Maryam Pourhajibagher1, Nasim Chiniforush2, Reza Raoofian3, Roghayeh Ghorbanzadeh4, Sima Shahabi5, Abbas Bahador6. 1. Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 2. Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 3. Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran; Innovative Research Center, Islamic Azad University, Mashhad Branch, Mashhad, Iran. 4. Private Practice, Tehran, Iran. 5. Dental Biomaterials Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. 6. Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: abahador@sina.tums.ac.ir.
Abstract
BACKGROUND: Microorganisms treated by photo-activated disinfection (PAD) in combined periodontal-endodontic (perio-endo) lesions would be exposed to sub-lethal doses of PAD (sPAD). This study evaluated the effect of sPAD using toluidine blue O (TBO) in combination with diode laser irradiation on the growth and biofilm-formation ability of Porphyromonas gingivalis as an endo-periodontal pathogen. METHODS: The antibacterial and antibiofilm potential of sPAD against P. gingivalis was analyzed at sub-lethal doses of TBO and irradiation time of diode laser on a colony-forming unit and crystal violet assays, respectively. RESULTS: TBO-mediated PAD, using 6.25-100μg/mL at a fluency of 171.87J/cm2 and 12.5-100μg/mL at a fluency of 137.5J/cm2, showed a significant dose-dependent reduction in P. gingivalis growth when compared to the control. TBO-mediated PAD showed a significantly inhibitory effect on biofilm formation in P. gingivalis than TBO-PAD at sub-lethal levels. CONCLUSION: High doses of sPAD revealed antibacterial and antibiofilm potential activity, whereas lower doses of sPAD had conflicting results. Therefore, when PAD is prescribed in combined perio-endo lesions treatment, the dose of PAD used in vivo should be taken into account. Copyright Â
BACKGROUND: Microorganisms treated by photo-activated disinfection (PAD) in combined periodontal-endodontic (perio-endo) lesions would be exposed to sub-lethal doses of PAD (sPAD). This study evaluated the effect of sPAD using toluidine blue O (TBO) in combination with diode laser irradiation on the growth and biofilm-formation ability of Porphyromonas gingivalis as an endo-periodontal pathogen. METHODS: The antibacterial and antibiofilm potential of sPAD against P. gingivalis was analyzed at sub-lethal doses of TBO and irradiation time of diode laser on a colony-forming unit and crystal violet assays, respectively. RESULTS:TBO-mediated PAD, using 6.25-100μg/mL at a fluency of 171.87J/cm2 and 12.5-100μg/mL at a fluency of 137.5J/cm2, showed a significant dose-dependent reduction in P. gingivalis growth when compared to the control. TBO-mediated PAD showed a significantly inhibitory effect on biofilm formation in P. gingivalis than TBO-PAD at sub-lethal levels. CONCLUSION: High doses of sPAD revealed antibacterial and antibiofilm potential activity, whereas lower doses of sPAD had conflicting results. Therefore, when PAD is prescribed in combined perio-endo lesions treatment, the dose of PAD used in vivo should be taken into account. Copyright Â