GARCEZ, Aguinaldo Silva; ROQUE, Juliano Alves; MURATA, Wilson H.    HAMBLIN, Michael R.. A new approach for antimicrobial Endodontic PDT. Rev. Assoc. Paul. Cir. Dent. []. 2016, 70, 2, pp. 126-130. ISSN 0004-5276.

This study evaluates different approach such as photossensitizer (PS) concentration, irradiation time/energy, and the use of optical fiber for intracanal microbial reduction. In a quartz curvet, aqueous solution of Methylene blue at 50, 100, 150 and 300μM was tested for reactive oxygen species production (ROS) after successive irradiations of 30s with a diode laser (660nm, 100mW). Using the same methodology, the ROS production was tested using an optical fiber. Image analyses evaluated the presence of optical shield in 3 different concentration of PS. Ten central incisors were contaminated with bioluminescent P. aeruginosas to test the ideal energy/ time for endodontic microbial reduction. Initial contamination was recorded by image after biofilm grown. The root canals were fulfilled with Ps and irradiated with successive energies of 2.4J. After every irradiation new images were recorded to compare the microbial reduction. ROS formation was improved using low concentration of PS, such as optical shield formation. The use of optical fiber did enhance the ROS formation when compared to irradiation with the laser tip. Energy of 7J was the minimal energy to achieve lost of bioluminescent signal. For more efficient ROS production and minor optical shield presence, a concentration between 50 and 100μM seams to be ideal. The use of an optical fiber improves ROS production. Energy of 7J promotes significative intracanal decontamination.

: endodontics; microbiology; lasers; photochemotherapy..