Development of cement for endodontic therapy consisting of bioactive glass, alpha-TCP, and poly-glutamic acid

• Project/Area Number: 15K11141
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Conservative dentistry
• Research Institution: Fukuoka Dental College
• Principal Investigator: Izumi Toshio 福岡歯科大学, 口腔歯学部, 准教授 (40248547)
• Co-Investigator(Kenkyū-buntansha): 丸田 道人 福岡歯科大学, 口腔歯学部, 講師 (40507802) ; 畠山 純子 福岡歯科大学, 口腔歯学部, 助教 (50374947)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 生体活性ガラス / ストロンチウム / ポリグルタミン酸 / 骨形成 / γ-ポリグルタミン酸 / 骨形成能 / 硫酸カルシウム / セメント / 穿孔 / 封鎖 / 歯内治療 / αTCP

Outline of Final Research Achievements

In order to avoid washing away or dissolution of the particles during the bleeding at the bone defects, we made the hardened material that consists of Bioactive glass (BAG) particles and γ-poly-glutamic acid (PGA). BAG without Sr(Sr0), and BAG (Sr100) containing 20SrO (wt%) were prepared. Then we mixed the powders and 5%γ- PGA, and got the discs. At 3 months after the operation, new bone formation was not observed around the Sr0 discs and at the center of the defects. New bone formation was observed at the surfaces of the Sr100 discs, and on the dura mater. New bone formation of Sr100 disc group increased than that of Sr0 disc group significantly. The present study suggested that Sr-containing BAG discs should be maintained in the bone defects, and that Sr released from the disc should enhance osteogenesis at rat calvarial defects. The endodontic application of the disc should be further considered.

Academic Significance and Societal Importance of the Research Achievements

BAGを歯内治療に応用したものとして、根管充填材の成分の一つとして使用した報告はあるが、その他の応用例はほとんどない．また、Sr-BAGを歯内治療に応用した報告はない。ガラス粒子のみを封鎖材として使用する場合、粒子径が大きいと粒子間の隙間が死腔になり感染を起こしやすく硬組織形成を阻害することになり、逆に小さすぎると大食細胞による異物反応が生じ炎症を引き起こす。粒子間の死腔をなくすため、および、組織液と接触した粒子が拡散しないためにも結合材を用いる必要がでてきた．結合材としてγ-PGAとリン酸溶液を初めて応用した．

Research Products

• [Journal Article] Micro-computed Tomographic and Histopathological Study on Osteogenic Ability of Bioactive Glass Disc Containing Strontium (2018)
  • Author(s): 泉 利雄, 丸田 道人, 水上 正彦, 松本 典祥, 畠山 純子, 中山 英明, 小嶺 文誉, 松崎 英津子, 阿南 壽
  • Journal Title: The Japanese Journal of Conservative Dentistry Volume: 61 Issue: 6 Pages: 378-387
  • DOI: 10.11471/shikahozon.61.378
  • NAID: 130007543131
  • ISSN: 0387-2343, 2188-0808
  • Peer Reviewed / Open Access
• [Presentation] ストロンチウム含有試作生体活性ガラスディスクの骨形成能 マイクロCT画像と病理組織像による検討 (2019)
  • Author(s): 泉 利雄, 丸田 道人, 水上 正彦, 松本 典祥, 畠山 純子, 中山 英明, 小嶺 文誉, 松崎 英津子, 阿南 壽
  • Organizer: 歯科保存学会春季学術大会
• [Presentation] Reparative dentin bridge formation on rat exposed dental pulp by bioactive glass containing strontium / calcium sulphate composite (2016)
  • Author(s): Toshio IZUMI, Michito MARUTA, Noriyoshi MATSUMOTO, Junko HATAKEYAMA, Masahiko MINAKAMI, Hideaki NAKAYAMA, Misaki NIKAIDO, Etsuko MATSUZAKI, Shigeki MATSUYA, Hisashi ANAN
  • Organizer: International Association for Dental Research (IADR) Pulp Biology Regeneration Group (PBRG) Symposium 2016
  • Place of Presentation: Nagoya, JAPAN
  • Year and Date: 2016-06-26
  • Int'l Joint Research