(PR035) Effect of Periodontal Health Status on the Intra-canal Microbiome of Vital Teeth

Objective(s): The periodontal ligament space and the dental pulp communicate through accessory pulp canals. Previous studies have shown similarities in the microbiome of a clinically diagnosed endo-perio lesion with a necrotic pulp. Our study aims to identify whether the severity of periodontally affected teeth impacts the microbiome in a vital pulp.

Methods: Thirty-seven root canal samples were collected from teeth with irreversible pulpitis associated with different periodontal status (healthy-PH, moderate-PM and severe-PS). 16S rRNA sequencing was performed using the Illumina MiSeq platform. Alpha diversity (Shannon index) and beta diversity (Bray-Curtis and Jaccard) metrics were used to analyze the microbiome. Linear discriminant analysis (LDA) was used for dimensionality reduction and the significance of clustering was interrogated with the PERMANOVA test. Linear discriminant analysis effect size was used to determine the drivers of the differences. PhyloToAST, and QIIME2 were used for data visualization and statistical analyses.

Results: The intra-canal microbiome of periodontally healthy teeth differ significantly from the samples with periodontitis (p < 0.05, PERMANOVA, LDA), therefore periodontal status of the patient seems to be the driver of the root canal oral microbiome. The drivers of differences among groups were species belonging to the genera Treponema denticola, Desulfobulbus HOT.041 and Delftia acidovorans for PS, while PM was Corynebacterium durum. Furthermore, Actinomyces HOT.140, and Streptococcus australis were identified among the 26 drives of differences for PH. The alpha diversity did not differ significantly within groups.

Conclusion: Our data suggests characteristics of the root canal microbiome are influenced by the periodontal status of the teeth.