Abstract
AIM: To assess and compare the antibacterial efficacy of methylene blue (MB) and red laser (660 nm) antimicrobial photodynamic therapy (aPDT), indocyanine green (ICG) and infrared laser (810 nm) aPDT, and dual-dye (MB and ICG) and dual light (red and infrared) aPDT on oral biofilms of Enterococcus faecalis (E. faecalis), Prevotella intermedia (P. intermedia), and Streptococcus mutans (S. mutans). MATERIALS AND METHODS: Biofilms of E. faecalis, S. mutans, and P. intermedia were grown at 36°C and 5% CO(2) for 7 days in a 96-well plate in a brain heart infusion (BHI) growth medium. Before aPDT, a total of 27 inoculums were collected from culture wells and grown on culture plates to assess baseline colony forming units (CFU). The microbial wells were treated with MBaPDT (group I), ICGaPDT (group II), and MBICGaPDT (group III). Post-aPDT, inoculums were collected from wells to be cultured to assess CFU. One-way analysis of variance (ANOVA) and student paired t-tests were used for statistical analysis. The significance level was fixed at p ≤ 0.05. RESULTS: Methylene blue antimicrobial photodynamic therapy (MBaPDT) caused a significant reduction in E. faecalis counts compared to other groups (f = 11.15, p = 0.01). aPDT on S. mutans resulted in a significant (p = 0.04) reduction of bacterial counts in the ICGaPDT group. aPDT on P. intermedia resulted in a significant reduction in bacterial counts (p ≤ 0.05) in MBaPDT and ICGaPDT groups. CONCLUSION: Dual-dye and dual light aPDT showed an antibacterial effect against E. faecalis. It was ineffective against S. mutans and P. intermedia. CLINICAL SIGNIFICANCE: Dual-dye aPDT may effectively reduce E. faecalis counts in infected root canals and improve the outcomes of root canal treatment. HOW TO CITE THIS ARTICLE: Yavagal C, Yavagal PC, Marwah N, et al. Antibacterial Efficacy of Dual-dye and Dual Laser Photodynamic Therapy on Oral Biofilms of Enterococcus faecalis, Streptococcus mutans, and Prevotella intermedia: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-2):S128-S132.