## 3 Results
### Smear Layer Removal  
[PERSON]'s kappa for interobserver agreement was 0.87 \(\pm\) 0.04 (Cl95% 0.78-0.95) for smear layer assessment and 0.84 \(\pm\) 0.07 (CI95% 0.73-0.95) for dentin erosion assessment, indicating almost perfect agreement. The repeatability of the smear layer grading was 0.88 \(\pm\) 0.04 (CI95% 0.81-0.95) and 0.86 \(\pm\) 0.04 (CI95% 0.79-0.94) for observers 1 and 2, respectively, while the repeatability of dentin erosion grading was 0.88 \(\pm\) 0.05 (CI95% 0.79-0.98) and 0.91 \(\pm\) 0.04 (CI95% 0.83-0.98) for observers 1 and 2, respectively.  
In all groups, apart from the NaOCl and ID18% ones, the apical thirds of the root canals demonstrated significantly heavier smear layers compared to the middle and coronal thirds (Table 3). The apical thirds showed a moderate to severe amount of smear layer in all studied groups: the median scores ranged between 3 and 5 (Figure 3). A relatively small amount of smear layer was observed in the DR9%, DR18%, and ID9% groups.  
In the middle third, complete removal of the smear layer was achieved either by alternating irrigation with NaOCl and EDTA solutions or by continuous chelation with NaOCl mixed with DR (all concentrations). The rest of the groups demonstrated a significantly worse smear layer-removing ability, with a median score of 4 (Figure 4). Similar results were found in the coronal third, with one exception: ID9% also removed the smear layer completely (Figure 5).  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Groups** & **Weight before, mg** & **Weight after, mg** & **Weight Loss, mg** & **Weight Loss, \%** \\ \hline NaOCl & 55.5 (6.2) & 37.8 (6.5) 1 [FOOTNOTE:1]Footnote 1: \(\bullet\)\(\bullet\  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Groups** & **Apical Third** & **Middle Third** & **Coronal Third** & \(p\)**-Value 1** ** \\ \hline NaOCl & 4 (3.25; 4.75) 2   [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE]  [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOTE] [ENDFOOTNOTE] [FOOTNOFigure 4: Smear layer removal by different irrigants in the middle third (\(\times\)2000 magnification, accelerating voltage–20.23 kV, working distance–19 mm, with backscattered detector); DW—distilled water; NaOCI—pure NaOCI; EDTA—sequential irrigation with NaOCI and EDTA; DR—DualRinse HEDP; ID—IsraDent HEDP.  
Figure 5: Smear layer removal by different irrigants in the coronal third (\(\times\)2000 magnification, accelerating voltage–20.23 kV, working distance–19 mm, with backscattered detector); DW—distilled water; NaOCI—pure NaOCI; EDTA—sequential irrigation with NaOCI and EDTA; DR—DualRinse HEDP; ID—IsraDent HEDP.