Objectives: The aim of this study was to analyse the prevalence of oral bacteria on the dorsum of the tongue. In addition, the relationship between the number of teeth and the microflora present on the coating of the tongue in a population of 85-year-old people was assessed.
Subjects and methods: Two hundred and five individuals (89 males, 116 females) from the same geographical area who were 85 years of age were examined. Five periodontopathic bacteria (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Treponema denticola) and one cariogenic bacterium (Streptococcus mutans) were analysed using a polymerase chain reaction assay of tongue samples from the population.
Results: Periodontal bacteria-positive individuals have more teeth than that of periodontal bacteria-negative people. Between the periodontal bacteria-positive and -negative individuals, there were significant differences in the mean number of teeth for P. gingivalis (p<0.0001), T. denticola (p<0.001), F. nucleatum (p=0.002), and T. forsythia (p=0.005), while there were no significant differences for A. actinomycetemcomitans (p=0.998) or S. mutans (p=0.147).
Conclusions: A wide range of species, including anaerobes, was detected in 85-year-old subjects. It was found that the detection of periodontal bacteria on the tongue coating increased with the number of teeth. There was a positive relationship between the tooth number and periodontopathic bacteria, except for A. actinomycetemcomitans. These results suggest that tongue care is essential for preventing oral disease and needs to be part of any oral care programme in elderly people.