A comparative scanning electron microscopic investigation of the efficacy of manual and automated instrumentation of root canals.

The cleaning effectiveness of automated and manual root canal instrumentation was investigated with the aid of a scanning electron microscope. Hand instrumentation was performed with K-Flexofiles used in a reaming working motion and according to the step-back technique and with Hedstrom files used in a filing motion. Automated preparation was performed with the KaVo-Endo Flash device featuring torque-limited rotation using K-Flexofiles, as well as with the mechanical ProFile system using rotary nickel-titanium instruments.