[Dental caries in young adults regarding saliva's microbiological and physical-chemical characteristics].

OBJECTIVE Determining the relationship between saliva's physicochemical properties, cariogenic microorganism count, facultative anaerobic and gram-negative bacteria based on caries' experience in young adults. MATERIALS AND METHODS Stimulated whole saliva was collected from 120 students aged 17 to 34 years old for analysing salivary flow rate, pH, calcium and phosphate ion concentration, lactic acid, cariogenic microorganism count and facultative and gram-negative bacteria. RESULTS Salivary flow rate was included in the biological reference interval but was not found to be associated with caries; the same thing happened regarding lactic acid. A direct relationship was found between calcium and phosphate concentration and dental cavities. Streptococcus mutans was associated with white spot lesion whereas Lactobacillus spp., facultative anaerobic and gram-negative bacteria were associated with advanced cavities. CONCLUSIONS Saliva's physicochemical and microbiological characteristics in the young adult group evaluated here were differentially related to caries in different degrees of progress.