A three-dimensional computer model of the patient's tooth, including the pulp chamber and root canals, is created by combining at least one 2D grey value image of said tooth and/or surface information about at least part of the intra-orally visible part of the tooth with a statistical, parameterized shape model of each tooth type (upper or lower incisors, canines, pre-molars, molars) as the patient's tooth to be treated. This allows for planning and/or simulation of one or more root canal treatments on the 3D computer model of the patient's tooth and that the dentist or dental specialist is given qualitative and/or quantitative information by the system in order to aid in adequately analysing the risks related to performing the root canal treatment with the proposed or user-selected endodontic tools.