Comparative evaluation of different chelators in removal of calcium hydroxide preparations from root canals

This study compared the efficacy of 10% citric acid, 17% EDTA and 7% maleic acid (MA) with ultrasonic agitation in the removal of calcium hydroxide (CH) from root canals.Seventy maxillary anterior teeth were enlarged to F3 using protaper files. Teeth were then divided into two groups: A and B. Group A was filled with (CH + iodoform + silicone oil) mixture and group B with CH and propylene glycol (PG). Ten teeth were divided into positive and negative control groups. The volume of CH preparations was estimated using spiral CT. After seven days, teeth in groups A and B were further divided into three subgroups based on irrigants used and CH was retrieved along with ultrasonic agitation. Volume analysis was undertaken using spiral CT. Mean percentage of CH removed was analysed using one-way ANOVA followed by Tukey's Honestly Significant Difference test.All irrigants removed (CH + PG) completely without any difference between them (p = 0.17). Removal of (CH + iodoform + silicone oil) was significantly higher for MA and citric acid than EDTA (p0.001). There was no difference between MA and citric acid.Concentrations of 7% MA and 10% citric acid were found to be superior to 17% EDTA in the removal of (CH + iodoform + silicone oil). (CH + PG) preparation was completely removed by all the irrigants.