INCORPORATION OF BACTERIAL INHIBITOR INTO RESIN COMPOSITE

Attempts to produce resin composite with antibacterial properties by i ncorporation of an antibacterial agent such as chlorhexidine have been reported, but problems can arise due to release of the inhibitory age nt from the composite, Such problems may include toxic effects, influe nce on mechanical properties, and loss of effectiveness. A new monomer , methacryloyloxydodecylpyridinium bromide (MDPB), was synthesized by combining an antibacterial agent and methacryloyl group. The monomer w as incorporated into resin composite to develop a non-releasing antiba cterial composite. The ability of composite incorporating MDPB to inhi bit growth and plaque accumulation by Streptococcus mutans in. vitro w as assayed, elution of antibacterial components from the material was investigated, and the influence of incorporation of MDPB on the mechan ical properties of composite was studied. Uncured MDPB revealed antiba cterial activity against S. mutans and six other species of oral strep tococci, with the minimum inhibitory concentration for S. mutans being comparable with that of triclosan. After composite incorporating MDPB was cured, no elution of the antibacterial components was observed fr om the material, even after 90 days' immersion in water or other solve nts. Growth of S. mutans on agar under specimens of MDPB-containing co mposite was inhibited compared with controls. In a bacterial accumulat ion study, S. mutans accumulated to a lesser degree on the surface of composite incorporating MDPB (p < 0.05) than on control. Incorporation of MDPB had no significant influence on the mechanical properties of the composite.