## 4 Discussion  
The objective in this study was to assess radiographic healing of teeth treated with commercial or experimental intracanal medicament between two endodontic appointments. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & **Dry Vegetable** & **Ca(OH)\({}_{2}\)** & \multicolumn{2}{c}{**Ca(OH)\({}_{2}\) Mixed**} & \multirow{2}{*}{**Walkhoff Paste**} \\  & **Extract** & & & & **with CHX Gel 2\%** & \\ \hline
**Period** & **Mean**\(\pm\) SD & **Mean**\(\pm\) SD & **Mean**\(\pm\) **SD** & **Mean**\(\pm\) **SD** & **Mean**\(\pm\) **SD** \\ \hline Preop & 4 \(\pm\) 0.73 & 3.9 \(\pm\) 0.87 & 4.26 \(\pm\) 0.57 & 4.18 \(\pm\) 0.47 \\
3 months & 3.5 \(\pm\) 1.08 & 3 \(\pm\) 1.05 & 1.94 \(\pm\) 1.82 & 1.17 \(\pm\) 1.33 \\
6 months & 2.6 \(\pm\) 1.34 & 1.9 \(\pm\) 0.99 & 0.32 \(\pm\) 0.37 & 0.39 \(\pm\) 0.91 \\
12 months & 1.6 \(\pm\) 0.84 & 1.3 \(\pm\) 0.48 & 0.19 \(\pm\) 0.42 & 0.03 \(\pm\) 0.11 \\ \hline \multicolumn{6}{l}{Ca(OH)\({}_{2}\) = Calcium hydroxide. SD = Standard deviation.} \\ \end{tabular}
\end{table} 
Table 2: Mean values and standard deviation of the PAI, at different time intervals, for the group with dehydrated plant extract, calcium hydroxide, calcium hydroxide with CHX gel 2%, Walkhoff paste. \begin{table}
\begin{tabular}{c c c c c} \hline  & **Dry Vegetable** & **Ca(OH)\({}_{2}\)** & \multicolumn{2}{c}{**Ca(OH)\({}_{2}\) with CHX**} & \multirow{2}{*}{**Walkhoff Paste**} \\  & **Extract** & & & **with CHX Gel 2\%** & \\ \hline
**Period** & **Correlation Index**\(\pm\)**p & **Correlation Index**\(\pm\)**p & **Correlation Index**\(\pm\)**p \\ \hline preop vs. 3 months & 0.88 \(\pm\) 0.258 & 0.95 \(\pm\) 0.001 & 0.95 \(\pm\) 0.001 & 0.93 \(\pm\) 0.001 \\ preop vs. 6 months & 0.90 \(\pm\) 0.011 & 0.84 \(\pm\) 0.001 & 0.92 \(\pm\) 0.001 & 0.68 \(\pm\) 0.001 \\ preop vs. 12 months & 0.80 \(\pm\) 0.001 & 0.80 \(\pm\) 0.001 & 0.58 \(\pm\) 0.001 & 0.52 \(\pm\) 0.001 \\
3 months vs. 6 months & 0.91 \(\pm\) 0.117 & 0.93 \(\pm\) 0.021 & 0.96 \(\pm\) 0.012 & 0.72 \(\pm\) 0.146 \\
3 months vs. 12 months & 0.85 \(\pm\) 0.001 & 0.87 \(\pm\) 0.001 & 0.74 \(\pm\) 0.008 & 0.54 \(\pm\) 0.014 \\
6 months vs. 12 months & 0.91 \(\pm\) 0.062 & 0.79 \(\pm\) 0.148 & 0.95 \(\pm\) 0.001 & 0.91 \(\pm\) 0.231 \\ \hline \end{tabular}
\end{table} 
Table 3: Correlations between PAI values recorded at different time intervals. To evaluate radiographic healing patterns, the PAI system was used, developed by [PERSON] et al. (1986). Since its inception, this scoring system has become increasingly popular in endodontic outcome studies [9]. At baseline, the teeth were classified as having a radiolucent lesion with a PAI score mean >4. By the latest follow-up, all of the teeth had a PAI score mean of <1.3; regression of the PAI score mean for all four substances studied demonstrates the effectiveness of the intracanal medicaments. The ratio of cured teeth is a majority in each study group, which demonstrates the effectiveness of the substances applied in endodontic therapy alongwith the canal filling and the success of endodontic treatment by radiological monitoring of apical healing. The results of the present study revealed significant information on intracanal medications, commercial and experimental, the role in the apical healing process monitored by recording the PAI score at 3, 6 and 12 months recall after root canal filling on a periapical radiography. In the present study, the dehydrated vegetable extract had a therapeutic effect, managing to produce apical healing in a percentage of 60%, reducing the PAI score from 4 preoperative to 1.6 after 12 months recall. The data obtained from the statistical processing demonstrate that the therapeutic value of the experimental paste is above that of the commercial medicament used in endodontic practice. In the accessed literature we did not find studies to test the therapeutic effect of alcoholic, aqueous or dehydrated vegetable extract obtained from _Epilobium parviforum Schreb_ in endodontic therapy.