Anaerobic oral and dental infection.

Anaerobes make up a significant part of the oral and dental indigenous and pathogenic flora. Their role in periodontal disease, root canal infections, infections of the hard and soft oral tissue, as well as their importance as foci for disseminated infectious disease is well established. Despite the ubiquitous involvement of bacteria, significant progress in our understanding of specific microbial etiologies has occurred only in the past decade. Estimates of the number of species recovered from samples of subgingival plaque range from 250 to 400, a large portion made up by anaerobes. Common anaerobic isolates include Fusobacterium, Bacteroides, Actinomyces, Peptococcus, Peptostreptococcus, Selenomonas, Eubacterium, Propionibacterium, and Treponema. Recently, several significant advances in our knowledge have set the stage for future research. First, circulating levels of hormones in pregnant women were shown to be stimulatory to Bacteroides species, which were associated with increased levels of gingival infection. Second, bacterial invasion of the soft and hard periodontal tissues has been documented in gingivitis, advanced periodontitis, and localized juvenile periodontitis. The frequency and identity of invading bacteria will determine the implications for diagnosis and treatment. Third, antibacterial "probes" aimed at anaerobic (and capnophilic) bacteria have had promising results in controlling and arresting oral, dental, and peridontal anaerobic infections.