Finite Element Analysis of the Load-Bearing Components of a Stackable Surgical Guide System During Flapless Implant Osteotomy in a Fully Edentulous Maxilla

Stackable surgical templates enable flapless, prosthetically driven implant placement and immediate provisionalization in full-arch rehabilitation; however, intraoperative guide fracture remains a recognized complication, and the biomechanical behavior of the multi-component assembly on the edentulous maxilla has not been fully characterized. This in silico study used 3D modeling, surface refinement and finite element analysis (CATIA V5) to evaluate stress and displacement distribution in a model comprising the maxilla, polymeric base guide, implant osteotomy guide, and five grade-4 titanium fixation pins, derived from a prosthetically driven virtual plan. Methods: Materials were modeled as homogeneous, isotropic, and linearly elastic. A maximum simulated axial drilling force of 10.14 N and an associated equivalent torsional load derived from the calculated cutting torque were applied for a 2 mm diameter osteotomy under Scenario 1 (idealized no-sliding contact) and Scenario 2 (frictional contact). Results: Under Scenario 1, the maximum von Mises stresses were 2.34 MPa in the Maxilla, 3.18 MPa in the Base guide, 4.32 MPa in the Implant osteotomy guide, and 1.13–3.26 MPa in the Fixation pins. The highest polymer stress occurred in the Implant osteotomy guide (4.32 MPa; 7.2% of the 60 MPa reference strength). Under Scenario 2, the maximum stresses were 2.48 MPa in the Maxilla, 7.63 MPa in the Base guide, 2.38 MPa in the Implant osteotomy guide, and 1.11–3.94 MPa in the Fixation pins, with the Base guide showing the highest polymer utilization (7.63 MPa; 12.7%). Across both contact formulations, the polymeric guide components exhibited greater relative material utilization than the grade-4 titanium fixation pins. The maximum predicted guide-component deformation was 0.093 mm. Conclusions: Within the assumptions and limitations of the model, these findings indicate that the mechanical response of the assembly is more strongly influenced by the polymeric guide components, while the distribution of stress between individual guide components depends on the assumed contact scenario.