Influence of Preventive Measures on Streptococcus mutans Levels in Adults

Objectives: To evaluate the effect of a dental care program with a strong preventive component on mutans group Streptococci (MGS) in an adult population.
Methods: The study was conducted in a non-probabilistic sample of 174 men and women (x=26 y.o. ±0.08). A calibrated researcher established diagnosis of dental status according to ICDAS II and collected samples of non-stimulated saliva for MGS group counts at baseline. The patients were identified as being at high or low cariogenic risk, based on the presence of active caries lesions. A dental care program was applied which included oral hygiene and diet counseling, fluoride varnish (NaF 2.26%), atraumatic restorative treatment, pits and fissures sealants and basic periodontal therapy. 90 days after the end of the treatment, saliva sample collection was repeated. Samples were homogenized and diluted to the tenth and hundredth; 100 µl of each dilution were cultured in modified Gold medium, according to the Adherence test in modified Gold’s selective medium (ADMGM), and incubated in an anaerobic atmosphere at 37° C for 48 hours. The cultures were agitated by inversion of the tubes, and washed with sterile distilled water. Calibrated researchers (Kappa >0.75) performed the reading and counted adhered colony forming units compatible with MGS (50X). Central tendency and dispersion measures were calculated and statistical analysis was performed using T test for independent and related samples. Pearson’s test was used to establish correlation between baseline values and the difference between pre- and post-protocol counts.
Results: ADMGM showed statistically significant differences in MGS before and after applying the dental care protocol, both in counts (p=0.013) and in the count Log (p=0.000), and in the difference between baseline and final Logs observed in subjects at high cariogenic risk compared to subjects at low cariogenic risk (p=0.000). A high correlation was observed between baseline MGS counts and the difference between baseline and final values; the decrease was more marked in subjects with higher baseline values (r=0.630, p=0.000).
Conclusions: The dental care protocol allowed modulating the patients’ oral ecology. This process is reflected in significant decrease in cariogenic microorganisms used as a predictive biological indicator of cariogenic risk.