• Journal of Technologic Dentistry
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• v.23 no.2
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• pp.179-188
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• 2002

With regard to the manufacture of dental prosthesis, all the dental mechanism is of vital significance at the aspect of activating its function by fixing the prosthesis to Patient's oral cavity. However, if there we will take our immediate action without the discretion about its process none the less for the importance of dental mechanism, then we might have a serious problem. Accordingly, there need to pay attention to the dilatability makes up for the shrinkage state occurring by the feature of metal materials and manufacturing process which appeared in the process of dental mechanism, which eventually is expected to playa very important role in casting a dental prosthesis appropriate to one's oral tissue. This study was designed to take into account of the effects on margin consistency of prosthesis according to the continued time of casting-ring in the course of the casting of dental alloy. For this, the researcher made an experiment on the casting of dental alloy, its dilatability, and the change of phase. The results of this study were as follows: First, the researcher could see that the sample which was cast under the condition of $650^{\circ}C/20$ Minutes(the continued time) was far superior to others at the aspect of margin consistency. Second, according to the measurement of expansion coefficient by Dilatometer, the researcher perceived the fact that the expansion-coefficient showed a maximum of $37.1{\mu}m$ considering the sample's length which was cast with ordinary temperature under the condition of $650^{\circ}C/20$ Minutes. Third, from the result of X-ray diffraction under the condition of $650^{\circ}C/20$ Minutes(the continued time), the researcher could find that there's no difference between the change of phase and its intensity. As mentioned above, the researcher could ascertain the fact that its contraction don't give rise to the change of phase.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.10 no.2
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• pp.68-77
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• 2014

An opportunity for dental students to come into contact with individuals with disabilities is insufficient. Therefore, prejudice and negative attitudes towards persons with disabilities persist. Working under the assumption that educating dental students regarding people with disabilities will bring about positive awareness, we conducted this study. We investigated the changes in the recognition of the issues and needs of people with disabilities before and after special care dentistry class of students of dental college that will include an experience in a dental clinic with a disabled person. Seventy-two Kyung Hee University School of Dentistry third-year dental students attended the special care dentistry class in one semester and they took the same survey was before and after the class. In the questionnaire, we used the disability factor scale (DFS) that Siller has proposed. The authoritarian virtuousness factor getting lower to a significant level after receiving an education. This means that after the education, the respondents realize that how hard to adapt the disabilities. After receiving an education, the rejection of intimacy factor score significantly get higher than before they took the class. This means that after the training, positive attitudes towards those with disabilities were better than those towards the opposite sex. We were able to confirm a positive change in the recognition for persons with disabilities through the special care dentistry class. Our study shows that educating dental students on the how to take care of individuals with disabilities can bring about a positive change in the attitudes students may have regarding them.

• The Journal of Advanced Prosthodontics
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• v.11 no.4
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• pp.215-222
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• 2019

PURPOSE. To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution. MATERIALS AND METHODS. 88 ceramic discs ($1.0mm{\times}10.0mm$) were manufactured - 44 nano-fluorapatite layering ceramics (IPS e.max Ceram. Group C) and 44 pressed lithium disilicate ceramic discs (IPS e. max Press - Group P). Each group was divided into 4 subgroups according to surface treatments: (G) Glaze, (S) Shofu polishing system (Shofu Inc.), (E) Edenta AG polishing System, (KG) $30-{\mu}m$ diamond granulation tip. Surface roughness (Ra) and color change (${\Delta}E$) measurings after the surface treatments were performed, before and 12 days after the immersion in coffee solution. A samples' qualitative analysis was conducted with a scanning electron microscopy (SEM). Data were statistically-treated with one-way-ANOVA and Duncan's tests, apart from paired t-test and Pearson's correlation test (${\alpha}=5%$). RESULTS. The decrescent order, both for surface roughness (Ra) and ${\Delta}E$ for both ceramics were: KG > E > S > G (P<.05). With exception for PG and CG subgroups, which did not present statistical difference between them, all other pressed ceramics subgroups presented smaller Ra values and greater ${\Delta}E$ values than the layering ceramics subgroups (P<.05). CONCLUSION. Although mechanical polishing systems presented intermediate Ra values, their colors were considered clinically acceptable. There is a strong correlation between the surface roughness and the color change of tested ceramics.

• The Journal of the Korean dental association
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• v.21 no.12 s.175
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• pp.997-1003
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• 1983

The author studied the quality and change of the effective demand for dental treatment of the cutpatients of the Wonkwang dental clinic from the March of 1982 to the August of 1983. The results were compared with the previous reports to find any changes that might come from the effect of dental insurance system. After discussing the results, the author concluded as follows: 1. The twenties were the most in the age groups, but it is desirable that age groups of mixed dentition be the most to enhance the dental health status of community. 2. The effective demand for dental treatment increased especially in the areas such as intraoral radiograph taking, amalgam filling, temporary filling, endodontic treatments, and drug application on the soft tissue, but decreased in the areas such as prosthodontic treatments, and there were no demand for the orthodontic treatment. 3. As compared with the absolute needs, the effective demand was relatively high for teeth extraction and amalgam filling, but it was generally very low. 4. So, the present extent of dental insurance system should be expanded, and the dental care delivery system should be established within the community. Finally, the economic and social status of Iri community should be enhance by political and educational plannings.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.395-403
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• 2007

The purpose of this study is to investigate the main factors that affect turnover of Dental Hygienists so that it leads to preventing high turnover and long-term service in their position. Data were obtained from 112 dental hygienists who are currently working for dental clinics from September 17th 2007 to October 16th 2007 via questionnaires. For this study, the demographic factors and unique characteristics of Dental Hygienists are considered as well as all the variables of statistic. The results derived from using SPSS 11.0 are as follows: 1. The average of job related factors is 2.55 point, the average of job satisfaction is 2.59 point, the average of salary related factor is 2.24 point and the average of changing their occupation is 2.85 point. 2. The difference between the factors related to age and changing their occupation shows the highest level on job related factors.(pM0.033) in the age between 26 and 30. 3. Dental Hygienists who are in their occupation for 6years to 9 years answer that salary would be the main reason to change their jobs. 4. For married dental hygienists, salary related factor is the main reason to make them change their occupation.(pM0.002)

• The Journal of the Korean dental association
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• v.49 no.10
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• pp.584-598
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• 2011

The age structure has been experiencing substantial change due to the decreased birth rate as well as the increased life expectancy. Gorge Magnus, an English economist, casts warnings of population ageing which has the potential of huge socioeconomic impact human society has never experienced before. The prediction that proportion of elderly people in need of oral health care will increase substantially is a new challenge to dentists in the future. The old paradigm that the aged person is just the person who was born earlier and needs the same conventional oral health care should be shifted to the new one. Elderly people tend to express their political interest related with health care system by actively participating in the national elections. The need to sustain economic status for the extended life span makes them seek eagerly esthetic health care to maintain sound social function. Most of them are under multiple chronic diseases and take related medicines. In addition, many studies report about mental change as well as physical change among the aged people. Since the prevalence of dental diseases among the aged is higher than other chronic devastating diseases, the aged seeking oral health care will increase. The aged who has different physical and psychological status as well as chronic disease and related medicine will show unexpected response to the conventional oral health care. In addition, the impact of tooth loss is substantial physically, mentally and emotionally. Dentist should prepare different approaches for the elderly dental patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.165-173
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• 2016

Purpose: This study was conducted to examine the color stability of temporary prosthetic materials for dental CAD-CAM. Method: 2 kinds of existing acrylic resin temporary filling materials and 2 kinds of polymer prosthetic materials for dental CAD-CAM were used for testing, and five specimens respectively were absorbed in soy sauce, red pepper paste, and coffee. A Chroma Meter was used as analysis equipment. The color change of the specimens was observed to calculate ${\Delta}E$ value throughout 2 days, 3 days, 4 days, and 5 days and this was analyzed and the following result was obtained. Results: Snap's ${\Delta}E$ value was bigger than Vipi block(p<0.05). Red pepper paste had the largest impact on the color change of resin(${\Delta}E$), followed by soy sauce and coffee(p<0.000). With the passage of time, ${\Delta}E$ value was inversely(-) related and decreased somewhat(p<0.000).

• Journal of Korean Dental Science
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• v.6 no.1
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• pp.4-12
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• 2013

Purpose: This study sought to verify the usefulness of mini-implant and surgical steel wire in the treatment of mandibular fracture through the objective identifi cation of the change of bone structure and bone density before and after reduction by evaluating radiological change through fractal analysis when mandibular fracture is treated using mini-implant and surgical wire. Materials and Methods: This study looked at 45 patients (males: 38, female: 7) diagnosed with mandibular fracture in the oral and maxillofacial surgery division of Chung-Ang University Dental Hospital and who received open reduction and intra-osseous fi xation. Result: The average fracture dimension values were higher for the group of the patients who had mini-implants and surgical wire treatment. Conclusion: Based on the results of the study on the usefulness of the reduction technique using mini-implant and surgical steel wire in the treatment of mandibular fracture through the fractal analysis method, the reduction technique using mini-implant and surgical steel wire is regarded as an effective method of minimizing the gap between mandibular fracture fragments.

• Journal of Korean Dental Hygiene Science
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• v.2 no.1
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• pp.31-39
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• 2019

This study focused on the change of environment and cognition of dental hygienists about dental calculus removal after the national health insurance. We conducted online and offline surveys for 290 dental hygienists working in dental clinics in Seoul, Gyeonggi and Incheon areas. Differences in perceptions were assessed by independent t-test and ANOVA. 62.1% answered that the health insurance coverage of dental calculus removal was appropriate, and 49.6% said that the desired number of health insurance coverage about the dental calculus removal should be applied twice a year. 54.3% said that the age after 20 years-old was not appropriate in national health insurance coverage of dental calculus removal, and 49.3% said that the appropriate starting age of dental calculus removal should be applied from high school students. 26.3% said that the number of national health insurance applications should be increased yearly, 20.5% said that oral care education should be added. Most of the dental hygienists said that the number of scaling patients increased, but that the quality of the scaling did not deteriorate. According to general characteristics, in the recognition of the removal of calculus, the dental hygienists having a career for 7~8 years felt less change. The dental hygienist wanted to expand the scope of national health insurance about scaling removal so that more subjects could remove dental calculus removal. Dental hygienists wanted that national health insurance should be systematically supplemented in order to contribute to the promotion of oral health of the people.