Adjunctive Antimicrobial Photodynamic Therapy to Conventional Chemo-mechanical Debridement of Infected Root Canal Systems: A Systematic Review and Meta-analysis

Background: To investigate the efficacy of antimicrobial photodynamic therapy (aPDT) adjunctive to conventional chemo-mechanical debridement of root canal system in patients with endodontic infections.

Methods: A meta-analysis was done according to the Cochrane Collaboration recommendations and PRISMA statement. Two independent reviewers performed an extensive literature search on electronic databases of MEDLINE, EMBASE, and SCOPUS up to January 2019. The search strategy was done from the following terms: antimicrobial photodynamic therapy OR photo-activated disinfection AND root canal therapy OR endodontic therapy OR root canal infection OR endodontic infection. The I test was used for determine the inter-study heterogeneity. Publication bias assessment carried out on the studies using the Egger's regression test.

Results: Sensitivity analysis of 10 randomized clinical trials (RCTs) revealed differences in microbial load reduction (0.143, 95% CI [0.06, 0.30], P = 0.000) in favor of aPDT plus conventional chemo-mechanical debridement. A high degree of heterogeneity (P = 0.000; Q- value = 154.74; I = 94.18%) was noticed among photosensitizer and light parameters. Subgroup analysis demonstrated the absence of heterogeneity in RCTs, with low risk of bias for microbial load reduction gain. No evidence of publication bias was determined.

Conclusions: Although the aPDT parameters may vary from one RCT to the next, all studies found a reduction in microbial load with adjunctive use of aPDT; however, further high-quality RCTs focused on the standardized aPDT parameters are needed.