Spatial and temporal dynamic changes of oral microbiome in removable partial denture wearers: a longitudinal study...

This longitudinal study aimed to characterize the spatial and temporal dynamics of oral microbiome colonization on removable partial dentures (RPDs) and corresponding dental surfaces at species-level resolution, to elucidate ecological succession patterns and identify potential pathogenic colonizers.

We conducted a longitudinal study of 10 participants requiring RPDs. Plaque samples were collected from four sites at five time points. The microbial communities were profiled using PacBio full-length 16S rRNA sequencing, enabling high accuracy taxonomic assignment to the species level. Bioinformatic analyses included alpha/beta diversity, LEfSe, and PICRUSt2 functional prediction.

Significant differences in microbial composition were observed between RPD and dental plaques, despite similar alpha diversity. Temporal analysis revealed a progressive decrease in RPD plaque diversity. Notably, the potential respiratory pathogen Klebsiella pneumoniae was detected in early RPD biofilms. A three-stage ecological succession model for RPD biofilm was proposed, initiating with acidogenic pioneers, followed by functional amplification of taxa involved in extracellular polysaccharide production, and culminating in a stable, acid-tolerant community.

This study provides a species-level understanding of microbiome changes associated with RPDs, confirms differences between RPD plaque and dental plaque, proposes a succession model for RPD-associated bacteria, and determines key turning points and potential pathogens.