Antibacterial efficacy of herbal extracts as photosensitizers in photodynamic root canal disinfection.

Context: Photodynamic root canal disinfection is a valuable adjunct in endodontics. However, the standard photosensitizer often causes tooth discoloration. Natural photosensitizers, such as curcumin (CUR) and Beta vulgaris (BV), can be explored for their antimicrobial efficacy against Enterococcus faecalis biofilms.

Aims: This study evaluates the antibacterial effectiveness of BV extract as a photosensitizer in antimicrobial photodynamic therapy (aPDT) against E. faecalis biofilms, comparing it to CUR and toluidine blue (TB).

Settings and design: A comprehensive study protocol outlining the objectives and methodologies was submitted to the Institutional Ethics Committee and received ethical approval (Approval No. 2024-25/1114).

Subjects and methods: Fifty-six single-rooted extracted teeth were prepared using Protaper Gold to #F3, irrigated with 3% sodium hypochlorite (NaOCl), and finalized with 17% ethylenediaminetetraacetic acid. The teeth were contaminated with E. faecalis suspension and divided into seven groups: NaOCl alone (positive control), NaOCl with TB, CUR, or BV; B. Vulgaris alone; CUR solvent alone; and Saline (negative control). Photosensitizers (0.5 mg/mL) were activated with a 640 nm diode laser for 120 s. Bacterial load was assessed through colony-forming unit counts.

Statistical analysis used: Data were subjected to statistical analysis using SPSS v22, with analysis of variance and post hoc Tukey's tests (P < 0.05).

Results: NaOCl combined with CUR-PDT showed the highest CFU reduction, followed by NaOCl with TB and BV. Nonphotoactivated photosensitizers were less effective in comparison.

Conclusions: Photoactivated CUR and BV extracts demonstrated superior antimicrobial activity compared to their nonphotoactivated forms, suggesting their potential as alternative photosensitizers in aPDT.