The relationships between streptococcal species and periodontopathic bacteria in human dental plaque
Authors: J.D. Hillman, S.S. Socransky, Myra Shivers — The Forsyth Dental Center, Boston, MA
Journal: Archives of Oral Biology | Published: 1985 | Vol. 30, No. 11/12: pp. 791–795
Abstract
The existence of antagonistic and commensal relationships between microorganisms was investigated. The predominant cultivable flora in 172 plaque samples from active and non-active sites in 32 human subjects with destructive periodontitis was determined.
The presence of putative periodontopathic organisms — Bacteroides gingivalis, Bacteroides intermedius, Bacteroides forsythus, Wolinella recta, Actinobacillus actinomycetemcomitans, and Eikenella corrodens — in a site was correlated with the absence of certain viridans streptococci (Streptococcus sanguis, Streptococcus uberis, and Streptococcus intermedius), and vice versa. Hydrogen-peroxide production by these organisms appears to be the principal mechanism of growth inhibition for periodontopathic organisms. Bacterial interactions may thus be causally related to both periodontal health and disease.
Key Results
Antagonistic Relationships in Active Periodontitis
Clear antagonisms (relative risk <0.5) were identified between viridans streptococcal species and several periodontal pathogens. Strep. sanguis types I and II and Strep. uberis all interacted antagonistically with 2–4 of the six test pathogen strains examined. The higher the proportion of Strep. sanguis in a site, the lower the relative risk of also finding A. actinomycetemcomitans.
Inhibitors in Plaque — Intractable Periodontitis vs. Healthy Subjects
| Test Strain | Active Disease Sites | Inactive Sites | Healthy Control |
|---|---|---|---|
| B. forsythus | 0% | 8% | 20% |
| B. intermedius | 0% | 13% | 37% |
| A. actinomycetemcomitans | 1% | 10% | 22% |
Conclusions
Certain viridans streptococci, by virtue of their ability to produce hydrogen peroxide, appear to promote periodontal health by keeping the numbers of potentially pathogenic organisms below the threshold level necessary to initiate disease. This study provides compelling evidence for the protective role of the ProBiora3® strains and forms a core part of the scientific rationale for oral probiotic therapy for periodontal health maintenance.
