Methods: Cylindrical specimens (5.0 x 2.5mm) of light-cured composite resin (m1) and resin sealant (m2) were immersed in 900µL Brain Heart Infusion (BHI) broth supplemented with 10% sucrose. The specimens were inoculated with 100µL of S. mutans suspension (106 CFU/mL) and incubated for 24h (t1) and 7 days (t2). After, the samples were shaken for 60 seconds in 1mL of supernatant from dentifrices or sterile physiological solution (control – g3). The organisms that adhered to the specimens were dispersed, diluted 100 and 1000 times and sowed on BHI agar plates. After incubation at 37ºC, for 48h, the number of Colony Forming Units per milliliter (CFU/mL) was determined for each sample. Statistical analysis was performed by independent t test, ANOVA and Tukey tests (α=0.05).
Results: The average of CFU/mL x 105 obtained from the action of g1, g2 and g3 on m1 were, respectively: 4.58, 4.60 and 30.00 (t1) and 2.83, 0.63 and 17.57 (t2). The average of CFU/mL x 105 obtained from the action of g1, g2 and g3 on m2 were, respectively: 2.35, 9.04 and 30.00 (t1) and 2.93, 2.77 and 15.92 (t2). The evaluated dentifrices (g1 and g2) presented average of CFU/mL significantly lower (p<0.01) than the control group (g3). There was no significant statistical difference (p>0.05) between the averages observed for dentifrices (g1 and g2), for the period of incubation (t1 and t2), and for the type of restorative material (m1 and m2).
Conclusions: The evaluated dentifrices have similar anti-adherent activity against S. mutans on the surface of restorative materials. There was no influence by the period of incubation and the type of restorative material.