“…The particular geometry of root canal models is obtained from selected natural root canal systems [2,6,11,46] or represents individual geometrical properties, with different Schneider angles (compare, e.g., [47]), the radiologically determined two-dimension radius of curvature [34] or the endodontic working width [65] being considered to generate these models. Most of the investigated root canal models show an apical diameter between 0.15 and 0.8 mm, a taper between 2 and 6% and a length in the range from 16 to 20 mm [14,[20][21][22]25,29,30,[33][34][35]47,55,56,70,71]. The geometry-based root canal model of the current study has an elliptical cross-sectional apical shape and dimension within the range of existing root canal models.…”