Evaluation of efficiency of laser systems on removal of debris and smear layer in maxillary canine root canals

The aim of this study is to analyze the efficiency of different laser systems and irrigating solutions on the removal of superficial debris and smear layer created during instrumentation in root canals. Seventy two extracted human maxillary canine teeth were sectioned and the root canals were prepared. The specimens were divided randomly into equal six groups as follows: 5.25% NaOCl in group 1 (control group), 15% ethylenediaminetetraacetic acid (EDTA) for 1 min followed by 5.25% NaOCl in group 2, 25% citric acid for 1 min followed by 5.25% NaOCl in group 3 were applied into the root canals. In the other groups treated with only laser, diode laser (2 W, 10 Hz) in group 4, Er:YAG laser (1 W, 10 Hz) in group 5, and Nd:YAG laser (1 W, 10 Hz) in group 6 were applied to the root canals. Photomicrographs were taken from the coronal, middle, and apical thirds of specimens by using scanning electron microscope. Statistical analyses were performed with Kruskal-Wallis and Mann-Whitney U tests (p = 0.05). On account of superficial debris, statistically significant differences were presented between the groups. According to the results of the study, statistically significant differences were determined between the control group and the other groups in the removal of the smear layer from the root canals (p < 0.05). Superficial debris was effectively removed by Er: YAG and diode laser. Combinations of EDTA + NaOCl and citric acid + NaOCl removed most effectively the smear layer. (C) 2014 Laser Institute of America