Evaluation of Calcium Hydroxide Removal from Simulated Internal Resorption Cavities by Different Irrigation Techniques

Background: Calcium hydroxide (CH) is a material that is very difficult to remove, especially in complex root canal anatomies and pathologic formations such as internal root resorption (IRR). The purpose of this study is to compare ultrasonic and sonic irrigation activation systems, as well as XP-endo Finisher, in terms of their efficiency in removing 2 forms of CH from simulated IRR cavities. Methods: Fifteen human maxillary central incisors were used for this study. The teeth were cut from their crowns to standardize the root lengths at 15 mm. After preparing root canals, the roots were split into 2 halves vertically using a diamond disc, and artificial resorption cavities were prepared 5 mm above the root apex. Two forms of CH were applied into the root canals and resorption cavities. Tested methods were manual irrigation, XP-endo Finisher, EDDY, and passive ultrasonic activation (PUI). After the experiments, samples were evaluated under a stereomicroscope at ×20 magnification and scored via pixel count. Results: Residual CH was observed in all samples after experiments. Passive ultrasonic activation revealed the best median scores, yet there was no significant difference between PUI and EDDY (P > .05). Passive ultrasonic activation was statistically superior to XP-endo Finisher (P < .05). Passive ultrasonic activation, EDDY, and XP-endo Finisher revealed superior results compared to manual irrigation (P < .05). There was no significant difference between CH prepared with distilled water and its injectable form (UltraCal XS) in terms of removability from simulated IRR cavities. Conclusion: None of the tested methods was able to remove CH completely from the simulated internal root resorption cavities. Cite this article as: Kürkçü O, Haznedaroğlu F, Kutlu Basmacı G. Evaluation of calcium hydroxide removal from simulated internal resorption cavities by different irrigation techniques. Essent Dent. 2025; 4, 0013, doi: 10.5152/EssentDent.2025.24013.