Evaluation the Efficacy of Er:YAG Laser in Removing the Smear Layer During Endodontic Treatment

Successful root canal treatment depends on the cleaning and disinfecting of root canal before obturation. The study aimed to evaluate the effectiveness of Laser-activated irrigation (LAI) Er:YAG laser with EDTA 17% and distilled water in removing the smear layer and enhancing the results of endodontic treatment. 90 human extracted single-rooted teeth were included. Root canal preparation was done using rotary instruments with irrigation 5.25% NaOCl. Teeth were randomized into 30 teeth in 3 groups; the first experimental group received Er:YAG laser (a 17 mm 400-μm conical tip, 10 Hz, 0.5W, 40 mJ) + EDTA 17% for 1 minute, the second experimental group received EDTA 17% for 1 minute and the control group received Er:YAG laser + distilled water for 1 minute. Teeth were bisected longitudinally, and root canal was examined in coronal, middle and apical regions for smear layer removal by scanning electronic microscope. Data were analyzed statistically by SPSS software. The smear layer removal was higher in all regions of walls of root canal when combined EDTA 17% with Er:YAG laser. Comparison between regions showed that smear layer removal was better in coronal, middle regions than apical region in both groups (P<0.05) Er:YAG laser has proved its efficacy when combined with EDTA 17% in removing smear layer and debris from the root canal surface, due to activation of the irrigant solution. Experimental article (J Int Dent Med Res 2021; 14(3): 933-937)