Initial engagement and axial force model for self-tapping bone screws

Abstract Correctly torquing bone screws is important for implant fixation longevity and strength. A model-based smart screwdriver has been proposed to regulate torque, however current models ignore axial force the initial engagement of screw. This was addressed here by deriving a model based on concept net generated difference in contact areas inward outward sides screw threads. opposed shear strength material around The results derivation were able predict effects different forces during insertion relation hole may be used compensate thread breakage future screwdrivers improve their accuracy.