Microbial Association with GenusActinomycesin Primary and Secondary Endodontic Lesions, Review

The main reason for root canal treatment failure is the persistence of microorganisms after therapy, or the recontamination of the root canal system due to an inadequate seal. In the mouth,Actinomycesspp. constitute a significant part of the normal flora, which is indicative of their ability to adhere to oral tissue and resist cleansing mechanisms, such as salivary flow. This review, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), aims to clarify the prevalence of microbial genera that are associated with the genusActinomycesin primary and secondary endodontic infections (primary outcome), and to identify the most prevalent species of theActinomycesgenus in endodontic lesions (secondary outcome). A total of 11 studies were included in the qualitative and quantitative analysis, and a total of 331 samples were analyzed. Bacteria of the genusActinomyceswere found in 58 samples, and 46 bacterial genera were detected in association with bacteria of the genusActinomyces. Bacteria of the genusStreptococcusandPropionibacteriumwere those most frequently associated withActinomycesin the endodontic lesions considered, andActinomyces israeliiwas the most frequently involved species.