Comparison of coronal leakage after smear layer removal with EDTA or Er:YAG laser

This study determined, in vitro, the coronal leakage of root canals evaluating the effect of smear layer removal by either EDTA or laser. Two sealers were also compared. Sixty-four canines were instrumented with the step-back technique and irrigated with 10 ml of 1% sodium hypochlorite. In Group 1, 10 teeth were sealed with Sealer 26((R)) and 10 teeth were sealed with Grossman cement with no attempt of smear layer removal. Group 2 received a final irrigation of 15 ml of 15% EDTA, and was sealed as in Group 1. Group 3 received Er:YAG laser application (2940 nm, 140 mJ, 15 Hz and 42 J, 300 pulses, 500milli-sec pulse duration), and sealed as in Group 1. Root canals sealed with Sealer 26 had significantly less coronal leakage than Grossman cement (p<0.05). Coronal leakage after smear layer removal with 15% EDTA or Er:YAG laser was not statistically different (p>0.01).