## 4 Discussion  
The efficacy of root canal debridement using the multisonic technology was evaluated in this study. This technology uses broad spectrum acoustic energy, advanced fluid dynamics, and accelerated chemistry to debide and disinfect the entire complex root canal system with minimal instrumentation [34; 40]. The ability to debide the root canal will depend on the pathological status of the pulp and the location of the pulp tissue within the root canal system. Vital teeth have vital pulp tissue that is very difficult to remove; while necrotic teeth have a combination of vital and necrotic tissue that can be easier to remove. Necrotic teeth also have bacteria in the main and lateral canals which can be very difficult to remove completely. The apical portion of the root is the most challenging area to clean. It has already been demonstrated that rotary or hand instrumentation performs differently in each zone of the root. Thus, the ability of the multisonic technology to efficiently debide different pulp tissues and different areas of the root was assessed. Several ex vivo, in vitro, and in vivo studies with various conventional instrumentation and irrigation techniques have shown that pulp tissue and bacteria may remain in complex root canal systems [41; 42; 43; 44]. In addition, no difference between hand and rotary instrumentation in the cleaning and disinfection of the root canal system has been \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**PULP** & **F** & **Df** & **Df. Res** & **Pr (>F)** \\ \hline Group & 0.0134 & 1 & 18.295 & 0.9090 \\ \hline Zone & 1.7792 & 2 & 152.262 & 0.1723 \\ \hline Location & 1.5550 & 3 & 156.963 & 0.2024 \\ \hline Group: zone & 0.3139 & 2 & 152.029 & 0.7310 \\ \hline Group: location & 1.0298 & 3 & 155.209 & 0.3811 \\ \hline Zone: location & 0.1182 & 6 & 153.266 & 0.9941 \\ \hline Group: Zone: Location & 0.4476 & 4 & 152.029 & 0.7740 \\ \hline F (value of the F distribution), Df (degrees of freedom), Df. Res (residual (or error denomination)), Pr (>F) (\(\eta\)-value; probability of getting value > F). & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Analysis of deviance table for the generalized linear mixed effect model on percentage of teeth with pulp tissue remnants. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**ISTHMUS** & **F** & **Df** & **Df. Res** & **Pr (>F)** \\ \hline Group & 0.1534 & 1 & 17.051 & 0.70015 \\ \hline Zone & 0.8005 & 2 & 110.061 & 0.45169 \\ \hline Location & 0.8315 & 3 & 116.571 & 0.47016 \\ \hline Group: zone & 2.5244 & 2 & 110.005 & 0.08474 \\ \hline Group: location & 1.9472 & 3 & 116.889 & 0.12582 \\ \hline Zone: location & 0.6081 & 6 & 110.609 & 0.72334 \\ \hline Group: Zone: Location & 0.6544 & 6 & 110.825 & 0.68646 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Analysis of deviance table for generalized linear mixed effect model (GLMM) for the fixed effects of group (vital, necrotic), zone (coronal, mid, apical), and location (isthmuses) on percent of teeth with pulp tissue remnants. reported. The use of chemical solutions appears to be important and helps in the root canal debridement. This points out the limitation of mechanical instrumentation [45; 46; 47; 48; 49; 50; 51; 52]. Tissue dissolution with NaOCl can be improved when the solution is activated, the time of exposure is extended, and the temperature is increased [53]. According to some authors [54; 55; 56], mechanical agitation, as well as fluid flow, can enhance the dissolving capacity of vital and necrotic pulp tissue by NaOCl. Even though this project did not evaluate the conventional irrigation needle technique, the clear differences between the needle technique and the multisonic technology make the comparison difficult.