Microbiome in the Apical Root Canal System of Teeth with Post-Treatment Apical Periodontitis

By Siqueira JF Jr, Antunes HS, Rôças IN, Rachid CT, Alves FR.

Date: 06/2017
Journal: PLoS One



To evaluate the apical root canal microbiome of teeth with post-treatment apical periodontitis.

N=   10 Apical root specimens                                                     


•Apical root specimens obtained during periradicular surgery were cryogenically ground.

•DNA was extracted from the powder and the microbiome was characterized using a next-generation DNA sequencing (NGS) approaches (Illumina sequencing)

Most highlighted Results: 

•All samples were positive for the presence of bacterial DNA

•Over 85% of the sequences belonged to 4 phyla: Proteobacteria (46%), Firmicutes (18%), Fusobacteria (15%) and Actinobacteria (8%) (Fig 1)Proteobacteria was the most abundant phylum in 6/10 samples.

Fusobacteria dominated 2 samples, and Firmicutes and Actinobacteria were the most dominant in 1 sample each

Enterococcus was found in 4 cases, always in relatively low abundance

Clinical significance

•The persistent apical periodontitis characterized by multispecies bacterial communities and has a heterogeneous etiology, because the community composition largely varied from case to case.