A comparison of the peri-implant bone stress generated by the preload with screw tightening between 'bonded' and 'contact' model.

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K19097
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57050:Prosthodontics-related
• Research Institution: Kyushu University
• Principal Investigator: MATSUZAKI MAKI 九州大学, 歯学研究院, 共同研究員 (50757987)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: テーパーコネクション / インプラント / バイオメカニクス

Outline of Final Research Achievements

One of the primary reasons for reduced predictability in implant treatment is peri-implantitis. In addition to biological factors (bacterial infection), mechanical factors, particularly stress within the bone that occurs after the attachment of the prosthesis to the implant and the tightening of the screw, are said to be involved in the resorption of peri-implant bone.
Since it is hard to measure stress within the bone directly, this study conducted simulations using the finite element method (FEM). The model, in which the components constituting the implant were created independently, showed that stress within the bone occurs at the point when the superstructure of the implant is tightened. Furthermore, in the model employing platform switching, which is said to be advantageous for reducing bone resorption, it was found that as the amount of shift increased, the stress within the bone decreased, demonstrating that platform switching is mechanically advantageous against bone resorption.

Free Research Field

歯科補綴学

Academic Significance and Societal Importance of the Research Achievements

インプラント治療において問題とされる周囲骨の吸収に、インプラントへの上部構造締結後に生じる骨内応力が関与していると言われている。骨内応力を実測することは困難であるため、本研究では有限要素法（FEM）にてインプラント、スクリュー、上部構造が独立した特殊なモデルを作成し、シミュレーションを行った。スクリューによる上部構造の締結を行った際にかねてより予測されていた、プレロードと呼ばれる骨の内部応力が発生していることが観察できた。このモデルの作成は今後のインプラントにおけるバイオメカニクスにおいて有用な手段となりうると考えられる。