Repozytorium publikacji - Politechnika Gdańska

While cementless implants are now widely used clinically, implant debonding still occur and is difficult to anticipate. Assessing the biomechanical strength of the bone–implant interface can help improving the understanding of osseointegration phenomena and thus preventing surgical failures. A dedicated and standardized implant model was considered. The samples were tested using a mode III cleavage device to assess the mechanical strength of the bone-implant interface by combining experimental and numerical approaches. Four rough (Sa = 24.5 μm) osseointegrated coin-shaped implants were left in sheep cortical bone during 15 weeks of healing time. Each sample was experimentally rotated at 0.03◦/sec until complete rupture of the interface. The maximum values of the torque were comprised between 0.48 and 0.72 Nm, while a significant increase of the normal force from 7-12 N to 31–43 N was observed during the bone-implant interface debonding, suggesting the generation of bone debris at the bone-implant interface. The experimental results were compared to an isogeometric finite element model describing the adhesion and debonding phenomena through a modified Coulomb’s law, based on a varying friction coefficient to represent the transition from an unbroken to a broken bone-implant interface. A good agreement was found between numerical and experimental torques, with numerical friction coefficients decreasing from 8.93 to 1.23 during the bone-implant interface rupture, which constitutes a validation of this model to simulate the debonding of an osseointegrated bone-implant interface subjected to torsion.

Autorzy

• Yoann Hériveaux,
• Sophie Le Cann,
• Katharina Immel,
• Elsa Vennat,
• Vu-Hieu Nguyen,
• Vladimir Brailovski,
• Patrick Karasinski,
• dr inż. Roger Sauer link otwiera się w nowej karcie ,
• Guillaume Haiat