• Journal of Technologic Dentistry
• /
• v.32 no.4
• /
• pp.307-315
• /
• 2010

Purpose: The purpose of this study was to investigate the change of microstructures and mechanical properties of pure titanium casting specimens as a function of mold temperatures. Methods: The pure titanium castings were fabricated using the centrifugal vacuum casting method with different mold temperatures of $200{\sim}500^{\circ}C$. The resulting castings were characterized by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and vicker,s hardness tester. Results: In case of the mold temperatures over $400^{\circ}C$, the porosity, surface crack and large grain size were observed in resulting castings. Conclusion: In this work, The most suitable mold temperature in casting of pure titanium was $300^{\circ}C$.

• Journal of Technologic Dentistry
• /
• v.23 no.2
• /
• pp.9-15
• /
• 2002

A new kind of 'All Ceramic Crown' could be manufactured by making improvements in the manufacturing technique for the current 'All Ceramic Crown' which does not use a special ceramic but rather a general one as a substitute. If we use the manufacturing technique for the 'All Ceramic Crown', metal coping and core are not produced. The effects of the new manufacturing technique for the 'All Ceramic Crown' are as follows: First. We do not need to use new material or special machinery or tools. Second. We can use general machinery and tools. Third. Using the basic 'All Ceramic Technique', we anticipate improvement in learning in our students. Forth. We can save effort, materials and time. Fifth. The technique also has advantages for esthetic 'temporary crown'.

• Journal of Technologic Dentistry
• /
• v.10 no.1
• /
• pp.47-54
• /
• 1988

The purpose of this study is to evaluate the castability of Ni-Cr alloys for crown and bridge. New young, Hi-Crown and CB-80 which are widely used in dental laboratory were chosen, casting and increased the temperature of furnace 100$^{\circ}C$ of each 7 grades from 600$^{\circ}C$ to 1200$^{\circ}C$. The results are as follows : 1. CB-80 is the most prominent castability among the three Ni-Cr alloys which are Hi-Crown, New-young and Hi-Cr. 2. The good burning temperatures of casting for CB-8p are 900$^{\circ}C$, 100$^{\circ}C$ and 1100$^{\circ}C$ which are obtained four complate casting body of five former patterns. 3. The most proper burning temperature for three Ni-Cr alloys is 900$^{\circ}C$.

• Journal of Technologic Dentistry
• /
• v.36 no.1
• /
• pp.17-23
• /
• 2014

Purpose: The purpose of this study was to analyze and compare the relative accuracy of digitized stone models of lower full arch, using two different scanning system. Methods: Replica stone models(N=20) were produced from lower arch acrylic model. Twenty digital models were made with the white light and blue LED($Medit^{(R)}$, Korea) scanner. Two-dimensional distance between the landmarks were measured on the Delcam $CopyCAD^{(R)}$(Delcam plc, UK). Independent samples t-test was applied for comparison of the groups. All statistical analyses were performed using the SPSS software package(Statistical Package for Social Sciences for Windows, version 12.0). Results: The absolute disagreement between measurements made directly on the two different scanner-based dental digital models was 0.02~0.04mm, and was not statistically significant(P>0.05). Conclusion: The precision of the blue LED optical scanner was comparable with the digitization device, and relative accuracy was similar. However, there still is room for improvement and further standardization of dental CAD technologies.

• Journal of Technologic Dentistry
• /
• v.37 no.3
• /
• pp.131-144
• /
• 2015

Purpose: This study set out to propose plans for more efficient and effective clinical practice by investigating the current state of clinical practice in the field of dental technology and thus provide basic data to develop pre- and post-education programs for clinical practice. Methods: The subjects include dental technicians at dental technical laboratories that were appointed as the place of clinical practice by the Department of Dental Technology of G University. The survey period spanned from December 22, 2014 to January 20, 2015. Total 250 questionnaires were distributed to them, and 190(76.0%) were returned. After excluding 23 whose answers were uncertain or seemed to lack reliability, total 167(66.8%) were used in final analysis. Results: 1. The most frequent practice the student did during clinical practice was articulator attachment, which was followed by pin operation or model making, one's own task and practice, sand and crow sculpturing, burying, casting, and grinding. 2. In case of going through the entire process, porcelain had the most students at 39(23.4%), being followed by crown & bridge at 28(16.8%), clinical model at 23(13.8%), full denture at 17(10.2%), and partial denture at 17(10.2%) in the order. 3. Of the students, 59.8%(30.5% for reinforced basic practice; 29.3% for intensive practice education) said that intensive practice education should be reinforced in school; and 22.3% said that intensive theory and practice education was needed, which indicates that 82.6% voiced their opinion of reinforcing education around practice. 4. The students felt that they lacked diligence, passion, and theoretical knowledge somewhat and were relatively good at clinical adaptation and operational skills. Conclusion: The findings show that the students felt an absolute lack of practice education as the school education was focused on theory and national exams in the field of dental technology, thus raising a need to reinforce practice education. Of all the respondents, 62.9% said there was a need to improve the current education with a focus on jobs. In future, education of dental technology should work to bring up able dental technicians that can perform in clinical dental technology right after graduation by reinforcing job-based practice education.

• Journal of Advanced Technology Convergence
• /
• v.2 no.4
• /
• pp.49-56
• /
• 2023

The purpose of this study was to investigate the effectiveness and perception of eco-friendly oral products by comparing and analyzing the dental bacterial film removal rate of eco-friendly toothbrushes and general toothbrushes, and by examining the satisfaction of the research subjects with toothbrushes through questionnaires. As a result of the study, there was no significant difference in the removal rate of dental bacterial film between eco-friendly toothbrushes and general toothbrushes, so it was found that the function of eco-friendly toothbrushes was not much different from that of ordinary toothbrushes, and the satisfaction with eco-friendly toothbrushes was generally positive.

• Journal of Technologic Dentistry
• /
• v.21 no.1
• /
• pp.87-96
• /
• 1999

In order to examine the influence of sprue(used to make crown supplements) on casting, 3 kinds of sprue materials(wax, wood, plastic) and 3 types of sprue(round, square, triangle) were made and buried and cast, then the comparison and analysis of casting characters among sprue materials and among sprue type show the following results : 1. The comparison of casting characters in accordance with sprue materials shows wax sprue of 83.3%, wood sprue 81.3%, and plastic sprue of 80.7%, Wax sprue was the bast materials for casting, However there was no statistically significant difference of casting characters among was, plastic and wood. 2. The comparison of casting in accordance with sprue types shows square sprue of 94.0%, round sprue of 86.9% and triangle sprue of 84.2%. square sprue had a best casting character. 3. When a ring cast using wood sprue was classified from burying materials. its cutting of casting body and sprue indicated much more than any other sprue material. It seems to be caused by the influence of wood residuals and carbon occurrence.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.11
• /
• pp.52-56
• /
• 1996

The elevation of present medical service using advanced science contributes to offer medical examination and treatment of good quality under the subject of patient satisfaction as well as patient impression. The dental service field charging some part of public health promotion and public welfare promotion also intends to improve the dental examination and treatment quality utilizing advanced science. The object of this research is the development of dental patient education system (DPES) using multimedia of new technology. DPES can be employed for these object, harmonious operation of dental examination and treatment, treatment quality improvement, disease notice to patient under the subject of patient satisfaction and patient impression, explanation of some selective treatment course, the verification of treatment necessities and treatment validation, and the improvement of treatment effect through the oral cavity sanitation education in the sense of prevention. This research also serves the development environment, the step to collect educational document, visual information and to structure those, and the examination of DPES efficiency in clinic.

• Journal of Technologic Dentistry
• /
• v.29 no.2
• /
• pp.119-128
• /
• 2007

Although there are many different ways that restorations can be made, it can be said that the biocompatibility of abutment and crown is very important in this experiment. When placed in the actual oral cavity, the differences were obvious. Compared to In-ceram Aluminium, the structure that is obtained after firing reveals a particularly homogeneous distribution of the crystal and glass phase. The In-ceram aluminium system had many problems, such as having weak tensile strength, and having low bonding strength due to the shrinking that occurs after firing. Because of the opaque finish of the metal frame, the two may look similar from the outside, but it is evident that there are differences between using a metal frame and In-ceram. VITA VM9 has been designed as a special ceramic featuring a fine structure or stabilized Zro2 substructures, and so the VITA VM9 excels in its light refraction and reflection behavior, which is similar to natural teeth. It also has outstanding chemical balance, which presents advantages such as considerably reduced accumulation of plaque on the ceramic surface.? This ultimately results in easier care and cleaning for the patient.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.10
• /
• pp.4484-4492
• /
• 2011

The purpose of this study was to analyze dental laboratory's self health recognition level and health behavior level and to examine its correlation. 250 dental technicians in Seoul, Incheon, and Jeonbuk area were selected. Survey was carried out from October 11, 2010 to November 25, 2010 by using self-administered questionnaire. The following are the analytical results in the collected data. The average in the self- health recognition was indicated to be high with 2.83, The average of health behavior was indicated to be high with 2.76. As for correlation between self health recognition and health behavior, most of variables were indicated to have reverse correlation, it was concluded that higher health behavior likely led to lower self health recognition. From the result of this study, the work environment of dental technician must be improved and do more Practice of Health Behavior to improve and maintain their health.