Optimization of Cutting Conditions to Improve the Machining Accuracy of CAD/CAM Crowns

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K10029
• 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: Tokyo Medical and Dental University
• Principal Investigator: Nemoto Reine 東京医科歯科大学, 東京医科歯科大学病院, 助教 (50706893)
• Co-Investigator(Kenkyū-buntansha): 野崎 浩佑 東京医科歯科大学, 大学院医歯学総合研究科, 講師 (00507767)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: CAD/CAM / 加工条件 / 接着ブリッジ

Outline of Final Research Achievements

This study investigated the influence of step-over, a cutting parameter in CAD/CAM crown fabrication, on the surface roughness of composite resin crowns. The results demonstrated that step-over has a dominant effect on surface roughness, and increasing the step-over from 0.01 mm to 0.2 mm has a minimal impact on flexural strength. Furthermore, by optimizing the machining parameters, we successfully fabricated D-shaped zirconia RBFDPs with tooth-shaped retainers and demonstrated their superior resistance to dislodgement compared to inlay-type and L-shaped designs. These findings provide fundamental insights for the clinical application of CAD/CAM composite resin crowns and zirconia RBFDPs.

Free Research Field

歯科補綴学

Academic Significance and Societal Importance of the Research Achievements

切削加工装置を用いて作製した補綴装置の利用は今後大幅に増加し，様々な症例に対応する必要がある．本研究で得られた知見は，微細加工可能な切削加工条件を明らかにし，複雑な形態を有する支台装置を作製することが可能となった．また，D字型リテーナーを有する臼歯部接着ブリッジの臨床応用により，長期に良好な予後が期待できる治療の選択肢を提示する上で極めて重要な意義をもち，今後の歯科補綴学および歯科保存学の発展に寄与するものと考えられる．