Antimicrobial Photodynamic Therapy Associated With the Conventional Endodontic Treatment: A Clinical and Microbiological Study

The aPDT was performed with 0.01% methylene blue and irradiated with low-level laser therapy (InGaAIP, 660 nm; 100 mW; 40 sec) with an optical fiber-coupled. Another irradiation (3 J; 30 sec; spot size of 3 mm2) was performed in the gingiva close to the apical foramen.

After local anesthesia the supragingival calculus, biofilm and the carious tissues were removed. The access cavity preparation was completed. The crown-down technique was performed using Gates Glidden and Kerr files with an anatomic diameter compatible to the radicular canal, and the irrigation was performed with 5 mL of 2.5% NaOCl solution between each endodontic file. The working length was established 1 mm short of the radiographic apex. Smear layer was removed by rinsing the canal with 17% ethylene diamine tetra-acetic acid solution, which was left in the canal for 5 min, followed by a final irrigation with 15 mL of 2.5% NaOCl solution. Calcium hydroxide paste with paramonoclorophenol, was inserted into the canal, filling the root canal as temporary medication between the sessions. The coronal sealing was performed using Coltosol, followed by glass ionomer Maxxion R. Seven days later the root canal was filled by the hybrid Tagger technique, with a Mc Spadden condenser.