Synergistic Antimicrobial Effect of Photodynamic Inactivation and SWEEPS in Combined Treatment against Enterococcus faecalis in a Root Canal Biofilm Model: An In Vitro Study

Abstract

Background: Persistent bacterial infections caused by biofilm-associated Enterococcus faecalis are a global public health concern. This study aims to compare the biofilm removal effects of methylene blue (MB) or hydrogen peroxide (HP) mediated photodynamic inactivation (PDI) with a shock wave enhanced emission photoacoustic streaming (SWEEPS) method laser irradiation enhanced bactericidal activity. Methods: A total of fifty extracted single-rooted human teeth were used. Each canal was then inoculated with a bacterial suspension of E. faecalis and left for ten days to induce biofilm formation. The antibacterial effects within treated root canals using MB or HP + diode laser or SWEEPS alone or in combination were assessed and compared with 5.25% sodium hypochlorite (NaOCl) as the positive control group. Data were analyzed using one-way ANOVA and Tukey’s post hoc test. Results: The MB + diode laser + SWEEPS and HP + diode laser + SWEEPS groups displayed significantly lower amounts of bacteria than either the MB + diode laser or SWEEPS and HP + diode laser or SWEEPS groups (p < 0.001). There was no statistically significant difference detected between the diode laser and SWEEPS groups (p = 0.982). Conclusions: SWEEPS can enhance the photosensitizer distribution in the root canal, leading to effective biofilm removal. This technique could thus help promote the future development of endodontic treatments.

The Evaluation of SWEEPS Plus Antimicrobial Photodynamic Therapy with Indocyanine Green in Eliminating Enterococcus faecalis Biofilm from Infected Root Canals: An In Vitro Study

“…Consistent with the present results, previous studies also showed that application of SWEEPS with a 660 and 980 nm diode laser or light-emitting diode (LED) can cause a more significant decrease in the root canal infected with E. faecalis [25,30]. However, in contrast with the results of this study, the diode laser and SWEEPS did not show significant differences with methylene blue in their use as a photosensitizer [30]. Since the type of photosensitizer, light source, and irradiation time affect the bactericidal properties, this difference might be related to the fact that the mechanism of action of ICG is different from that of other photosensitizers.…”

“…The SWEEPS technique mechanically detaches the biofilm from the root canal, therefore increasing the penetration depth and efficacy of the photosensitizer, due to the frequent generation of cavitation [1]. Consistent with the present results, previous studies also showed that application of SWEEPS with a 660 and 980 nm diode laser or light-emitting diode (LED) can cause a more significant decrease in the root canal infected with E. faecalis [25,30]. However, in contrast with the results of this study, the diode laser and SWEEPS did not show significant differences with methylene blue in their use as a photosensitizer [30].…”

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

“…Deeper penetration into biofilms as well as low interference from radiation are the advantages of HP [20]. The use of HP as a photosensitizer has been investigated in several studies [21][22][23].…”

Biofilm Removal from In Vitro Narrow Geometries Using Single and Dual Pulse Er:YAG Laser Photoacoustic Irrigation

“…The objective of this work was to fabricate two different narrow confined geometries and compare the efficiency of two laser pulse modalities for biofilm removal. We hypothesized that Er:YAG-AutoSWEEPS photoacoustic irrigation would better reach inaccessible sites and increase fluid flow rate in narrow geometries which would in turn increase the cleaning of Enterococcus faecalis biofilms, the main causative agent of persistent bacterial infection in oral cavity [ 36 , 37 , 38 , 39 ]. Biofilms were grown on titanium disks of different dimensions for 3 days to reach maturity.…”