Aim: To characterize and compare the role of the oral microbiota and host biomarkers in patients with peri-implant mucositis and peri-implantitis.

Methods: Patients diagnosed with either peri-implant mucositis (N=13) or peri-implantitis (N=20) were recruited from the Dr. Sam Borden Graduate Periodontics Clinic at the University of Manitoba. Subgingival plaque samples and crevicular fluid samples were collected from diseased implant sites and healthy natural teeth to study the local microbiome and host biomarker profiles, respectively. 16 rRNA and ITS rRNA amplicon sequencing were performed to detect bacterial and fungal species. Eight different cytokines were isolated and analyzed: IL-1β, IL-2, IL-4, IL-6, IL8, IL-10, IFN-γ, TNF-α.

Results: Bacterial differential abundance analysis indicated statistically significant differences in the abundance of 17 different bacterial taxa and species between sites with peri-implant mucositis and peri-implantitis, most notably Tannerella forsythia was significantly more abundant at sites with peri-implantitis compared to sites with peri-implant mucositis. Fungal differential abundance analysis indicated that Malassezia species were significantly reduced in sites with peri-implant mucositis compared to sites with peri-implantitis. Cytokine analysis indicated no statistically significant differences in the crevicular concentrations of any cytokines analyzed between the peri-implant mucositis and peri-implantitis groups.

Conclusion: Peri-implant mucositis and peri-implantitis have similar microbial communities and cytokine profiles; however, the presence of certain bacterial and fungal species may play a role in the transition between peri-implant diseases.