Fibronectin levels in stimulated whole-saliva and their relationship with cariogenic oral bacteria.

AIM: Fibronectin is a multifunctional glycoprotein that plays a fundamental role in mechanism of cellular union and in bacterial adhesion in the oral cavity. The aim of this study was to test the clinical relationship between fibronectin concentration in stimulated whole-saliva and the number of Mutans streptococci bacteria. PARTICIPANTS: The sample consisted of 167 children aged 12 years. METHODS: Saliva samples were collected from the subjects. Bacterial quantification was carried out using a semiquantitative method (Dentocult SM, Vivadent). Fibronectin was measured by the ELISA method with modifications. RESULTS: An inverse clinical relation was found between the levels of soluble fibronectin and the number of SM colony forming units. CONCLUSIONS: Bacterial counts sufficiently high to destroy the protein films increase bacterial binding to dental surfaces, thereby contributing to the regulation of bacterial plaque composition and its pathogenic potential. This capacity of glycoproteins to reduce the adhesion of microorganisms to the oral tissues and favour macrophage action supports the hypothesis that such proteins contribute to the first line of immune defence together with secretory antibodies.

Cariogenic oral flora and its relation to dental caries.

Many attempts have been made to establish the risk profile of dental caries; however, no diagnostic procedures are yet available to reliably predict such risk particularly among the pediatric and adolescent population. Age of subject, a history of caries affecting the primary dentition, the prevalence of Streptococcus mutans, pH values, salivary flow, and the frequency and amount of sugar consumption have been the factors most studied. A cross-sectional study is made of schoolchildren in the 12-13-year age-range to evaluate the relationship between dental caries and CFU/ml of S. mutans and Lactobacillus, salivary buffer capacity, and salivary flow. Likewise, an evaluation is made of the predictive value of the variables, bacterial count and salivary pH with respect to caries. A total of 167 children were subjected to oral examination to establish the DMFT and DMFS indices, followed by the collection of saliva for quantitating S. mutans, Lactobacillus, pH and salivary flow, by the Dentocult (SM)(LB) and Dentobuff systems (Vivadent). The data obtained were subjected to descriptive analysis, comparisons among variables were made by nonparametric testing with a confidence level of 95 percent. Test predictive value was studied in terms of sensitivity, specificity, positive and negative predictive values, and probability ratio. Statistically significant (p < 0.001) correlations were observed between the caries indices and bacterial counts. No significant association was recorded with the rest of the variables studied. Bacterial counts as well as salivary buffer capacities exhibited greater negative than positive predictive values, i.e., they were more effective in identifying healthy individuals than patients who required treatment.