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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Acedemy of Dental Technology
Journal Basic Information
Journal DOI :
Korean Academy of Dental Technology
Editor in Chief :
Volume & Issues
Volume 14, Issue 1 - Jun 1992
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Morphological Correction about Process of Fabrication of Ceramo-Metallic Crown
Park, Jong-Ouk ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 5~14
A Study on the use of Titanium as the Prosthetic Dental Materials
Baik, Ju-Jyun ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 15~21
Study on the Corrosin Properties of Au-Ag-Cu Dental Alloys
Kim, Bu-Sob ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 23~43
Corrosion characteristics of four commerial gold-based dental alloys(C-1; Au75%, Ag13.9%, Pd3%, Cu & etc.,8.1%, C-2 ;Au 52.08, Ag 24%, Pd 5%, Cu & etc.,18.92, C-3 ; Au 53%, Ag 22%, Pd 5%, Pt 3% Cu & etc.,17%, C-4 ; Au 53%, Pd4, Pt1.5%, Ag & Cu & etc.,41.5%) and four experimental ternary Au-Ag-Cu alloys(E-1 ; Au 50%, Ag 30%, Cu 20%, E-2 ; Au 50%, Ag 20%, Cu 30%, E-3 ; Au 50%, Ag 10%, Cu 40%, E-4 ; Au 50%, Ag 40%, Cu 10%) were investigated by potentiodynamic polarization analysis and the structure was examined by optical microscope and SEM. All corrosion testing was conducted in 1% NaCl solution. The main results are as follows : 1. The corrosion resistence of commercial alloys was decreased in the order of C-1, C-3, C-4, C-2. C-2. 2. The E-1 and E-3 ternary alloys exhibits the higher corrosion resistence than E-2 and E-4 alloys. 3. The cast microstructure of alloys reveals dendrite morphology which shows the significant microsegregation caused by the difference in the diffusion rate between liquid and solid. 4. It is found that the surface corrosion products were mainly AgCl by X-ray diffraction results.
An Experimental Study of Marginal Distortion Related to Heat treatment and Surface Treatment in Metal Copings for Metal-Ceramic Restorations
Kim, Uoong-Chul ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 45~54
The purpose of this study was to observe the change of marginal distortion related to heat treatment and surface treatment in. Thirty copings were made on the self-curing resin dies and twenty coping among them were treated by heat and surface grinding. All copings were adapted on the respective dies and then were invested into the plastic boxes with tray resin. Both copiong and die invested in tray resin were cut through labio-lingually by a separating disc. This cross-cutting surface was ground and polished. Specimens were mounted on a light microscope and photographed. Marginal discrepancies were measured on photographes by a scale. The obtained results could be summarized in the followings : 1. In all metal copings, the distortion of cervical margin was shown after heat treatment and surface treatment. 2. There were no statistically significant differences in marginal fitness between shoulder and deep chamfer. 3. There were no statistically significant differences in marginal fitness between labial margin and lingual margin in one die. 4. In case of the copings which were not treated with preheating and were treated with surface grinding, the marginal distortion shows a tendency to increase.
A Study on the Comparison of hardness, Strength and Microstructure of dental Non-precious Metal Alloys Colored Goldish Yeller
Kim, Jae-Do ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 55~65
The purpose of this study was to investigate the comparison of physical properties of nonprecious metal alloys colored goldish yellow. The experimental groups were copper based dental alloy and control group was Ni-Cr based dental alloy used crown and bridges frameworks. Hardness was tested by vickers hardness tester, tensile strength was tested by universal tension tester. After testing the tensile strength of castings, the microstrucure and the pattern of fracture were investigated by scanning electron microscope and metallurgical microscope. The results were as follows : Hardness of Ni based alloy was higher than Cu based alloys. Hardness number of A group was 200.41
16.10 Hv, B group was 194.33
1.69 Hv, C group was 139.29
2.19 Hv and D group was 293.81
27.17 Hv, respectively. Tensile strength of D group was 56.42
, A group was 50.39
, C group was 45.13
, B group was 45.25
, in order, and D group was maximum tensile strength. The fractured surfaces of tensile specimens in the all groups showed the tendency to form large voids in the center of specimens. Thus the ductile fracture was changed into the brittle fracture with the fine grain size.
Dental Care Utilization pattern of City Residents
Park, Myung-Ja ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 67~79
This study was conducted to analyze the dental care utilization pattern of the city residents. An interview and questionnaire survey was carried for 1008 people who lived in Kimchun-city, Kyungsangpook-do, from february 1 to March 30, 1992. The summarized results are as follows : The rate of persons who experienced the oral disease was 32.7 per 100 persons during 1 year and it was highest in the age group of 20
29. During 1 year period, 90.3% of the cases had treated the perceived oral disease, 9.7% had done no action. 65.8% had treated experienced oral disease at dental clinics. The rate of person who dad experienced dental prosthesis during ten-year period was 37.5% among 18year and older, and it was higher in male as compared to female and it was highest in age group of 40
64 year old. The rate of person who had treated dental prosthetics by the unauthorized illegally was 27.0%, and the reason for it was cheap-price free(44.2%). Of the person who dad treated dental prosthetics by the unauthorized illegally, 64.3% had satisfied and 4.3% had done out of use, while each was 80.1%, 2.7% at dental clinics. The rate of persons with missing teeth was 18.0%. Of the persons with missing teeth, 57.6% did not treat the missing teeth due to economic reason and 89.6% hopped treating the dental prosthetics at dental clinics. In consideration of above finding, we may conclude that oral health community program to prevent oral diseases should be intensified, oral health education to raise oral health knowledge should be performed periodically and the control of unlicensed activities should be enforce at community health center and allows benefits for prosthetics.
A study on the Job Satisfaction Degree of Korean Dental Technicians
Park, Jong-Hee ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 81~90
1. The dental technicians are worn to a frazzle by a hard work. Therfore, the term of manufacturing denture should be prolonged as 4
5 days. 2. The dental technicians work under the harmful environments. It should be improved the working conditions for the dental technicians. 3. In case of the women dental technicians, they feel like being treated discriminality. It should be take over a portion of the work in dental laboratory as the accountant' section and the technical section. 4. It should be abolished a pressent instruction dentist system.
A Study on the Linear Distoration of Self-Curing Resin by Various Curing Technics
Lee, Do-Kyung ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 91~94
This study was made to change dimension of self-curing resin by various curing technics. Specimens were fabricated 45 by 7 curing method. Six measurements(distances AB,BC,CD, AD, AC, and BD) were made of mold section and recorded with micrometer(1/20 mm). The results of the experiment were as follows : 1. The air pressure cured specimens exhibited more distoration than the bench-cured, watercured, and monomer atmosphere-cured specimens(P < 0.05). 2. The water pressure cured specimens exhibited more distoration sphere-cured specimens (P < 0.(15).
A Study on the Crystallization of Glass-Ceramics for Dental Crown
Chung, In-Sung ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 95~118
Glass ceramics for crown were prepared by adding 3
11 wt% TiO2 to the weight percent composition of 34.7 CaO, 27.8 SiO2, 18.3P2O5, 12.6MgO and 6.6 TiO2. The starting glasses were prepared by melting the powdered batch in alumina crucible at 1350
1400 for 1 hr and then quenching into a distilled water. The nucleation and crystallization of the crystalline glass ceramics for crown were studied by DTA, SME and X-ray diffraction analysis. Frit containing 9.11 wt% TiO2 had crystallization temperature of 850
1075 and major crystalline phase was identified by X-ray diffraction as diopside(CaO-MgO-2SiO2). Activation energies for the crystallization processes were obtained from DTA by varing rates for the fits, and were calculated from modified Ozawa and Kissinger equations. Activation energy for the crystallization processes of the S-4 frit was 489.6 KJ/mol.
Effect Boron and Silicon on Various Properties of Dental Cobalt-Chromium Alloys
Jung, Jong-Hyun ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 119~132
This paper aims to investigate the effect of B and Si upon the mechanical properties, microstructure and corrosion resistance of Co-Cr base alloy. Ten groups of alloy ingot ingot with various contents of B and Si were remelted by high frequency electrical induction furnace and cast into tensile specimen of ADA Specification No. 14 Tensile and hardness test were carried out by Amsler and Rockwell hardness tester(R-30N), respectively. The microstructures of specimen were observed by SEM. The results obtained are summarized as follows : 1. As B content is increased, tensile strength, yield strength and Rockwell hardness number(R-30N) are also increased significantly, while the elongation is decreased significantly. 2. As Si contect os increased, no significant chang in tensile strength is noticed, yield strength is slightly decreased, but Rockwell hardness number(R-30N) is moderately in creased, Elongation marks maxium value with 1% Si content while with more than 1% Si it is decreased. 3. As B content is increased corrosion resistance is decreased and is at best with 1.5% B content. Corrosion resistance is increased with the increase of Si content and the alloys with Si over 3.0% showed corrosion resistance. 4. As B content increased, precipitates are increased in number at grain boundaries. The grain size tends to become coarse with the increase of Si content. 5. Co rich-Cr alloy is present through matrix whereas at the grain boundaries Cr base precipitates are primarily formed.
A Study on the Improvement of Denture Base construction
Shin, Moo-Hak ;
Journal of Korean Acedemy of Dental Technology, volume 14, issue 1, 1992, Pages 133~138
The base of a metal base denture that is made of acrylic resin base and metal in lined by soft liner named silicon rubber and its merits are as follows. 1. It has a good retention and fastness. 2. It has a good comfort and stability. 3. It is easy to mix various kinds of base materials. 4. It is easy to repair. 5. The pressure of bone and mucosal tissue is decreased and bite force is dispersed.