The tooth to be fitted with a crown has to be reduced to a cylindrical or conical stump with a step around the lower edge. The new design of a tool (1) has a shaft (1) for being clamped to the operating handle and the front part (2) covered with an abrasive material (5). The tip (3) of the tool (1) is kept free (6) of the material, facilitating the creation of a quirk surrounding the lower end of the tooth without injuring the gum. If the step is not satisfying the tool (1) can be started again at a lower point.
