| Project/Area Number |
05557087
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
WATARI Fumio HOKKAIDO UNIVERSITY,SCHOOL OF DENTISTRY,PROFESSOR, 歯学部, 教授 (70158682)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIMOTO Takeo KOBE STEEL,LTD., DEPARTMENT OF TECHNOLOGY,CHIEF RESEARCH INVESTIGATOR, 技術部・第二技術室, 次長
OHKAWA Syoji HOKKAIDO UNIVERSITY,SCHOOL OF DENTISTRY,RESEARCH ASSOCIATE, 歯学部, 助手 (40001945)
KONDO Seiichiro HOKKAIDO UNIVERSITY,SCHOOL OF DENTISTRY,ASSOCIATE PROFESSOR, 歯学部, 助教授 (80018431)
塙 隆夫 北海道大学, 歯学部, 助手 (90142736)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥12,400,000 (Direct Cost: ¥12,400,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥12,000,000 (Direct Cost: ¥12,000,000)
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| Keywords | Functionally gradient materials / Implant / Biobompatibility / Atomic force microscopy / In situ observation / Mechanical properties / Titanium / Apatite / 歯科用インプラント / 人工歯根 / CIP |
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| Research Abstract |
To apply functionally gradient materials (FGM) for dentistry and develop for clinical use the functionally gradient dental implants composed of the metal titanium (Ti) and ceramics hydroxyapatite (HAP) were made and tested. HAP,which has the excellent biocompatibility with bone, is brittle and easily results in fracture in the ptactical use. Ti, one of the best biocompatible metals, can maintain the mechanical toughness. The implant was designed to provide more Ti for the upper part where the occlusal force is directly imposed and more HAP for the lower part which is implanted in side the jawbone. After the fundamental research of preparation method, choice of materials, mechanical test and microanalysis, animal test was done to estimate the biocompatibility. The in-situ observation of change of surface morphology of human enamel and dentin immersed in etching agents was also done using atomic force microscopy. The principal accomplishments were as follows ;
1.Preparation : Mixed powders with the different composition packed from part to part into the silicon rubber mold were compressed at the pressure 400MPa by CIP.The compact was sintere in the argon gas by high frequency induction heating at 1300ﾟC.
2.Mechanical Properties : The compressive and flexural tests were done. The average flexural strength of the FGM specimens was 150 MPa which is approximately comparative to the human bone strength.
3.Observation & Analysis : The surface and cross-section observed by optical and electron microscopy showed the distribution of porosity and HAP in the Ti matrix. The gradual change of concentration was confirmed by the analysis of elemental distribution using EPMA.
4.Biocompatibility : The implant test into the femora of rats was done to estimate the biocompatibility. Newly formed bone was partially in contact with the implant in the case of Ti, wheras in the Ti/HAP FGM new bone was in contact with the most part of the implant.
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