• 한국산학기술학회논문지
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• 제21권12호
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• pp.434-439
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• 2020

최근, 치과 산업에서 레이저를 열원으로 합금을 제조하는 선택적 레이저 용융법(Selective laser melting, SLM)이 소개되고 있다. 하지만 SLM으로 제작된 금속-세라믹 수복물에 대한 연구가 부족한 실정이다. 따라서 본 연구의 목적은 SLM 그리고 CAST(casting)에 의해 제조된 Co-Cr 합금의 금속-세라믹(metal-ceramic) 결합 강도(bond strength)를 평가하는 것이다. SLM 그리고 CAST 방법을 사용하여 Co-Cr 시편을 제조하고 세라믹을 소결하여 시료를 제작하였다. 연구의 실험은 표본 준비 및 분석을 통해 2020년 1월부터 6월까지 수행되었다. 금속-세라믹 결합 강도는 만능 시험기에 의해 측정되었다. 부착 세라믹의 면적분(The area fraction of adherence ceramic, AFAC)은 SEM/EDS로 시편의 Si 함량을 측정하였다. 금속-세라믹 결합 강도 및 AFAC 결과는 t-test를 사용하여 분석하였다(α = .05). SLM 그리고 CAST Co-Cr 합금 사이의 결합 강도에 대해서는 유의한 차이가 발견되지 않았다(P>.05). SLM은 CAST 그룹보다 많은 세라믹 부착성(ceramic adherence)을 나타냈다(P<.001). 세라믹과 합금의 결합 강도는 제조 방법엥 영향을 받지 않았다. 그러나 SLM은 더 우수한 세라믹 부착성을 보였다. 이는 향후 임플란트 상부 보철물 제작에도 SLM으로 제작한 합금이 사용 가능한 것을 시사한다. CAST 방식의 단점을 극복하고 시간과 비용을 절약할 수 있을 것으로 기대된다.

• 대한치과기공학회지
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• 제38권2호
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• pp.69-77
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• 2016

Purpose: This study was to evaluate the shear bond strength of ceramic fused to Ni-Cr alloy(Alophaloy) by heat treatment. Methods: The specimens were divided into 5 groups according to heat treatment conditions prior to porcelain application. Eighteen specimens from each group were subjected to the shear load a universal testing machine using a 0.1mm/min cross-head speed and two specimens from each group were observed with SEM and EDX line profile. Results: The observation of the oxide film on the metal surface by SEM photograph showed a coarsening with an increasing degassing hold time. The diffusion of metal oxide was observed farther from the opaque layer in the heat treated specimen than no heat treated specimen. The shear bond strength measured highest to A5(55.23MPa) in the 10min holding group and measured lowest from A1(24.38MPa) in the no heat treated group, and there was a significant difference(p<0.05). Conclusion: The shear bond strength of Ni-Cr alloy improved in the heat treatment compared to the no heat treatment specimen.

• 대한치과보철학회지
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• 제32권1호
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• pp.47-76
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• 1994

This study was carried out to evaluate the effect of the crack propagation characteristics and bond stress of ceramo-metal system. In order to characterize the crack propagation, the static crack propagation stored in $37^{\circ}C$ distilled water of two commerical porcelains and the dynamic crack propagation under cyclic flexure load of ceramo-metal system were examined. In order to characterize the bond stress, the shear bond test, the 3-point flexure bond test, and the finite element stress analysis of ceramo-metal system were conducted. The results obtained were as follows : 1. Bulk densities and Young's moduli of opaque porcelains increased with repeated firing. 2. Maximum fracture toughness during 4 firing cycles showed at the group of 4 firing cycles in Ceramco porcelain and 2 firing cycles in Vita porcelain. 3. Shear bond strength and flexure bond strength of Ceramco-Verabond specimen were larger than those of Ceramco-Degudent G specimen (p<0.05). 4. Interfacial stresses under three point flexure bond test were concentrated at the edges of ceramometal system. 5. When a cyclic flexure load was applied, the crack growth rate of porcelain surface of ceramometal specimens was decreased as load cycles increased.

• 대한치과기공학회지
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• 제11권1호
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• pp.103-109
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• 1989

Bond strength between alloy and ceramic plays an important role in deciding the quaring the processing of metalceramic restorations. Now the author had an experiment on the measurement of bond strength differences accoding to the contents of recast alloy used during the processing of metal-ceramic restorations. In the experiment, Anusavice's Planar Interface Shear Bond Test was employed to determine the bond strength. Total 25 specimens were divided as 5 groups, that is, 5 specimens in a group respections : Group I (new alloy 100%) Group II (new 75%$\cdot$recast 25%), Group III (new 50%$\cdot$recast 50%), Group IV (new 25%$\cdot$recast 75%), Group V(recast 100%). All specimens examined micropically and respective strength values of the group specimens were checked simultaneously. The results were as follows, 1. In the analtsis of variance the result showed the significant differences of 1%(P<0.01) among the each group classifid according to the recast contents. 2. When the interfaces of specimens were examined with an electron microscope, the air bubble were evenly occurred in all the specimens, and the occurrence frequencies and the sizes of air bubble were different between Group I and Group III, especially marked different Group I and Croup V. 3. In respective verification of each group through T-test, between Group I and Group II, between Group I and Group III did not show significant differences. 4. There was significant difference between Group I and Group IV, between Group I and Group V as 1%(P<0.01). 5. In the Shear Bond Test of all the groups, Croup V showed the lowest value. Explanatoion of Figures Fig 1. Main fracture type of metal-porcelain interlace showed in group I, II, III from shear Bond Test resets. Fig 2. Main fracture type of metal-porcelain interface showed In group Ⅳ, Ⅴ form shear Bond Test resets. Air bubble and their size appeared around interface of metal-porcelain. Fig 3. Group I, Fig 4. Group II Fig 5. Group III, Fig 6. Group IV, Fig 7. Group V.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.109-110
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• 2016

The recent introduction of Metal spraying method apply to construction and civil steel structure is increasing. In applying the metal spraying lining process of construction and civil steel structure to secure the adhesion strength between the metal thermal spray coating and the steel structure and the highest priority requirements are required bond strength test reliable measurement accordingly. In this study, by calculating the deposition intensity and the standard deviation, coefficient of variation corresponding to the bonding area, unlike the shape of the attachment we compared the results.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4329-4335
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• 2014

본 연구의 목적은 금속 도재관과 지르코니아 도재관 보철물의 하부 구조물인 금속과 상부 도재의 결합강도 (금속군), 하부 구조물인 지르코니아와 상부 도재의 전단결합강도 (지르코니아군)를 결정함에 있어서 각각 하부 구조물인 금속과 지르코니아의 표면 처리를 다르게 하였을 때, 전단결합강도에 미치는 영향을 평가하고자 한다. 금속군에서는 금속 표면에 각각 아무 처리를 하지 않은 집단(NM), 모래분사를 실시한 집단(SM), 불투명 도재를 도포한 집단(OM), 모래분사와 함께 불투명 도재를 도포한 집단(SOM) 총 4집단으로 나누어 실시하였고, 지르코니아군에서는 아무 처리를 하지 않은 집단(NZ), 표면에 모래 분사를 실시한 집단(SZ), 지르코니아 표면에 이장재(지르라이너)를 처리한 집단(LZ), 모래분사와 이장재 처리를 함께한 집단(SLZ) 총 4집단으로 시편을 제작하였다. 금속군과 지르코니아군 각각의 4집단의 표면 처리에 따른 전단결합강도에 영향이 있는지 알아보기 위하여 SPSS를 사용하여 일원배치 분산분석을 시행하였다. 금속 도재관의 경우 하부 구조물인 금속 표면에 모래분사를 한 후 불투명 도재를 도포하는 것이 가장 권장되며, 지르코니아 도재관의 경우 하부 구조물인 지르코니아 표면에 모래분사를 한 후 지르라이너를 도포하는 것이 권장된다.

• 대한치과보철학회지
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• 제38권1호
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• pp.1-11
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• 2000

Relining and rebasing are essential for long-term success and oral health in removable prosthodontics. Major features of failures between metal base and relining resins are adhesive failure due to lack of chemical bonding. The purpose of this study was to find a better metal primer and metal surface treatment method that enhance the bonding strength with relining resin materials. The surfaces of ticonium alloys were treated with $25{\mu}m$ sandblasting (Group A), stone wheel(Group B), stone wheel and EZ oxisor(Group C), $75{\mu}m$ sandblasting(Group D) and EZ oxisor application after $75{\mu}m$ sandblasting(Group E). They were subdivided into no primer application (Group I), MR bond application(Group II) and Metafast bonding liner (Group III). Then specimens were completed though being bonded with relining resins. The specimens were stored in $38^{\circ}C$ water for 48 hours and tensile strength was measured using the universal testing machine. The results were as follows, 1. Primer application groups showed higher bond strength than no primer application group(p<0.05). 2. In comparison with primer application groups, MR bond group showed higher bond strength than Meta fast bonding liner application group(p<0.05). 3. In comparison with surface treatment methods, Bond strengths of group A and B were significantly different with group C, D, and E, and group C were significantly different with group D, and E in no primer application group()(0.05). In primer application groups, group A, B, C were significantly different with group D and E(p<0.05). According to results of this study, Metal primer application and metal surface roughening were considered to be advantageous for relining of metal base dentures.

• 대한치과기공학회지
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• 제33권1호
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• pp.37-45
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• 2011

Purpose: Heat pressed ceramics, used for all ceramic restorations, have the additional advantage of being technically less change through using of the lost-wax technique. Conceptually, combining the ceramic with the clinically proven reinforcing ability of a metal framework would be advantageous; however, cause of mismatching of fusion between ceramics and metal frameworks which from differences of casting temperature and coefficient of thermal expansion, pressed ceramics could not be used with a metal framework. The purpose of this study was to compare shear bond strength of press-to metal ceramic to porcelain fused non precious metal and feldspatic porcelain fused non precious metal. Methods: The 30 metal specimens were casted in a porcelain fused non precious metal nickel-chromium alloy. They were divided into 3 groups by surface treatment and applied ceramic: $125{\mu}m$ aluminium oxide sandblasting and veneered feldspatic porcelain (group FP), $125{\mu}m$ aluminium oxide sandblasting and had press-to-metal ceramic applied (group PC), porcelain bonder (gold bonder) fused on surface of metal specimens and had press-to-metal ceramic applied (group PCG). In each group 10 metal specimens were used. The press-to-metal ceramic applied 20 specimens had ash-free wax pattern applied, the metal-wax complexes invested, and were pressed with heat press ceramic. All specimens were subjected to shear bond strength test at a crosshead speed of 1.0 mm/min. Results: The results of measured in Mean SD and data were analyzed by one-way AVOVA (p= .05) and Tukey HSD test (p= .05).: group FP $16.090{\pm}1.841$ MPa, group PC $12.620{\pm}1.8256$ MPa, group PCG $10.920{\pm}0.9283$, significant differences between all groups (p < .05). Significant differences were found in each between group FP and group PC, group FP and group PCG (p < .05). Conclusion: The shear bond strength of press-to-metal ceramic to porcelain fused non precious metal was described higher in unused gold bonder group than used gold bonder groups.

• 대한치과교정학회지
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• 제22권2호
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• pp.289-296
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• 1992

The purpose of this study was to evaluate and compare the shear bond strengths and failure sites of metal brackets bonded with chemically cured adhesive and light-cured adhesive. 10 brackets were bonded on prepared enamel surfaces with $Transbond^{circledR}$ (Unitek/3M; U.S.A.) light-cured orthodontic adhesive and another 10 brackets were bonded with $Ortho-one^{\circledR}$ (Bisco:U.S.A.) chemically cured orthodontic adhesive. 24 hours after bonding, the Instron universal testing machine was used to measure the shear bond strengths. The failure sites were examined under streoscopic microscope. The results were as follows: 1 . The mean shear bond strength of metal brackets bonded with light-cured adhesive was lower than that of metal brackets bonded with chemically cured adhesive, but the difference was not statistically significant (p < 0.05). 2. Regardless of the type of adhesives, the brackets were failed primarily at the bracket base-adhesive interface. 3. Bonding of metal brackets with light-cured adhesive is considered to be clinically acceptable.

• 한국재료학회지
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• 제10권8호
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• pp.532-539
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• 2000

Diamond 공구용 Co-0.5C-(15∼20)Cr-20Ni-8W-(2∼7)Fe 합금 결합제를 볼밍링(ball-milling)법과 기계적 합금화(mechanical alloying) 법으로 합성하였다. stearic acid의 첨가 유무에 상관없이 Co-0.5C-(15∼20)Cr-20Ni-8W-(2∼7)Fe 합금의 경우 6시간 동안 합금화된 금속 분말에서 미세 접합(micro welding) 형상이 균일하게 관찰되었다. stearic acid를 첨가하지 않을 때는 부분적으로 조대화된 분말이 형성되었으나 2% 첨가한 경우 미세하고 판상의 분말이 얻어졌다. stearic acid가 첨가된 복합분말을 열간 압축하여 기계적 성질을 평가한 결과 굽힘강도 1100MPa, 경도 46H(sub)Rc의 특성을 나타냈다.