Inhibition of bacterial growth found in fluoride containing restorative materials

Objectives: The goal of this investigation was to find out the restoratives which possess the best possible anti-cariogenic potentials. Inhibition of bacterial growth was compared between fluoride containing polymer-based adhesives and glass-ionomers. Methods: Root caries of the patients were sampled, from which Streptococcus mutans and Actinomyces naeslundii were dominantly isolated. Agar plates were freshly prepared with mixing each bacteria in Gifu-Anaerobic medium. On the agar plates, each restorative material was carefully placed. Fluoride containing restoratives tested were, IMPERVA FLUORO BOND (FB:SHOFU INC., Japan) and REACTOMER BOND (RB:SHOFU INC.) as polymer-based adhesives, and Fuji …§GP (F…§:GC,Japan) as an acid-base glass-ionomer and Fuji II LC (FII:GC) as a resin-modified glass-ionomer. An application of each restorative on the agar was done according to the clinical procedure in which the primer/adhesive was applied using a micro sponge, glass-ionomers were placed using a syringe and the contact area of all materials was regulated by a stainless-steel tube. For positive control, F^-100 PPM standard solution was tested and for negative control, physiological saline solution was tested. Samples were then cultured anaerobicaly at 37 Ž for 48 hours, after which inhibition of bacterial growth was observed and determined by an inhibition zone(n=10, mm) between the circumference of each material and bacterial colonies in the agar. Results: An average (S.D.) of inhibition zone for S. mutans was 1.4 (0.7) for FB, 1.3 (0.6) for RB, 2.8 (0.4) for F…§, 4.0 (0.7) for FII and 2.2 (1.0) for positive control. And for A.naeslundii the zone was 1.9 (0.6) for FB, 1.1 (0.6) for RB, 3.1 (0.5) for Fuji…§, 4.2 (1.3) for FII and 2.0 (0.8) for positive control. All negative controls showed 0 mm. Conclusions: Glass-ionomers showed greater inhibition zone than that shown in polymer-based adhesives indicating greater possibility of anti-cariogenic potentials.