## 3 Results  
The initial bacterial counts taken before chemomechanical preparation produced similar values for all groups. This result indicates the homogeneity of the initial bacterial count in the experimental groups. The multiple variance analysis of the data revealed a statistically significant decrease in _E. faecalis_ in all groups after instrumentation utilizing various cavity designs (\(p<0.05\)) (Table 2).  
Figure 1: The schematic diagram of the methods used in this study.  
When the effectiveness of the mechanical preparations in reducing bacterial load in the TEC groups was evaluated, a significantly greater bacterial reduction was observed in the TEC-ProTaper Gold group than in the TEC-Reciproc Blue, TEC-WaveOne Gold, and TEC-TruNatomy groups. In addition, the TEC-2 Shape group exhibited greater bacterial reduction compared to the TEC-Reciproc Blue (\(p<0.05\)) group. In the CEC groups, differences between the tested file systems were not significant (\(p>0.05\)). In the TAC groups, bacterial reduction was significantly greater in the TAC-ProTaper Gold group in comparison to the TAC-WaveOne Gold and TAC-Reciproc Blue groups.  
When the efficacy of the access cavity design in reducing the _E. faecalis_ count was assessed, the CEC design was less effective in bacterial reduction than the TEC and TAC designs in the ProTaper Gold and 2 Shape groups. No statistically significant differences were observed among other groups with respect to the access cavity design (\(p>0.05\)) (Figure 2).  
\begin{table}
\begin{tabular}{c c c c c c} \hline  & \multicolumn{5}{c}{**Conservative Endodontic Cavity (CEC)**} \\ \hline  & WaveOne Gold \({}^{\text{Aa}}\) & 2 Shape \({}^{\text{Aab}}\) & ProTaper Gold \({}^{\text{Aa}}\) & TruNatomy \({}^{\text{Aa}}\) & Reciproc Blue \({}^{\text{Aa}}\) \\
**Pre (mean \(\pm\) SD)** & 5.25 \(\pm\) 0.61 & 5.32 \(\pm\) 0.56 & 4.74 \(\pm\) 0.18 & 4.73 \(\pm\) 0.22 & 4.79 \(\pm\) 0.30 \\
**Post (mean \(\pm\) SD)** & 3.98 \(\pm\) 0.38 & 4.35 \(\pm\) 0.39 & 3.96 \(\pm\) 0.46 & 4.08 \(\pm\) 0.49 & 4.12 \(\pm\) 0.077 \\
**Reduction mean (\%)** & 94.73\% & 89.25\% & 83.31\% & 77.15\% & 78.35\% \\ \hline  & \multicolumn{5}{c}{**Truss Access Cavity (TAC)**} \\ \hline  & WaveOne Gold \({}^{\text{Aa}}\) & 2 Shape \({}^{\text{Aab}}\) & ProTaper Gold \({}^{\text{Bb}}\) & TruNatomy \({}^{\text{ABa}}\) & Reciproc Blue \({}^{\text{Aa}}\) \\
**Pre (mean \(\pm\) SD)** & 4.95 \(\pm\) 0.24 & 5.70 \(\pm\) 0.45 & 5.97 \(\pm\) 0.61 & 5.08 \(\pm\) 0.61 & 4.64 \(\pm\) 0.41 \\
**Post (mean \(\pm\) SD)** & 4.15 \(\pm\) 0.35 & 4.47 \(\pm\) 0.23 & 4.42 \(\pm\) 0.68 & 4.22 \(\pm\) 0.51 & 3.87 \(\pm\) 0.41 \\
**Reduction mean (\%)** & 84.06\% & 94.18\% & 97.17\% & 85.99\% & 82.92\% \\ \hline  & \multicolumn{5}{c}{**Traditional Endodontic Cavity (TEC)**} \\ \hline  & WaveOne Gold & 2 Shape \({}^{\text{Abb}}\) & ProTaper Gold \({}^{\text{Bb}}\) & TruNatomy \({}^{\text{ACa}}\) & Reciproc Blue \({}^{\text{Ca}}\) \\
**Pre (mean \(\pm\) SD)** & 5.83 \(\pm\) 0.46 & 6.80 \(\pm\) 0.51 & 6.89 \(\pm\) 0.39 & 5.60 \(\pm\) 1.04 & 5.76 \(\pm\) 0.69 \\
**Post (mean \(\pm\) SD)** & 4.71 \(\pm\) 0.37 & 4.98 \(\pm\) 0.10 & 4.65 \(\pm\) 0.62 & 4.46 \(\pm\) 0.82 & 4.97 \(\pm\) 0.37 \\
**Reduction mean (\%)** & 92.41\% & 98.49\% & 99.43\% & 92.75\% & 83.83\% \\ \hline  & \multicolumn{5}{c}{Values with different superscript letters are statistically significantly different according to two-way ANOVA test. Uppercase letters compare means in each row. Lowercase letters compare means in each column.} \\ \hline \end{tabular}
\end{table}
Table 2: Mean values of bacterial counts (in log colony-forming units/mL) in the root canals before and after mechanical instrumentation using different endodontic cavities.  
Figure 2: Percentage differences in bacterial reduction in root canals utilizing WaveOne Gold, Reciproc Blue, 2 Shape, TruNatomy, and ProTaper Gold between different access cavity designs, \(\textbf{{}^{\bullet}}p<0.05\).