Abstract: A method and apparatus for scanning an object (10) with a surface measurement probe (26) mounted on a coordinate positioning machine (24). Translational movement of the coordinate positioning machine (24) is used to move the probe along an at least part nominally spiral path about an axis (14) which intersects the object (10). The servo direction vector (16) for the probe (26) is directed nominally towards the axis (14) of the at least part nominally spiral path. The servo direction vector (16) for the probe is at an angle to said axis (14) of the nominally spiral path and at an angle to a plane perpendicular to said axis of the at least part nominally spiral path, which enables scanning of surfaces both parallel and perpendicular to the axis without the probe slipping off the surface of the object.

Abstract: A method of determining the shape of a dental prosthesis is disclosed comprising, scanning at least a connecting portion of a preparation, wherein the preparation comprises a first anchor and a connecting portion connected thereto, forming a physical model on the connecting portion to produce a pontic, and scanning at least the pontic whereby the surface of the first anchor is also scanned during a scanning step whereby the scanning steps can be carried out in either order. The preparation may be scanned to provide data concerning relative locations of the first anchor and connecting portion, which may be used to align data obtained during the scanning steps. Also disclosed is a method of producing a model of a dental prosthesis and a method of manufacturing a dental prosthesis.