Comparison of root canal preparation using different automated devices and hand instrumentation

The pre- and postinstrumentation degree of curvatures in curved mesial root canals of mandibular molars were compared after preparation with eight automated devices and hand instrumentation. The straightening of the root canal was measured before preparation and after preparation to size 25 and 35. Procedural mistakes such as loss of working length or file fractures were also recorded. Following preparation to ISO 25, only the Endoplaner and the Canal Finder system showed significantly more straightening than hand instrumentation. After preparation to ISO 35, the Endoplaner and the Intra-Endo 3-LDSY showed significantly more straightening than hand instrumentation. Mecasonic, Excalibur, and the Canal Finder system also straightened the root canal more than hand instruments, but the results did not differ significantly. The best results with only moderate straightening and few cases of loss of working length were obtained by the Endolift and Giromatic handpieces, which both were comparable to hand instrumentation.