Clinically relevant insertion torque influences the microstructure of CP Grade 4 titanium implants. Minimal changes occurred at 30 Ncm, while 60 Ncm produced early plastic deformation and 80 Ncm generated pronounced deformation banding with evidence of localized microcrack initiation. These findings suggest that high insertion torques, even when not causing visible deformation, may introduce subsurface plastic damage with potential implications for long-term mechanical behavior under cyclic loading. Moderate insertion torques were most consistent with preserving the as-manufactured microstructure in this implant configuration.
Elkahly et al. (Mon,) studied this question.