Clinical, salivary, and microbiological parameters in Down syndrome individuals

Objective: This study aimed to determine the occurrence of caries, to evaluate the salivary profile (flow rate and buffering capacity), and to assess the number of colonies forming units (CFU) and the prevalence of S. mutans/S. sobrinus in Down syndrome individuals. Methods: Sixty subjects aged from 1 to 48 year-old were clinically examined by a calibrated dentist (kappa= 0.92), under natural light with dental mirrors and probe using DMFT/DMFS/dmft/dmfs according to World Health Organization (WHO). Stimulated saliva was collected and flow rate and buffering capacity were also measured. Salivary flow was calculated as ml/min and buffering capacity was measured using a standard pH tape. In addition, 25µL of saliva was diluted using a 10-fold dilution method and then placed on Mitis-Salivarius-Bacitracin (MSB) agar that was cultivated anaerobically for 48 hours. After incubation, the number of colonies of mutans streptococci on MSB was counted, and the colony-forming-units (CFU/mL) were calculated. Polymerase Chain Reaction analysis identified species. Data of caries indexes, salivary profile, and microbiological parameters were analyzed using Pearson's Correlation and Chi-square test at a probability level of 0.05 to determine the relationship between all parameters evaluated. Results: Caries indexes were 0.65 to 26.0 and 0.44 to 7.0. Ninety-four percent of subjects had low flow rate and 44% had low buffering capacity. Besides, 60% had more than 1x10⁶ CFU/mL of mutans streptococci, 60% had S. mutans, and 41.4% had S. sobrinus. Caries indexes did not significantly correlate with flow rate, buffering capacity, and CFU/mL by Pearson's correlation (p>0.05). Moreover, Chi-square test showed no significant association of caries with prevalence of species (p>0.05). Conclusions: This study supports the evidence that there is no association between clinical picture and salivary or microbiological parameters in Down syndrome individuals. This study was supported by FAPESP (04/12925-0), Sao Paulo, Brazil.