Efficacy of Three Irrigation Methods in Removing Calcium Hydroxide from Curved Root Canals: An In Vitro Micro-CT Study

AIMS AND OBJECTIVES: This in vitro study aimed to compare the efficacy of three different irrigation methods in removing calcium hydroxide from curved root canals and to estimate the amount of residual medicament using microcomputed tomography. MATERIALS AND METHODS: Thirty extracted molars with curved mesial root canals, ranging from 25° to 30°, were prepared with ProTaper Next using X2 to full working length and were filled with calcium hydroxide. Teeth also were randomly divided into four groups: group 1 (n = 8)— Erbium: Yttrium-Aluminum-Garnet (Er:YAG) laser; group 2 (n = 8)—EndoActivator; group 3 (n = 8)—EndoVac; and a control group (n = 6)—negative control with no calcium hydroxide. Microcomputed tomography was used to evaluate the residual amount of filling material. Statistical analysis was performed using IBM SPSS Statistics 26, with a significance level of 0.05. Descriptive statistics, student t test, and Chi-square test were applied for data analysis. RESULTS: The greatest amount of residual calcium hydroxide was observed in the samples with EndoVac irrigation (0.515 mm(3)), followed by EndoActivator (0.381 mm(3)) and Er:YAG laser (0.121 mm(3)). However, no statistically significant difference was observed between the groups. The greatest residual amount was observed in the apical third (0.419 mm(3)), followed by the middle (0.050 mm(3)) and the coronal (0.015 mm(3)). CONCLUSIONS: No statistically significant differences were observed in the efficacy of the tested techniques for removing calcium hydroxide from curved root canals, whereas a significant difference was observed in the distribution of residual material depending on the technique used. The removal of the calcium hydroxide was more effective in the coronal and middle third of the canal. The greatest residual material was found in the apical portion of the root canal.