Antimicrobial Photodynamic Therapy associated with long term success in endodontic treatment with separated instruments: A case report

This paper describes a case with a 5- year follow-up of Antimicrobial Photodynamic Therapy (aPDT) associated with long-term success in endodontic treatment in a tooth with separated instruments. The patient presented with a tooth exhibiting a periapical lesion, slight swelling, and severe pain. A radiograph revealed the presence of two separated files in the middle and apical thirds of the mesial root on a lower first molar. Attempts at bypassing were not successful. In the mesial root, instrumentation was limited to the corona] ends of the separated instruments. The apical patency could not be achieved due to the blockage of the separated files. aPDT was performed in two visits, at a 660-nm wavelength and 100 mW of power, for 90 s to a total energy of 9.0 Joules. Methylene blue solution was used as photosensitizer at concentration of 0005%. A 300-mu m light diffusor was coupled to the diode laser and was inserted into the root canal 2 mm short of WL, where it was set to allow better diffusion of light. Each root canal was sealed with gutta-percha by warm vertical compaction and Pulp Canal Sealer (TM). After 5 years of follow-up, clear evidence of remineralization of the radiolucency and bone healing was observed. This case report suggests that the addition of aPDT to conventional endodontic treatment improved microbial disinfection leading to a successful long-term outcome.