| Project/Area Number |
61570928
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
補綴理工系歯学
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| Research Institution | Osaka University |
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Principal Investigator |
KIMURA Hiroshi Osaka University Faculty of Dentistry Professor, 歯学部, 教授 (70036218)
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| Co-Investigator(Kenkyū-buntansha) |
OKAZAKI Masayuki Osaka University Faculty of Dentistry Assistant Professor, 歯学部, 講師 (30107073)
SOHMURA Taiji Osaka University Faculty of Dentistry Research Assistant, 歯学部, 助手 (10154692)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | implant / thermal spraying / shape memory alloy / TiーNi / Ti / Ti系合金 / Ti-Ni |
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| Research Abstract |
Recently, many implants with several materials are utilized. In the case of metal implant, higher corrosion resistance is required. The porous surface of the implant is effective to obtain the high adhesion with living bone. In the present study the corrosion resistance in some Ti base alloys were investigated in 1% NaCl water solution by means of the anodic polarlization measurement, which instrument was equipped by the present grant-inaid. In Ti-6Al-4V and especially in TiNi shape memory alloys which is used for dental implant, the corrosion resistance at sample edge and surface with high surface roughness was found to decrease seriousely. The prepolarlization treatment to increase the corrosion resistance was attempted and the dissolution current density in Ti-6Al-4V was decreased to 1/100 relative to that of febore treatment. On the other hand. in TiNi alloys any treatments including oxide film coating, TiN and TiCN coating by means of PVD and CVD method couldn't improve the corrosion resistance when they were fairly plastic deformed upon shape memory effect, and the pitting corrosion occurred at even 500 mV and dissolution of toxic Ni was recognized. This results conclude that TiNi alloy is unsuitable for implant materials. Thermal spraying of Ti under depressured atmosphare was attempted on Ti. Ti-6Al-4V alloys in order to obtain the porous metal surface. Anodic polarlization measurements were carried out. In the case of as sprayed specimen the serious dissolution of Ti was observed, but it was fairly depressed after the heat treatment at 950 C under vacuum for an hour, and besides. High adhesion between coated layer and matrix was obtained without losing the porousity on the surface. At present the implants with sprayed surface by Ti are commercially available, but the dissolution of Ti in the human body may be possible if it is used as sprayed. Heat treatment mentioned above is necessary for biocompatible implant.
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