Evaluation of the effectiveness of different final irrigation activation systems in the retreatment of teeth treated using calcium silicate based root canal sealer

The aim of this study is to compare the effectiveness of SNI, PUI, XPFR, EDDY, PIPS, SWEEPS final irrigation activation methods used after retreatment with confocal laser scanning microscopy (CLSM) analysis. In the present study were included 90 teeth with a single root and canal. Root canals were instrumented with ProTaper Next X3 file (Dentsply Maillefer, Ballaigues, Switzerland) and obturation with 0.1% sodium fluorescein (Sigma Aldrich, Steinheim, Germany) marked Totalfill BC Sealer HiFlow (FKG Dentaire, La Chaux-de-Fonds, Switzerland) in accordance with the single-cone technique. Root canals were retreatment with Protaper Universal Retreatment (Dentsply Maillefer, Ballaigues, Switzerland) files. After the root canal treatment was completed, roots were randomly divided into 6 groups according to the final irrigation activation procedures (n = 15); SNI, EDDY, PUI, XPFR, PIPS and SWEEPS. In all groups, the activation process was applied in 3 activation cycles (1 ml irrigation solution / 30 sec activation). After the final irrigation activation procedure, all root canals were obturated with a TotalFill BC Sealer HiFlow (FKG) root canal sealer marked with Rhodamine B (Sigma Aldrich, Steinheim, Germany), in accordance with the single cone technique. All samples were stored at 37 ° C for 14 days after obturation in order for the root canal sealer to setting completely. From each sample, sections with a thickness of 1 ± 0.1 mm were obtained from the apical, middle and coronal. The sections obtained were imaged under CLSM in dual fluorescence mode. Dentinal tubule penetration depth and area were calculated using Image J software (LOCI, University of Wisconsin, USA) on the obtained images. The data obtained were statistically analyzed with Two-Way Anova and post-hoc Tukey tests, at the significance level of p <0.05, with SPSS software. As a result of the present study, in all final irrigation activation systems tested, the penetration depth and penetration area of the root canal sealer in the dentinal tubules were found to be higher in the coronal section compared to the apical section (p <0.05). The maximum penetration depth and area of the root canal sealer to the dentin tubules were higher in PIPS and SWEEPS in the coronal section, EDDY and SWEEPS in the middle section, and SWEEPS in the apical section compared to the SNI (p <0.05). Penetration depth ratio was higher in SWEEPS and EDDY compared to SNI in all sections, and penetration area ratio was found higher in apical and middle section compared to SNI in SWEEPS (p <0.05). Within the limitations of the current study, none of the final irrigation activation systems tested could completely remove the residual root canal filling material. In all tested parameters, SWEEPS, a new irrigation activation procedure, removed residual root canal filling material more compared to SNI, and a higher root canal sealer penetration was obtained in obturation (p <0.05). Keywords: Retreatment, final irrigation activation, XP Finisher R, PIPS, SWEEPS