Abstract
Objectives: This study aims to evaluate the efficacy of the rotary instrument XP-endo Finisher for the removal of Ca(OH)
2
aided by different irrigation regimens. Methods: Sixteen double-rooted upper premolar human teeth were selected for the study. Thirty-two canals were prepared using a ProTaper Next rotary system up to X3. Then, the canals were filled with Ca(OH)
2
. The volume of Ca(OH)
2
inside the canals was measured by microcomputed tomography (micro-CT). After that, the teeth were randomly allocated into two experimental groups, i.e., A and B (n = 16 canals). In group A, Ca(OH)
2
was removed using the master apical file (X3). In group B, Ca(OH)
2
was removed using a XP-endo finisher. In half of both groups (n = 8), syringe irrigation (SI) was used, while passive ultrasonic irrigation (PUI) was used for the other half. After removal, the remaining volume of Ca(OH)
2
was measured. All data were statistically analyzed using two-way ANOVA with Tukey’s post hoc test. Results: The percentages of remaining Ca(OH)
2
in the apical thirds of all canals were significantly higher as compared with the middle and coronal thirds in all groups (
p
< 0.05). There was no significant difference between different files and techniques (
p
> 0.05). Clinical Significance: This study presents a new method for the removal of Ca(OH)
2
from root canals.