Comparison of the efficacy of various files and irrigations on calcium hydroxide removal: An in vitro study

This study aimed to assess how effective hand K-files and XP-Endo Finisher rotary files, combined with two different irrigation solutions (chlorhexidine [CHX] and sodium hypochlorite), are in eliminating calcium hydroxide (CH) from the walls of root canals.

Eighty-two single-root canal teeth were included in this in vitro study. After decoronation, the root canals were prepared with master apical file #30, and to shape the coronal part, #1-3 Gates-Glidden drills were used. The specimens were divided into four experimental groups (n = 18) and two control groups (n = 5). In all groups except the negative control group, CH was applied to the root canal system, and the access cavity was temporarily restored with zinc oxide eugenol. The samples were incubated for 1 week at a temperature of 37°C and a humidity level of 100%. For CH removal, the experimental groups received different irrigation regimens and file types: group 1: hand K-file + 5.25% sodium hypochlorite, group 2: XP-Endo Finisher rotary file + 5.25% sodium hypochlorite, group 3: hand K-file + 0.12% CHX, and group 4: XP-Endo Finisher rotary file + 0.12% CHX. CH was not removed from the positive control group. The root canals were then longitudinally sectioned, and the remaining CH in the apical, middle, and coronal thirds was quantified using a stereomicroscope. Statistical analysis was performed using one-way and two-way ANOVA and the Kruskal-Wallis test (P < 0.05).

The XP-Endo Finisher rotary file and CHX irrigation resulted in significantly higher residual CH in the apical third (P < 0.05). Conversely, the lowest mean residual CH was observed in the coronal third with hand K-file and sodium hypochlorite irrigation (P < 0.05). Sodium hypochlorite exhibited superior effectiveness in CH removal compared to CHX (P < 0.05).

There was no discernible advantage of using XP-Endo Finisher over hand K-file for the removal of CH. However, sodium hypochlorite proved to be more effective than CHX in achieving CH removal.