• 대한치과기공학회지
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• 제7권1호
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• pp.53-59
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• 1985

This paper aims to examine baes metal alloy in all its aspects - the roles of elements, the content of every element according to uses, characters, laboratory technique methods and the kind of artificial base metal alloy registered in A.D.A. Specification. The results are as follows; 1. Base metal alloy is used widely bacaues it is rather cheap, but it should be handled appropriately in operating because its quality is bad. 2. Classifying base metal alloy, it is classified into Co-Cr alloy, Ni-Cr alloy, and Ni-Cr-Co alloy according to element, it is classified into partial denture alloy, surgical alloy and crown & bridge alloy according to use. 3. Among elements of base metal alloy, Bellium lowers the melting point of the alloy and increases the strength, but the amount should be limited when it is used because it destroys the organization of a living body. 4. The investments for base metal alloy are ethyl silcate bonded investment and phosphate bonded investment which endure well at high burn out temperature. 5. A.D.A specification No.14 in Kore contains Niranium, Nobilium, regalloy, Ticonium and Vitallium.

• The Journal of Advanced Prosthodontics
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• 제6권5호
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• pp.372-378
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• 2014

PURPOSE. The porcelain fused to gold has been widely used as a restoration both with the natural esthetics of the porcelain and durability and marginal fit of metal casting. However, recently, due to the continuous rise in the price of gold, an interest towards materials to replace gold alloy is getting higher. This study compared the bond strength of porcelain to millingable palladium-silver (Pd-Ag) alloy, with that of 3 conventionally used metal-ceramic alloys. MATERIALS AND METHODS. Four types of metal-ceramic alloys, castable nonprecious nickel-chrome alloy, castable precious metal alloys containing 83% and 32% of gold, and millingable Pd-Ag alloy were used to make metal specimens (n=40). And porcelain was applied on the center area of metal specimen. Three-point bending test was performed with universal testing machine. The bond strength data were analyzed with a one-way ANOVA and post hoc Scheffe's tests (${\alpha}=.05$). RESULTS. The 3-point bending test showed the strongest ($40.42{\pm}5.72$ MPa) metal-ceramic bond in the nonprecious Ni-Cr alloy, followed by millingable Pd-Ag alloy ($37.71{\pm}2.46$ MPa), precious metal alloy containing 83% of gold ($35.89{\pm}1.93$ MPa), and precious metal alloy containing 32% of gold ($34.59{\pm}2.63$ MPa). Nonprecious Ni-Cr alloy and precious metal alloy containing 32% of gold showed significant difference (P<.05). CONCLUSION. The type of metal-ceramic alloys affects the bond strength of porcelain. Every metal-ceramic alloy used in this study showed clinically applicable bond strength with porcelain (25 MPa).

• 대한치과기공학회지
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• 제35권2호
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• pp.89-95
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• 2013

Purpose: The purpose of this study was to evaluate bond strength of Metal Disk alloy and casting alloy. Methods: Metal specimens were divided into 4 groups for each alloy. Three point flexural test were used to measure the bond strength of CAD/CAM metal alloy and casting alloy. Statistical analysis was done using the Statistical Package for Social Sciences version 19.0 for Windows. As for the analysis methods, the study used Kruskal-Wallis test. Results: The average bonding strengths of Group 1 to porcelain was $36.7{\pm}9.90$ MPa, Group 2 to porcelain was $37.68{\pm}4.51$ MPa, Group 3 to porcelain was $36.43{\pm}6.57$ MPa, Group 4 to porcelain was $42.88{\pm}6.81$ MPa, Each group was not significantly different. Conclusion: Bond strength of Casting alloy is equal to or higher than bond strength of CAD/CAM Metal Disk alloy. Alloy clinical bond strength is 25 MPa, So CAD/CAM Metal Disk alloy can be used as dental material.

• 한국응용과학기술학회지
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• 제26권1호
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• pp.69-73
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• 2009

Copper alloy metal fiber was incorporated into the conventional water-soluble metal working fluids to increase the antimicrobial activity. Fluid treated by copper alloy metal fiber is shown that bacteria is disappeared whereas that untreated metal fiber is increased bacteria as increasing the life time. When the electrochemical potential of Cu/Zn ion is -268mV, radicals with molecular oxygen are easily made. Especially, hydroperoxide radical shows strong toxicity to the strains, leading to the conformational change of plasma membrane. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

• 대한치과기공학회지
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• 제9권1호
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• pp.21-29
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• 1987

The purpose of this investigation was to determine the effect of recasting on the castability and physical properties of the nonprecious metal alloy. Using 2 sorts of the nonprecious metal alloy for production of Crown and Bridge prosthetics, such as 1) sankin C. B 80 metal 2) C & B alloy, the result of experimental research on the castability and hardness according to the recasting, is as followes; 1. The difference of castability between sankin CB80 metal and C & B alloy was statistically significant (p < 0.01) and the difference of castability among the test groups, was statistically significant (p <0.01). 2. In the case of sankin C.B 80 metal, the difference of castability among the New alloy and first mixed alloy and second mixed alloy and old alloy was not significant statistically (p >0.05). 3. In the case of C & B alloy, the difference of castability among the New alloy and mixed alloys and old alloy, was not significant statistically (p >0.05). 4. The difference of hardness between sankin C & B alloy was not significant statistically (p >0.05), but the difference of hardness among the test groups was statistically significant (p <0.01). 5. In the case of Sankin C.B 80 metal, the difference of hardness among the new ally and mixed alloys and old alloy was not significant statistically (p >0.05). 6. In the case of C & B alloy, the difference of hardness between New alloy and mixed alloys was not significant statistically (p >0.05) but the difference of hardness among the old alloy and New alloy and mixed alloys was statistically significant (p <0.01).

• 대한치과기공학회지
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• 제34권4호
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• pp.337-344
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• 2012

Purpose: This study examined the corrosion level by alloy type and pH, and used the corrosion levels as the dental health data. The study utilized one Ni-Cr alloy for the full and removable partial denture metal frameworks and two Ni-Cr alloys for porcelain-fused-to-metal crown, among the non-beryllium dental casting non-precious Ni-Cr alloys. Methods: The alloy specimens were manufactured in $10cm^2$ and stored in the corrosive solution(pH 2.2-4.4) in the electrical water bath($37^{\circ}C$) for seven days. Afterwards, the metal ions were quantitatively analyzed using the ICP. Results: Of the three metal alloys, Bellabond-Plus$^{(R)}$alloy and SOLIBOND N$^{(R)}$alloy, with 22% or higher chrome chemical contents, had higher corrosion resistance than Jdium-100$^{(R)}$alloy with 20% chrome chemical content. In all three alloys, the corrosion of Ni was highest, and metal ion corrosion was higher in the pH 2.2 corrosive solution. Conclusion: Although Ni-Cr alloy was not very corrosive, a Ni-allergic patient should not have Ni-Cr alloy prosthesis. The Ni-Cr alloy for porcelain-fused-to-metal crown should be designed for the dental porcelain to cover the whole crown.

• 한국응용과학기술학회지
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• 제24권3호
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• pp.233-237
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• 2007

This study is focused on the possibility of copper alloy metal fiber for an antimicrobial activity in the water soluble metal working fluids. Electrochemical potential of Cu/Zn ion is -268mV, and easily makes radicals with molecular oxygen. Especially, hydroperoxide radical shows strong toxicity to the strains. Plasma membrane causes conformational change when hydroperoxide radical binds to plasma membrane. Elution of copper ion from copper alloy metal fiber is detected in metal working fluid. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

• 대한치과기공학회지
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• 제35권4호
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• pp.359-364
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• 2013

Purpose: This study was to observe characteristic of metal oxidation and bonding strength according to composition of Ni-Cr alloy for porcelain fused to metal crown. The three kinds of Ni-Cr alloy with different composition ratio of parent metal were observed general properties and chemical properties of each alloy surface and measured the shear bonding strength between ceramic and each alloys. The aim of study was to suggest the material for design of parent metal's composition ratio to development of alloy for porcelain fused to metal crown. Methods: The three kinds of alloy as test specimen was Ni(59wt%)-Cr(24wt%), Ni(67wt.%)-Cr(16wt.%) alloy and Ni(71wt%)-Cr(12wt%)alloy. The oxide on surface was observed by EDX. And the shear test was performed by MTS. Results: The surface property and oxide characteristic analysis of oxide layer, weight percentage of Element O within $Ni_{59}Cr_{24}$ alloy measured 23.03wt%, $Ni_{67}Cr_{16}$ alloy measured 21.13wt% and $Ni_{71}Cr_{12}$ alloy was measured 48.55wt%. And the maximum shear bonding strength was measured 58.02Mpa between $Ni_{59}Cr_{24}$ alloy and vintage halo(H2 group). Conclusion: The surface property and oxide characteristic three kind of Ni-Cr alloy was similar. and shear bonding strength showed the highest bonding strength in H2 specimens.

• 한국재료학회지
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• 제24권8호
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• pp.393-400
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• 2014

NiO catalysts were successfully coated onto FeCrAl metal alloy foam as a catalyst support via a dip-coating method. To demonstrate the optimum amount of NiO catalyst on the FeCrAl metal alloy foam, the molar concentration of the Ni precursor in a coating solution was controlled, with five different amounts of 0.4 M, 0.6 M, 0.8 M, 1.0 M, and 1.2 M for a dip-coating process. The structural, morphological, and chemical bonding properties of the NiO-catalyst-coated FeCrAl metal alloy foam samples were assessed by means of field-emission scanning electron microscopy(FESEM), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), X-ray diffraction(XRD), and X-ray photoelectron spectroscopy(XPS). In particular, when the FeCrAl metal alloy foam samples were coated using a coating solution with a 0.8 M Ni precursor, well-dispersed NiO catalysts on the FeCrAl metal alloy foam compared to the other samples were confirmed. Also, the XPS results exhibited the chemical bonding states of the NiO phases and the FeCrAl metal alloy foam. The results showed that a dip-coating method is one of best ways to coat well-dispersed NiO catalysts onto FeCrAl metal alloy foam.

• 대한치과기공학회지
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• 제35권2호
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• pp.105-112
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• 2013

Purpose: This study was to analyze the castability, surface oxide characteristic of Co-Cr alloy for porcelain fused to metal crown and the bonding strength of porcelain fused to metal crown. Co-Cr and Ni-Cr alloy for porcelain fused to metal crown was used for tests of the castability and surface oxide state and shear bonding strength by various porcelain. The aim of this study was to suggest the differences of result according to Co-Cr and Ni-Cr alloy. Methods: The kinds of alloy as test specimen was Co-Cr and Ni-Cr alloy. The castability index on the alloy specimens. The surfaces of two alloys were analyzed by SEM and EDX in order to observe oxide characteristic. And the shear test was performed by MTS. Results: The castability index of Co-Cr alloy was 96.8% and Ni-Cr alloy was 94.4%. The strongest bonding strength of Co-Cr alloy was shown 67.37 MPa. Conclusion: The shear bonding strength between Co-Cr alloy and EX3 porcelain was the strongest comparing with others. And all of each alloy was indicated as same level about the castability.