From model validation to biomechanical analysis: In silico study of multirooted root analogue implants using 3D finite element analysis

Objectives: To create a validated 3D finite element model and employ it to examine the biomechanical behaviour of multirooted root analogue implants (RAIs). Methods: A validated finite element model comprising either an RAI or a threaded implant (TI) and an idealised bone block was developed based on a previously conducted in vitro study. All the experimental boundary conditions and material properties were reproduced. Force/displacement curves were plotted to ensure complete alignment with the in vitro findings. Following the validation of the FE model, the material properties were adjusted to align with those reported in the literature. Two contact scenarios were then examined: immediate placement with touching contact and osseointegration with glued contact. The bone block was constrained in all directions, and a 300 N point load was applied along the long axis of the implant, and with an angulation of 30°. The resulting values for equivalent stress, maximum principal stress, microstrain, and displacement were evaluated. Results: The numerical model demonstrated a high degree of agreement with the experimental results, particularly regarding displacement in the loading direction (Z). The findings of the applied FEA indicated that RAIs generally outperformed TIs. The RAI exhibited lower equivalent stress, with values of 3.3 MPa for axial loading and 13.1 MPa for oblique loading, compared to 5.4 MPa and 29.5 MPa for the TI, respectively. Furthermore, microstrain was observed to be lower in the RAI, with a value of 4,000 μΕ compared to 13,000 μΕ in the TI under oblique loading. Additionally, the RAI exhibited superior primary and secondary stability, with lower micromotion values compared to the TI. Conclusions: The root analogue implant showed superior biomechanical performance, with more uniform stress distribution and greater stability compared to the conventional threaded implant, positioning it as a promising alternative. © 2025 The Authors