IADR Abstract Archives
Metagenomic Analysis of Microbiota in Healthy Dental Pulps
Objectives: This study aims to contribute to clarify the definition of a bacteria-free dental pulp by performing a 16S rRNA gene-based metataxonomic analysis of the pulp tissues of impacted sound teeth presenting no clinical symptoms and no carious lesions or fissures.
Methods: Specimen of the coronal pulp and outer radicular dentin of impacted mandibular third molars, as well as negative control samples were collected in 20 patients. DNA was extracted from pulp samples spiked with a known number of environmental bacteria not found in the human microbiome, for quantification purposes. Bacterial DNA content was assessed through metataxonomic analysis, based on the sequencing of the V3-V4 region of the 16S rRNA marker.
Results: Bacterial DNA was present in all specimens of healthy pulp, but human DNA represented the bulk of the total DNA extracted. The three sample types exhibited substantial similarities, sharing sixteen genera across pulp, dentin and negative controls specimens. When considering the variability in inter-individual microbiota, certain species and genera demonstrated significantly higher abundance in the pulp compared to the corresponding dentin or negative control samples. Finegoldia magna and Fusobacterium nucleatum, both well-known oral species, were found to be enriched in dental pulp relative to outer radicular dentin alone or to the combination of dentin and control samples.
Conclusions: The present study confirmed the presence of bacterial DNA in all specimens of healthy pulps collected from pristine teeth. Because of the low bacterial DNA burden in the pulp tissue, the inclusion of multiple negative controls and DNA quantification are of upmost importance when studying dental pulp disease using metagenomic methods. The assessment of the pulpal microbiome is a complex matter that warrants further investigations.
Methods: Specimen of the coronal pulp and outer radicular dentin of impacted mandibular third molars, as well as negative control samples were collected in 20 patients. DNA was extracted from pulp samples spiked with a known number of environmental bacteria not found in the human microbiome, for quantification purposes. Bacterial DNA content was assessed through metataxonomic analysis, based on the sequencing of the V3-V4 region of the 16S rRNA marker.
Results: Bacterial DNA was present in all specimens of healthy pulp, but human DNA represented the bulk of the total DNA extracted. The three sample types exhibited substantial similarities, sharing sixteen genera across pulp, dentin and negative controls specimens. When considering the variability in inter-individual microbiota, certain species and genera demonstrated significantly higher abundance in the pulp compared to the corresponding dentin or negative control samples. Finegoldia magna and Fusobacterium nucleatum, both well-known oral species, were found to be enriched in dental pulp relative to outer radicular dentin alone or to the combination of dentin and control samples.
Conclusions: The present study confirmed the presence of bacterial DNA in all specimens of healthy pulps collected from pristine teeth. Because of the low bacterial DNA burden in the pulp tissue, the inclusion of multiple negative controls and DNA quantification are of upmost importance when studying dental pulp disease using metagenomic methods. The assessment of the pulpal microbiome is a complex matter that warrants further investigations.