The habitat of periodontopathic micro-organisms.

The purpose of the present study was to investigate the significance of oral mucosal surfaces as a habitat of periodontopathic micro-organisms. For this investigation, 7 young adults were selected for an experimental gingivitis study. At the start of the experiment, bacterial samples were taken by means of a sterile swab from 4 oral mucosal surfaces: the buccal mucosa, the vestibular fold, the dorsum of the tongue and a tonsil. All individuals were asked to abstain from oral hygiene procedures in 1 quadrant of the mouth for a period of 23 days. At the end of this period, plaque samples were taken from 4 tooth surfaces by means of a sterile periodontal probe just coronal from the gingival margin. The study included evaluation of spirochetes and motile organisms by means of phase-contrast microscopy and of black-pigmented Bacteroides, Fusobacterium, Actinomyces, Actinobacillus actinomycetemcomitans and Capnocytophaga by means of cultural studies. Results showed a relationship between the prevalence of motile organisms and black-pigmented Bacteroides in samples from both the mucosal surfaces and the 23-day-old plaque. In addition, a relationship was found between the presence of motile organisms on the dorsum of the tongue at the start of the experiment and their prevalence in the 23-day-old plaque. It was suggested that the dorsum of the tongue may function as a nidus for periodontopathic micro-organisms.