Maryam Pourhajibagher - Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
Abbas Bahador - Oral Microbiology Laboratory, Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

Introduction and Objectives: Porphyromonas gingivalis is an etiological agent frequently found in both chronic and aggressive periodontitis as well as peri-implantitis. This study assessed the effect of antimicrobial photodynamic therapy (aPDT), as an alternative treatment modality, by nano-chitosan doped with curcumin (CNPs-Cur), as a photosensitizer, on the virulence features of cell-surviving aPDT against P. gingivalis. Materials and Methods: P. gingivalis photosensitized with CNPs-Cur was irradiated with diode laser at a wavelength of 435 nm for 3 min, and then bacterial viability measurements were done. The biofilm formation ability, metabolic activity, and antimicrobial susceptibility profiles were assessed for cell-surviving aPDT. Results: CNPs-Cur-aPDT resulted in a significant reduction of cell viability (89.2%), biofilm formation capacity (57.4%), and metabolic activity (44.6%) of P. gingivalis when compared to the control group (P < 0.05). Conclusion: The virulence of P. gingivalis strain reduced in cells surviving aPDT with CNPs-Cur, indicating the potential implications of aPDT for the treatment of P. gingivalis infections in periodontitis and peri-implantitis in vivo.

Antimicrobial photodynamic therapy, Porphyromonas gingivalis, Nano-chitosan,Curcumin