A SEM evaluation of smear layer removal using two rotary instrument systems with EDTA and vinegar as a root canal irrigant

Introduction: As the smear layer (SL) produced during instrumentation adheres to the dentinal surface and prevents penetration of irrigants and medicaments, it should be removed. The aim of this study was to evaluate the ability of 17% ethylenediaminetetraacetic acid (EDTA) and white vinegar (5% pure acetic acid) to remove debris and SL produced during root canal preparation with two nickel-titanium (NiTi) file systems, Hyflex (Coltene Whaledent, Allstetten, Switzerland) and ProTaper (Dentsply, Tulsa, OK, USA). Materials and Methods: Twenty freshly extracted human, single-rooted teeth were sectioned at the cementoenamel junction and were randomly divided into four groups of five samples each. In each group, 0.5 mL of 5% NaOCl was used as the first irrigant, which was followed by either 17% EDTA or vinegar. Two groups were prepared with Hyflex rotary files and the other two with ProTaper files. Scanning electron microscopy (SEM) study was done to evaluate the SL, and the collected data were submitted for statistical analysis. Statistical analysis was performed based on Student′s t-test with P value >0.05. Results: There was no statistically significant difference between the types of instruments used (Hyflex files and ProTaper files), and 17% EDTA solution and vinegar (5% acetic acid). Conclusion: Vinegar can be relied on as an endodontic irrigant for SL removal was comparable to 17% EDTA. In addition, both types of NiTi instrument produced similar dentin surface in terms of SL when used along with EDTA and vinegar.