Simultaneous Dual-Wavelength Laser Irradiation against Implant-Adherent Biofilms of Staphylococcus aureus, Escherichia coli, and Candida albicans for Improved Antimicrobial Photodynamic Therapy

Abstract

The efficiency of antimicrobial photodynamic therapy (PDT) might be improved by using multiple wavelengths. This study investigates the sensitivity of implant-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Candida albicans to indocyanine green (ICG)-808 nm diode laser, toluidine blue O (TBO)-635 nm diode laser, and hydrogen peroxide (HP)-980 nm diode laser and their combination when irradiated with dual-wavelength laser irradiation (simultaneously 980–635 nm or 980–808 nm). After an incubation period of 72 h, the infected implants were randomly divided into seven different treatment modalities: Control, HP, HP-PDT, TBO-PDT, HP-TBO-PDT, ICG-PDT, and HP-ICG-PDT. After the treatments, the colony-forming units (CFUs)/mL and reactive oxygen species (ROS) generation were determined. All evaluated disinfection methods were significantly effective against the three investigated bacteria compared to the control. The combined treatment of HP-ICG-PDT or HP-TBO-PDT had the greatest antibacterial effect compared to each treatment alone. There were statistical differences between HP-ICG-PDT and ICG-PDT or HP-TBO-PDT and TBO-PDT for all three bacteria studied. PDT with simultaneous dual-wavelength laser irradiation is an efficient strategy to improve the therapeutic effect of PDT.

Evaluation of Different Procedures for Titanium Dental Implant Surface Decontamination—In Vitro Study

“…Similarly, Sousa et al [22] achieved better results with chemical treatment with sodium hypochlorite and chlorhexidine after mechanical cleaning with a titanium brush. The results of the aforementioned studies show that using a chemical agent in addition to mechanical biofilm removal can improve the decontamination of the implant surface [22,30,31]. This is in accordance with the results of our study, where after treatment with a chitosan brush and chlorhexidine, fewer bacteria were found than if a chitosan brush was used alone.…”

“…Although different concentrations of chlorhexidine were used, i.e., in their research, 0.12%, and in ours, 0.20%, the chlorhexidine reduced the number of bacteria on the implant surface. Afrasiabi et al showed that the combined use of hydrogen peroxide with a photosensitizer and photodynamic therapy has a more efficient antibacterial effect on biofilms of Staphylococcus aureus, Escherichia coli and Candida albicans compared to each treatment alone [31]. Similarly, Sousa et al [22] achieved better results with chemical treatment with sodium hypochlorite and chlorhexidine after mechanical cleaning with a titanium brush.…”