A fluted osteotome is rotated in one direction to enlarge an osteotomy by burnishing, and by cutting/drilling when turned in an opposite direction. A conically tapered body has an apical end with lips. The lips are set to grind bone when rotated in the burnishing direction and cut bone when turned in the cutting/drilling direction. Helical flutes and interposed lands are disposed about the body. The flutes each have a working edge that burnishes bone when rotated in the burnishing direction and cuts bone when turned in the cutting/drilling direction. The lips and lands generate an opposing axial reaction force that improves surgical control. The osteotome auto-grafts bone by reapplying ground particles in a compacted manner along the entire depth of the osteotomy, particularly at the bottom.