• Journal of Oral Medicine and Pain
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• v.23 no.2
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• pp.193-209
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• 1998

In identifying bodies that are severely decayed or damaged, methods using fingerprints and various biochemical tests are known to have its limits. To overcome this, forensic odontological method which is based on the analysis of the cranium, tooth and dental restoration is used to enhance the accuracey of individual identification. For this reason, I have come to analysis of the dental materials that exists between the teeth that is perceived to have been previously restored and the one adjacent to it. By analyzing the constituents of gold crown-restored, non-precious metal-restored, gold inlay-restored and amalgam -restored teeth, and adjacent teeth using EDX(energy dispersive X-ray microanalysis) which was invented to analyze very small amount of elements, the nature of the restoration could be predicted and the results obtained were as follows. 1. Some of constitute of gold alloy was extracted from residual cement of gold crown restoration, but that was not extracted from the restored tooth and the one adjacent to it. 2. Some of constituents of non-precious metal alloy was extracted both in the residual cement on the tooth with no-precious metal restoration and in the tooth with the restoration itself. However, none of its constituents were found in the tooth adjacent to it. 3. Some of constituents of gold alloy were found in the residual cement of gold inlay, but they were not found in the restored tooth and the adjacent tooth. 4. Some of constituents of amalgam alloy were found both in tooth restored with amalgam and in the adjacent tooth. From the results obtained above, it is possible to utilize the data obtained from analyizing residual dental materials in a more effective way. This data compensates for the lost data due to any harm done to the restorations prior to individual identification and further enhances the accuracy. Therefore, it could be concluded that this process of analyzing residual dental materials could be beneficial to individual identification in the area of forensic odontoldogy.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.172-189
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• 2016

In this research, literature research on the Odong material, mixture ratio, casting method and casting facility was conducted on contemporary documents, such as Cheongong Geamul. Also, a long sword was produced using the Odong inlay technique. The sword reproduction steps were as follows; Odong alloying, silver soldering alloying, Odong plate and Silver plate production, hilt and sheath production, metal frame and decorative elements, such as a Dugup (metal frame), production, Odong inlay assembly and final assembly. For the Odong alloy production, the mixture ratio of the true Odong, which has copper and gold ratio of 20:1, was used. This is traditional ratio for high quality product according to $17^{th}$ century metallurgy instruction manual. The silver soldering alloy was produced with silver and brass(Cu 7 : Zn 3) ratio of 5:1 for inlay purpose and 5:2 ratio for simple welding purpose. The true Odong alloy laminated with silver plate was used to produce hilt and sheath. The alloy went through annealing and forging steps to make it into 0.6 mm thick plate and its backing layer, which is a silver plate, had the matching thickness. After the two plates were adhered, the laminated plate went through annealing, forging, engraving, silver inlaying, shaping, silver welding, finishing and polishing steps. During the Odong colouring process, its red surface turns black by induced corrosion and different hues can be achieved depending on its quality. To accomplish the silver inlay Odong techniques, a Hanji saturated with thirty day old urine is wrapped around a hilt and sheath material, then it is left at warm room temperature for two to three hours. The Odong's surface will turn black when silver inlay remains unchanged. Various scientific analysis were conducted to study composition of recreated Odong panel, silver soldering, silver plate and the colouring agent on Odong's surface. The recreated Odong had average out at Cu 95.57 wt% Au 4.16wt% and Cu 98.04 wt% Au 1.95wt%, when documented ratio in the old record is Cu 95wt% and Au 5wt%. The recreated Odong was prone to surface breakage during manufacturing process unlike material made with composition ratio written in the old record. On the silver plate of the silver and Odong laminate, 100wt% Ag was detected and between the two layers Cu, Ag and Au were detected. This proves that the adhesion between the two layers was successfully achieved. The silver soldering had varied composition of Ag depending on the location. This shows uneven composition of the silver welding. A large quantities of S, that was not initially present, was detected on the surface of the black Odong. This indicates that presence of S has influence on Odong colour. Additional study on the chromaticity, additional chemical compounds and its restoration are needed for the further understanding of the origin of Odong colour. The result of Odong alloy testing and recreation, Odong silver inlay long sword production, scientific analysis of the Odong black colouring agent will form an important foundation of knowledge for conservation of Odong artifact.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.233-239
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• 1999

Recently, a second generation composite resin system(ceromer) was introduced with significantly improved mechanical properties. The purpose of this study was to compare a ceromer with the other restorative materials and to assess its clinical usefulness. In this study, we used four restorative materials : amalgam (BESTALOY$^{(R)}$), indirect composite resin (Clearfil CR Inlay$^{(R)}$), ceromer (Targis$^{(R)}$) and ceramic (Vintage$^{(R)}$). And then we devided into four groups. The materials of each group were as follows : Amalgam group : BESTALOY$^{(R)}$ (Dong Myung Dental Industrial Co.) Composite Resin group : Clearfil CR Inlay$^{(R)}$ (Kuraray) Ceromer group : Targis$^{(R)}$ Dentin (Ivoclar-Vivadent) Ceramic group : Vintage$^{(R)}$ (Shofu Inc.) According to the above classification, we made samples through the polymerization of BESTALOY$^{(R)}$, Clearfil CR Inlay$^{(R)}$ and Targis$^{(R)}$ with separable cylindrical metal mold and firing of Vintage$^{(R)}$ in a investment mold. And then, we measured and compared the value of compressive strength, diametral tensile strength and Vicker's microhardness of each sample. The results were as follows : 1. Amalgam showed the highest value of compressive strength (390.37${\pm}$42.22MPa) and the value of ceromer was somewhere between ceramic and indirect composite resin. There were significant differences among the experimental groups(p<0.001). 2. Indirect composite resin showed the highest value of diametral tensile strength (74.21${\pm}$15.33MPa) and there was no significant difference with ceromer. Ceromer was higher diametral tensile strength than amalgam and ceramic (p<0.001). 3. Ceramic showed the highest value of microhardness (538.44${\pm}$37.38Hv) and the value of ceromer was somewhere between ceramic and indirect composite resin. There were significant differences among the experimental groups (p<0.001).

• Archives of design research
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• v.16 no.2
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• pp.291-300
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• 2003

In metalcraft, there are two kind of skills, one is forming and the other is decoration. And we could discern these skills as metal casting and metal hammering.. In metal casting, there are sand mould, cire perdus, stone mould and sealed monld; In metal hammering, metal forging, repousse technique and metal sheet making. After make form, craftman can use the decoration skills. There are chasing hammering, line carving, dotted line engraving, hair line engraving, kicking line engraving, ring punched ground, inlay, filigee and granulation skills. In korean traditional copper alloy, the craftman used forming and decoration skills. In Korea, tradionally the clatter use bronze for copper alloy; in case of Japan, they use violet coloring, and in case of Chinese, they like to use bronze used copper alloy. In case of Alloy, korean craftman used bronze traditionally, but recently the copper alloy skill is usually used; in case of Japan shibuichi and shakudo skills are used; and in Chinese copper, brass and cupronikel alloy are used.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.254-266
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• 1997

This study was to know the usefulness of argon laser for composite resin, to prove the polymerized effect of heat treatment of composite resin inlay and to get the curing method for optimal physical properties of composite resin inlay. In this study we used four light curing units and one heat curing unit: Visilux $II^{TM}$, a visible light gun: $SPECTRUM^{TM}$, an argon laser: Unilux AC$^{(R)}$ and Astorn XL$^{(R)}$, visible light curing unit: CRC-$100^{TM}$ for heat treatment. Compared to a control group, we divided the experemental groups into five as follows: Control group: Light curing(Visilux $II^{TM}$) Experimental group 1 : Light curing(Visilux $II^{TM}$) + Light curing(Unilux AC$^{(R)}$) Experimental group 2: Light curing(Visilux $II^{TM}$) + Light curing(Astron XL$^{(R)}$) + Heat treatment(CRC-$100^{TM}$) Experimental group 3 : Laser curing($SPECTRUM^{TM}$) Experimental group 4 : Laser curing($SPECTRUM^{TM}$) + Light curing(Unilux AC$^{(R)}$) Experimental group 5 : Laser curing($SPECTRUM^{TM}$) + Light curing(Astron XL$^{(R)}$) + Heat treatment (CRC-$100^{TM}$) According to the above classification, we made samples through the curing of Clearfil CR Inlay$^{(R)}$, which is a composite resin for inlay, in a separable cylindrical metal mold and polycarbonate plate. And then, we measured and compared the value of compressive strength, diametral tensile strength and the surface micro hardness of each sample. The results were as follows : 1. Among the experimental groups, group 5 showed the highest value of compressive strength, $157.50{\pm}10.24$ kgf and control group showed the lowest value of compressive strength, $103.93{\pm}21.93$ kgf. Control group showed significant difference with the experimental groups(p<0.001). Group 2 which was treated by the heat showed higher compressive strength than that of group 1 which was not, and there was significant difference between group 1 and group 2(p<0.001). Group 5 which was treated by heat showed higher compressive strength than group 4 which was not, and there was significant difference group 4 and group 5(p<0.001). 2. Among the experimental groups, group 5 showed the highest value of diametral tensile strength, $95.84{\pm}1.97$ kgf and control group showed the lowest value of diametral tensile strength, $81.80{\pm}2.17$ kgf. Control group which was cured by visible light showed higher diametral tensile strength than group 3 which was cured Argon Laser. Group 2 which was treated by heat showed higher compressive strength than that of group 1 which was not, and there was significant difference between group 1 and group 2(p<0.001). Group 5 which was treated by heat showed higher compressive strength than group 4 which was not, and there was a significant difference group 4 and group 5(p<0.001). 3. Among the experimental groups, group 5 showed the highest value of microhardness of top surface, $148.42{\pm}9.57$ kgf and control group showed the lowest value of microhardness, $111.43{\pm}7.63$ kgf. In the case of bottom surface, group 5 showed the highest value of $146.19{\pm}7.62$ kgf, and control group showed the lowest, $104.03{\pm}11.05$ kgf. Group 3 which was cured by Argon Laser showed higher diametral tensile strength than control group which was cured only with a visible light gun. Group 2 which was treated by heat showed higher compressive strength than that of group 1 which was not, and there was a significant difference between group 1 and group 2(p<0.001). Group 5 which was treated by heat showed higher compressive strength than group 4 which was not, and there was a significant difference group 4 and group 5(p<0.001). 4. According to the above results, we took a conclusion that argon laser can be used as a useful unit for curing the composite resin and heat treatment can improve the physical properties of the composite resin inlay.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.349-355
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• 2020

The Fourth Industrial Revolution has emerged, and technologies of various industries are being converged, compounded, or clouded computing, mobile, or big data. The emergence of a variety of skills and new jobs to match them is bringing the public out of the education and occupation of traditional metal crafts. In this change, craft education should find and study the education method suitable for the present times, and apply it to the educational field to raise public interest and revival. To this end, we will investigate the cases of education in other industries where new materials or technologies have been introduced, and use them in education of traditional metal craft techniques. In addition, we will investigate various cases and features of 3D printing technology and use it for education in craft techniques that have limited time, space and resources.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.24-41
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• 2020

The engraved line expression in metal crafts is a detailed technique of carving or decorating metal surfaces. This technique engraves a line using a tool on the surface of a metal craft. This technique was used extensively in articles made of various metal materials during the Goryeo Dynasty, and the range of patterns that could be expressed and the width of users was wide. In this paper, based on relics and literature, the concept of line representation of this engraving technique used in the metal crafts of the Goryeo Dynasty and the perceptions and terms of the Goryeo Dynasty were examined. In addition, the users engaged in this craft and the specific patterns and patterns of decoration were reviewed. Through these means, it was possible to confirm various aspects of a technique that was thought previously to involve just simple expression of lines using tools. In addition, through the literature, Geumseokmun Gate, and relics currently being transmitted, it was possible to confirm the utilization patterns of techniques used in various types of objects. Various uses have led to the combination with other metal craft techniques that were popular at the time, and while utilizing unique characteristics of the techniques, this maximized the molding of various patterns. In the meantime, it is true that the intaglio technique in metal crafts has not received much attention compared to the decoration techniques of other metal crafts, such as inlay, embossing, and openwork techniques in which decorative effects are maximized due to the recognition that the technique was used so widely in relics. However, the universality of the technique is premised on its wide use across all eras. As such, it was used in metal craft relics that reflect the various cultural characteristics of Korea and various cultural aspects that are currently passed down. On the one hand, technology has been passed down as a form of intangible heritage that embodies a longstanding craft culture which continues to the present in the fields of sculpture and intangible cultural properties. As such, the universality of Seongak contains many cultural meanings. In addition, the uniqueness of the technique is distinct, and it is deeply related to Goryeo, who was in charge of the use of technology and craftsmanship of the Joseon Dynasty and the metal craft technology that is currently handed down. I think research on future techniques should be continued in depth.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.25-32
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• 2019

Purpose: The size, shape, and volume of prosthetic appliance depend on the metal artifacts resulting from dental implant during head and neck treatment with radiation. This reduced the accuracy of contouring targets and surrounding normal tissues in radiation treatment plan. Therefore, the purpose of this study is to obtain the images of metal representing the size of tooth through MVCT, SMART-MAR CT and KVCT, evaluate the volumes, apply them into the proton therapy plan, and analyze the difference of dose distribution. Materials and Methods : Metal A ($0.5{\times}0.5{\times}0.5cm$), Metal B ($1{\times}1{\times}1cm$), and Metal C ($1{\times}2{\times}1cm$) similar in size to inlay, crown, and bridge taking the treatments used at the dentist's into account were made with Cerrobend ($9.64g/cm^3$). Metal was placed into the In House Head & Neck Phantom and by using CT Simulator (Discovery CT 590RT, GE, USA) the images of KVCT and SMART-MAR were obtained with slice thickness 1.25 mm. The images of MVCT were obtained in the same way with $RADIXACT^{(R)}$ Series (Accuracy $Precision^{(R)}$, USA). The images of metal obtained through MVCT, SMART-MAR CT, and KVCT were compared in both size of axis X, Y, and Z and volume based on the Autocontour Thresholds Raw Values from the computerized treatment planning equipment Pinnacle (Ver 9.10, Philips, Palo Alto, USA). The proton treatment plan (Ray station 5.1, RaySearch, USA) was set by fusing the contour of metal B ($1{\times}1{\times}1cm$) obtained from the above experiment by each CT into KVCT in order to compare the difference of dose distribution. Result: Referencing the actual sizes, it was appeared: Metal A (MVCT: 1.0 times, SMART-MAR CT: 1.84 times, and KVCT: 1.92 times), Metal B (MVCT: 1.02 times, SMART-MAR CT: 1.47 times, and KVCT: 1.82 times), and Metal C (MVCT: 1.0 times, SMART-MAR CT: 1.46 times, and KVCT: 1.66 times). MVCT was measured most similarly to the actual metal volume. As a result of measurement by applying the volume of metal B into proton treatment plan, the dose of $D_{99%}$ volume was measured as: MVCT: 3094 CcGE, SMART-MAR CT: 2902 CcGE, and KVCT: 2880 CcGE, against the reference 3082 CcGE Conclusion: Overall volume and axes X and Z were most identical to the actual sizes in MVCT and axis Y, which is in the superior-Inferior direction, was regular in length without differences in CT. The best dose distribution was shown in MVCT having similar size, shape, and volume of metal when treating head and neck protons. Thus it is thought that it would be very useful if the contour of prosthetic appliance using MVCT is applied into KVCT for proton treatment plan.

• Journal of Technologic Dentistry
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• v.23 no.2
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• pp.75-93
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• 2002

This research was preformed for the purpose of preparing the items of standard model of the national dental technician test base on the duty analysis of the dental technician. The results of the duty analysis for the dental technician follows. 1. The dental technician is a profession to make the oral function smooth through the dental supplement and equipment in a scientific method and the skilled technique. 2. The duty of the dental technician are determined as A. preparation for manufacture B. manufacture C. management of the place of the dental technology D. self-development. A. The field of "the preparation for manufacture" are determined as 1. to confirm work authorization 2. To confirm the working model, B. The field of "In manufacture" are determined as 1. to manufacture the temporary crown 2. to manufacture the inlay and crown & bridge prosthesis 3. to manufacture the porcelain fused metal crown prosthesis 4. to manufacture the all ceramic crown prosthesis 5. to manufacture the temporary denture prosthesis 6. to manufacture the partial denture prosthesis 7. to manufacture the complete denture prosthesis 8. to manufacture the attachment prosthesis 9. to manufacture implant prosthesis 10. to manufacture the removable orthodontic device, 11. to manufacture the fixed orthodontic device, 12. to manufacture the orthodontic study cast C. The field of "in management of the dental lab." are determined as 1. management 2. to control the dental lab. D. The field of "In the self-development" are determined as 1. to improve the professionalism 2. self-control. 3. The developing items selected under the duty evaluation of the dental technician are l7s in the manufacture preparation, 1,011s in the manufacture, 7s in the management for the dental technology, 5s in self-development, and in all together 1,040s

• The Journal of Korean Academy of Prosthodontics
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• v.18 no.1
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• pp.99-109
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• 1980

An investigation was made Into 1,357 fixed bridges which had been performed at the Department of Prosthetic Dentistry, Seoul National University Hospital from 1973 to 1979. The purpose of this investigation was to establish a basic reference of the treatment with fixed bridges by obtaining statistical conclusions from the data concerning the patients who had been treated with fixed bridges. The following conclusions were obtained; 1. The ratio of the fixed bridges made on the maxillae to those made on the mandible was 1:1. 2. The cases of fixed bridges with one pontic were the most frequent, i.e., 946 cases out of total 1,357 cases, which were 69.7% of the total. 3. As the number of missing teeth increased, the number of the relevant cases of fixed bridges decreased. 4. The most frequent age group of the patients who had been treated with fixed bridges was the twenties, which was 40.8% of the total. As the age of the patients increased, the number of corresponding cases of fixed bridges decreased. 5. Most of the fixed bridges with more than three pontics were made at the anterior portion samely on the maxilla and on the mandible. 6. As for the retainers, the porcelain fused to metal crown and the partial veneer crown were frequently used at the anterior portion, while the full veneer crown was frequently used and the inlay and the attachment were used in some cases at the posterior portion. The locations of fixed bridges in the order of their frequency were: canine, lateral incisor, second bicuspid, central incisor, second molar, first bicuspid, first molar, and third molar on the maxilla; second bicuspid, second molar, first bicuspid, first molar, canine, third molar, lateral incisor, and central incisor on the mandible.