Low-Energy Electron Beam Irradiation Prevents Fracture of Dental Cutting (CAD/CAM) Resin

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K09657
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Niigata University
• Principal Investigator: Kanatani Mitsugu 新潟大学, 医歯学系, 講師 (40177499)
• Co-Investigator(Kenkyū-buntansha): 木村 勇雄 新潟大学, 自然科学系, 教授 (00169921) ; 伊藤 圭一 明倫短期大学, 歯科技工士学科, 准教授 (60389955)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 低エネルギー電子線 / LEB / 歯科切削加工用レジン / CAD/CAMレジン / 接触角 / せん断接着強さ / 濡れ

Outline of Final Research Achievements

The effect of low-energy electron beam (LEB) irradiation on the bond strength of composite resins for CAD/CAM was investigated. Three types of resin were prepared without and with LEB irradiation. Contact angles were determined from lateral droplet images of each resin surface. In addition, copper cylinders were bonded and fixed to each resin with Superbond, immersed in distilled water at 37°C for 24 hours, and then subjected to shear tests.
The contact angle of distilled water was 62-72° without LEB and 19-22 with LEB, and the shear bond strength was 14-23 MPa without LEB and 27-34 with LEB. Significant differences were observed in both contact angle and shear bond strength. LEB irradiation was tested at least 50 hours after irradiation in anticipation of an outsourcing request, which was confirmed to be valid.

Free Research Field

歯科理工学

Academic Significance and Societal Importance of the Research Achievements

低エネルギー電子線(LEB)照射装置は現時点では高額なため、歯科医院や歯科技工所に照射装置を設置することには無理がある。そこで、LEB照射は外部委託を想定した。LEB照射後のCAD/CAM用コンポジットレジンを宅配・郵送した後に口腔内装着することを想定して、照射後50時間以上経過後に接触角測定や接着操作を行った。接触角およびせん断接着強さの結果ともにLEB照射の有効性が確認された。
以上のように本研究成果はLEB照射装置が近くにない状況でもLEB照射を有効に活用できるという、臨床的な学術的意義を有する。また、現在の運送業を含む社会状況下での有効性を示しているという、社会的意義を有する。