A bone mill for preparing the second-stage opening in crestal bone
surrounding the gingival surface of a dental implant in a jawbone is
tubular in form and has teeth with a negative rake on an end surface and
the adjacent side surface for forming a shaped opening to the implant. The
side surface of the mill near the end surface is tapered to the desired
shape of the opening. A guide pin fixed in the implant mates with an
opening in the bone mill to center the mill relative to the implant.
