Methods and tools for expanding a precursor hole in a host material to receive an anchor or fixture. The precursor hole is enlarged by a rotary tool having helical flutes and interposed lands. The lands each have a working edge that densifies bone when the tool is rotated in a non-cutting direction. When the tool is used with a copious wash of irrigating fluid, hydraulic pressure builds inside the precursor hole. The operator can modulate the hydraulic pressure by axially stroking the rotating tool. The working edges sweep against the interior surface of the hole to gently expand its diameter by incremental plastic deformations with little to no removal of host material. The host material may be bone and the hole formed may be an osteotomy that is prepared with dense, compacted sidewalls to receive a bone implant with a high degree of primary stability.
