Effect of Nd : YAG laser irradiation on the apical leakage of obturated root canals: an electrochemical study

Aim The purpose of this laboratory study was to evaluate the effect of Nd:Y AG laser irradiation on the apical leakage of obturated root canals using a n electrochemical method. Methodology Forty extracted single-rooted teeth were selected and the anato mic crown of each tooth was removed. The specimens were randomly divided in to four groups. In group 1, the root canals were prepared with K-files and irradiated with Nd:YAG laser (5 W, 20 Hz) via a 300 mum optical fibre. Then the root canals were obturated with laterally condensed gutta-percha and P ulp Canal Sealer EWT. In group 2, the root canals were treated with the sam e method as those of group 1 but without laser irradiation. In group 3, the root canals were prepared with Profiles, laser irradiated and then obturat ed with vertically condensed gutta-percha and Pulp Canal Sealer EWT. In gro up 4, the root canals were treated with the same method as those of group 3 but without laser irradiation. The electric resistance between standard an d experimental electrodes in the canals was measured over a period of 10 da ys. Results At 2 h, groups 1 and 3 irradiated with laser had significantly less apical leakage than group 2 (P < 0.05). After 10 days, group 4 had the hig hest Leakage, followed by groups 2, 1 and 3: the differences between the gr oups was statistically significant (P < 0.05). Conclusions Laser irradiation following root canal preparation reduced apic al leakage following root canal obturation.