Clinical Efficiency of the Reciprocating Nickel-Titanium Instruments according to the Canal Anatomy

Abstract

Introduction The application of the single-file technique using the reciprocating motion is gaining concern in root canal preparation. The purpose of this research is to compare the efficiency of the reciprocating motion-employing files (RECIPROC and WaveOne) by measuring the working time to achieve complete canal preparation, and to analyze the varying factors that may influence their efficiency.

Materials and methods One hundred curved root canals of the extracted molars were used. The working length was determined and the glide path was confirmed using a #15 K-file. Canals shaping was completed to the length either with RECIPROC R25 file (n=50), or with WaveOne Primary file (n=50). The time taken for the file to reach the working length was measured. Each file was repeatedly used in a maximum of 10 canals for comparing the change of the efficiency (preparation time) according to the working length, canal curvature, and number of file re-use. The microscopic surface features of the files after use were observed using a scanning electron microscope (SEM).

Results WaveOne Primary file showed significantly shorter working time than RECIPROC R25 (p < .05). There was a statistically significant correlation between the working time and 3 variables (working length, canal curvature, number of file re-use). There were no significant changes under the SEM on the 2 file groups in the formation and propagation of microcracks or tip abrasions until they were re-used up to 5 canals.

Conclusion Within the limits of this study, WaveOne Primary had better clinical efficiency than RECIPROC R25 in preparation time. Although the manufacturers recommend discarding the files after single use, they could be re-used more than once.