“…It can be used with antibacterial purpose, preparation of the root canal, debris removal, 5,9,11,12 vaporization of soft tissues, 9,13 melting of hard tissues surface, 11 and reduction of dentin permeability. 1,2,4,5,11,14,15 It is verified that after Nd:YAG laser application on the dentin, melting, recrystallization and glazing occur, with consequent reduction of the fluids permeability. 1,15, 16 Folwaczny et al, 17 in 2002, suggested that use of the laser in the root canal walls leads to a reduction in the number of opened tubules, promoting a decrease of apical permeability, and this reduction in the permeability of the dentin walls can improve the sealing of root canal filling.…”