Abstract
Aim: to assess the removal of the smear layer using Protaper Gold (PTG), HyFlex EDM (HEDM) and K3XF. Methodology: Forty-five extracted human permanent single-rooted teeth were selected and randomly divided into three experimental groups (n=15 each) according to the rotary system used during cleaning and shaping procedure. Group 1: PTG; group 2, HEDM; group 3, K3XF. Samples were instrumented according to the manufacturer instructions. The presence of smear layer was evaluated under scanning electron microscope (SEM). Results: K3XF showed the least amount of remaining smear layer followed by PTG. HEDM showed the highest amount of remaining smear layer. Statistically, there was significant difference either in comparison between the three tested systems or between different location on the root in each group. Conclusions: Under the condition of the current study, complete removal of the smear layer cannot be achieved with root canal instrumentation solely. To aid in the removal of the smear layer, additional strategies such as dental laser systems and irrigating solutions with tissue-dissolving capabilities should be employed.