The Treponema denticola content of plaque was quantitatively estimated for samples taken from periodontitis patients as well as periodontally healthy subjects among two separate human populations. The populations studied included military volunteers and civilians at a university dental clinic. The plaque samples from each population were grouped according to pocket depth measurements at the collection site. A biotin-avidin enzyme-linked immunosorbent assay procedure was developed with a monoclonal antibody specific for a serovariety of T. denticola. T. denticola was present at significantly elevated levels in plaque samples collected from deep-pocket sites of patients with severe periodontitis relative to the healthy controls and a group with moderate disease. The ratio of T. denticola content per milligram of plaque in the deep pocket groups to that of the other two groups was about 2:1 for both populations. This is the first quantitative evidence of a positive relationship between a specific spirochete species and severe periodontitis.

The spirochetes found in dental plaque from patients with ulcerative gingivitis or chronic periodontitis have antigens that are thought to be unique to pathogenic treponemes. This close antigenic relation suggests that T. pallidum or a closely related organism may be involved in the pathogenesis of periodontal disease.

Treponema denticola and Porphyromonas gingivalis have been associated with human adult severe periodontitis. In this study, we quantified these putative pathogens in subgingival plaque samples collected from 74 Fijians, 74 Colombians and 73 U.S. Americans stationed at the Multinational Force and Observers encampment in the Sinai Desert, Egypt. A contingency table of T. denticola and P. gingivalis frequency revealed a highly significant synergistic relationship. We discovered that the occurrence of T. denticola apparently requires the presence of P. gingivalis. This represents the first observation of a synergistic relationship between these putative oral pathogens associated with adult severe periodontal disease.

Subgingival plaque samples were collected from individuals with advanced Periodontitis before and 3 to 11 weeks after scaling and root planing periodontal treatment. The plaque levels of Treponema denticola and Porphyromonas gingivalis antigens were measured before and after treatment by a quantitative immunoassay procedure using monoclonal antibodies specific for these oral bacteria. A decrease in mean levels of T. denticola (P < .05) and P. gingivalis antigens (P <. 09) were observed following periodontal therapy. Improved health, as measured by a decrease in probing depth, was associated with a decrease in T. denticola antigen (P < .05). These results suggest that the T. denticola levels of successfully treated sites decreased, while non-responding sites had levels of this microbial marker which were equal to or greater than the pre-treatment levels. These results provide additional evidence that T. denticola is associated with human adult severe periodontal disease, and can serve as a prognostic marker for disease recurrence.

The purpose of this investigation was to determine whether monoclonal antibodies against pathogenrestricted antigens of Treponema pallidum subsp. pallidum could be used as probes for spirochetes in diseased gingival tissue from subjects with acute necrotizing ulcerative gingivitis. A biotin-streptavidin system was used to identify spirochetes bound by monoclonal antibodies in cryostat sections of tissue. Twelve of 16 tissue samples from diseased sites, but none of 8 tissue specimens from healthy sites, reacted with pathogen-restricted antibodies. Organisms were found in intact epithelium and connective tissues adjacent to ulcers. Staining intensity was often high in perivascular locations and around vesicular spaces. Monoclonal antibodies to Bacteroides gingivalis and Treponema denticola were each reactive with diseased gingival tissues, but staining was usually restricted to ulcerated areas. These studies extend recent observations that showed that subjects with acute necrotizing ulcerative gingivitis had both pathogen-related spirochetes in dental plaque and serum immunoglobulin G to pathogen-restricted antigens on T. pallidum subspecies, suggesting that pathogen-related spirochetes may be associated with the pathogenesis of certain periodontal diseases.