“SEM evaluation of smear layer formation after using three different nickel titanium rotary instruments-endowave, K3 and protaper - An invitro study”

Abstract

Background and Objectives: The purpose of this invitro study was to evaluate the smear layer formation after using three different nickel titanium rotary instruments-Endowave, K3 and Protaper using Scanning Electron Microscope. Materials and method: A total of 30 freshly extracted human mandibular premolars were subjected for the study. They were divided into 3 groups, each group consisting of 10 teeth. Group 1: Endowave rotary; Group 2: ProTaper rotary; Group 3: K3 rotary. Crowns of each tooth were removed with carborundum disks at the level of cementoenamel junction in order to obtain root segments of approximately 12mm. Canal length was determined by placing a size 15 K-file. The working length was 0.5 mm short of canal length. Two longitudinal grooves were prepared on the lingual and buccal surfaces of each root to facilitate vertical splitting with a chisel after canal instrumentation. The sections were then observed under SEM for presence or absence of smear layer and photographs were taken at coronal, middle and apical 1/3 with a magnification of 4000 X. Results: There was no significant difference between three groups. All three groups resulted in significantly more smear layer in the apical 1/3 of the canal, compared to coronal and middle 1/3. Interpretation and Conclusion: The study demonstrated that, Endowave, Protaper and K3 resulted in significantly more smear layer in the apical 1/3 of the canal, compared to coronal and middle 1/3. Cleaning was significantly more effective in the coronal and middle 1/3 of the canals