Background: This prospective and controlled study elucidates the impact of smoking on the salivary microbiome and its further influence on marginal bone loss (MBL) around an implant during a 3-month bone-healing period.
Methods: Saliva samples were collected preoperatively from 20 periodontally healthy patients with single-tooth replacement in the posterior mandible (smokers [n = 10] and non-smokers [n = 10]). Sequencing of 16S recombinant RNA gene amplicons was used to characterize the salivary microbiome. Each patient received implant surgery after oral clinical assessment, and MBL around the implant was measured during a 3-month healing period.
Results: In total, 871,389 sequences were compared against the Human Oral Microbiome Database for bacterial identification. Microbial signatures of smokers exhibited lower diversity and richness, with a significant decrease in uncultured species. The phyla Gracilibacteria and Saccharibacteria showed a significant decrease in smokers. The genera Streptococcus, Lachnoanaerobaculum, Stomatobaculum, and Eubacterium were significantly increased in smokers, whereas Selenomonas, Selenomonas [G-3], and Catonella were significantly decreased. Specifically, Porphyromonas gingivalis was significantly more abundant in smokers, which was positively related to the severity of MBL during bone healing.
Conclusions: Smoking shapes the salivary microbiome in states of clinical health, and further may influence MBL during bone healing by creating high at-risk-for-harm communities. Understanding of the distinctly divergent oral microbiome in smokers and non-smokers is a base for personalized therapeutics for this high-risk cohort and also a base for further study on the pathologic mechanisms.
Keywords: Alveolar bone loss; dental implants; microbiota; smoking.