Odor characteristics and associated bacterial profiles in peri-implantitis using a novel odor measurement device

This study assessed peri-implantitis risk by measuring odor using a novel device capable of identifying odorous components and bacteria specific to peri-implantitis.

Implants from eight peri-implantitis patients and superstructures from 20 maintenance patients were evaluated using organoleptic testing and an odor detection device (nose@MEMS, I-PEX, Kyoto, Japan). In the maintenance group, 13 superstructures emitted odor, while 7 did not. Plaque samples were collected from peri-implant sites, and bacterial composition was analyzed via 16S rRNA sequencing.

Principal component analysis of odor measurements obtained with the I-PEX system revealed that implants from peri-implantitis patients and odor-positive superstructures during maintenance formed a distribution distinct from odor-negative superstructures. Comparative analysis of bacterial composition between samples in the odor-associated region (Region A) and those including odor-negative superstructures (Region B) showed that Region A had a higher proportion of anaerobic bacteria, while Region B was enriched in commensal oral bacteria. Among 14 bacterial species previously linked to peri-implantitis, Porphyromonas gingivalis, Tannerella forsythia, and Porphyromonas endodontalis were significantly more abundant in Region A, whereas Fretibacterium fastidiosum and Mogibacterium were significantly lower.

The odor characteristics of peri-implantitis and odor-positive superstructures were similar and clearly distinguishable from odor-negative counterparts. The shared odor profile was associated with higher proportions of bacterial species previously linked to peri-implantitis. These findings imply that odor analysis using this novel device may provide a promising strategy for implant maintenance and peri-implantitis risk prediction.