Antimicrobial photodynamic therapy mediated by methylene blue in surfactant vehicle as adjuvant to periodontal treatment. Randomized, controlled, double-blind clinical trial

Background: Antimicrobial photodymanic therapy mediated by methylene blue has been investigated as an adjunctive to periodontal treatment but the dimerization of photosensitizer molecules reduces the phototoxic effects. Sodium dodecyl sulfate is a surfactant that may control this aggregation. The aim of this study was evaluated the photodynamic effect of methylene blue in sodium dodecyl sulfate in periodontitis.Methods: 36 participants with periodontitis were selected and allocated randomly in two group for intervention and other two for control - all of them were treated with scaling and root planing before aPDT. Three periodontal evaluations were done: at the selection time, at the day of intervention and thirty-day after this. Pre-irradiation time was 1 min and 2 min for irradiation. Laser (Therapy XT, DMC, Sa tilde o Carlos, Brazil) with wavelength of 660 nm and 100 mW of power was used. Two photosensitizer solutions with 100 mu M methylene blue was used, one of them was in water and other in 0,25% of sodium dodecyl sulfate. Two sites of each participant were selected for the experimental procedures. Microbiological evaluations were performed to quantify microorganisms before and immediately after intervention. Quantitative microbiological evaluation was the primary outcome; morphological aspects of bacterial colony, and clinical probing depth was the secondary one.Results: There was no significant difference between the groups in both bacterial reduction and the clinical parameter evaluated. Conclusion: The effect of methylene blue in surfactant did not cause enough phototoxic effects that could promote reduction of periodontal pocket depth.