary glycocalyx thickness. Venular capillary flow was estimated by analysis of the perfusion images and mean blood velocity/acceleration in the capillaroscopic images. Readings were recorded at baseline and weekly over the 3 weeks of plaque accumulation and 2 weeks after brushing was resumed. Results: Perfusion imaging demonstrated a significant reduction of gingival blood flow after 1 and 2 weeks of plaque accumulation (P<0.05), but by 3 weeks of plaque accumulation there was a more mixed picture, with reduced flow in some participants and increased flow in others. Participants with reduced flux at 3 weeks also demonstrated venular-type flow as determined by perfusion images and evidence of the development of venular capillaries as assessed by the velocity/acceleration ratio in capillaroscopic images. After brushing resumed, these venular capillaries were broken down and replaced by arteriolar capillaries. Conclusions: After 3 weeks of plaque accumulation, there was wide variation in microvascular reactions between the participants. Reduced capillary flow was associated with the development of venular capillaries in some individuals. This is noteworthy, as an early increase in venous capillaries is a key vascular feature of cardiovascular disease, psoriasis, Sjögren syndrome, and rheumatoid arthritis-diseases with a significant association with the development of severe gingival inflammation, which leads to periodontitis. Future investigations of microvascular changes in gingival inflammation might benefit from accurate capillary flow velocity measurements to assess the development of venular capillaries.

• Restorative Dentistry and Endodontics
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• v.47 no.1
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• pp.10.1-10.11
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• 2022

Objectives: This study aimed to investigate the color stability, solubility, and surface characteristics of 3 calcium silicate-based cements (CSCs) after immersion in different solutions. Materials and Methods: ProRoot white mineral trioxide aggregate (MTA), Biodentine, and Endosequence Root Repair Material (ERRM) were placed in cylindrical molds and stored at 37℃ for 24 hours. Each specimen was immersed in distilled water, 5% sodium hypochlorite (NaOCl), 2% chlorhexidine, or 0.1% octenidine hydrochloride (OCT) for 24 hours. Color changes were measured with a spectrophotometer. Solubility was determined using an analytical balance with 10^-5 g accuracy. The surface characteristics were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. Data were analyzed using 2-way analysis of variance, the Tukey test, and the paired t-test. Results: MTA exhibited significant discoloration in contact with NaOCl (p < 0.05). White precipitation occurred on the surfaces of Biodentine and ERRM after contact with the solutions, and none of the materials presented dark brown discoloration. All materials showed significant solubility after immersion in the solutions (p < 0.05), irrespective of the solution type (p > 0.05). The surface topography and elemental composition of the samples showed different patterns of crystal formation and precipitation depending on the solution type. Conclusions: All materials presented some amount of solubility and showed crystal precipitation after contact with the solutions. Biodentine and ERRM are suitable alternatives to ProRoot MTA as they do not exhibit discoloration. The use of OCT can be considered safe for CSCs.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.159-165
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• 2017

This study was accomplished to get to know the actual condition of denture management in understanding of denture management education relate to the post denture management of elderly, by meeting directly, among elderly people (more than 65 years old) wearing dentures, using structured guestionnaire from 15th Oct. to 15th Dec. 2016 in Daegu Metropolitan City. As a result, there was a significant difference in understanding of denture management education according to age, education level, cost of denture, general health condition, position of denture, period of wearing upper and bottom denture, frequencies of dental treatment and degree of halitosis(p<0.05). As a result, it is considered that continuing denture management education by studying characteristics of the elderly is needed and standardized denture management manual has to be made.

• Journal of Technologic Dentistry
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• v.13 no.1
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• pp.37-51
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• 1991

In order to evaluate health status of dental technicians as an individual and a group, this study was conducted with Todai Health Index Questionaire on randomly sampled 277 persons(236 males and 41 females) from Aug. 20 to Oct. 6, in 1990 obtained Following conclusions were drawn. 1. Age composition of the subjects was 136 males(57.6%) in the age of 20$\sim$29 and 28 females(68.3%) in the age of 20$\sim$24. As for working places, 215 males(91.1%) and 38 females (92.7%) were working for dental laboratories and rest of them were at clinics and hospitals. In working years, male technicians who have been working for 5$\sim$10 years amounted to 80 (33.8%) and 12 females(29.3%) were working for 1$\sim$3years. 2. Responses to psychosomatic subjective symptom complaints rated as the highest in multiple subjective symptom(males : 40.00%, females : 41.98%) and those in physical items and mental irritability(male : 24%, female : 25%) and in mental items came next in order. The rate of complaint in depression was higher in female group than in male group (p<0.05). 3. Resonses to psychosomatic subjective symptom complaints in male group were high in the age of 20$\sim$29 and in the age of 20$\sim$24 in female group. The rates of complaint were higher in multiple subjective symptom, respiratory, eye and skin(p<0.05) and digestives(p<0.01) complaints. 4. Responses to psychosomatic subjective symptom complaints were higher among persons working at dental laboratories than at other working places : dental clinics and hospitals in all the items except for respiratory, depression and aggressiveness. Rates of complaints in eye and skin showed significant difference between working places(p<0.05). 5. Those who are engaged in polishing part tended to complain more about psychosomatic subjective symptoms. 6. The higher the level of education is the more they complained the psychosomatic subjective symptoms both in male and female group. In the difference of complaint respones, male group showed high rates of complaint in depression and female group in aggressiveness(p<0.05). 7. Responses to psychosomatic complaints by the length of working service were moderate in males who were working less than 10 years, and they decreased after 10 years of service. Females showed the highest response rate in the group of 3$\sim$5 years service and the lowest response in the group of 5 years service. Male complained more in aggressiveness and female in respiratory and aggressiveness(p<0.05). 8. Responses to psychosomatic subjective symptom complaint varied according to working hours of a day both in male and female group, showing high complaint rates in multiple subjective symptom, respiratory, eye and skin, mouth and anus, digestive, mental irritability and irregular life in male group(p<0.05).

• Journal of dental hygiene science
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• v.9 no.4
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• pp.369-374
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• 2009

The purpose of this study was to survey Korean soldiers' oral healthcare practice and attitudes along with their stress level, and thereby to identify possible correlations among those factors. The survey was conducted from June 11 to Oct. 10, 2008 in G-gun, Chungbuk. province for soldiers. The questionnaire was consisted of the oral healthcare practice and attitude, stress level. As a result, it was found that our respondents scored 3.55 out of possible 9 point in their stress level, which indicated that they had relatively low stress on the whole. According to survey on their oral healthcare practice and attitude depending on their general characteristics, it was found that the higher academic career was associated directly with the more practices of oral healthcare, and nonsmoking group showed more practices of oral healthcare than smoking group. It was found that 'schoolwork and workplace' and 'sexual problem' were critical stress factors on our respondents' oral healthcare attitudes. And it was also found that 'outward appearance complex', 'personality complex', 'conflicts with parents' and 'sexual problem' were critical stress factors on their oral healthcare practices. Since our soldiers' maintenance of their oral healthcare is beneficial to both individual and national aspects, it is necessary for interested parties including dental surgeons to make efforts to develop a promotional program for military dental healthcare project and provide a series of reorientations for soldiers, so that they can have more positive oral healthcare practices and attitudes.

• Journal of dental hygiene science
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• v.3 no.1
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• pp.23-31
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• 2003

In this research, dental health awareness of 3rd graders of high schools in Icheon-city was investigated in order to use the result of this research as the basic data for school dental health program, education direction, and educational purpose. The research was done from Sep. 23. to Oct. 5 and the followings are the results of survey. (1) 85.0% of the students brush their teeth once or twice a day and more female students brush their teeth 3 times a day than male students. (2) 77% of the students had experienced dental caries and 38.0% of the students have periodontal disease, which has lower percentage than cavity. (3) Most of the students can not go to the dentists because they do not have time and 84.0% of the students have been treated in dental clinics so this tells that most of the students had experienced dental treatment. (4) 46.8% of the students had interests in dental health and male students showed more interests than female students and the difference was statistically significant(p<0.05). (5) Most of the students hear the importance and information of dental health from mass media such as TV and radio or from people around. The research shows that most of the students do not get periodic dental checkups. (6) 80.8% of the students had never taught dental health education for improvement of dental health and 76.2% of the students think that the dental health education is needed. There was no difference according to the gender. (7) Most of the students think that the dental health education is needed to prevent cavity and gingiva disease and it shows that more students tend to attend the dental health education. (8) 69.3% of the students think that brushing your teeth is important to maintain good dental health and there was no difference according to the gender. Most of the students weren't aware that periodic dental checkups, right brushing, and using fluoric toothpaste is effective for cavity protection. (9) After looking into the knowledge of the students on dental health, it shows that the knowledge is low and there is no difference according to the gender.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.37-54
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• 2009

The purpose of this thesis is to address the imbalance between supply and demand of dental lab technicians and to propose its solutions by analyzing the improvement of employment rate of graduates of dental technology schools in Daegu area and the supply and demand of the technician workforce. Preliminary and full-scale surveys were performed from Aug. 10 to Oct. 10 in 2008 on 150 junior students of dental technology schools who finished their on-the-job-training and 150 dental technicians who were working for dental laboratory in Daegu by self-assessment questionnaire. Followings are the findings of this study. First, regarding the gender of the dental technicians, 32.7% of respondents were female 67.3% were male. Concerning age, respondents younger than 29 years-old occupied the highest percentage(39.3%). With respect to the lab technology school they graduated, DaeguHealthCollege took the largest proportion of 87.3%. With regard to interpersonal relationship at the school, 58.0% of respondents felt their relationship 'smooth'. Second, about the motive of choosing to be a lab technician, the biggest proportion of the respondents(34.7%) replied that 'because it is professional'. Regarding the degree of satisfaction about the profession, 'so-so' was the answer with the biggest percentage(51.3%) followed by 'satisfied'(32.0%) and 'unsatisfied'(16.7%). It showed that respondents were generally satisfied with their major. Third, regarding relevance of on-the-job-training with 'preparation for the employment', highest percentage of both students and lab technicians(50.0%) replied 'so-so'. With respect to 'necessity of practical education', highest percentage of the students and lab technicians replied 'relating didactic education in college to the real world' with 52.7% and 40.7% respectively. With regard to 'the aim of on-the-sport-training', 'practical training of didactic education' was chosen by 54.0% and 47.3% respectively. Fourth, with regard to the 'types of college education advantageous for the employment', both students and lab technicians groups chose 'practical training' with the highest percentage. Concerning 'helpfulness of clinical training on employment', students answered 'so-so' and 'helpful' by 50.0% and 42.7% respectively and dental technicians replied similarly by 50.0% and 46.0% respectively. Fifth, with regard to the influence of financial factors on the supply and demand of dental technician(question #1), 68.0% of respondents agreed that 'salary plays key role in the supply and demand of the work force'. Concerning the question about working condition, respondents requested better working environment. With reference to interpersonal relationship at the laboratory, respondents replied that interpersonal relationship affects the duration of the employment it was found out that there were many conflicts with colleagues or dental office. Sixth, regarding the satisfaction about their profession according to the characteristics of the respondents more respondents were 'satisfied'(10.30 points) with their profession and 'unsatisfied' were 9.47 points and the difference was statistically significant(p<0.05). According to the findings of this study, practical education on campus and on-the-job-training are as important as didactic education at class due to the characteristics of dental technology major. It was found that more practical training is related to higher employment rate. Therefore, efficiency of on-the-job-training by college education should be increased raise employment rate of the graduates and reduce the unemployment. Up-to-date information needs to be promptly delivered and future vision should be presented to the students to raise their satisfaction about the profession. In addition, to reduce dental technician's frequent change of their workplace after facing with the reality of the profession after graduation, related organizations should make an effort to present better future than now.