DOES ADJUNCTIVE PHOTODYNAMIC THERAPY ENHANCE SODIUM HYPOCHLORITE-BASED ROOT CANAL DISINFECTION? A SYSTEMATIC REVIEW AND META-ANALYSIS.

OBJECTIVE Photodynamic therapy (PDT) combining a photosensitizer with laser activation has been proposed as an adjunct to enhance disinfection. This systematic review and meta-analysis aimed to synthesize evidence on the effectiveness of NaOCl irrigation combined with PDT compared with NaOCl alone for disinfecting root canal system.

MATERIALS AND METHODS Following PRISMA guidelines, searches were conducted in PubMed, Scopus, Embase, and Web of Science. Inclusion criteria were ex-vivo studies on human teeth infected with E. faecalis, comparing NaOCl alone with NaOCl + PDT and reporting colony forming unit (CFU) outcomes. Standardized mean differences (SMD) in CFU reduction were synthesized using random effects models, with subgroup analyses by photosensitizer (methylene blue and toluidine blue). The certainty of evidence was rated using GRADE.

RESULTS The review included 7 studies. CFU counts decreased in both NaOCl alone and NaOCl+PDT groups; NaOCl alone achieved 19.36-99.93% reduction, while adjunctive PDT achieved 65.85-99.92%. Meta-analysis favored PDT+NaOCl over NaOCl alone (SMD = 5.64; 95% CI = 2.67-8.62; p = 0.0002) with high heterogeneity (I² = 95%). Subgroup analyses showed a significant benefit with methylene blue, whereas toluidine blue showed no significant effect. The risk of bias indicated overall medium risk of bias.

CONCLUSIONS NaOCl + PDT with methylene blue enhances disinfection compared with NaOCl alone, in extracted teeth, while toluidine blue shows no clear added benefit. High heterogeneity limits certainty, underscoring the need for standardized protocols and reporting.

CLINICAL RELEVANCE Although limited to ex vivo evidence, the findings provide microbiological support for adjunctive antimicrobial strategies and may inform the design of future clinical disinfection protocols.