Profiling the Bacterial Microbiome Across Peri-Implant Conditions

To comprehensively characterise the bacterial microbiome in peri-implant health, peri-implant mucositis and peri-implantitis.

A re-analysis of raw microbiome data was performed from 15 studies, which were finally selected based on the availability of 16S rRNA sequencing. Reads were pre-processed using mothur and classified using the HOMD database. A total of 522 samples were analysed to evaluate diversity estimates and bacterial relative abundance, identifying discriminant features via LEfSe, while predictions of functional potential were obtained using PICRUSt2. Bacterial co-occurrence networks were constructed, and dysbiosis was measured by employing the subgingival microbiome dysbiosis index.

Peri-implantitis showed higher bacterial diversity compared to health and greater microbial richness than peri-mucositis. Each clinical condition displayed a distinct community structure and bacterial co-occurrence networks. The representative species in peri-implant health were Rothia aeria , R. dentocariosa and Veillonella parvula_dispar. Peri-mucositis is characterised by Leptotrichia hongkongensis , L. wadei and Fusobacterium nucleatum subsp. polymorphum, while peri-implantitis is defined by Porphyromonas gingivalis , F. nucleatum subsp. vincentii and Tannerella forsythia . Peri-implantitis exhibited enrichment in predicted microbial pathogenesis pathways and greater bacterial dysbiosis.

These results provide deeper insights into the peri-implant microbiome, identifying key bacterial species, functional processes and interactions that may be crucial to inflammation and destruction during peri-implant diseases.