Fig. 2

Radiographs showing typical treatment errors done in student courses (a, c, e) that led to the development of the initial model. Graphics and pictures of the modified endodontic tooth models (b, d, f). a Tooth 12 with j-shape root canal and a via falsa; b Premolar tooth model with an apically strongly curved root canal (draft + produced model); c Tooth 45 with a Type II shaped root canal and an incomplete obturated root canal; d Incisor tooth model with a Type II shaped root canal (draft + produced model); e Tooth 36 with a perforation of the pulp ground that was assumed to be a further root canal by students; f Molar tooth model with a hidden mb2 (draft + produced model)