Cleaning efficacy of different root canal preparation systems and irrigation regimens

Purpose: To compare the cleaning efficacy of root canal walls after using two Nickel-Titanium (Ni-Ti) rotary files (Flexmaster and Mtwo) and one hand Ni-Ti file (Ni-Ti flex-K) when associated with different final irrigation regimens (SmearClear, 17% ethylene diamine tetra acetic acid (EDTA) and sodium hypochlorite). Materials and methods: Ninety extracted human premolars with similar range of canal curvature (21-39) were selected. After crown removal and working length determination, roots were divided into three equal groups according to root canal instrumentation: Group I and Group II were prepared using Flexmaster, Mtwo Ni-Ti rotary systems respectively where Group III was prepared using hand Ni-Ti flex-K files. Each group was further subdivided into three equal subgroups according to root canal final irrigation; subgroup A: SmearClear, subgroup B: 17% EDTA and subgroup C: NaOCl. Roots were then splitted longitudinally and processed for scanning electron microscopic (SEM) examination to evaluate and score the root canal cleanliness. Results: Final root canal irrigation using either SmearClear or 17% EDTA had significantly better cleaning efficiency than that of NaOCl in all tested groups. Ni-Ti hand files had significantly less cleaning efficacy than that of rotary systems except in subgroup C using NaOCl.