## 3 Results  
The ICC values around 0.90 allow a high level of agreement between the examiners. Regarding the percentage of sealer penetration in the apical sections, there was no statistical evidence according to the type of staining (\(p\) = 0.141). However, both Fluo-3 and Rhodamine B had a significantly higher percentage compared with their respective control group (\(p\) < 0.01) (Figure 3). There was no statistical evidence (\(p\) = 0.396) in the percentage of sealer penetration according to the type of staining in the medial slices (Figure 4). In these medial slices, the Fluo-3 group had significantly lower tubular percentages than its control group (\(p\) < 0.05), and the Rhodamine B group had a similar sealer penetration to its control group (\(p\) > 0.05). Comparing the apical and medial slices, the percentages of sealer penetration in the medial slices was significantly higher than that in the apical slices in both groups; in the Fluo-3 group \(p\) < 0.001, and in the Rhodamine group \(p\) = 0.042, although it had a lower level of reliability (Figure 5). Figure 3: (**A**) An image of the apical slice of the Fluo-3 control group. (**B**) An image of an apical slice of the Fluo-3 group. (**C**) An image of the apical slice of the Rhodamine B control group. (**D**) An image of an apical slice of the Rhodamine B group. The traced lines (red in image (**B**) and green in image (**D**)) show the wall of the canal where the infiltration has happened. Regarding maximum penetration, in the apical slices, Rhodamine-B implied a significantly higher penetration than Fluo-3 (\(p\) = 0.026) in addition to having significant differences in maximum penetration with its control tooth (\(p\) < 0.01), as the maximum penetration of the control tooth is significantly lower (\(p\) < 0.01). The same occurred with Fluo-3, whose maximum penetration was also significantly higher than its control (\(p\) < 0.01). There were no significant differences in the maximum penetration in the medial slices according to the type of fluorescent staining (\(p\) = 0.181). Fluo-3 had a significantly higher maximum penetration than its control group (\(p\) < 0.05), and Rhodamine B obtained similar results to its control (\(p\) > 0.05). In the Fluo-3 group, the filtration in medial slices was significantly superior to that in apical slices (\(p\) < 0.001), and in the Rhodamine group the same result occurred (\(p\) = 0.042), although with much lower level of reliability. Regarding the maximum penetration according to the fluorescent stain used, there were differences between the two groups (\(p\) = 0.008). With Fluo-3, there were fewer penetrations and these differences were similar in magnitude in both types of slice (\(p\) = 0.230) (Figure 6). Figure 4: (**A**) A medial slice image of the Fluo-3 control group. (**B**) A medial slice image of the Fluo-3 group. (**C**) A medial slice image of the control group Rhodamine B. (**D**) A medial slice image of the group Rhodamine B. The traced lines (red in images (**A**,**B**) and green in images (**C**,**D**)) show the wall of the canal where the infiltration has happened. Figure 5: The percentage of sealer penetration according to the apical or medial slice in each sample. The percentages of sealer penetration in medial slices were higher than those in apical slices in both groups. Figure 6: Maximum penetration according to the apical or medial slice in each sample. In the Fluo-3 group, the infiltration in the medial slice was significantly superior to that in the apical slice (\(p<0.001\)), and in the Rhodamine group the same result occurred (\(p=0.042\)), although with much lower level of reliability. * its related to an apical slice with an extreme value of maximum penetration within the sample. The interquartile range (IQR) is a way of calculating the dispersion of the samples in each group.