ABSTRACT
The purpose of this study was to evaluate in vitro the dentin permeability of the deciduous pulp chamber floor after employing 2-octyl cyanoacrylate and Er:YAG laser. Twenty four deciduous molars were used, divided into four groups. After chemical-surgical preparation each group received a different treatment: Group 1 - control, without treatment; Group 2 - the floor of the pulp chamber was covered with a fine layer of 2-octyl cyanoacrylate; Group 3 - the floor of the pulp chamber was irradiated with Er:YAG laser (250 mJ, 10 Hz for 30 seconds, 80 J of energy and 320 pulses), and covered with a fine layer of 2-octyl cyanoacrylate; and Group 4 - the floor of the pulp chamber was irradiated with Er:YAG laser set at the parameters already described. After that the specimens received application of 0.5 percent methylene blue, for 15 minutes. The teeth were cut, photographed, and the digitalized images were analyzed using the ImageLab program. The results obtained were submitted to statistical analysis. Group 4 (Er:YAG) presented the largest averages in percentage of dye penetration area (19.5 percent), followed by Group 1 (11.1 percent), Group 3 (1.4 percent) and Group 2 (0.2 percent). The experimental model allowed to conclude that the specimens conditioned with 2-octyl cyanoacrylate (Group 2) and Er:YAG laser associated to 2-octyl cyanoacrylate (Group 3) presented a decrease in permeability, and the specimens treated with Er:YAG laser (Group 4) presented an increase in permeability of the analyzed area