Patent ID: 7367801

Claim:
A method of moving a hand instrument which includes a machining tool and a camera located at a specific distance from the machining tool to provide a cavity in a bone for a dental implant at a preparation site, comprising the following steps: computing position-dependent surface features of a three-dimensional data set relating to a surface of an area at the preparation site relative to a desired position of the implant, the area in which the cavity is to be created being adjacent a tooth defining a horizon line and present in the form of a three-dimensional set of volume data; detecting at least one section of the preparation site which exhibits a visible real surface feature by means of the camera on the hand instrument and a display providing a video image; and superimposing a computed surface feature for a target position of said hand instrument such that altering the position and angle of said hand instrument causes a change in the position of said superimposed surface feature relative to the visible real surface feature, and moving the hand instrument relative to the preparation site until the computed horizon line coincides with the horizon line of the adjacent tooth.