Antibacterial activity of various self-etching adhesive systems against oral streptococci

The antibacterial properties of self-etching adhesive systems constitute an important issue in operative dentistry, since viable bacteria can still be present after cavity preparation. The current study evaluated the antibacterial activity of five one-step self-etching adhesives (SEAs) and four self-etching primers (SEPs) against oral streptococci. Clearfil S3 (S3), One-Up Bond F Plus (OU), Futurabond NR (FB), GBond (GB), Xeno IV (X4), Clearfil SE Bond (SE), Clearfil Protect Bond (PB), Adper SE Plus (AS) and AdheSE (AD) were tested for antibacterial activity against five streptococci species: S oralis, S sanguinis, S cricetus, S mutans and S sobrinus. Chlorhexidine (0.12%) and phosphoric acid (37%) gel were used as control. The agar diffusion test method was used. Plates containing BHI agar and 300 uL of bacterial cell suspension (0.5 MacFarland) were prepared. Holes 6 mm in diameter were made and partially filled with bacteriological agar. Then, 10 uL of each SEA or SEP was dropped and the plates were incubated under microaerophilic atmosphere at 37 degrees C for 48 hours and the diameter of each halo was registered. The results were analyzed by two-way ANOVA and Tukey test. PB exhibited the most effective antibacterial activity against oral streptococci. The performances of SE and FB were similar or better than chlorhexidine for all bacteria. S3, X4, AS, AD, OU and GB showed significantly lower inhibition values. Among the species tested, S oralis was the most sensitive to all self-etching adhesive systems; on the other hand, S cricetus, S mutans and S sobrinus were more resistant. Among the self-etching adhesive systems evaluated, Clearfil Protect Bond exhibited the most effective antibacterial activity against oral streptococci.