Cleaning ability of reciprocation and rotation motions in conjunction with either continuous or sequential chelation:...

Recent advancements have introduced a debate over the most effective combination of file kinematics and irrigation timing. While continuous rotation and reciprocation motions each offer distinct advantages in debris extrusion and file safety, their synergistic effect with different chelation protocols remains a critical area of investigation.

The aim was to evaluate the cleaning performance of reciprocation and continuous motions in combination with continuous versus sequential chelation irrigation protocols.

Sixty single-rooted single-canalled teeth were prepared and divided into two groups according to the type of file used (n = 30). Group A: one curve (OC) file system (rotation motion) and Group B: one RECI (OR) file system (reciprocation motion). Prepared teeth were then subdivided into three subgroups according to the irrigation protocol used (n = 10): Subgroup 1: saline, Subgroup 2: sequential chelation (sodium hypochlorite [NaOCl] + ethylenediaminetetraacetic acid), and Subgroup 3: continuous chelation (NaOCl/etidronic acid). Samples were observed using an environmental scanning electron microscope to measure the percentage of opened dentinal tubules.

Data were analyzed using one-way analysis of variance followed by Tukey's post hoc test for pairwise comparisons between the different groups and thirds.

In all the groups, the coronal third had significantly cleaner dentinal tubules (P < 0.001). The difference between the two files was not statistically significant (P = 0.643). Sequential chelation showed the highest mean values of the opened dentinal tubules in conjunction with OC and OR (7.89 ± 2.95 and 8.95 ± 5.14, respectively). With continuous chelation, the mean values of the opened dentinal tubules in conjunction with OR were significantly higher than with OC (4.22 ± 3.21 and 2.39 ± 1.19, respectively).

The cleaning abilities of the OC and OR file systems are comparable. Sequential chelation resulted in cleaner and more open dentinal tubules regardless of the file system used. Continuous chelation with reciprocation yielded cleaner canals than with rotation motion.