Photodynamic Therapy in Endodontic Treatment

This randomized clinical trial evaluated the effectiveness of supplemental photodynamic therapy (PDT) in optimizing the removal of bacteria and endotoxins from primarily infected root canals after one-visit and two-visit treatments.Twenty-four primarily infected root canals with apical periodontitis were selected and randomly divided into one-visit (n=12) and two-visit treatments (n=12). Chemo-mechanical preparation (CMP) was performed by using the single-file reciprocating technique + 2.5% NaOCL and a final rinse with 17% Ethylenediamine tetraacetic acid (EDTA). The photosensitizer agent (methylene blue 10 mg/mL) was applied to root canals for 60 seconds and submitted to laser with a potency of 60 milliwatts (mW) and energy density of 129 J/cm2 for 120 seconds after CMP in the one-visit treatment and after 14-day inter-appointment medication with Ca(OH)2 + saline solution (SSL) in the two-visit treatment. Samples were collected before and after root canal procedures. Endotoxins were quantified by chromogenic limulus amebocyte lysate assay. Culture techniques were used to determine bacterial colony-forming unit counts.