• 대한치과보철학회지
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• 제9권1호
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• pp.17-22
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• 1969

Intra-oral films of 155 patients were taken on the areas of Gold Crown-Bridges, S. P. Bridges and Partial Dentures. And the author observed periodontal ligaments widening rates, the presence of periapical lesions and the alveolar bone patterns on the Partial Denture Saddle portions. The results were as follows : 1. Periodontal ligaments a) Periodontal ligaments widening rate increased obviously with the duration of wearing those prosthetic appliances. b) Periodontal ligaments widening rate was the highest in partial denture wearing patients, and then that of S. P. Crown Bridge patients, Gold Crown Bridge wearing females, Gold Crown Bridge males were the sequences. 2. Periapical lesions a) Periapical lesions increased with the wearing duration of those prosthetic appliances. But they did not increase in proportion to the duration. Periapical lesions were about the same in the teeth with those appliances showing relatively higher rate in Partial Denture abutment teeth and the lowest in Gold-Bridge abutment teeth. 3. Alveolar bone of Partial Denture saddle portion One third of all(32%) were normal with their smooth and compact bone pattern so that they were considered to perform normal function.

• 대한치과보철학회지
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• 제56권4호
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• pp.368-374
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• 2018

본 증례의 환자는 약 10여년 전 2개의 임플란트를 이용하여 Gold Hader bar 하악 임플란트 피개 의치로 수복하였고, 3년 6개월의 사용으로 인한 bar의 심한 마모로 유지력을 상실하였다. 이를 Locator 부착장치를 이용하여 하악 피개 의치를 수리하였으나, Locator 사용 6년 6개월 후 male 부위가 완전히 닳은 상태로 내원하게 되었다. 다음으로는 하이브리드 이중관(Hybrid telescopic double crown with friction pin)을 사용하여 임플란트 피개 의치를 새로 제작하였고, 이를 2년동안 관찰한 결과 우수한 예후를 보여주고 있다. 여기에서 한 환자에서 2가지(Gold Hader bar, Locator)방법으로 수복한 임플란트 피개 의치에서 각 부착장치의 실패원인에 대해서 알아보고, 이중관 피개 의치의 장단점과 성공을 위한 조건에 대해서 보고하고자 한다.

• 한국융합학회논문지
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• 제9권9호
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• pp.117-122
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• 2018

본 연구는 PET-CT 검사를 시행할 때 치과보철물에 의해 발생되는 CT의 HU(Hounsfield Unit) 값을 금속의 종류에 따라 측정하고, PET 영상의 왜곡정도와 표준섭취계수(SUV)의 변화를 확인하여 영상 판독 시 오류의 감소방안을 제시하고자 하였다. 실험방법은 실제 치아와 메탈 크라운, 골드크라운, 티타늄, 지르코니아의 치과보철물을 이용하여 PET-CT 검사를 실시하였다. 일반 치아와 비교한 결과 HU 값이 증가함에 따라 SUV 값이 증가되는 것을 확인하였고, 메탈 크라운, 티타늄, 지르코니아의 SUV 값은 37% 정도 증가되었고, 골드 크라운에서는 45.4%로 가장 많이 증가했다. 그리고 일반치아, 메탈크라운, 티타늄, 지르코니아에서 영상 왜곡은 미미했지만, 골드 크라운에서는 선속경화현상이 심하게 발생하였고, 영상 왜곡이 나타났다. 따라서 치과보철물의 금속종류는 SUV 값에 영향을 미치기 때문에 치과 보철물 중에서 골드 재질을 사용한 환자를 진단할 때에는 영상 판독 시 보정된 PET 영상보다는 NAC(무보정) PET 영상을 확인한다면 판독에 도움을 줄 수 있을 것으로 생각된다.

• 대한치과보철학회지
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• 제11권1호
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• pp.43-48
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• 1971

• 대한치과기공학회지
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• 제22권1호
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• pp.49-55
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• 2000

In manufacturing the all-ceramic crown whick look close to natural teeth, the effectiveness of the improved technique is expectected the technique of the heat treatment of gold plating coating die was experimented of a refractory cast model. The following results were obtainde 1. An advantage of build up on east die with out manufacturing veneer, crown, core, or masking(reduction of technical process, and retrenchment of time and money) 2. Esthetically more close to natural teeth than other technique 3. Easy to remove a refractors cast die 4. In manufacturing ceramo-metal crown the enomous effectiveness was obtainde on applying in the areas of cervical margin, the metal surface, and in the treatment of pinhole.

• The Journal of Advanced Prosthodontics
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• 제9권4호
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• pp.308-314
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• 2017

PURPOSE. The purpose of this study was to analyze the retention force changes and wear behaviours of double-crown systems over long-term use. MATERIALS AND METHODS. Ten groups, each consisting of six samples, were evaluated. Specifically, casting gold alloy primary crown - casting gold alloy secondary crown (AA), laser sintering primary crown - laser sintering secondary crown (LL), casting Cr alloy primary crown - casting Cr alloy secondary crown, (CC) zirconia primary crown - electroformed secondary crown (ZA), and CAD/CAM titanium alloy primary crown - CAD/CAM titanium alloy secondary crown (TT) groups were evaluated at cone angles of $4^{\circ}$ and $6^{\circ}$. The samples were subjected to 5,000 insertion-separation cycles in artificial saliva, and the retention forces were measured every 500 cycles. The wear levels were analyzed via SEM at the beginning and end of the 5,000 cycles. RESULTS. In all samples, the retention forces increased when the conus angle decreased. The highest initial and final retention force values were found in the $LL-4^{\circ}$ group (32.89 N-32.65 N), and the lowest retention force values were found in the $ZA6^{\circ}$ group (5.41 N-6.27 N). The ZA groups' samples showed the least change in the retention force, and no wear was observed. In the other groups, wear was observed mostly in the primary crowns. CONCLUSION. More predictable, clinically relevant, and less excursive retention forces can be observed in the ZA groups. The retention force values of the LL groups were statically similar to those of the other groups, except the ZA groups.

• 패션비즈니스
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• 제8권3호
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• pp.1-9
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• 2004

Scythians kept herds of horses, cattle, and sheep, lived in tent-covered wagons, and fought with bows and arrows on horseback. They developed a rich culture characterized by opulent tombs, fine metalwork, and a brilliant art style. The excavations of royal burials have provided the most complete record of the jewelry of the Scythians. Typical art objects were in the form of stags or other animals, hammered or stamped out of gold and often inlaid with colored stones or glass. The Bracelet consisted of two of distinct technique : One made from heavy forged gold bars, terminated with more delicate spiraled finals. Another technique used beaten gold foil, perhaps as thick as a piece of paper with fabulous designs repousse and chased (impressed in relief into the gold with small hammers and chisels) into the metal. They also used stones and clay dies to form gold foil into people repeated also motifs for use in torques and belts. The Scythian Bracelet were divided into 4 styles according to the shape, Bracelets with ends shaped like beasts style, Spiral style, Layers style, Crown with openwork style. Scythian Bracelet in the Black Sea region had completely degenerated, stifled by motifs and shapes of Greek origin, retaining its representational realism and its full emotional vitality.

• 대한치과보철학회지
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• 제40권1호
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• pp.68-78
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• 2002

The post core system has been used for reconstructon of severely damaged crown by caries or trauma. But problems such as crown exfoliation, post core fracture and root fracture have been reported. Ideal mechanical properies of the post require high fracture strength, high elastic limit and high resistance against fatigue and corrosion Modulus of elasticity of the post should be similar with that of dentine. Low hardness is also required for the convenience of post removal in failure. Furthermore, the post itself must be translucent for the esthetical purpose. Several types of the post have been developed to satisfy the criteria above mentioned. The purpose of this study was to find out the mechanical properties of quartz fiber post by comparing with those of gold post and zirconia post. The results of this study were as follows : 1. Maximal fracture strength and stiffness of quartz fiber post were similar with those of gold post and zirconia post. 2. Young's modulus and hardness of quartz fiber post were lower than those of gold post and zirconia post. Mechanical property of quartz fiber post against post fracture was similar with that of gold post and zirconia post. Mechanical property of quartz fiber post against root fracture was higher than that of gold post and zirconia post. Quartz fiber post could be removed easily due to low hardness.

• 대한치과보철학회지
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• 제40권1호
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• pp.53-67
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• 2002

This study was aimed to analyze the stress distribution of implant and supporting tissue in single tooth implant restoration using Branemark $system^{(R)}$(Nobel Biocare, Gothenberg, Sweden) and Bicon system(Bicon Dental Implants, Boston, MA). Two dimensional finite element analysis model was made at mandibular first premolar area As a crown materials porcelain, ceromer, ADA type III gold alloy were used. Tests have been performed at 25Kgf vertical load on central fossa of crown portion and at 10Kgf load with $45^{\circ}$ lateral direction on cusp inclination. The displacement and stresses of implant and supporting structures were analyzed to investigate the influence of the crown material and the type of implant systems by finite element analysis. The results were obtained as follows : 1. The type of crown material influenced the stress distribution of superstructure, but did not influence that of the supporting alveolar bone. 2. The stress distribution of ceromer and type III gold alloy and porcelain is similar. 3. Stress under lateral load was about twice higher than that of vertical load in all occlusal restorative materials. 4. In Bicon system, stress concentration is similar in supporting bone area but CerOne system generated about 1.5times eater stress more in superstructure material. 5. In Branemark models, if severe occlusal overload is loaded in superstvucture. gold screw or abutment will be fractured or loosened to buffer the occlusal overload but in Bicon models such buffering effect is not expected, so in Bicon model, load can be concentrated in alveolar bone area.

• 보존과학연구
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• 통권7호
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• pp.48-55
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• 1986

The gold crown unearthed from the ancient tombs at Imdang-dong, Kyongsan-gun, Kyongsangbuk-do was in a state of severe corrosion that its original pattern couldn't be identified. Therefore, for the conservation of the relics, the following methods are employed :1. With 10% formic acid are used for the elimination of the bronze-rust and then plated them with gold.2. As a rust-proof treatment, 1% Benzotriazole is used for stem corrosion as well3. For protection and reinforcement of the surface of the relics, 30% incralac agentsare used.4. Pieces of fragments are bonded together by cyanoacrylate and on the backside are coated partially with Araldite for the reinforcement of the glass-wool.5. Silica-gels are kept into the acryl box for perfect maintenance.