Materials wich use like base,and those used for direct and indirect capping should be, except certain physicalchemical and biological performance have and antibacterial effect, to act after the application on residual microorganisms. The aim of this study is that in vitro display antimicrobial activity of some selected resources that are used to protect the dentin below the permanent restoration, and some of this as medication in treating deep surface carious lesions and to directly cover any caries, either artificially open pulp. Antimicrobial activity was tested against microorganisms. On agar plates into the grooves 4 mm in diameter was inserted freshly prepared paste or base. After inserting the material into the surface of bloî od agar, was performed by incubation under aerobic conditions for 24 h in a thermostat at 37 C. Negative effect on the microorganisms, tested materials, it was estimated by the size of growth inhibition zone.