Antibacterial activity of dentine primer containing MDPB after curing

Objectives. A monomer methacryloyloxydodecylpyridinium bromide (MDPB) has antibacterial activity before polymerization. Furthermore, the antibacterial agent is immobilized by the polymerization of MDPB and the resin-based material incorporating MDPB is able to show an antibacterial effect even after being cured. The purpose of this study was to investigate the antibacterial effect of a dentine primer containing MDPB after curing. Methods. The inhibitory effect of a cured MDPB-containing primer on the growth of Streptococcus mutans, Actinomyces viscosus and Lactobacillus casei was determined by the agar-disc method. The bactericidal activity of cured primer during a I-h contact period was assessed using S. mutans, and the elution of unpolymerized MDPB was measured with high performance liquid chromatography. Results. Cured MDPB-containing primer showed an inhibitory effect on the growth of all species which were in contact with the specimen surface, and displayed a little bactericidal effect on S. mutans without releasing any unpolymerized antibacterial components. Conclusion. Incorporation of antibacterial monomer MDPB into dentine primer is beneficial for providing antibacterial activity after curing. (C) 1998 Elsevier Science Ltd. All rights reserved.