Ultrasonically assisted bone drilling-effect of process parameters on delamination

Bone drilling is a crucial operation in orthopedic, maxillofacial, and trauma surgery. Delamination is a familiar defect in the drilling process and can seriously disrupt postoperative regeneration near the implant site in bone surgery. This research experimentally investigates the problem of delamination around drilled holes in vibration-assisted drilling of in cortical bone on the delamination around drill holes in cortical bone. Drilling speed and amplitude of vibration were found to have almost no influence on delamination, while higher feed rate was found to moderately increase delamination. Highest reduction in delamination was found to occur at higher frequencies of vibration imposed on the drill in the feed direction. Statistical analysis (ANOVA) also indicated that delamination is most significantly affected by frequency of drilling, only slightly by feed rate, and almost negligibly by drill speed. Overall, it can be concluded that ultrasonically assisted drilling, with an appropriately selected frequency and feed rate, would yield far lower amount of bone delamination than conventional drilling. Results from this work can be useful for researchers and practitioners in the fields of biomechanics and orthopedic surgery.