ObjectiveThis study aimed to compare the capabilities of sonic, ultrasonic, and laser-activated irrigation for debris removal in the root canal isthmus.MethodsA total of 32 human maxillary first premolars with root canal isthmus were prepared by Reciproc Blue, and were randomly divided into four groups (n=8, each group). The groups were subsequently subjected to different regimens as follows: the conventional syringe group (control group) was irrigated by No.27 side opening syringe, the sonic group with EDDY connected pneumatic motor, the ultrasonic group with IRRI Safe connected to a ultrasonic P5 handle, and the laser group with Er:YAG laser device connected to a 9 mm fiber tip for 20 s in each root canal. The first and last four samples in each group were irrigated for 80 and 120 s, respectively. All samples were fixed, decalcified, embedded, sectioned, and stained with hematoxylin-eosin. Image J software was used for measurement analysis of the isthmus and canal debridement efficacy, and SPSS 25.0 was utilized for statistical analysis of all data.ResultsThe isthmus debridement efficacy of conventional syringe irrigation, sonic, ultrasonic, and laser groups after 80 s irrigation were 30.91%±3.14%, 52.22%±0.31%, 83.77%±5.64%, and 77.97%±7.97%, respectively. The isthmus debridement efficacy of the three experimental groups were better than the conventional syringe irrigation group (P<0 .05). the isthmus debridement efficacies of ultrasonic and laser groups after 80 s were better than that of the sonic group (P<0 .01,P<0 .05). however, no significant difference was observed between the ultrasonic and laser groups. the isthmus debridement efficacy of conventional syringe irrigation, sonic, ultrasonic, and laser groups after 120 s were 75.72%±2.38%, 85.66%±4.42%, 88.07%±4.09%, and 89.12%±3.63%, respectively. the isthmus debridement efficacies of the three experimental groups were better than that of the conventional syringe irrigation group (P<0 .05), but no significant difference was observed among the groups (P>0.05). The root canal debridement efficacy among the four groups also exhibited no significant difference (P>0.05). The debridement efficacies of the root canal and isthmus after 120 s irrigation were better than those after 80 s irrigation (P<0 .01,P<0 .001).ConclusionUltrasonic, sonic, and laser-activated irrigation have better results in removing debris from the isthmus than conventional syringe irrigation. The isthmus debridement efficacy of sonic- and laser-activated irrigation are slightly better than that of ultrasonic activated irrigation. The debridement efficacies of 120 s irrigation are better than those of 80 s irrigaion.
