• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.13 no.1
• /
• pp.97-105
• /
• 1983

For the assessment of changes in the bone architecture of the maxilla and mandible in renal osteodystrophy, 31 chronic renal failure patients who were undergoing hemodialysis therapy were selected. They were evaluated through clinical oral examination, radiographic and biochemical examination. The results were as follows: 1. In 17 cases (54.8%), there were evidences of bony change in jawbone. 2. The most common dental radiographic finding was decreased bone density (14 cases, 45.2%). 3. The second most common dental radiographic finding was total or partial loss of lamina alveolar dura (11 cases, 35.5%). 4. The third most common dental radiographic finding was total or partial loss of inferior canal wall (8 cases, 25.8%). 5 cases showed evidences of bony change only in jawbone, and 5 cases only in hand, and 12 cases in both. 6. Serum creatinine, urea nitrogen and alkaline phosphatase values in hemodialysis group were much higher than in control group. 7. There were statistically significant correlation between bone density and lamina dura, and inferior alveolar canal wall.

• Journal of Technologic Dentistry
• /
• v.31 no.4
• /
• pp.9-15
• /
• 2009

The purpose of this study was to observe the change of mechanical property and microstructure in porcelain fused to gold alloy by heat treatment. PFG alloys are composed with Au-Pd-Ag alloy of the additional elements with indium, tin and copper. Specimens were tested in hardness using vicker,s micro-hardness tester and the surface micro structural changes were analysed by SEM and EDS. The results were as fellows: 1. The vickers hardness showed highest in Au-Pd-Ag alloy of the additional element with tin. 2. By hardening-oxiding result, the vicker,s hardness increased in additional element with tin but there was no significant difference in additional elements with indium and copper. 3. The surface oxide layer of Au-Pd-Ag alloy with added indium and tin increased but there was small change in additional element with copper. 4. The elements of indium and tin increased with increasing heat treatment in the surface alloy.

• Korea-Australia Rheology Journal
• /
• v.20 no.4
• /
• pp.221-226
• /
• 2008

The purpose of this study was to compare rheological properties of six dental interocclusal recording materials and to investigate the effect of temperature on the rheological properties during setting. Five polyvinylsiloxane materials and one polyether material were investigated in this study. The storage modulus (G') and the loss factor ($tan{\delta}$) were measured from 30s after mixing during setting, using the universal dynamic spectrometer. Viscoelastic properties were evaluated by means of G' and $tan{\delta}$ from 5 repeats at $21^{\circ}C$ and $33^{\circ}C$. Individual changes during setting were also evaluated. All data were statistically analyzed using one-way ANOVA and multiple comparison $Scheff{\acute{e}}$ test at the significance level of 0.05. The mean of G was checked at $t_{set}$ (the setting time provided from manufacturer) and $t_{300}$ (the end of experimental time) and the mean of $tan{\delta}$ was checked at to and $t_{set}$. Whereas the increase of the G' value showed generally exponential changes at $21^{\circ}C$, the change of the G' value at $33^{\circ}C$ displayed sigmoidal curves during setting. The change of loss factor $tan{\delta}$ during setting varied. Within the limitations of this study, dental interocclusal recording materials had different viscoelastic properties and most of the materials showed different fluidity at $21^{\circ}C$ and $33^{\circ}C$.

• Restorative Dentistry and Endodontics
• /
• v.45 no.3
• /
• pp.29.1-29.9
• /
• 2020

This study describes the clinical steps taken in the treatment of a patient who had an avulsed right upper central incisor that presented with incomplete root development and chronic apical periodontitis. A 7-year-old boy was referred from a private dentist to a dental office specializing in endodontics. The tooth had remained in a dry environment for 20 minutes, and tooth replantation was performed at an emergency appointment. After clinical and radiographic examinations, root canal decontamination was performed, followed by several changes in intracanal calcium hydroxide medication. Blood clot formation was attempted, but bleeding within the root canal was insufficient; therefore, we opted for an intracanal medication change to stimulate mineralized tissue formation in the apical region. Root obturation was performed 45 days after the last change of intracanal medication, and clinical, radiographic, and tomographic follow-up examinations were performed at 3, 6, 18, and 40 months after the endodontic intervention. The increase in thickness and length of the root structure and the absence of root resorption were verified through follow-up examinations. Therefore, it was concluded that the procedures used were successful for tooth replantation.

• Journal of Korean Academy of Dental Administration
• /
• v.9 no.1
• /
• pp.7-13
• /
• 2021

The present randomized controlled trial aimed to evaluate changes in occlusion of indirect restorations before and after attachment using resin cement according to universal adhesives. This study included patients who underwent indirect restoration treatment at the Yonsei University Dental Hospital between April and October 2016. Universal adhesives requiring light curing and those not requiring light curing were used in this study. Changes in occlusion before and after adhesion of the indirect restoration were evaluated using articulating paper and shimstock as well as through the discomfort felt by the patients. To analyze the differences between the universal adhesive, Fisher's exact tests were performed using SPSS ver. 22.0 software. Of the 39 cases of indirect restoration, 29 were included in the study. A change in occlusion after adhesion of the indirect restoration was observed in only one case of universal adhesive that required light curing. The patient felt that the occlusion increased after the attachment of the restoration, and it was observed that the occlusion point was different from that before attachment. However, the results of the analysis were not statistically significant. Based on the findings, the universal adhesives did not affect the occlusion before and after indirect adhesion restoration using RelyX Ultimate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.49 no.4
• /
• pp.233-238
• /
• 2023

Schwannomas exhibit histopathological variation that leads to diagnostic dilemmas, although less frequent in the oral cavity. We describe a case with unique histopathology and no relevant clinical history that adds to the breadth of literature on the diversity presented by Schwannoma. A 60-year-old female patient presented with a small dome-shaped, asymptomatic swelling on the alveolar ridge 6 years in duration. Histopathologically, it showed rich cellular pathology with a unique arrangement of tumor cells forming irregular rosettes. Each rosette presented with a central core of fibrin-collagenous material and the tumor cells were arranged on the periphery, exhibiting epithelioid change with evidence of mild cellular and nuclear pleomorphism. On immunohistochemical evaluation, the cells were strongly and diffusely positive for S-100 and negative for Ki-67. A diagnosis of benign Schwannoma with a rosette-like arrangement with epithelioid change was made. The case report emphasizes the risk of misdiagnosis and the importance of awareness regarding rare histopathological variants of Schwannoma.

• Journal of Technologic Dentistry
• /
• v.33 no.4
• /
• pp.505-516
• /
• 2011

Purpose: The purpose of this study is to supply basic data to establish new image for dental technicians by reflecting onto the education of dental technicians by grasping the image of dental technicians with the subjects of students in department of dental technology. Methods: It was studied with self-filling-in method through structured questionnaire from September 26, to October 21, 2011, with 421 subjects of the students in the department of dental technology in two colleges in Daegu. SPSS 18.0 for Windows was used to analyze the data, and frequency and percentage were used for statistic analysis, and correlation analysis and Multiple Linear Regression Analysis were used with mean and SD per each question. Results: It showed the highest recognition that the dental technicians is a 'specialist' as 4.66; the dental technicians has strong responsibility in his work as 4.42; the dental technicians takes an important role in improvement of public oral health as 4.39; and the dental technicians has professional intelligence and high technique as 4.33. So, it was found that they had image of professional and important role for oral health, and had their pride and selfconfidence as future dental technicians. Meanwhile, it showed that they had negative related-image as well as a job, that the dental technicians is too busy as 4.48; it requires improvement on image in the future as 4.27; it is a hard job with too much stress as 4.13. Conclusion: It is required for us and school to have continuous change and effort to make the students in the department of dental technology have positive mind for the dental technology to make them have pride for their job.

• Journal of Korean society of Dental Hygiene
• /
• v.18 no.2
• /
• pp.177-189
• /
• 2018

Objectives: To provide necessary information for stable establishment of the national dental scaling reimbursement system. Methods: This study was conducted in 380 adults in their twenties or older for about one month from July 2017. The questionnaires were composed of general characteristics, recognition (awareness) of dental scaling, knowledge of the dental scaling reimbursement program, changes in perception before versus after introduction of the dental scaling reimbursement program, and interest in oral health. To investigate into any factors affecting changes of interest in oral health care after introduction of the dental scaling reimbursement program, a multiple regression analysis was performed. Results: The investigation into any factors affecting changes of interest in oral health care after introduction of the dental scaling reimbursement program showed that higher usual interest in oral health (p<0.001) and the consideration that the dental scaling charges have been affordable after introduction of the scaling reimbursement program (p<0.01) led to more changes in interest in oral health care. Conclusions: The above-mentioned results suggest that the dental scaling reimbursement program has brought favorable changes in the perception of dental scaling. It is expected that the said program will contribute significantly to the improved national oral health, and the Government should make constant efforts to develop it as a long-term policy for oral health improvement.

• Journal of Korean society of Dental Hygiene
• /
• v.9 no.2
• /
• pp.165-178
• /
• 2009

The purpose of this study was to provide basic information for improving oral health and dental hygiene through comprehensive dental hygiene care. The subjects in this study were 54 patients who had been treated for 4 weeks in clinic of the Dental Hygiene Department of G University under comprehensive dental hygiene control and care and measured their oral condition, intensity of oral malodor, Simplified Oral Hygiene Index (S-OHI), and Modified Personal Hygiene Performance Index (PHP-M), and surveyed their oral health behavior and oral health consciousness. The results of the study were as follows: 1. The intensity of malodor decreased by 16.49ppb from 75.33ppb on the first visit to 50.84ppb on the last visit when the comprehensive dental hygiene care had been finished. 2. As to change in S-OHI according to gender between the first visit and the last visit for comprehensive dental hygiene care, S-OHI decreased from 2.89 on the first visit to 1.16 on the last visit, and the difference was statistically highly significant. 3. As to change in PHP-M index by tooth according to gender and age between the first visit and the last visit, PHP-M index of the first 6 teeth decreased very significantly from 0.50 on the first visit to 0.34 on the last visit. 4. As a whole, significant improvement was observed in every tooth. According to gender and age, PHP-M index for Tooth No. 26, 36 and 32 decreased significantly in men and women, and those aged under 30 and those aged 30 or over, but for Tooth No. 13 and 15 and 44 it decreased significantly only in men and those aged 30 or over, and for Tooth No. 44 only in men. As presented above, the oral health behavior and oral health consciousness of the visitors to the oral prophylaxis practice room are very important, and it is necessary to enhance their interest in and knowledge of how to improve oral health. Furthermore, comprehensive dental hygiene care required for improving the visitors' oral health.

• Journal of Korean society of Dental Hygiene
• /
• v.15 no.1
• /
• pp.101-109
• /
• 2015

Objectives: The purpose of the study is to investigate the knowledge and attitude towards radiation protection after radiation safety management education in dental hygiene students. Methods: After receiving informed consents, a self-reported questionnaire was carried out for 135 dental hygiene students in Busan on June 17 for preliminary survey and September 3 for post-education survey, 2011. The questionnaire was modified from Han and consisted of 5 questions of general characteristics, 6 questions of radiation use, 7 questions of scholastic characteristics, 15 questions of knowledge towards radiation safety management, and 15 questions of attitude towards radiation safety management. Cronbach's alpha was 0.808 in the knowledge towards radiation safety management. Attitude towards radiation safety management included 15 questions of general attitude towards radiation safety management, individual and patient, and attitude toward radiation exposure reduction measured by Likert 5 scale. Cronbach's alpha was 0.970 in the attitude towards radiation safety management. Data were analyzed using SAS version 9.2 for educational analysis, technical analysis and multivariate analysis, paired t-test, and GLM. Results: Significant differences were shown in the knowledge and attitudes towards radiation safety management; the level of knowledge was respectively $9.8{\pm}3.0$ and $12.9{\pm}1.9$ points before and after education, and the level of attitude was $4.28{\pm}0.51$ and $4.53{\pm}0.47$ before and after the education. The levels of knowledge and attitude according to general characteristics showed a significant differences in grade and academic results. Post-education survey suggested that the education is very important and necessary and can change the knowledge and attitude towards radiation safety management in the dental hygiene students. Conclusions: Through the radiation safety management education, the levels of knowledge and attitude towards radiation safety management have changed significantly, which showed that the radiation safety management education proved to be very effective. Therefore, an effective radiation safety management education program is necessary to improve the levels of knowledge and attitude towards radiation safety management in the dental hygiene students.