Peri-implant mucositis sites with suppuration have higher microbial risk than sites without suppuration

The aims of the present study were to compare the microbial differences between peri-implant mucositis sites with or without suppuration, and to construct a classification model with microbiota.

Twenty-four implants with peri-implant mucositis were divided into suppuration (SUP) group and non-suppuration (Non-SUP) group. Clinical assessments of bleeding index, probing depth, suppuration following probing (SUP) were recorded. Submucosal samples were collected from mesiobuccal sites and distobuccal sites, and analyzed by 16S rRNA gene sequencing. Generalized linear mixed model was used to adjust age, gender, location of implants, and intraindividual correlation.

It was demonstrated that the microbial richness was lower in SUP group. The relative abundance of some pathogenic taxa, such as genera of Fusobacterium, Tannerella, and Peptostreptococcus, were significantly higher in SUP group than Non-SUP group. In addition, SUP group had less Gram-positive bacteria, aerobic bacteria, and more metabolic pathway related to life activity. The classification model constructed with 12 genera got a 100% accuracy in identifying sites with or without suppuration.

The results from this study demonstrate a higher pathogenicity of microbiome at peri-implant mucositis sites with suppuration than without suppuration, which supports suppuration as a clinical indicator for higher microbial risk.