Growth-inhibitory effect of antibacterial self-etching primer on mutans streptococci obtained from arrested carious...

An antibacterial self-etching primer has been developed to inhibit bacterial attachment and plaque accumulation on the tooth surfaces. The purpose of this study was to evaluate the growth-inhibitory effect of an antibacterial self-etching primer on mutans streptococci obtained from arrested carious lesions.

Softened dentin specimens were obtained from arrested carious lesions with an excavator or a round steel bur. The effect of a commercial antibacterial self-etching primer and a commercial self-etching primer on the total streptococci on Mitis-Salivarius (MS) agar plates and on Streptococcus mutans on MS agar plates containing 0.02 M bacitracin (MSB) was evaluated. Specimens with no primer were used as controls. The number of colonies of both total streptococci and S. mutans were compared statistically with two-way analysis of variance and Fisher's Protected Least Squares Differences (PLSD) test (p < .05).

The number of colonies of total streptococci (CFU/mL) for the two methods (excavator and round steel bur) were as follows: for the control, 5.0 x 10(6) and 5.0 x 10(6); for the self-etching primer, 1.0 x 10(5) and 1.0 x 10(5); and for the antibacterial self-etching primer, 0 and 0. The number of colonies of S. mutans for the two methods (excavator and round steel bur) were as follows: for the control, 5.0 x 10(6) and 1.8 x 10(5); for the self-etching primer, 3.5 x 10(4) and 5.0 x 10(3); and for the antibacterial self-etching primer, 0 and 0. Regardless of the method of softened dentin removal, the antibacterial effect was significantly higher for the group that had antibacterial self-etching primer compared with that of the control group and the group that had commercial self-etching primer (p < .05).

The antibacterial self-etching primer showed a high level of antibacterial activity against mutans streptococci obtained from the arrested carious lesions.