• 대한치과보철학회지
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• 제41권4호
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• pp.451-465
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• 2003

Statement of problem : Recently various implant components such as premachined gold cylinder, plastic cylinder gold UCLA abutment and plastic abutment were developed and used clinically without clinical investigation. Purpose : The purpose of this study was to evaluate the effects of fabrication of gold cylinder on the fitness and preload of the standard abutment and also the effects of fabrication of UCLA gold abutment on the fitness and stress transfer around the implant fixture. Material and method : Three kinds of gold cylinders such as, as-received gold cylinder (Nobel Biocare, Sweden), gold cylinder after casting, and plastic cylinder after casting with type IV gold alloy were tested over the top of the standard abutment. At the same time, three types of abutments such as, gold UCLA abutment before and after casting, and plastic abutment after casting were tested. The cylinder and abutment was secured over the fixture with conventional pre-load values using an electronic torque controller (Nobel Biocare, Sweden). The fitness of the abutment on the fixture and gold cylinder over the standard abutment were measured using the microhardness tester (MXT 70, Matsuzawa, Japan). Preload and the strain values were recorded using the strain balance unit (SB-10, Measurement group, Raleigh, USA) and strain indicator (P-3500, Measurement group, Raleigh, USA) systems. Results and conclusion : 1. Significant differences were found in the fit between the gold cylinder and plastic cylinder. 2 There were significant differences between the preload of the gold cylinder and that of the plastic cylinder. 3. Significant differences were found in the fit between the gold UCLA abutment and plastic UCLA abutment. 4. There were no significant differences in the stress generated on the supporting structure of the fixture among different cylinder and abutment groups.

• 대한치과보철학회지
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• 제37권6호
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• pp.825-834
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• 1999

Recently, various implant cylinders were supplied. especially received gold cylinders, cast cylinders produced from premade gold and plastic cylinders and plastic cylinders. This study measured and compared precise fit produced when using conventional gold and plastic cylinders. The comparative fit of lapped and non-lapped castings made from plastic pattern was examined. The implant/abutment interface fit was evaluated by scanning electron microscopy(SEM) for each of four cylinders. The following results were obtained: 1. The case of plastic cylinder showed $9.67{\pm}1.50{\mu}m$ gap when Steri-Oss fixture was connected. 2. The case of lapped casting made from plastic cylinder showed $3.01{\pm}2.81{\mu}m$ gap when Steri-Oss fixture was connected. 3 The case of gold/plastic cylinder showed $9.80{\pm}1.68{\mu}m$ gap when Steri-Oss fixture was connected. 4. The case of gold cylinder showed ${5.47{\pm}2.43\mu}m$ gap when Steri-Oss fixture was connected. 5. In case of each cylinder which was connected with Steri-Oss fixture, the size of gap was showed less in the order of the case of gold/plastic cylinder, the case of plastic cylinder, the case of gold cylinder and the case of lapped casting made from plastic cylinder As results of this study, the use of premade gold cylinder offers an advantage over plastic pat-terns in precise fit. When plastic patterns are used, polishing of implant cylinder components should provide precise fit.

• 대한치과보철학회지
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• 제38권5호
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• pp.695-703
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• 2000

The purpose of this study was to evaluate the effects of fabrication and tightening methods of gold cyliner on the preload of the standard abutment. Three linear strain gauges (KFR-02N-120-C1-23, Kyowa, Japan) were mounted longitudinally on the 5.5mm Standard abutment (Nobel Biocare, Sweden) and three kinds of gold cylinders such as, as-received gold cylinder, gold cylinder after casting, and plastic cylinder after casting with type IV gold alloy were connected over the top of the standard abutment. Two kinds of tightening methods, such as manual torque with handhold screwdriver and electronic torque using Electronic torque controller were used to generate preload on the abutment. The result were as follows; 1. The preload generated by tightening cast plastic cylinder with handhold screw driver, was the lowest among the six groups. 2. The preload generated by cast plastic cylinder was lower than those by gold cylinders regardless of the tightening methods. 3. The electronic torque controller produced higher torque values than the handheld screwdriver.

• 대한치과보철학회지
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• 제34권3호
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• pp.438-447
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• 1996

This study was performed to determine the failure strength and pattern of implant prosthesis luted with resin cement between gold cylinder and superstructure, and to evaluate the bonding strength of resin cement. To evaluate failure strength and pattern, the groups were divided into 2. Group 1 : Casted gold cylinder Group 2 : Luted with resin cement between gold cylinder ans superstructure. To evaluate effects of the bonding strength of the implant prosthesis luted with resin cement according to storage condition, the groups were divided into 3 : Group A : Stored in waste at $37^{\circ}C$ for 24 hours. Group B : 1000 cycles thermocycled between $5^{\circ}C\;and\;55^{\circ}C$ in water. Group C : Stored in water at $37^{\circ}C$ for 30 days. The results were as follows. 1. Failure was found at gold screw in all specimens of group 1 & 2. 2. The bond strength in group 1 and 2 was 189.86 and 188.14kgf. There was no statistically significant difference between group 1 and 2(P>0.05). 3. The bond strength of group A, B and C was 53.28, 45,86 and 39.29Kgf. There result suggest the advantage of an improved fit of superstructure to the abutment and a simple procedure. But there was a measurable decrease of the bond strength according to storage condition. So, Further research is necessary to evaluate of the implant prosthesis luted with resin cement between gold cylinder and superstructure.

• 대한치과기공학회지
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• 제23권1호
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• pp.115-121
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• 2001

This study was investigated on effect of implant system about investment condition and burn out temperature. Posterior bridges were fabricated by using plastic sleeve and gold sylinder. The results were as follows; In plastic sleeve test and fitting cast copings. the phosphate bonded investment showed better gypsum bonded investment. The pure special liquid showed better margin fitness compared with mixed liquid (special liquid + distilled water). In gold cylinder test. the good burn out temperature of Ceramic PFG and Crown Gold was evaluated $0^{\circ}C$ to $820^{\circ}C$ and was decreased on $780^{\circ}C$ for 30 minutes. $0^{\circ}C$ to $750^{\circ}C$ and was decreased on $650^{\circ}C$ for 30 minutes.

• 대한치과보철학회지
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• 제39권1호
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• pp.1-13
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• 2001

An absolutely passive fit at the interface with the superstructure and the abutment cylinders is need for implant longevity. In this study, a method of cast framework correction using spark erosion technology was evaluated. Electric discharge machining(EDM) is a process that uses electrical discharges, or sparks, to machine metal, The surface being machined is bombared with high-intensity electrical energy pulses that gradually melt away the stock until the desired configuration is obtained. Master model was fabricated by using metal block impression analogue, which fired 5 Branemark squared impression coping in an arc shaped metal block. Then framework using 4mm standard gold cylinder and type IV gold alloy was fabricated. In order to measure the fit of the framework we used both contact and noncontact coordinate measurement machine and data was processed by computer program. After superimposition of gold framework and master model numeric image data the distances between gold cylinder bearing surfaces and abutment replica bearing surfaces, and the angle deviations between gold cylinder and abutment replica centroid points were calculated. The results were as follows 1 The total mean distance (p<0.01) and standard deviation (p<0.001) between the gold cylinders and abutment bearing surfaces were significantly decreased after EDM 2. The total mean of maximum distances was significantly decreased after EDM (p<0.05). 3. After EDM, the mean angle deviation between centroid points was decreased.

• 한국자기학회지
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• 제17권2호
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• pp.103-107
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• 2007

본 연구에서는 고체 안에 둘러쌓인 감마선 원천핵 $^{133}Cs$를 금판(gold plate)으로 된 실린더 안에 놓았을 때 첫 여기상태인 81 keV 에너지 준위폭이 더 좁아짐을 볼 수 있었다. 이러한 결과는 에너지 준위의 수명이 연장된 것을 의미한다. 두께 0.5 mm, 길이 5 cm, 반경 1 mm의 실린더를 사용했을 때 4.2 K에서 에너지 준위폭은 6.1 %정도 좁아지는 결과를 얻었다.

• 대한치과기공학회지
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• 제26권1호
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• pp.69-76
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• 2004

The objective of this finite element method study was to analyze the stress distribution induced on a supporting bone by 3.75mm, 4.0mm, 5.0mm diameter of dental implant fixture(13mm length). 3-dimensional finite element models of simplified gold alloy crown(7mm height) and dental implant structures(gold cylinder screw, gold cylinder, abutment screw, abutment, fixture and supporting bone(cortical bone, cancellous bone) designs were subjected to a simulated biting force of 100 N which was forced over occlusal plane of gold alloy crown vertically. Maximum von Mises stresses(MPa) under vertical loading were 9.693(3.75mm diameter of fixture), 8.885(4.0mm diameter of fixture), 6.301(5.0mm diameter of fixture) and the highest von Mises stresses of all models were concentrated in the surrounding crestal cortical bone. The wide diameter implant was the good choice for minimizing cortical bone-fixture interface stress.

• 대한방사선기술학회지:방사선기술과학
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• 제32권2호
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• pp.213-218
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• 2009

감마선 원천핵을 두 개의 금속 평행판 사이, 실린더나 구와 같은 유한한 공간 내부에 놓았을 때 에너지 준위폭이 어떻게 변경되는가에 대하여 이론적으로 조사했다. 2개의 금속판에 의해 뒤쪽 산란된 감마선이 원천핵에 재흡수됨으로써 $^{133}Cs$핵의 여기상태(81 keV)의 에너지폭은 평행판 간격이 1.0 mm일 때 4.2 K에서 3.7% 정도 감소됨을 볼 수 있었다. 여기서 금속판은 두께 0,5 mm, 반경이 3 cm이며 금으로 만들었다. 반경 1.0 mm, 두께 0.5 mm, 길이 5 cm의 실린더 금판에 의해 뒤쪽 산란되었을 때에는 4.2 K에서 6.5% 에너지 폭이 좁아지는 결과를 얻었다. 또한, 두께 0.5 mm, 반경 1.0 mm의 금으로 된 구 안에 원천핵을 놓았을 때 4.2 K에서 18.2% 에너지준위 폭이 감소하였다. 이러한 에너지 준위 폭의 감소는 그 준위의 반감기가 연장된 것을 의미한다.

• Elastomers and Composites
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• 제34권1호
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• pp.45-52
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• 1999

본 논문에서는 미세 상분리된 블럭 공중합체 박막의 특이상에서 금 입자들이 어떻게 자기응집(self assemble) 되고 잘 배열된 패턴을 형성하는지를 살펴보았다. 본 연구에서는 원통형 모폴로지를 갖는 PS-PB-PS 삼블럭 공중합체(30wt% PS) 박막(${\sim}100nm$)을 0.1wt% 톨루엔 용액으로부터 캐스팅하여 고분자 박막 형판(template)으로 사용하였다. 각각의 상이한 용매 증발조건으로부터 PB matrix내에 수평배열 PS cylinder와 수직 PS cylinder를 함께 갖는 막이 얻어졌다. 블럭 공중합체박막의 표면 및 bulk 몰폴로지를 살펴보기 위하여 단면투과전자현미경(TEM)을 사용하였다. Nano-scale 패턴을 얻기 위하여는 소량의 금입자를 블럭 공중합체 박막상에 증발시켰다. 캐스팅된 상태 그 대로의 박막형판이 사용되어질때 금입자들은 표면 장력이 적은 PB상에 우선적으로 자기응집(self as-semble)하여 비교적 잘 배열된 nano-scale의 패턴을 형성하였다. 그러나 열처리(annealing)에 의하여 표면장력이 적은 PB-rich충이 형성된 후에는 금입자의 자기응집에 의한 패턴은 관찰되지 않았다.