Evaluation of Photodynamic Therapy in Pieces With Presence of Fistula.

Mechanized endodontic treatment using an endodontic rotatory device (DENTSPLY) will be used to prepare the root canals. Following, it will be applied the methylene blue solution in surfactant medium and after 1 minute a diode laser equipment (DMC THERAPY/EC, Sao Carlos, Brazil) will be used to shine light at a wavelength of 660nm, 100 mW (miliWatts) and irradiation time of 3 min. CaOH (calcium hydroxide) paste will be applied at the root canals canals as a long-term dressing for endodontic treatment..

Mechanized endodontic treatment using an endodontic rotatory device (DENTSPLY) will be used to prepare the root canals. Following, it will be applied the methylene blue solution in surfactant medium and after 1 minute a diode laser equipment (DMC, THERAPY/EC, Sao Carlos, Brazil) will be used with an aluminium foil at the tip of the equipment to block light and use during 3 min as study group. CaOH (calcium hydroxide) will be applied at the root canals as a long-term dressing for endodontic treatment.