Relationship between oral status and prevalence of periodontopathic bacteria on the tongues of elderly individuals.

Colonization of periodontopathic bacteria is associated with increased risk of systemic diseases. However, few studies have investigated the relationships between oral status factors and health-related quality of life (HR-QOL) and the prevalence of such bacteria in elderly individuals. This study investigated the prevalence of Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia in 165 community-dwelling functionally independent 85-year-old Japanese individuals (93 dentate, 72 edentulous) and the relationship to oral status, including oral malodour and HR-QOL. All four of the studied periodontopathic bacteria were found more frequently in tongue coating samples from dentate than edentulous subjects, and the prevalence of Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola was significantly related to the number of teeth with a periodontal pocket depth ≥4 mm. These results suggest the existence of a stable circulation of periodontopathic bacteria between the gingival sulcus and tongue coating over time with teeth. In addition, the presence of teeth with a deep pocket and colonization of Treponema denticola were positively related to the level of CH(3)SH, whilst the number of present teeth contributed positively to HR-QOL, especially with regard to mental health. In conclusion, as the dentate state can retain colonization of periodontopathic pathogens in the oral cavity, both periodontal treatment and tongue care are important for maintaining a healthy oral status in the elderly, and possibly result in avoidance of risk for tooth loss and decline in HR-QOL, as well as protecting from systemic diseases.