Taxonomic abundance in primary and secondary root canal infections

Abstract

Aim: To evaluate the root canal microbiome composition in cases of primary and secondary apical periodontitis. Methodology: Thirty-nine samples from patients with primary root canal infections obtained before root canal treatment, and 40 samples obtained during root-end resection procedures from previously filled cases with apical periodontitis were evaluated using 16S rRNA next-generation sequencing analysis (NGS). Demographic and clinical factors included age, sex, infection type, percussion sensitivity, and presence of pain. Differences in abundances of genera were evaluated using Kruskal-Wallis test. Alpha and beta diversity indices were calculated using mothur. The Shannon and Chao1 indices were used to measure alpha diversity. The Bray–Curtis dissimilarity was used to measure beta diversity. Differences in community composition were evaluated using analysis of similarity (ANOSIM) with Bonferroni correction for multiple comparisons. Results: Significantly fewer operational taxonomic units values were observed from samples from secondary infections (p 3.3%) and included Parvimonas, Fusobacterium, Campylobacter, Arachnia, Eubacterium, Prevotella, Peptostreptococcus, Fretibacterirum, and Pseudoramibacter. Significantly greater relative abundances of Prevotella, Peptostreptococcus, Veillonella, Lactucaseibacillus, and Dialister were observed in primary infections. Conclusions: Primary endodontic infections are more diverse than secondary infections. The microbial composition is not associated with the clinical manifestations of apical periodontitis.