Efficacy of ethanol and EDTA solution for the removalof epoxy resin and bioceramic based sealers from theroot canal walls

The aim of this study was to compare of efficacy of saline, EDTA and ethanol solutions as the final irrigation solution on the removal of root canal filling material during root canal retreatment. In this study, ninety single-rooted teeth were prepared to apical size # 30 using the Protaper Next rotary instrument system (Dentsply Maillefer, Ballaigues, Switzerland) with the irrigation solution of 6 ml of 2.5% NaOCl, 17% EDTA and 5 ml of saline. The root canals were filled with the single cone method using AH Plus Jet, MTA Fillapex and BioRoot RCS root canal sealer (n=30). The specimens were randomly divided into 3 subgroups according to the final irrigation solution; group I: saline, group II: %17 EDTA, group III: Ethanol. Samples were split longitudinally and examined under stereo microscope to evaluate the root canal filling material that could not be removed after retreatment. The images obtained were transferred to the computer, the percentage of the filling material remaining in the root canal walls was calculated as the coronal, middle, and apical regions. Then, the area of the entire root canal and the area of all residual root canal filling material were calculated. The amount of the residual root canal filling material in the entire root canal was calculated as a percentage. Also, residual filling materials were evaluated using a scanning electron microscope at the coronal, middle, and apical thirds of the root canal. Twoway ANOVA and post hoc Tukey tests were used to evaluate the effect of canal sealer and irrigation solution on the amount of filling material remaining in the canal. Analysis of Variance and post hoc Bonferroni test were used for repeated measurements in comparisons between regions. The significance was set at 0.05. There was no statistically significant difference between the final irrigation solution groups used in terms of total residual canal filling amounts (p>0.05). In the apical third when EDTA is used as an irrigation solution during root canal retreatment; the amount of residual filling materials in the group using AH Plus was statistically significantly higher than the group using BioRoot RCS (p:0.042; p<0.05). When using MTA Fillapex during root canal filling; residual canal filling material in the middle third was significantly higher in the saline group than the ethanol group (p:0.027; p<0.05). Within the limitations of this study, it can be concluded that no final irrigation solution tested in this study was able to completely remove the canal fillling from the root canals.