Are Host or Microflora Changes Related to Oral Infections?

The oral cavity is prone to a variety of infections including dental caries, periodontal disease, infections of the maxillofacial region and oral candidiasis. Objectives: This paper investigated whether oral infections are caused by an increase in the normal micro flora, by pathogenic members of the oral flora or defects in the host response. Methods: Data obtained from studies undertaken by the author on 94 caries prone subjects, 24 patients with periodontal disease, 8 patients with denture stomatitis, 221 HIV/ AIDS patients with oral candidiasis, 9 patients with Ludwig's angina and 54 with odontogenic abscess of the maxillofacial region was examined. All microbiological samples were cultured on selective and non-selective media and where appropriate salivary or serum antibody titers were measured. Results: The results from dental caries studies showed that the levels of mutans streptococci and Lactobacilli were 3.26 x 103 and 2.59 x 102 CFU respectively in patients with no decay and increased 100 fold in prosthetic rehabilitation patients and in subjects wearing orthodontic appliances. Periodontal pathogens isolated from HIV positive and negative patients were similar while serum antibody levels varied from site to site and decreased with treatment. Staphylococcus aureus, Eikonella, Nocardia, Actinomyces and Prevotella were isolated from odontogenic abscesses but not Ludwig's angina suggesting host factors are involved. Antibody levels to Candida and normal bacterial commensals were raised in denture stomatitis patients and decreased with treatment while antibody levels correlated with the number of Candida organisms in saliva in HIV/AIDS patients. No defect in the mucosal immune response could account for the increase of these micoorganisms suggesting the cellular response plays a role. Conclusion: These observations suggest that oral diseases are complex and may be related to pathogenic members of the oral flora, changes in the microbial load and the host response.