Analysis of microorganisms in periapical lesions: A systematic review and meta-analysis

Aims: The aim of this study was to systematically review the literature on prevalence of microorganisms and their viability/activity in endodontic periapical lesions. Design: Literature research was performed on five electronic biomedical databases from their start dates to June 2020. Only studies evaluating the presence of microorganisms in periapical lesions in human permanent teeth with secondary/persistent infection were included. Two reviewers independently assessed the eligibility for inclusion, extracted data and evaluated the risk of bias. Meta-analysis and binominal tests were used to analyse the resulting data. Results: From the 1,313 records found, 23 full-texts were included for qualitative and quantitative analysis. The prevalence of microorganisms in endodontic periapical lesions was 87 % (95 % CI, 75-94) and the prevalence of viable/active microorganisms was 82 % (95 % CI, 66-91). There were statistical differences in the geographic area subgroup and between viable bacteria and active viruses. The most common detection method of microorganisms was the molecular one (69 %), and the most prevalent bacteria were the species Actinomyces, Fusobacterium and Prevotella (40 %). Most of the included studies had moderate risk of bias. Conclusions: The prevalence of microorganisms in endodontic periapical lesions was 87 % and the prevalence of viable/active microorganisms was 82 %.

Automated summary

The study systematically reviewed the literature on the prevalence of microorganisms in endodontic periapical lesions and found that the prevalence was high, with 87% of lesions containing microorganisms. The prevalence of viable/active microorganisms was slightly lower at 82%. Different geographic areas showed statistical differences, as did viable bacteria compared to active viruses. The most common detection method for microorganisms was molecular, with Actinomyces, Fusobacterium, and Prevotella being the most prevalent bacteria.