Method for producing a dentist tool formed by an overlay to be used by a dentist in removing tooth structure, said method comprising the steps of: acquiring three-dimensional data relating to a shape of a tooth and at least a part of a neighbouring tooth； processing said three-dimensional data with a computer so as to determine an overlay fitting said tooth and fitting at least said part of said neighbouring tooth； further processing said three-dimensional data with said computer so as to determine a predetermined part of tooth structure to be removed from said tooth so as to prepare said tooth for further treatment； determining at least two guiding edges of which a first and a second guiding edge are spaced apart from each other by a distance d of at least 0.5 mm, said guiding edges being configured so as to enable said dentist cutting tool to be guided by simultaneously contacting said first and said second guiding edge in such a manner as to enable a guided removal of at least partially said predetermined part of tooth structure； producing said determined overlay having said determined guiding edges.
