Effect of a Combination of Photodynamic Therapy and Chitosan on Streptococcus mutans (An In Vitro Study)

Abstract

Introduction: This study aimed to assess the effect of photodynamic therapy (PDT) and chitosan separately and in combination on Streptococcus mutans. Methods: This in vitro experimental study evaluated 216 microbial samples in 6 groups. First, 5 µL of 0.5 McFarland standard suspension of S. mutans was added to each well of an ELISA microplate; 100 µL of Mueller Hinton broth was also added to each well; 180 wells contained S. mutans suspension while 36 wells were devoid of bacteria. Group 1 served as the negative control and had no bacteria. Group 2 served as the positive control and S. mutans in the positive control wells did not undergo any intervention. In groups 3 and 4, PDT with a 50 mW low-level laser was performed for 30 and 40 seconds respectively. In group 5, 3 mg/mL of chitosan (100 µL) was used. In group 6, 3 mg/mL (100 µL) of chitosan was used in combination with PDT (50 mW laser for 30 seconds). The laser was irradiated under aseptic conditions at a 660 nm wavelength with 50 mW power. Data were analyzed using one-way ANOVA and Tukey's test. Results: PDT combined with chitosan showed maximum bactericidal effect followed by PDT for 40 seconds and chitosan groups (P < 0.05). PDT for 30 seconds showed a minimum bactericidal effect (P < 0.05). All pairwise comparisons revealed significant differences (P < 0.001). Conclusion:Chitosan and PDT alone can be used to decrease the S. mutans count. However, their combined use has a greater bactericidal effect on S. mutans.

Antimicrobial photodynamic therapy for the treatment of oral infections: A systematic review

“… 115 Chitosan The combination of chitosan and aPDT had a greater bactericidal effect on S. mutans than either treatment alone. 116 β-cyclodextrin aPDT using MB encapsulated β-cyclodextrin activated by laser or LED effectively decreased microbial populations in multispecies biofilms composed of early colonizing microorganisms. 117 Potassium Iodide Potassium iodide significantly enhanced the efficacy of TB-mediated aPDT in eliminating S. mutans and C. albicans due to the synergistic effect of molecular iodine and H 2 O 2 .…”

Antibacterial Effect of Chitosan and Low-Level Diode Laser Against Enterococcus faecalis in Infected Root Canals in Primary Molars

“…In this study, the 2.5% concentration of NaOCl was chosen to avid its high toxicity (23) . Also, chitosan was chosen as an irrigant solution because it has strong bactericidal activity and is not toxic for mammals (24) . However, diode laser was chosen as a disinfectant system because laser achieves better disinfection of root canal system by deep penetrating and cleaning complex endodontic system (18) .…”

The effect of photodynamic therapy in controlling the oral biofilm: A comprehensive overview

“…Also, PDT was found to be a viable alternative to dental caries treatment [85]. PDT and chitosan have been studied individually as well as combined by Mirfasihi et al [49]. PDT combined with chitosan showed the highest bactericidal effect, followed by chitosan groups and PDT alone.…”

“…S. mutans counts could be reduced with just PDT and Chitosan. S. mutans is more susceptible to their combined bactericidal effects [49].…”