Assessment of the Effect of Denture-Wearing and Periodontal Disease on the Microbial Load of Respiratory Pathogens

Objective: This study aimed to quantitatively evaluate five opportunistic respiratory pathogens among individuals, with or without dentures, who have either healthy or diseased periodontal conditions. Methods: Saliva samples were obtained from 24 older adults. DNA extraction was performed, followed by a quantitative Polymerase Chain Reaction targeting five opportunistic respiratory pathogens, namely Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, Klebsiella pneumoniae, and Streptococcus agalactiae. The abundance of opportunistic pathogens among the four groups [denture-wearing with active periodontal disease (DAP), non-denture-wearing with active periodontal disease (NDAP), denture-wearing with stable periodontal health (DSP), and non-denture-wearing with stable periodontal health (NDSP)] were compared. Results: Saliva samples of all participants (100%) carried at least one opportunistic respiratory pathogen. Of the five pathogens, S. aureus, P. aeruginosa, K. pneumoniae, and S. agalactiae were present in more than 50% of the samples. A significant difference in the bacterial load of K. pneumoniae and P. aeruginosa was observed (p < 0.05). The quantity of P. aeruginosa in the NDAP group was significantly lower than the DSP group. However, for K. pneumoniae, no significant differences between the groups were detected. Conclusions: In this small pilot cohort, a relatively high prevalence and substantial microbial load of opportunistic respiratory pathogens were identified in the saliva of older adults. On the basis of these preliminary findings, optimal oral and denture hygiene care is suggested as a potential approach to reduce the presence and burden of respiratory pathogens in this population, although larger studies are required to confirm these associations and determine their clinical significance.