Efficiency and complications in root canal retreatment using nickel titanium rotary file with continuous rotation, reciprocating, or adaptive motion in curved root canals: A laboratory investigation

Abstract

Abstract Objectives Study compared efficacy, efficiency, and complications of curved root canal retreatment using single-use NiTi rotary files with different motions. Materials and Methods Forty mesial curved root canals of extracted mandibular molars, obturated with gutta-percha and AH Plus sealer, were randomly divided into four groups. Reciproc blue R25 was used with reciprocating motion (RB), VDW.ROTATE retreatment files with continuous rotation (VR), and ProTaper Next X2 with continuous rotation (X2c) or adaptive motion (X2a). The percentage of root canal filling removal was analyzed using Micro-Computed Tomography. The retreatment time and complications were recorded and statistically analyzed (p-value < 0.05). Results The study found a statistically significant difference in the percentage of root canal filling removal between the X2c and VR groups in both the whole canal and apical-third. Additionally, VR demonstrated a shorter retreatment time compared to RB and X2a. Instrument fracture occurred in 40% of the VR group and 20% of the X2a group. Conclusions X2 (continuous rotation) and RB files are highly effective and efficient for curved root canal retreatment. Continuous rotation is more efficacious and efficient than adaptive motion with NiTi rotary files. Clinical Relevance Single-file retreatment is highly efficacious, cost-effective, and time-efficient in small curved canals.