## 3 Results  
### Bond Strength  
The MTA retrograde filling groups had a mean bond strength of 15.403 MPa, while those placed with Biodentine had a mean bond strength of 17.957 MPa. Also, those placed with CIS had a mean bond strength of 14.12 MPa as a result of three-way analysis of variance. Although the bond strength value of retrograde fillings with manual condensation was 15.323 MPa, it was calculated as 16.268 MPa for those placed with indirect ultrasonic vibration. Retrograde fillings placed in retrograde cavities prepared with tungsten carbide burs had a mean bond strength of 8.244 MPa, whereas retrograde fillings placed in cavities prepared with ultrasonic retro-tips had a mean bond strength of 22.981 MPa (Table 1, Figures 3 and 4).  
The cavity*material*placement triple interaction between cavity*material*placement was not statistically significant (\(p\) = 0.939), as seen in Table 2, which shows the results of three-way analysis of variance for MPa. Cavity*material, cavity*placement, and material*placement binary interactions were also not statistically significant (\(p\) = 0.191, \(p\) = 0.104, and \(p\) = 0.543, respectively). Placement factors were not statistically significant (\(p\) = 0.128 and \(p\) = 0.508), whereas the difference between the levels of the cavity method factor was statistically significant (\(p\) = 0.000). The mean bonding value of retrograde fillings placed in retrograde cavities prepared with an ultrasonic retrogrape with an ultrasonic retrogrape with a tungsten carbide burs (Table 2).  
\begin{table}
\begin{tabular}{l l c c c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Cavities**} & & & & & & \\ \cline{3-10}
**Material** & **Method** & \multicolumn{2}{c}{**TC**} & & & \multicolumn{2}{c}{**U**} & & \multicolumn{2}{c}{**Total**} & \\ \cline{3-10}  & **n** & **Mean** & **SD** & **n** & **Mean** & **SD** & **n** & **Mean** & **SD** \\ \hline CIS & MC & 10 & 7.58 & 4.64 & 10 & 21.90 & 5.47 & 40 & 14.12 & 9.23 \\ \cline{2-10}  & IVV & 10 & 9.36 & 5.99 & 10 & 17.63 & 11.34 & & & \\ \hline MTA & MC & 8 & 4.35 & 3.68 & 8 & 23.86 & 8.04 & 35 & 15.40 & 11.08 \\ \cline{2-10}  & IVV & 9 & 8.42 & 7.06 & 10 & 23.75 & 7.79 & & & \\ \hline BIO & MC & 9 & 7.63 & 4.77 & 10 & 25.34 & 11.68 & 38 & 17.95 & 11.34 \\ \cline{2-10}  & IVV & 9 & 11.62 & 4.81 & 10 & 25.56 & 8.96 & & & \\ \hline Total & MC & & & & & & 55 & 15.32 & 11.00 \\ \cline{2-10}  & IVV & & & & & & 58 & 16.26 & 10.26 \\ \hline  & Total & 55 & 8.24 & 5.48 & 58 & 22.98 & 9.18 & & \\ \hline \hline \end{tabular}
\begin{tabular}{l l} CIS: Cam ionomer cement, MTA: Mineral trioxide aggregate, BIO: Biodentin, MC: Manual condensation, IUV: Indirect ultrasonic vibration, SD: Standard deviation, TC: Tungsten carbide, U: Ultrasonic. \\ \end{tabular}
\end{table}
Table 1: Introductory statistical values of MPa.  
Figure 4: Retrograde filling materials placed in the cavity prepared with ultrasonic retro tips and mean MPa values after retreatment according to the placement factors of the materials. CIS: Cam ionomer cement, MTA: Mineral trioxide aggregate, MC: Manual condensation, IUV: Indirect ultrasonic vibration.  
Figure 3: Retrograde filling materials placed in the cavity prepared with tungsten carbide drill and mean MPa values after retreatment, according to the placement factors of the materials. CIS: Cam ionomer cement, MTA: Mineral trioxide aggregate, MC: Manual condensation, IUV: ultrasonic vibration.