| Project/Area Number |
12470426
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | The Nippon Dental University |
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Principal Investigator |
NAKAYAMA Masahiko The Nippon Dental University, Department of Dental Materials Science, Associate Professor, 歯学部, 助教授 (90095068)
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| Co-Investigator(Kenkyū-buntansha) |
ANDO Nobuo The Nippon Dental University, Department of Dental Materials Science, Associate Professor, 歯学部, 助教授 (00095051)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥10,800,000 (Direct Cost: ¥10,800,000)
Fiscal Year 2001: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2000: ¥10,400,000 (Direct Cost: ¥10,400,000)
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| Keywords | dental alloys / titanium / corrosion / galvanic corrosion / galvanic potential / corrosion products / fluorescent X-ray / electrolytes |
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| Research Abstract |
(1) Anodic polarization measurements were performed for 13 kinds of dental alloys and 7 pure metals in five kinds of solutions. The polarization curves were very different depending on alloy constitutions and solutions. The lactic and nitric acid solutions were not active for most of alloys. The sodium sulfide solution was the most active for all of the alloys.
(2) The precipitated materials in the solution was analyzed by the fluorescent X-ray analysis. In gold alloys Au and Cu first precipitated. Ag precipitated at the higher potential. In Ag-Pd-Cu-Au alloy, first Cu precipitated and at the higher potential, all of the composition elements precipitated.
(3) Titanium and alloy specimens were connected and measured the polarization curve. In most cases, the curve was consistent with the either curve of titanium or alloy. Some exceptional cases were found. The area ratio (alloy/Ti) was changed between 0.5 and 2.0, but large change was not found.
(4) Titanium and alloy specimens were connected and immersed in the sodium sulfide solution for 3 days at 35℃. The reflectance change was used to estimate the color-change. The difference between single and connected immersion was small. Precipitation of the alloy component was not detected by the fluorescent X-ray analysis.
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