Evaluation and comparison of lactobacilli characteristics in the mouths of patients with or without cavities.

Lactobacilli were considered the prime cariogenic microorganisms until phylogenetic related bacteria, mutans streptococci, were associated with caries. Today, lactobacilli are still considered a factor in determining the predisposition to develop cavities. As a first step in colonization, microorganisms adhere to oral tissues. Based on this fact, the purpose of our study was to determine if there was a statistical association or difference related to the state of oral health with the surface characteristics of lactobacilli. Patients were classified as caries-free and caries-active. Interviews were performed to establish the nutritional and oral hygiene habits. The previously reported characteristics of isolated lactobacilli's quantification and association to dental tissues were determined. Although the nutritional habits for caries-free and caries-active patients were similar, the patients' oral hygiene and dental care determined differences in risk indices. The number of lactobacilli was statistically lower in saliva of subjects with good oral health. Certain species of lactobacilli could not be associated to specific areas of the mouth, although some species could be localized. Lactobacilli from caries active (CA) subjects showed a greater ability to adhere to hydrophobic substances, had a greater salt agglutination property, and showed lower production of inhibitory substances. Lactobacilli from caries free (CF) subjects were better able to inhibit oral, potentially pathogenic, microorganisms. These studies prove that preliminary differences between oral lactobacilli in CF and CA patients exist. Non-specific and specific adhesion mechanisms in bacteria should be further demonstrated.