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The Bulletin of Tokyo Dental College May 2000Dental alloy surface finishing procedures of may influence their electrochemical behavior, which is used to evaluate their corrosion resistance. We examined the... (Comparative Study)
Comparative Study
Dental alloy surface finishing procedures of may influence their electrochemical behavior, which is used to evaluate their corrosion resistance. We examined the polarization resistance and potentiodynamic polarization profile of the precious-metal alloys, Type 4 gold alloy and silver-palladium alloy, and the base-metal alloys, nickel-chromium alloy, cobalt-chromium alloy, and CP-titanium. Three types of finishing procedure were examined: mirror-finishing using 0.05 micron alumina particles, polishing using #600 abrasive paper and sandblasting. Dissolution of the alloy elements in 0.9% NaCl solution was also measured and compared with the electrochemical evaluation. The corrosion resistance of the dental alloys was found to relate to finishing as follows: The polarization resistance and potentiodynamic polarization behavior revealed that the corrosion resistance improved in the order of sandblasting, #600-abrasive-paper polishing, and mirror-finishing. While the corrosion potential, critical current density and passive current density varied depending on the type of finishing, the transpassive potential remained unchanged. The influence of finishing on the corrosion resistance of precious-metal alloys was less significant than on that of base-metal alloys. A mirror-finishing specimen was recommended for use in evaluation of the corrosion resistance of various dental alloys.
Topics: Alloys; Aluminum Oxide; Chromium Alloys; Corrosion; Dental Alloys; Dental Polishing; Electric Impedance; Electrochemistry; Gold Alloys; Humans; Materials Testing; Palladium; Paper; Potentiometry; Silicon Dioxide; Silver; Sodium Chloride; Solubility; Surface Properties; Titanium
PubMed: 11212579
DOI: 10.2209/tdcpublication.41.49 -
Journal of Prosthodontics : Official... Jul 2015The aim of this study was to evaluate changes in electrochemical corrosion properties of porcelain firing simulated nickel-chromium dental casting alloy exposed to a 10%...
PURPOSE
The aim of this study was to evaluate changes in electrochemical corrosion properties of porcelain firing simulated nickel-chromium dental casting alloy exposed to a 10% hydrogen peroxide bleaching agent.
MATERIALS AND METHODS
The electrochemical corrosion behavior of a Ni-Cr alloy was evaluated by cyclic polarization test in the aerated electrolyte (pH = 6.5). Test groups were produced in as-cast (group 1, control group) and simulated porcelain firing (group 2: heat-treated/mean value; group 3: heat-treated/cycle) conditions. Scanning electron microscopy (SEM) was also used to examine the alloy surfaces before and after the corrosion test.
RESULTS
The ranking of the groups with respect to Ecorr and Icorr was as follows: 1, 2, 3 and 3, 1, 2, respectively. Group 3 exhibited the greatest and group 2 displayed the least corrosion tendencies. An increase in corrosion rates was observed after heat treatment/cycle state. Post-corrosion SEM photographs were also consistent with the test results.
CONCLUSION
Within the parameters of this study, a single heat treatment is insufficient to cause upheaval in corrosion behavior of a Ni-Cr alloy subjected to 10% hydrogen peroxide.
Topics: Chromium Alloys; Corrosion; Dental Alloys; Dental Porcelain; Hydrogen Peroxide; Surface Properties
PubMed: 25313456
DOI: 10.1111/jopr.12215 -
Journal of Dental Research Jun 1991Ten dental casting alloys were tested for alloy-element release into cell-culture medium, and this release was related to alloy composition, alloy microstructure, and...
Ten dental casting alloys were tested for alloy-element release into cell-culture medium, and this release was related to alloy composition, alloy microstructure, and alloy cytotoxicity (previously determined). Cell-culture medium was analyzed for alloy elements by flame atomic absorption. Concentrations of elements in the medium were normalized by dividing them by their atomic abundance in the alloy, giving element medium-alloy ratios (EMA ratios). Results showed that Au, In, and Pd generally did not dissolve into the medium, but that Ag, Cd, Cu, Ga, Ni, and Zn frequently dissolved. Comparison of EMA ratios for Ag, Cu, and Zn showed that each element retained a behavioral identity in diverse metallurgical environments, but that these environments influenced the release behavior to some degree. Some EMA ratios in multiphase alloys were greater than those in solid solutions, and EMA ratios showed great diversity within all the alloys. Nominal composition seemed to be of little value in the prediction of metal release unless the composition supported multiple-phase formation. In addition, release of alloy elements did not, in itself, completely predict alloy cytotoxicity measured previously. However, cytotoxicity was associated with metal release in each case. The commercial alloys used in this study exhibited more complex and less predictable release behavior than did the simpler ternary alloy systems used by previous investigators. It is believed that the use of commercial preparations is necessary for their in vivo behavior to be modeled.
Topics: Copper; Culture Media; Dental Alloys; Dental Casting Investment; Dental Polishing; Diffusion; Palladium; Silver; Spectrophotometry, Atomic; Time Factors; Zinc
PubMed: 2045570
DOI: 10.1177/00220345910700060301 -
Kokubyo Gakkai Zasshi. the Journal of... Dec 1973
Topics: Dental Alloys; Dental Amalgam; Gallium
PubMed: 4527373
DOI: No ID Found -
DE; the Journal of Dental Engeering 1983
Topics: Dental Alloys; Dental Casting Investment; Dental Casting Technique; Nickel; Titanium
PubMed: 6414768
DOI: No ID Found -
Shanghai Kou Qiang Yi Xue = Shanghai... Feb 2020To study the change of ion precipitation and surface roughness of three dental alloys'coexisting in standard electrolyte solution, in order to provide a reference for...
PURPOSE
To study the change of ion precipitation and surface roughness of three dental alloys'coexisting in standard electrolyte solution, in order to provide a reference for the selection of clinical alloy materials.
METHODS
Standard samples of Ni-Cr alloy, Co-Cr alloy and Au-Ag-Pd alloy were prepared and divided into 5 groups: Ni-Cr alloy(group N), Co-Cr alloy(group C), Au-Ag-Pd alloy(Group A), Ni-Cr alloy contact with Au-Ag-Pd alloy(group NA), Ni-Cr alloy contact with Co-Cr alloy(group NC). All groups of alloys were soaked in standard electrolyte solution (T=37 ℃, pH=2.31) for 7 days. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the amount of ions released from each group. The surface morphology of each group was observed and the surface roughness(Ra) was measured using atomic force microscope(AFM). SPSS 18.0 software package was used for statistical analysis.
RESULTS
The amount of nickel ions released from group N, NA, NC was (1.32±0.03) μg/cm, (2.13±0.07) μg/cm, (1.53±0.08) μg/cm, respectively. Nickel ions of group NA and NC was significantly more than that of group N(P<0.05), nickel ions of group NA was significantly more than that of group NC(P<0.05). The amount of chromium ions released from group N, NA, NC was (0.06±0.01) μg/cm, (0.08±0.01) μg/cm, (0.05±0.01) μg/cm, respectively, the amount of chromium ions of group NA was significantly more than that of group NC(P<0.05). The surface roughness of Ni-Cr alloy in group N, NA, NC was (4.60±0.16) nm, (5.37±0.08) nm, (5.04±0.15) nm, respectively. The surface roughness of Ni-Cr alloy in group NA and group NC was significantly larger than that in group N (P<0.05). When contact with Au-Ag-Pd alloy or Co-Cr alloy, the amount of nickel ions released and the surface roughness of Ni-Cr alloy both significantly increased. Compared with Co-Cr alloy, Au-Ag-Pd alloy caused Ni-Cr alloy to release more nickel, chromium ions and formed a rougher surface.
Topics: Chromium Alloys; Dental Alloys; Ions; Materials Testing; Nickel; Surface Properties
PubMed: 32524119
DOI: No ID Found -
PloS One 2021Due to the characteristics of high strength, high chemical activity and low heat conduction, titanium alloy materials are generally difficult to machine. As a typical...
Due to the characteristics of high strength, high chemical activity and low heat conduction, titanium alloy materials are generally difficult to machine. As a typical titanium alloy with higher strength and lower heat conductivity, the machinability of titanium alloy TC21 is very poor and its cutting process is companied with larger cutting force and rapid tool wear. Straight-tooth milling tool is often used to cut the groove and side surface in the titanium alloy parts. And the milling method can be used to investigate the cutting mechanism because the cutting force has only two components and the better chip morphology is obtained. To investigate the straight-tooth milling process of TC21 alloy, a series of milling force experiments have been done. In addition, a 3D finite element model (FEM) for the straight-tooth milling process of TC21 alloy is presented to simulate the milling process. In the model, the constitutive material model, the failure model, the friction model and the heat transfer model were adopted. Through the simulation, chip formation, stress distribution, cutting force and milling temperature were obtained. The cutting force reaches its maximum when the spindle speed reaches about 13000 rpm, and then decreases as the speed continues to increase. The results confirmed that the similar "Salomon" phenomenon existed in the cutting process of TC21 alloy.
Topics: Computer Simulation; Dental Alloys; Dental Soldering; Finite Element Analysis; Titanium
PubMed: 34649269
DOI: 10.1371/journal.pone.0258403 -
DE; the Journal of Dental Engeering 1980
Topics: Dental Alloys
PubMed: 6774855
DOI: No ID Found -
Journal of Biomedical Materials Research Nov 1972
Topics: Crystallization; Dental Alloys; Dental Amalgam; Mercury; Microscopy, Electron, Scanning; Silver; Tin; X-Ray Diffraction
PubMed: 4642984
DOI: 10.1002/jbm.820060607 -
The Journal of Prosthetic Dentistry Jan 1986
Topics: Chemical Phenomena; Chemistry, Physical; Chromium Alloys; Dental Alloys; Dental Casting Technique; Surface Properties; Tensile Strength
PubMed: 3511224
DOI: 10.1016/0022-3913(86)90087-9