Photodynamic therapy for endodontic disinfection

Area of Science:

• Microbiology
• Biomedical Engineering
• Dental Science

Background:

• Endodontic treatment aims to eradicate bacteria from the root canal system.
• Persistent infections, particularly those involving Enterococcus faecalis biofilms, pose a challenge to conventional endodontic therapy.
• Novel antimicrobial strategies are needed to improve treatment outcomes.

Purpose of the Study:

• To evaluate the efficacy of photodynamic therapy (PDT) against planktonic endodontic pathogens.
• To assess the effectiveness of PDT in eliminating Enterococcus faecalis biofilms within experimentally infected root canals.
• To determine the potential of PDT as an adjunctive treatment in endodontics.

Main Methods:

• Bacterial strains were sensitized with methylene blue (25 µg/ml) for 5 minutes.
• Sensitized microorganisms were exposed to red light (665 nm) with specific energy fluences (30 J/cm² or 222 J/cm²).
• Root canals of extracted teeth infected with E. faecalis biofilms were treated using an optical fiber with 360-degree light distribution.

Main Results:

• Methylene blue and red light eradicated all tested bacterial species except E. faecalis (53% killing).
• A higher energy fluence (222 J/cm²) of PDT eliminated 97% of E. faecalis biofilm bacteria in root canals.
• Uniform light distribution via a multi-diffuser optical fiber enhanced PDT efficacy against biofilms.

Conclusions:

• Photodynamic therapy demonstrates significant potential for eliminating residual endodontic pathogens, including E. faecalis biofilms.
• PDT can be considered a promising adjunctive therapeutic approach to complement standard endodontic procedures.
• Further development of PDT could lead to improved disinfection protocols in root canal treatment.