Tools and methods for expanding a precursor hole in a host material to receive a fixture. The precursor hole is enlarged by a rotary tool having helical flutes and interposed lands. The flutes have a negative rake angle. The lands each have a working edge that cuts the host material when the tool is rotated in a cutting direction, and that condenses the host material when the tool is rotated in a densifying direction. The body of the rotary tool has a stopper section that plugs the hole when a certain depth is reached. When the tool is used with a copious wash of irrigating fluid at or below the necessary depth, hydraulic pressure builds inside the precursor hole. The hydraulic pressure can be advantageously exploited in cutting mode to autograft a slurry of host material particles into the sidewalls of the hole and create an incipient densifying crust.
