Bioactivation of oxide ceramics and clarification of the strength degradation mechanism

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02030
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Kobayashi Satoshi 東京都立大学, システムデザイン研究科, 教授 (80326016)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: イオン注入 / 生体活性 / 酸化物セラミックス / 表面処理

Outline of Final Research Achievements

We have developed a method to impart bioactivity by immersing a zirconia material (3Y-TZP, ATZ) in a solution of NaOH or H3PO4 at 95 C for 7 days. The amount of apatite formed was higher with H3PO4 treatment than with NaOH. In particular, on 3Y-TZP treated with H3PO4, almost the entire surface was covered with an apatite layer, showing high apatite forming ability. In addition, a biaxial bending test and measurement of the monoclinic crystal ratio, which is an index of zirconia deterioration, were performed. As a result, the biaxial bending strength of 3Y-TZP and ATZ materials did not decrease even after treatment with NaOH or H3PO4, but about 30% of tetragonal zirconia was transformed into monoclinic crystals. Therefore, a zirconia material that can suppress deterioration and a treatment method thereof are desired.

Free Research Field

生体材料，複合材料

Academic Significance and Societal Importance of the Research Achievements

アルミナやジルコニアといった酸化物セラミックスは，機械的特性に優れ耐摩耗特性なども有し，生体組織と有害な反応を起こさないが，逆に生体活性に乏しい，本研究により，生体活性発現のメカニズムが明らかとなり，また，そのメカニズムに基づき，酸化物セラミックス表面に対し，選択的に生体活性を付与することを可能とする手法が開発されたことは，今後の表面処理技術開発における指針を与えるものであり，学術的に意義があると考えられる．また，単一材料での大規模骨欠損の治療への適用可能性が明らかとなった．これにより患者のQuality of Lifeの向上に寄与することが期待され，社会的意義も深いと考える．