Comparative Evaluation of Bone Stress Distribution around Various Mini-implant Materials: A Finite Element Analysis

Aim: To evaluate the stress distribution around three different mini-implant materials when used for direct anchorage during anterior retraction in a finite element model (FEM). Materials and methods:A three-dimensional model of the maxillary arch was created using cone-beam computed tomography (CBCT), and a three-dimensional file of the small implant structure was obtained using a nanoCT picture.To provide anchoring for anterior retraction, the mini-implant was positioned between the first molar and second premolar roots.The force levels were simulated at 250 gm per side.Three FEMs were generated for the use of different mini-implant materials: (1) Titanium (Ti-6Al-4V), (2) stainless steel, and (3) magnesium alloy (WE43 alloy).The stresses generated in each of the three FEMs were evaluated using linear structural analysis on ANSYS Software.The distribution of bone stresses around the three mini-implant materials was assessed using von Mises stress hypothesis and calculated in megapascal (MPa) for the following parameters: Peri-implant bone stresses and stresses within implant structure. Results:The greatest peri-implant bone stress was observed around WE43 magnesium implants (9.71 MPa).Titanium implants showed moderate stresses (6.80 MPa), followed by the least in stainless steel implants (5.51 MPa).Conversely, the stresses on the implant surface were the highest in stainless steel and least in magnesium. Conclusion:The greatest peri-implant stress was observed around WE43 magnesium implants, followed by titanium-based implants, and the least by stainless steel implants.Clinical significance: The finite element analysis (FEA) provides insights into the biomechanical behavior of different mini-implant materials, aiding in the selection of implants that minimize peri-implant bone stress.Understanding material-specific stress patterns enhances clinical decision-making, contributing to improved implant stability and long-term treatment success.